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    Biguanide and Sodium Glucose Co-transporter 2 (SGLT2) Inhibitors Antidiabetic Combinations

    BOXED WARNING

    Acidemia, hypoxemia, lactic acidosis, metabolic acidosis

    Ertugliflozin; metformin is contraindicated in patients with acute or chronic metabolic acidosis. It should not be used in patients with lactic acidosis. Lactic acidosis should be suspected in any diabetic patient with metabolic acidosis lacking evidence of ketoacidosis (ketonuria and ketonemia). Lactic acidosis is a rare but serious complication that can occur due to metformin accumulation; when it occurs, it is fatal in approximately 50% of cases. Lactic acidosis may also occur in association with a number of pathophysiologic conditions, including diabetes mellitus, and whenever there is significant tissue hypoperfusion and hypoxemia or significant renal dysfunction. Certain medications used concomitantly with metformin may also increase the risk of lactic acidosis. Lactic acidosis is characterized by elevated blood lactate levels, acidemia, electrolyte disturbances, an increased anion gap, and an increased lactate/pyruvate ratio. When metformin is implicated as the cause of lactic acidosis, metformin plasma levels more than 5 mcg/mL are generally found. The reported incidence of lactic acidosis in patients receiving metformin is very low; in more than 20,000 patient-years exposure to metformin in clinical trials, there have been no reports of lactic acidosis and approximately 0.03 cases/1000 patient-years have been estimated with post-marketing surveillance. A nested case-control study of 50,048 patients with type 2 diabetes mellitus demonstrated that during concurrent use of oral diabetes drugs, there were 6 identified cases of lactic acidosis. The crude incidence rate was 3.3 cases per 100,000 person-years in patients treated with metformin; it should be noted that all of the subjects had relevant comorbidities known to be risk factors for lactic acidosis. The onset of lactic acidosis often is subtle, and accompanied only by nonspecific symptoms such as malaise, myalgias, respiratory distress, increasing somnolence, and nonspecific abdominal distress. There may be associated hypothermia, hypotension, and resistant bradycardia with more marked acidemia. The patient and the prescriber must be aware of such symptoms and the patient should be instructed to notify the physician immediately if they occur. If ketoacidosis or lactic acidosis is suspected, evaluation of the following parameters is necessary: serum electrolytes, ketones, blood glucose, and if indicated, blood pH, lactate, pyruvate, and metformin levels. In addition, ertugliflozin; metformin must be stopped immediately and appropriate corrective measures initiated.

    DEA CLASS

    Rx

    DESCRIPTION

    Oral combination of metformin with a sodium-glucose co-transporter 2 (SGLT2) inhibitor
    Used in adults with type 2 diabetes mellitus
    Contraindicated in severe renal impairment due to reduced ertugliflozin efficacy and increased risk of metformin-related lactic acidosis

    COMMON BRAND NAMES

    Segluromet

    HOW SUPPLIED

    Ertugliflozin, Metformin/Ertugliflozin, Metformin Hydrochloride/Segluromet Oral Tab: 2.5-1000mg, 2.5-500mg, 7.5-1000mg, 7.5-500mg

    DOSAGE & INDICATIONS

    For the treatment of type 2 diabetes mellitus in combination with diet and exercise.
    Oral dosage
    Adults

    Individualize the starting dose based on the patients current regimen. Adjust according to efficacy and tolerability. Give ertugliflozin; metformin PO twice daily with meals. Max: ertugliflozin 7.5 mg/metformin 1,000 mg PO twice daily with meals. PATIENTS CURRENTLY TAKING ERTUGLIFLOZIN: Initiate at current dose of ertugliflozin in combination with metformin 500 mg; give PO twice daily with meals; increase gradually to reduce the GI side effects due to metformin. PATIENTS CURRENTLY TAKING METFORMIN: Initiate at ertugliflozin 2.5 mg/metformin (either 500 mg or 1,000 mg) PO twice daily with meals, using a metformin dose that is the same or closest to the current metformin dose. PATIENTS CURRENTLY TAKING ERTUGLIFLOZIN AND METFORMIN: Switch using the same daily doses of each component, divided and given PO twice daily with meals. In older patients, use a conservative initial and maintenance dose; adjust ertugliflozin; metformin dose based on careful assessment of renal function.

    MAXIMUM DOSAGE

    Adults

    Ertugliflozin 15 mg/day PO and metformin 2,000 mg/day PO.

    Geriatric

    Ertugliflozin 15 mg/day PO and metformin 2,000 mg/day PO.

    Adolescents

    Safety and efficacy have not been established.

    Children

    Safety and efficacy have not been established.

    Infants

    Not indicated.

    Neonates

    Not indicated.

    DOSING CONSIDERATIONS

    Hepatic Impairment

    Avoid use in patients with clinical or laboratory evidence of hepatic disease as there is an increased risk of lactic acidosis secondary to the use of metformin.

    Renal Impairment

    eGFR 45 mL/minute/1.73 m2 or more: No dosage adjustment needed.
    eGFR less than 45 mL/minute/1.73 m2: Use is not recommended.
    eGFR less than 30 mL/minute/1.73 m2: Use is contraindicated.
     
    Intermittent hemodialysis:
    Use is contraindicated.

    ADMINISTRATION

    Oral Administration
    Oral Solid Formulations

    Administer the tablets twice daily with food.

    STORAGE

    Segluromet:
    - Protect from moisture
    - Store between 68 to 77 degrees F, excursions permitted 59 to 86 degrees F
    - Store in a dry place

    CONTRAINDICATIONS / PRECAUTIONS

    General Information

    Ertugliflozin; metformin is contraindicated in patients with a known history of a serious hypersensitivity to ertugliflozin or metformin. Hypersensitivity reactions such as angioedema or anaphylaxis have occurred during postmarketing with ertugliflozin. Discontinue use of ertugliflozin; metformin if hypersensitivity reactions occur, and treat per standard of care; monitor until signs and symptoms resolve.

    Diabetic ketoacidosis, surgery, type 1 diabetes mellitus

    The use of ertugliflozin; metformin is contraindicated in patients with diabetic ketoacidosis (DKA). This combination is also not recommended for the treatment of type 1 diabetes mellitus. Both conditions require the use of insulin. Ertugliflozin may increase the risk of DKA. Across the clinical program, ketoacidosis was identified in 3 of 3,409 (0.1%) of ertugliflozin-treated patients and 0% of comparator-treated patients. Fatal cases of ketoacidosis have been reported in patients receiving SGLT2 inhibitors. In placebo-controlled trials of patients with type 1 diabetes, the risk of ketoacidosis was increased in patients who received SGLT2 inhibitors compared to patients who received placebo. The risk of ketoacidosis may be greater with higher doses. In addition, the FDA has identified 73 cases of ketoacidosis in patients with type 1 or type 2 diabetes treated with SGLT2 inhibitors. All patients required emergency room visits or hospitalization to treat the ketoacidosis. Signs and symptoms at presentation were consistent with severe metabolic acidosis and included nausea, vomiting, abdominal pain, generalized malaise, and shortness of breath. However, the presence of ketoacidosis was not immediately recognized, and treatment was delayed because the presenting blood glucose levels were below those typically expected for DKA (often less than 250 mg/dL). Factors identified in some reports as having potentially triggered the ketoacidosis included infection, low carbohydrate diet or an overall reduction of caloric intake, reduction in dose of exogenous insulin or discontinuation of exogenous insulin, discontinuation of an oral insulin secretagogue, and alcohol use. The FDA is continuing to investigate this issue and is requiring manufacturers of SGLT2 inhibitors to conduct a required postmarketing study, including specialized follow-up to collect additional information for a period of 5 years. Before initiating an SGLT2 inhibitor, consider factors in the patients' histories that may predispose them to ketoacidosis, including pancreatic insulin deficiency from any cause, caloric restriction, and alcohol abuse. For patients who undergo scheduled surgery, ertugliflozin; metformin should be temporarily discontinued for at least 4 days before surgery. Temporarily suspend therapy for restricted food or fluid intake and consider monitoring for ketoacidosis (e.g., prolonged fasting due to acute illness or surgical procedure). Ensure risk factors for ketoacidosis are resolved before restarting therapy. Educate patients on the signs and symptoms of ketoacidosis and instruct patients to discontinue this product and seek medical attention immediately if signs and symptoms occur.

    Acidemia, hypoxemia, lactic acidosis, metabolic acidosis

    Ertugliflozin; metformin is contraindicated in patients with acute or chronic metabolic acidosis. It should not be used in patients with lactic acidosis. Lactic acidosis should be suspected in any diabetic patient with metabolic acidosis lacking evidence of ketoacidosis (ketonuria and ketonemia). Lactic acidosis is a rare but serious complication that can occur due to metformin accumulation; when it occurs, it is fatal in approximately 50% of cases. Lactic acidosis may also occur in association with a number of pathophysiologic conditions, including diabetes mellitus, and whenever there is significant tissue hypoperfusion and hypoxemia or significant renal dysfunction. Certain medications used concomitantly with metformin may also increase the risk of lactic acidosis. Lactic acidosis is characterized by elevated blood lactate levels, acidemia, electrolyte disturbances, an increased anion gap, and an increased lactate/pyruvate ratio. When metformin is implicated as the cause of lactic acidosis, metformin plasma levels more than 5 mcg/mL are generally found. The reported incidence of lactic acidosis in patients receiving metformin is very low; in more than 20,000 patient-years exposure to metformin in clinical trials, there have been no reports of lactic acidosis and approximately 0.03 cases/1000 patient-years have been estimated with post-marketing surveillance. A nested case-control study of 50,048 patients with type 2 diabetes mellitus demonstrated that during concurrent use of oral diabetes drugs, there were 6 identified cases of lactic acidosis. The crude incidence rate was 3.3 cases per 100,000 person-years in patients treated with metformin; it should be noted that all of the subjects had relevant comorbidities known to be risk factors for lactic acidosis. The onset of lactic acidosis often is subtle, and accompanied only by nonspecific symptoms such as malaise, myalgias, respiratory distress, increasing somnolence, and nonspecific abdominal distress. There may be associated hypothermia, hypotension, and resistant bradycardia with more marked acidemia. The patient and the prescriber must be aware of such symptoms and the patient should be instructed to notify the physician immediately if they occur. If ketoacidosis or lactic acidosis is suspected, evaluation of the following parameters is necessary: serum electrolytes, ketones, blood glucose, and if indicated, blood pH, lactate, pyruvate, and metformin levels. In addition, ertugliflozin; metformin must be stopped immediately and appropriate corrective measures initiated.

    Acute heart failure, acute myocardial infarction, cardiac disease, cardiogenic shock, heart failure

    Lactic acidosis has occurred in patients with acute congestive heart failure characterized by acute hypoxia taking metformin. To reduce the risk of lactic acidosis, metformin should be promptly withheld in the presence of any condition associated with hypoxemia. Acute hypoxia and acute cardiac disease (e.g., acute heart failure, cardiogenic shock, or acute myocardial infarction) and other conditions characterized by acute hypoxia have been associated with the development of lactic acidosis and may cause prerenal azotemia. If such events occur, discontinue ertugliflozin; metformin. Metformin should be used with caution in patients with congestive heart failure requiring pharmacologic treatment. However, a systematic review evaluating antidiabetic agents and outcomes in patients with heart failure and diabetes concluded that metformin is not associated with any measurable harm in patients with heart failure; in this analysis, metformin was associated with reduced mortality.

    Dialysis, renal disease, renal failure, renal impairment

    Ertugliflozin; metformin is contraindicated in patients with severe renal impairment (eGFR less than 30 mL/minute/1.73 m2), end stage renal failure or patients on dialysis. Ertugliflozin; metformin is not recommended in patients with an eGFR less than 45 mL/minute/1.73 m2. Metformin is substantially eliminated by the kidney and the risk of lactic acidosis increases with the degree of intrinsic renal disease or impairment. Assess renal function in all patients prior to initiation of ertugliflozin; metformin therapy and as clinically indicated. The efficacy and safety of ertugliflozin were evaluated in a study that included patients with moderate renal impairment (eGFR 30 to 59 mL/minute/1.73 m2); these patients did not have improvement in glycemic control and had a higher occurrence of renal-related adverse reactions compared to placebo-treated patients. In the VERTIS CV study, there were 1,370 patients (25%) with an eGFR greater than or equal to 90 mL/min/1.73 m2, 2,929 patients (53%) with an eGFR of greater than or equal to 60 to less than 90 mL/min/1.73 m2, 879 patients (16%) with an eGFR of greater than or equal to 45 to less than 60 mL/min/1.73 m2, and 299 patients (5%) with eGFR of 30 to less than 45 mL/min/1.73 m2 treated with ertugliflozin. Similar effects on glycemic control at Week 18 were observed in patients treated with ertugliflozin in each eGFR subgroup and also in the overall patient population. Obtain an eGFR at least annually in all patients taking ertugliflozin; metformin. In patients at increased risk for the development of renal impairment (e.g., the elderly), renal function should be assessed more frequently. The measure of kidney function used to determine whether a patient can receive metformin has been changed from serum creatinine to the eGFR; this is because in addition to serum creatinine concentration, the eGFR takes into account additional parameters that are important, such as the patient's age, gender, race and/or weight. Acute kidney injury, some requiring hospitalization and dialysis, has been reported during the postmarketing period in patients receiving other SGLT2 inhibitors. Consider factors that may predispose patients to acute kidney injury prior to starting them on ertugliflozin; metformin, including hypovolemia; chronic renal disease; congestive heart failure; and concomitant medications such as diuretics, ACE inhibitors, angiotensin II receptor blockers (ARBs), and NSAIDs. Consider temporarily discontinuing ertugliflozin; metformin in any setting of reduced oral intake such as acute illness or fasting, or with fluid losses such as gastrointestinal illness or excessive heat exposure. Based on the results of a comprehensive FDA safety review, the FDA concluded that metformin can be used safely in patients with mild renal impairment, and in some patients with moderate renal impairment.

    Dehydration, hypotension, hypovolemia

    Ertugliflozin causes intravascular volume contraction which may sometimes manifest as symptomatic hypotension or acute transient changes in serum creatinine. Patients at risk include those with dehydration or hypovolemia, particularly in patients with impaired renal function (eGFR less than 60 mL/minute/1.73 m2), the elderly, patients receiving diuretics or other medications that interfere with the renin-angiotensin-aldosterone (RAA) system (e.g., angiotensin-converting-enzyme [ACE] inhibitors, angiotensin receptor blockers [ARBs]), or patients with low systolic blood pressure. Volume status should be assessed and corrected before initiating ertugliflozin; metformin in patients with one or more of these characteristics. Additionally, withholding food and fluids during surgical or other procedures may increase the risk for volume depletion, hypotension, and renal impairment. Ertugliflozin; metformin should be temporarily discontinued while patients have restricted food and fluid intake. Monitor for signs and symptoms of hypotension and/or dehydration after initiating therapy.

    Alcoholism, ethanol ingestion, ethanol intoxication, hepatic disease

    Metformin administration increases the risk for lactic acidosis. Since the liver is important for clearing accumulated lactic acid, ertugliflozin; metformin should be avoided in patients with clinical or laboratory evidence of hepatic disease as the risk of lactic acidosis may be increased. Hepatic disease also causes altered gluconeogenesis, which may affect glycemic control. Alcohol is known to potentiate the effect of metformin on lactate metabolism. Patients should be warned against excessive ethanol ingestion (ethanol intoxication) while taking ertugliflozin; metformin due to the increased risk for lactic acidosis. Those with ethanol intoxication are also particularly susceptible to hypoglycemic effects of oral antidiabetic agents. Ertugliflozin; metformin use should be avoided by those patients with alcoholism.

    Diarrhea, vomiting

    Gastrointestinal side effects are common during metformin initiation. However, once a patient is stabilized on any dose of metformin, GI symptoms are unlikely to be drug related. Later occurrence of GI symptoms may be due to a change in clinical status and may increase the risk of lactic acidosis or other serious disease. Patients stable on metformin therapy who complain of an increase in GI symptoms should undergo laboratory investigation to determine the etiology of the GI symptoms. These include, but are not limited to, diarrhea and nausea/vomiting. Furthermore, withholding metformin therapy until the cause of the GI symptoms is known may be necessary. Finally, diarrhea and nausea/vomiting may alter gastric emptying and caloric intake, which could all affect blood glucose control, especially increasing the risk of low blood glucose. Patients should be advised to contact their prescriber if an increase in gastrointestinal symptoms occurs while taking ertugliflozin; metformin; patients should also be advised to monitor their blood glucose concentrations more frequently.

    Burns, fever, sepsis, trauma

    To reduce the risk of lactic acidosis, ertugliflozin; metformin should be promptly withheld in the presence of any condition associated with hypoxemia, dehydration, or sepsis. Temporary use of insulin in place of oral antidiabetic agents may be necessary during periods of physiologic stress (e.g., burns, sepsis, trauma, surgery, or fever). Temporarily suspend therapy for restricted food or fluid intake and consider monitoring for ketoacidosis (e.g., prolonged fasting due to acute illness or surgical procedure). Any change in clinical status, including diarrhea or vomiting, may also increase the risk of lactic acidosis and may require laboratory evaluation in patients on ertugliflozin; metformin and may require the drug to be withheld.

    Infection, lower limb amputation

    An increased risk for lower limb amputation (primarily of the toe) has been reported in clinical studies with another SGLT2 inhibitor, canagliflozin. Increased risk has also been reported in some studies with ertugliflozin. In a long-term cardiovascular (CV) outcomes study in patients with type 2 diabetes and established CV disease, the occurrence of non-traumatic lower limb amputations was reported with event rates of 4.7, 5.7, and 6 events per 1,000 patient-years in the placebo, ertugliflozin 5 mg, and ertugliflozin 15 mg treatment arms, respectively. In 7 clinical studies with ertugliflozin, non-traumatic lower limb amputations were reported in 3 patients (0.2%) in the ertugliflozin 5 mg group and 8 patients (0.5%) in the ertugliflozin 15 mg group compared with 1 patient (0.1%) in the comparator group. A causal relationship between ertugliflozin and lower limb amputations has not been definitively established. Before initiating ertugliflozin, consider factors that may predispose patients to the need for amputations such as baseline history of prior amputation, peripheral vascular disease, peripheral neuropathy, or history of diabetic foot ulcers. Monitor patients for infection (including osteomyelitis) of the legs and feet and instruct patients to notify their health care professional immediately if they notice any new pain or tenderness, unusual sensations, skin color changes, sores or ulcers, or infection in their legs or feet. The patient should self-examine their feet daily in routine diabetes care, and a health care professional should routinely perform a complete foot exam.

    Balanitis, pyelonephritis, tissue necrosis, urinary tract infection (UTI), vaginitis

    Sodium-glucose co-transporter 2 (SGLT2) inhibitors such as ertugliflozin may cause an increased risk for severe urinary tract infection (UTI), including urosepsis and pyelonephritis, and these cases can result in hospitalization. Patients should be told to report any signs of UTI and seek medical attention if they experience symptoms such as a feeling of burning when urinating or the need to urinate often or right away, pain in the lower part of the stomach area or pelvis, fever, or blood in the urine. Promptly treat if indicated if a UTI is suspected. [60400] Treatment with ertugliflozin also increases the risk of genital mycotic infections. Use ertugliflozin; metformin cautiously in patients with a history of genital fungal infections, including vaginitis or balanitis, and uncircumcised males; these patients were more likely to develop genital mycotic infections during treatment with ertugliflozin. Monitor and treat appropriately if genital mycotic infection occurs. All patients beginning therapy with a sodium-glucose co-transporter 2 (SGLT2) inhibitor or currently receiving ertugliflozin; metformin should be closely monitored for a serious, rare, and life-threatening infection called necrotizing fasciitis (tissue necrosis) of the perineum, also referred to as Fournier's gangrene. Patients should be warned to promptly seek medical attention if they experience any symptoms of tenderness, erythema, or swelling in the genital or perineal area, fever, or malaise, and such patients should be evaluated for necrotizing fasciitis. Cases have been reported in both females and males. Serious outcomes have included hospitalization, multiple surgeries, and death. If Fournier's gangrene is suspected, discontinue ertugliflozin; metformin and institute prompt treatment with antibiotics and if necessary, surgical debridement. Closely monitor blood glucose levels, and provide appropriate alternative therapy for glycemic control.

    Adrenal insufficiency, hypoglycemia, hypothyroidism, malnutrition, pituitary insufficiency

    Conditions that predispose patients to developing hypoglycemia may alter antidiabetic agent needs, and may require close monitoring during the use of ertugliflozin; metformin. Conditions associated with hypoglycemia include debilitated physical condition, drug interactions, malnutrition, uncontrolled adrenal insufficiency, pituitary insufficiency, or hypothyroidism. More frequent blood glucose monitoring may be necessary in patients with these conditions. Insulin and insulin secretagogues are also known to cause hypoglycemia. Ertugliflozin; metformin can increase the risk of hypoglycemia when combined with insulin or an insulin secretagogue. Therefore, a lower dose of insulin or insulin secretagogue may be required to minimize the risk of hypoglycemia when used in combination with ertugliflozin; metformin.

    Pernicious anemia

    Metformin may result in suboptimal vitamin B12 absorption, possibly due to interference with the B12-intrinsic factor complex. The interaction very rarely results in a pernicious anemia that appears reversible with discontinuation of metformin or with cyanocobalamin supplementation. Certain individuals (those inadequate vitamin B12 or calcium intake or absorption) may be predisposed to this type of anemia. Measure hematologic parameters on an annual basis and serum vitamin B12 at 2- to 3-year intervals in patients receiving ertugliflozin; metformin; abnormalities should be investigated and managed appropriately.

    Radiographic contrast administration

    Administration of intravascular iodinated radiographic contrast in patients taking metformin has led to an acute decrease in renal function and an increased risk for lactic acidosis. Discontinue ertugliflozin; metformin at the time of or before iodinated radiographic contrast administration in patients with a history of hepatic disease, alcoholism, or heart failure; or in patients who will be administered intra-arterial iodinated contrast. Re-evaluate the estimated glomerular filtration rate (eGFR) 48 hours after the imaging procedure; restart ertugliflozin; metformin if renal function is stable.

    Geriatric

    Geriatric patients receiving ertugliflozin experienced a higher incidence of adverse reactions related to volume depletion (e.g., hypotension, postural dizziness, orthostatic hypotension, syncope, and dehydration) compared with patients treated with placebo. Geriatric patients are also more likely to have renal impairment which increases the risk for hypovolemia. In the VERTIS CV trial, a total of 2,780 patients treated with ertugliflozin were 65 years and older; safety and efficacy were generally similar for these patients compared to patients younger than 65. Before initiating ertugliflozin; metformin, assess renal function and volume status, and correct hypovolemia. Metformin treatment should not be initiated in a geriatric patient unless assessment of renal function determines that renal function is not reduced. Metformin is substantially excreted by the kidney and the risk of adverse reactions, including lactic acidosis, is greater in geriatric patients with reduced renal function. Ertugliflozin is expected to have reduced efficacy in geriatric patients with renal impairment. Extra care should be taken with dose selection and titration. Assess renal function at least annually once therapy is initiated; geriatric patients should have renal function assessed more frequently. Ertugliflozin; metformin should be discontinued if evidence of renal impairment is present. The federal Omnibus Budget Reconciliation Act (OBRA) regulates medication use in residents of long-term care facilities (LTCFs). According to OBRA, the use of antidiabetic medications should include monitoring (e.g., periodic blood glucose) for effectiveness based on desired goals for that individual and to identify complications of treatment such as hypoglycemia or impaired renal function. Metformin has been associated with lactic acidosis, which is more likely to occur under certain conditions (e.g., serum creatinine of 1.5 mg/dL or higher in males or 1.4 mg/dL or higher in females, age of 80 years or older unless measurements verify normal renal function, radiologic studies with iodinated contrast, congestive heart failure, or acute/chronic metabolic acidosis including diabetic ketoacidosis).

    Polycystic ovary syndrome, pregnancy

    There are no adequate and well-controlled studies of ertugliflozin; metformin during human pregnancy to determine a drug-associated risk of adverse developmental outcomes. However, based on animal data showing adverse renal effects with ertugliflozin, the use of ertugliflozin; metformin is not recommended during the second and third trimesters of pregnancy. In animal studies, doses approximately 13 times the maximum clinical dose caused renal pelvic and tubule dilatations and renal mineralization during periods of renal development that correspond to the late second and third trimester that were not fully reversible. There was no evidence of fetal harm in rats or rabbits at exposures approximately 300 times higher than the maximum clinical dose of 15 mg/day when administered during organogenesis. Based on the results of a small study, it appears that metformin does pass through the placenta and the fetus is exposed to therapeutic concentrations of metformin. A study of 109 women with PCOS who were treated with metformin 1.5 grams/day to 2.55 grams/day at the time of conception and continued treatment throughout pregnancy found no difference in the development of preeclampsia and a lower rate of gestational diabetes when compared to a control group of pregnant women without PCOS. Among the 126 infants born to the women with PCOS, 2 birth defects occurred: 1 sacrococcygeal teratoma and 1 tethered spinal cord. Follow up to 18 months of age found no differences in height or weight in infants exposed to metformin compared to controls and no abnormalities in motor or social development. Other epidemiologic data suggest no increase in the rates of expected birth defects in women taking metformin who become pregnant. Metformin has been studied during the second and third trimesters of pregnancy. The neonatal mortality rate appeared lower in patients receiving metformin than in mildly diabetic controls, but slightly higher incidences of polycythemia and necrotizing enterocolitis were noted in the metformin group. The most frequently encountered infant problems were jaundice, polycythemia, and hypoglycemia. Poorly controlled diabetes during pregnancy also increases fetal risk. The American College of Obstetricians and Gynecologists (ACOG) and the American Diabetes Association (ADA) continue to recommend human insulin as the standard of care in pregnant women with diabetes mellitus and gestational diabetes mellitus (GDM) requiring medical therapy; insulin does not cross the placenta. Premenopausal anovulatory females with insulin resistance (i.e., those with polycystic ovary syndrome (PCOS)) may resume ovulation as a result of metformin therapy; patients may be at risk of conception if adequate contraception is not used.

    Breast-feeding

    Due to the potential for serious adverse reactions in a nursing infant, breast-feeding during use of ertugliflozin; metformin is not recommended. There are no data available regarding the presence of ertugliflozin or ertugliflozin; metformin in human milk, the effects on a breast-fed infant, or the effects on milk production. However, since ertugliflozin is present in the milk of lactating rats and human kidney maturation occurs in utero and during the first 2 years of life when lactational exposure may occur, there may be risk to the developing human kidney. Metformin monotherapy may be an option during lactation. Small studies indicate that metformin is excreted in human breast milk. Infant hypoglycemia or other side effects are a possibility; however, adverse effects on infant plasma glucose have not been reported in human studies. Furthermore, the use of metformin 2,550 mg/day by mothers breast-feeding their infants for 6 months does not affect growth, motor, or social development; the effects beyond 6 months are not known. In all of these studies, the estimated weight-adjusted infant exposure to metformin ranged from 0.11% to 1.08% of the mother's dose. While the manufacturers of metformin recommend that a decision should be made to discontinue breast-feeding or discontinue the drug, the results of these studies indicate that maternal ingestion of metformin during breast-feeding is probably safe to the infant. However, a risk and benefit analysis should be made for each mother and her infant; if patients elect to continue metformin monotherapy while breast-feeding, the mother should be aware of the potential risks to the infant. Other oral hypoglycemics may be considered as possible alternatives during breast-feeding. Because acarbose has limited systemic absorption, which results in minimal maternal plasma concentrations, clinically significant exposure via breast milk is not expected. Tolbutamide is usually considered compatible with breast-feeding. Glyburide may be a suitable alternative since it was not detected in the breast milk of lactating women who received single and multiple doses of glyburide. If any oral hypoglycemics are used during breast-feeding, the nursing infant should be monitored for signs of hypoglycemia, such as increased fussiness or somnolence. Consider the benefits of breast-feeding, the risk of potential infant drug exposure, and the risk of an untreated or inadequately treated condition. If a breast-feeding infant experiences an adverse effect related to a maternally ingested drug, healthcare providers are encouraged to report the adverse effect to the FDA.

    Children, infants

    The safety and effectiveness of ertugliflozin; metformin have not been established in adolescents and children under 18 years of age; there is no role for ertugliflozin; metformin in the treatment of infants.

    Laboratory test interference

    Ertugliflozin may cause a laboratory test interference. Monitoring of glycemic control with urine glucose tests and the 1,5 Anhydroglucitol assay (1,5-AG assay) is not recommended in patients receiving ertugliflozin; metformin. Use of urine glucose tests will result in positive urine glucose tests and measurements of 1,5-AG are unreliable in patients taking ertugliflozin. Use alternative methods to monitor glycemic control.

    ADVERSE REACTIONS

    Severe

    megaloblastic anemia / Delayed / 0-1.0
    phimosis / Delayed / 0.5-0.5
    lower limb amputation / Delayed / 0.2-0.4
    diabetic ketoacidosis / Delayed / 0.1-0.3
    lactic acidosis / Delayed / Incidence not known
    renal failure / Delayed / Incidence not known
    necrotizing fasciitis / Delayed / Incidence not known
    tissue necrosis / Early / Incidence not known
    rhabdomyolysis / Delayed / Incidence not known
    angioedema / Rapid / Incidence not known
    anaphylactoid reactions / Rapid / Incidence not known

    Moderate

    candidiasis / Delayed / 3.7-12.2
    hypoglycemia / Early / 2.0-7.8
    vitamin B12 deficiency / Delayed / 7.0-7.0
    hypovolemia / Early / 1.9-4.4
    balanitis / Delayed / 3.7-4.2
    cystitis / Delayed / 4.0-4.0
    vaginitis / Delayed / 2.4-2.8
    dehydration / Delayed / Incidence not known
    hypotension / Rapid / Incidence not known
    orthostatic hypotension / Delayed / Incidence not known
    dysuria / Early / Incidence not known
    hyperlipidemia / Delayed / Incidence not known
    hypercholesterolemia / Delayed / Incidence not known
    hyperphosphatemia / Delayed / Incidence not known
    skin ulcer / Delayed / Incidence not known
    folate deficiency / Delayed / Incidence not known
    elevated hepatic enzymes / Delayed / Incidence not known
    cholestasis / Delayed / Incidence not known

    Mild

    diarrhea / Early / 5.0-53.2
    vomiting / Early / 6.5-25.5
    nausea / Early / 6.5-25.5
    infection / Delayed / 2.4-12.2
    flatulence / Early / 1.0-12.1
    dyspepsia / Early / 1.0-7.1
    abdominal pain / Early / 1.0-6.4
    dysgeusia / Early / 1.0-5.0
    metallic taste / Early / 1.0-5.0
    anorexia / Delayed / 1.0-5.0
    headache / Early / 2.9-3.5
    increased urinary frequency / Early / 2.4-2.7
    polydipsia / Early / 1.4-2.7
    xerostomia / Early / 1.4-2.7
    back pain / Delayed / 1.7-2.5
    pharyngitis / Delayed / 2.0-2.5
    weight loss / Delayed / 1.2-2.4
    diuresis / Early / 10.0
    asthenia / Delayed / 5.0
    syncope / Early / Incidence not known
    urinary urgency / Early / Incidence not known
    nocturia / Early / Incidence not known
    polyuria / Early / Incidence not known
    rash / Early / Incidence not known

    DRUG INTERACTIONS

    Abacavir; Dolutegravir; Lamivudine: (Major) If these drugs are used in combination, the total daily dose of metformin must not exceed 1,000 mg/day. Dolutegravir may increase exposure to metformin. Increased exposure to metformin may increase the risk for hypoglycemia, gastrointestinal side effects, and potentially increase the risk for lactic acidosis. Consider the benefits and risks of concomitant use of dolutegravir with metformin. Close monitoring of blood glucose and patient clinical status (gastrointestinal side effects, renal function, electrolytes and acid-base balance) is recommended. When stopping dolutegravir, the metformin dose may need to be adjusted. In drug interaction studies, dolutegravir increased both the Cmax and AUC of metformin when metformin 500 mg PO twice daily was coadministered. Dolutegravir inhibits common renal tubular transport systems involved in the renal elimination of metformin (e.g., organic cationic transporter-2 [OCT2]/multidrug and toxin extrusion [MATE1 and MATE2k]). (Moderate) Certain medications used concomitantly with metformin may increase the risk of lactic acidosis. Cationic drugs that are eliminated by renal tubular secretion, such as lamivudine, may decrease metformin elimination by competing for common renal tubular transport systems.
    Abacavir; Lamivudine, 3TC: (Moderate) Certain medications used concomitantly with metformin may increase the risk of lactic acidosis. Cationic drugs that are eliminated by renal tubular secretion, such as lamivudine, may decrease metformin elimination by competing for common renal tubular transport systems.
    Abacavir; Lamivudine, 3TC; Zidovudine, ZDV: (Moderate) Certain medications used concomitantly with metformin may increase the risk of lactic acidosis. Cationic drugs that are eliminated by renal tubular secretion, such as lamivudine, may decrease metformin elimination by competing for common renal tubular transport systems.
    Acebutolol: (Moderate) Increased frequency of blood glucose monitoring may be required when a beta blocker is given with antidiabetic agents. Since beta blockers inhibit the release of catecholamines, these medications may hide symptoms of hypoglycemia such as tremor, tachycardia, and blood pressure changes. Other symptoms, like headache, dizziness, nervousness, mood changes, or hunger are not blunted. Beta-blockers also exert complex actions on the body's ability to regulate blood glucose. Some beta-blockers, particularly non-selective beta-blockers such as propranolol, have been noted to potentiate insulin-induced hypoglycemia and a delay in recovery of blood glucose to normal levels. Hyperglycemia has been reported as well and is possibly due to beta-2 receptor blockade in the beta cells of the pancreas. A selective beta-blocker may be preferred in patients with diabetes mellitus, if appropriate for the patient's condition. Selective beta-blockers, such as atenolol or metoprolol, do not appear to potentiate insulin-induced hypoglycemia. While beta-blockers may have negative effects on glycemic control, they reduce the risk of cardiovascular disease and stroke in patients with diabetes and their use should not be avoided in patients with compelling indications for beta-blocker therapy when no other contraindications are present.
    Acetaminophen; Chlorpheniramine; Dextromethorphan; Phenylephrine: (Moderate) Sympathomimetic agents and adrenergic agonists tend to increase blood glucose concentrations when administered systemically. Monitor for loss of glycemic control when pseudoephedrine, phenylephrine, and other sympathomimetics are administered to patients taking antidiabetic agents. Epinephrine and other sympathomimetics, through stimulation of alpha- and beta- receptors, increase hepatic glucose production and glycogenolysis and inhibit insulin secretion. Also, adrenergic medications may decrease glucose uptake by muscle cells. For treatment of cold symptoms, nasal decongestants may be preferable for short term, limited use (1 to 3 days) as an alternative to systemic decongestants in patients taking medications for diabetes.
    Acetaminophen; Chlorpheniramine; Dextromethorphan; Pseudoephedrine: (Moderate) Sympathomimetic agents and adrenergic agonists tend to increase blood glucose concentrations when administered systemically. Monitor for loss of glycemic control when pseudoephedrine, phenylephrine, and other sympathomimetics are administered to patients taking antidiabetic agents. Epinephrine and other sympathomimetics, through stimulation of alpha- and beta- receptors, increase hepatic glucose production and glycogenolysis and inhibit insulin secretion. Also, adrenergic medications may decrease glucose uptake by muscle cells. For treatment of cold symptoms, nasal decongestants may be preferable for short term, limited use (1 to 3 days) as an alternative to systemic decongestants in patients taking medications for diabetes.
    Acetaminophen; Chlorpheniramine; Phenylephrine : (Moderate) Sympathomimetic agents and adrenergic agonists tend to increase blood glucose concentrations when administered systemically. Monitor for loss of glycemic control when pseudoephedrine, phenylephrine, and other sympathomimetics are administered to patients taking antidiabetic agents. Epinephrine and other sympathomimetics, through stimulation of alpha- and beta- receptors, increase hepatic glucose production and glycogenolysis and inhibit insulin secretion. Also, adrenergic medications may decrease glucose uptake by muscle cells. For treatment of cold symptoms, nasal decongestants may be preferable for short term, limited use (1 to 3 days) as an alternative to systemic decongestants in patients taking medications for diabetes.
    Acetaminophen; Chlorpheniramine; Phenylephrine; Phenyltoloxamine: (Moderate) Sympathomimetic agents and adrenergic agonists tend to increase blood glucose concentrations when administered systemically. Monitor for loss of glycemic control when pseudoephedrine, phenylephrine, and other sympathomimetics are administered to patients taking antidiabetic agents. Epinephrine and other sympathomimetics, through stimulation of alpha- and beta- receptors, increase hepatic glucose production and glycogenolysis and inhibit insulin secretion. Also, adrenergic medications may decrease glucose uptake by muscle cells. For treatment of cold symptoms, nasal decongestants may be preferable for short term, limited use (1 to 3 days) as an alternative to systemic decongestants in patients taking medications for diabetes.
    Acetaminophen; Dextromethorphan; Guaifenesin; Phenylephrine: (Moderate) Sympathomimetic agents and adrenergic agonists tend to increase blood glucose concentrations when administered systemically. Monitor for loss of glycemic control when pseudoephedrine, phenylephrine, and other sympathomimetics are administered to patients taking antidiabetic agents. Epinephrine and other sympathomimetics, through stimulation of alpha- and beta- receptors, increase hepatic glucose production and glycogenolysis and inhibit insulin secretion. Also, adrenergic medications may decrease glucose uptake by muscle cells. For treatment of cold symptoms, nasal decongestants may be preferable for short term, limited use (1 to 3 days) as an alternative to systemic decongestants in patients taking medications for diabetes.
    Acetaminophen; Dextromethorphan; Guaifenesin; Pseudoephedrine: (Moderate) Sympathomimetic agents and adrenergic agonists tend to increase blood glucose concentrations when administered systemically. Monitor for loss of glycemic control when pseudoephedrine, phenylephrine, and other sympathomimetics are administered to patients taking antidiabetic agents. Epinephrine and other sympathomimetics, through stimulation of alpha- and beta- receptors, increase hepatic glucose production and glycogenolysis and inhibit insulin secretion. Also, adrenergic medications may decrease glucose uptake by muscle cells. For treatment of cold symptoms, nasal decongestants may be preferable for short term, limited use (1 to 3 days) as an alternative to systemic decongestants in patients taking medications for diabetes.
    Acetaminophen; Dextromethorphan; Phenylephrine: (Moderate) Sympathomimetic agents and adrenergic agonists tend to increase blood glucose concentrations when administered systemically. Monitor for loss of glycemic control when pseudoephedrine, phenylephrine, and other sympathomimetics are administered to patients taking antidiabetic agents. Epinephrine and other sympathomimetics, through stimulation of alpha- and beta- receptors, increase hepatic glucose production and glycogenolysis and inhibit insulin secretion. Also, adrenergic medications may decrease glucose uptake by muscle cells. For treatment of cold symptoms, nasal decongestants may be preferable for short term, limited use (1 to 3 days) as an alternative to systemic decongestants in patients taking medications for diabetes.
    Acetaminophen; Dextromethorphan; Pseudoephedrine: (Moderate) Sympathomimetic agents and adrenergic agonists tend to increase blood glucose concentrations when administered systemically. Monitor for loss of glycemic control when pseudoephedrine, phenylephrine, and other sympathomimetics are administered to patients taking antidiabetic agents. Epinephrine and other sympathomimetics, through stimulation of alpha- and beta- receptors, increase hepatic glucose production and glycogenolysis and inhibit insulin secretion. Also, adrenergic medications may decrease glucose uptake by muscle cells. For treatment of cold symptoms, nasal decongestants may be preferable for short term, limited use (1 to 3 days) as an alternative to systemic decongestants in patients taking medications for diabetes.
    Acetaminophen; Guaifenesin; Phenylephrine: (Moderate) Sympathomimetic agents and adrenergic agonists tend to increase blood glucose concentrations when administered systemically. Monitor for loss of glycemic control when pseudoephedrine, phenylephrine, and other sympathomimetics are administered to patients taking antidiabetic agents. Epinephrine and other sympathomimetics, through stimulation of alpha- and beta- receptors, increase hepatic glucose production and glycogenolysis and inhibit insulin secretion. Also, adrenergic medications may decrease glucose uptake by muscle cells. For treatment of cold symptoms, nasal decongestants may be preferable for short term, limited use (1 to 3 days) as an alternative to systemic decongestants in patients taking medications for diabetes.
    Acetaminophen; Propoxyphene: (Moderate) Propoxyphene may enhance the hypoglycemic action of antidiabetic agents. Patients should be closely monitored for changes in glycemic control while receiving propoxyphene in combination with antidiabetic agents.
    Acetaminophen; Pseudoephedrine: (Moderate) Sympathomimetic agents and adrenergic agonists tend to increase blood glucose concentrations when administered systemically. Monitor for loss of glycemic control when pseudoephedrine, phenylephrine, and other sympathomimetics are administered to patients taking antidiabetic agents. Epinephrine and other sympathomimetics, through stimulation of alpha- and beta- receptors, increase hepatic glucose production and glycogenolysis and inhibit insulin secretion. Also, adrenergic medications may decrease glucose uptake by muscle cells. For treatment of cold symptoms, nasal decongestants may be preferable for short term, limited use (1 to 3 days) as an alternative to systemic decongestants in patients taking medications for diabetes.
    Acetazolamide: (Moderate) Carbonic anhydrase inhibitors such as acetazolamide frequently cause a decrease in serum bicarbonate and induce non-anion gap, hyperchloremic metabolic acidosis. Concomitant use of acetazolamide with metformin may increase the risk for lactic acidosis; consider more frequent monitoring. Carbonic anhydrase inhibitors may also alter blood sugar; both hyperglycemia and hypoglycemia have been described. Monitor blood glucose and for changes in glycemic control and be alert for evidence of an interaction. (Minor) Carbonic anhydrase inhibitors may alter blood sugar. Both hyperglycemia and hypoglycemia have been described in patients treated with acetazolamide. This should be taken into consideration in patients with impaired glucose tolerance or diabetes mellitus who are receiving antidiabetic agents. Monitor blood glucose and for changes in glycemic control and be alert for evidence of an interaction.
    Acetohexamide: (Moderate) Use of metformin with a sulfonylurea may increase the risk of hypoglycemia. Sulfonylureas are known to cause hypoglycemia. To manage hypoglycemic risk, lower doses of the sulfonylurea may be needed. Monitor blood sugar.
    Acrivastine; Pseudoephedrine: (Moderate) Sympathomimetic agents and adrenergic agonists tend to increase blood glucose concentrations when administered systemically. Monitor for loss of glycemic control when pseudoephedrine, phenylephrine, and other sympathomimetics are administered to patients taking antidiabetic agents. Epinephrine and other sympathomimetics, through stimulation of alpha- and beta- receptors, increase hepatic glucose production and glycogenolysis and inhibit insulin secretion. Also, adrenergic medications may decrease glucose uptake by muscle cells. For treatment of cold symptoms, nasal decongestants may be preferable for short term, limited use (1 to 3 days) as an alternative to systemic decongestants in patients taking medications for diabetes.
    Adefovir: (Moderate) Certain medications used concomitantly with metformin may increase the risk of lactic acidosis. Cationic drugs that are eliminated by renal tubular secretion (e.g., adefovir) may decrease metformin elimination by competing for common renal tubular transport systems. Although such interactions remain theoretical, careful patient monitoring and dose adjustment of metformin and/or the interfering cationic drug are recommended.
    Aliskiren; Amlodipine; Hydrochlorothiazide, HCTZ: (Moderate) Certain drugs, such as thiazide diuretics, tend to produce hyperglycemia and may lead to loss of glycemic control. The effects of thiazide diuretics on glycemic control appear to be dose-related and low doses can be instituted without deleterious effects on glycemic control. In addition, thiazide diuretics reduce the risk of stroke and cardiovascular disease in patients with diabetes. Patients receiving metformin should be monitored for changes in blood glucose control if any of these diuretics are added or deleted. Dosage adjustments may be necessary in some patients.
    Aliskiren; Hydrochlorothiazide, HCTZ: (Moderate) Certain drugs, such as thiazide diuretics, tend to produce hyperglycemia and may lead to loss of glycemic control. The effects of thiazide diuretics on glycemic control appear to be dose-related and low doses can be instituted without deleterious effects on glycemic control. In addition, thiazide diuretics reduce the risk of stroke and cardiovascular disease in patients with diabetes. Patients receiving metformin should be monitored for changes in blood glucose control if any of these diuretics are added or deleted. Dosage adjustments may be necessary in some patients.
    Aliskiren; Valsartan: (Moderate) Angiotensin II receptor antagonists (ARBs) may enhance the hypoglycemic effects of metformin by improving insulin sensitivity. In addition, angiotensin II receptor antagonists have been associated with a reduced incidence in the development of new-onset diabetes in patients with hypertension or other cardiac disease. ARBs may rarely reduce renal function, a risk factor for reduced renal clearance of metformin. Patients receiving these drugs together should be monitored for changes in renal function and glycemic control. (Moderate) Patients receiving these drugs concomitantly should be monitored for changes in blood pressure, volume status, renal function, serum potassium and other electrolytes, and for glycemic control. When an SGLT2 inhibitor is initiated, mild diuresis and naturesis occurs, producing intravascular volume contraction. These effects may be additive to certain antihypertensive medications, such as the angiotensin II receptor antagonists (also known as angiotensin receptor blockers or ARBs). Patients with impaired renal function (eGFR less than 60 mL/minute/1.73 m2), low systolic blood pressure, or who are elderly may also be at a greater risk. Volume status should be assessed and corrected. In addition, some SGLT2 inhibitors, like canagliflozin, can increase serum potassium. Monitor serum potassium levels periodically and monitor for hyperkalemia. ARBs may also enhance the hypoglycemic effects of antidiabetic agents by improving insulin sensitivity.
    Amiloride; Hydrochlorothiazide, HCTZ: (Moderate) Certain drugs, such as thiazide diuretics, tend to produce hyperglycemia and may lead to loss of glycemic control. The effects of thiazide diuretics on glycemic control appear to be dose-related and low doses can be instituted without deleterious effects on glycemic control. In addition, thiazide diuretics reduce the risk of stroke and cardiovascular disease in patients with diabetes. Patients receiving metformin should be monitored for changes in blood glucose control if any of these diuretics are added or deleted. Dosage adjustments may be necessary in some patients.
    Amlodipine; Benazepril: (Moderate) Angiotensin-converting enzyme (ACE) inhibitors may enhance the hypoglycemic effects of insulin or other antidiabetic agents by improving insulin sensitivity. Patients receiving antidiabetic agents can become hypoglycemic if ACE inhibitors are administered concomitantly. ACE inhibitors may rarely reduce renal function, a risk factor for reduced renal clearance of metformin. Patients receiving these drugs together should be monitored for changes in renal function and glycemic control. (Moderate) Patients receiving these drugs concomitantly should be monitored for changes in blood pressure, volume status, renal function, serum potassium, and glycemic control. When an SGLT2 inhibitor is initiated, mild diuresis and naturesis occurs, producing intravascular volume contraction. These effects may be additive to certain antihypertensive medications, such as the angiotensin-converting enzyme inhibitors (ACE inhibitors). Patients with impaired renal function (eGFR less than 60 mL/minute/1.73 m2), low systolic blood pressure, or who are elderly may also be at a greater risk. Volume status should be assessed and corrected. In addition, some SGLT2 inhibitors, like canagliflozin, can increase serum potassium. Monitor serum potassium levels periodically and monitor for hyperkalemia. ACE inhibitors may also enhance the hypoglycemic effects of antidiabetic agents by improving insulin sensitivity.
    Amlodipine; Olmesartan: (Moderate) Angiotensin II receptor antagonists (ARBs) may enhance the hypoglycemic effects of metformin by improving insulin sensitivity. In addition, angiotensin II receptor antagonists have been associated with a reduced incidence in the development of new-onset diabetes in patients with hypertension or other cardiac disease. ARBs may rarely reduce renal function, a risk factor for reduced renal clearance of metformin. Patients receiving these drugs together should be monitored for changes in renal function and glycemic control. (Moderate) Patients receiving these drugs concomitantly should be monitored for changes in blood pressure, volume status, renal function, serum potassium and other electrolytes, and for glycemic control. When an SGLT2 inhibitor is initiated, mild diuresis and naturesis occurs, producing intravascular volume contraction. These effects may be additive to certain antihypertensive medications, such as the angiotensin II receptor antagonists (also known as angiotensin receptor blockers or ARBs). Patients with impaired renal function (eGFR less than 60 mL/minute/1.73 m2), low systolic blood pressure, or who are elderly may also be at a greater risk. Volume status should be assessed and corrected. In addition, some SGLT2 inhibitors, like canagliflozin, can increase serum potassium. Monitor serum potassium levels periodically and monitor for hyperkalemia. ARBs may also enhance the hypoglycemic effects of antidiabetic agents by improving insulin sensitivity.
    Amlodipine; Valsartan: (Moderate) Angiotensin II receptor antagonists (ARBs) may enhance the hypoglycemic effects of metformin by improving insulin sensitivity. In addition, angiotensin II receptor antagonists have been associated with a reduced incidence in the development of new-onset diabetes in patients with hypertension or other cardiac disease. ARBs may rarely reduce renal function, a risk factor for reduced renal clearance of metformin. Patients receiving these drugs together should be monitored for changes in renal function and glycemic control. (Moderate) Patients receiving these drugs concomitantly should be monitored for changes in blood pressure, volume status, renal function, serum potassium and other electrolytes, and for glycemic control. When an SGLT2 inhibitor is initiated, mild diuresis and naturesis occurs, producing intravascular volume contraction. These effects may be additive to certain antihypertensive medications, such as the angiotensin II receptor antagonists (also known as angiotensin receptor blockers or ARBs). Patients with impaired renal function (eGFR less than 60 mL/minute/1.73 m2), low systolic blood pressure, or who are elderly may also be at a greater risk. Volume status should be assessed and corrected. In addition, some SGLT2 inhibitors, like canagliflozin, can increase serum potassium. Monitor serum potassium levels periodically and monitor for hyperkalemia. ARBs may also enhance the hypoglycemic effects of antidiabetic agents by improving insulin sensitivity.
    Amlodipine; Valsartan; Hydrochlorothiazide, HCTZ: (Moderate) Angiotensin II receptor antagonists (ARBs) may enhance the hypoglycemic effects of metformin by improving insulin sensitivity. In addition, angiotensin II receptor antagonists have been associated with a reduced incidence in the development of new-onset diabetes in patients with hypertension or other cardiac disease. ARBs may rarely reduce renal function, a risk factor for reduced renal clearance of metformin. Patients receiving these drugs together should be monitored for changes in renal function and glycemic control. (Moderate) Certain drugs, such as thiazide diuretics, tend to produce hyperglycemia and may lead to loss of glycemic control. The effects of thiazide diuretics on glycemic control appear to be dose-related and low doses can be instituted without deleterious effects on glycemic control. In addition, thiazide diuretics reduce the risk of stroke and cardiovascular disease in patients with diabetes. Patients receiving metformin should be monitored for changes in blood glucose control if any of these diuretics are added or deleted. Dosage adjustments may be necessary in some patients. (Moderate) Patients receiving these drugs concomitantly should be monitored for changes in blood pressure, volume status, renal function, serum potassium and other electrolytes, and for glycemic control. When an SGLT2 inhibitor is initiated, mild diuresis and naturesis occurs, producing intravascular volume contraction. These effects may be additive to certain antihypertensive medications, such as the angiotensin II receptor antagonists (also known as angiotensin receptor blockers or ARBs). Patients with impaired renal function (eGFR less than 60 mL/minute/1.73 m2), low systolic blood pressure, or who are elderly may also be at a greater risk. Volume status should be assessed and corrected. In addition, some SGLT2 inhibitors, like canagliflozin, can increase serum potassium. Monitor serum potassium levels periodically and monitor for hyperkalemia. ARBs may also enhance the hypoglycemic effects of antidiabetic agents by improving insulin sensitivity.
    Amoxicillin; Clarithromycin; Omeprazole: (Moderate) The concomitant use of clarithromycin and antidiabetic agents can result in significant hypoglycemia. Careful monitoring of blood glucose is recommended.
    Amphetamine: (Moderate) Sympathomimetic agents and adrenergic agonists tend to increase blood glucose concentrations when administered systemically. Monitor for loss of glycemic control when pseudoephedrine, phenylephrine, and other sympathomimetics are administered to patients taking antidiabetic agents. Epinephrine and other sympathomimetics, through stimulation of alpha- and beta- receptors, increase hepatic glucose production and glycogenolysis and inhibit insulin secretion. Also, adrenergic medications may decrease glucose uptake by muscle cells. For treatment of cold symptoms, nasal decongestants may be preferable for short term, limited use (1 to 3 days) as an alternative to systemic decongestants in patients taking medications for diabetes.
    Amphetamine; Dextroamphetamine: (Moderate) Sympathomimetic agents and adrenergic agonists tend to increase blood glucose concentrations when administered systemically. Monitor for loss of glycemic control when pseudoephedrine, phenylephrine, and other sympathomimetics are administered to patients taking antidiabetic agents. Epinephrine and other sympathomimetics, through stimulation of alpha- and beta- receptors, increase hepatic glucose production and glycogenolysis and inhibit insulin secretion. Also, adrenergic medications may decrease glucose uptake by muscle cells. For treatment of cold symptoms, nasal decongestants may be preferable for short term, limited use (1 to 3 days) as an alternative to systemic decongestants in patients taking medications for diabetes.
    Amphetamines: (Moderate) Sympathomimetic agents and adrenergic agonists tend to increase blood glucose concentrations when administered systemically. Monitor for loss of glycemic control when pseudoephedrine, phenylephrine, and other sympathomimetics are administered to patients taking antidiabetic agents. Epinephrine and other sympathomimetics, through stimulation of alpha- and beta- receptors, increase hepatic glucose production and glycogenolysis and inhibit insulin secretion. Also, adrenergic medications may decrease glucose uptake by muscle cells. For treatment of cold symptoms, nasal decongestants may be preferable for short term, limited use (1 to 3 days) as an alternative to systemic decongestants in patients taking medications for diabetes.
    Androgens: (Moderate) Changes in insulin sensitivity or glycemic control may occur in patients treated with androgens. In diabetic patients, the metabolic effects of androgens may decrease blood glucose and, therefore, may decrease antidiabetic agent dosage requirements. Monitor blood glucose and HbA1C when these drugs are used together.
    Angiotensin II receptor antagonists: (Moderate) Angiotensin II receptor antagonists (ARBs) may enhance the hypoglycemic effects of metformin by improving insulin sensitivity. In addition, angiotensin II receptor antagonists have been associated with a reduced incidence in the development of new-onset diabetes in patients with hypertension or other cardiac disease. ARBs may rarely reduce renal function, a risk factor for reduced renal clearance of metformin. Patients receiving these drugs together should be monitored for changes in renal function and glycemic control. (Moderate) Patients receiving these drugs concomitantly should be monitored for changes in blood pressure, volume status, renal function, serum potassium and other electrolytes, and for glycemic control. When an SGLT2 inhibitor is initiated, mild diuresis and naturesis occurs, producing intravascular volume contraction. These effects may be additive to certain antihypertensive medications, such as the angiotensin II receptor antagonists (also known as angiotensin receptor blockers or ARBs). Patients with impaired renal function (eGFR less than 60 mL/minute/1.73 m2), low systolic blood pressure, or who are elderly may also be at a greater risk. Volume status should be assessed and corrected. In addition, some SGLT2 inhibitors, like canagliflozin, can increase serum potassium. Monitor serum potassium levels periodically and monitor for hyperkalemia. ARBs may also enhance the hypoglycemic effects of antidiabetic agents by improving insulin sensitivity.
    Angiotensin-converting enzyme inhibitors: (Moderate) Angiotensin-converting enzyme (ACE) inhibitors may enhance the hypoglycemic effects of insulin or other antidiabetic agents by improving insulin sensitivity. Patients receiving antidiabetic agents can become hypoglycemic if ACE inhibitors are administered concomitantly. ACE inhibitors may rarely reduce renal function, a risk factor for reduced renal clearance of metformin. Patients receiving these drugs together should be monitored for changes in renal function and glycemic control. (Moderate) Patients receiving these drugs concomitantly should be monitored for changes in blood pressure, volume status, renal function, serum potassium, and glycemic control. When an SGLT2 inhibitor is initiated, mild diuresis and naturesis occurs, producing intravascular volume contraction. These effects may be additive to certain antihypertensive medications, such as the angiotensin-converting enzyme inhibitors (ACE inhibitors). Patients with impaired renal function (eGFR less than 60 mL/minute/1.73 m2), low systolic blood pressure, or who are elderly may also be at a greater risk. Volume status should be assessed and corrected. In addition, some SGLT2 inhibitors, like canagliflozin, can increase serum potassium. Monitor serum potassium levels periodically and monitor for hyperkalemia. ACE inhibitors may also enhance the hypoglycemic effects of antidiabetic agents by improving insulin sensitivity.
    Atazanavir; Cobicistat: (Moderate) Concurrent administration of metformin and cobicistat may increase the risk of lactic acidosis. Cobicistat is a potent inhibitor of the human multidrug and toxic extrusion 1 (MATE1) on proximal renal tubular cells; metformin is a MATE1 substrate. Inhibition of MATE1 by cobicistat may decrease metformin eliminiation by blocking renal tubular secretion. If these drugs are given together, closely monitor for signs of metformin toxicity; metformin dose adjustments may be needed.
    Atenolol: (Moderate) Increased frequency of blood glucose monitoring may be required when a beta blocker is given with antidiabetic agents. Since beta blockers inhibit the release of catecholamines, these medications may hide symptoms of hypoglycemia such as tremor, tachycardia, and blood pressure changes. Other symptoms, like headache, dizziness, nervousness, mood changes, or hunger are not blunted. Beta-blockers also exert complex actions on the body's ability to regulate blood glucose. Some beta-blockers, particularly non-selective beta-blockers such as propranolol, have been noted to potentiate insulin-induced hypoglycemia and a delay in recovery of blood glucose to normal levels. Hyperglycemia has been reported as well and is possibly due to beta-2 receptor blockade in the beta cells of the pancreas. A selective beta-blocker may be preferred in patients with diabetes mellitus, if appropriate for the patient's condition. Selective beta-blockers, such as atenolol or metoprolol, do not appear to potentiate insulin-induced hypoglycemia. While beta-blockers may have negative effects on glycemic control, they reduce the risk of cardiovascular disease and stroke in patients with diabetes and their use should not be avoided in patients with compelling indications for beta-blocker therapy when no other contraindications are present.
    Atenolol; Chlorthalidone: (Moderate) Certain drugs, such as thiazide diuretics, tend to produce hyperglycemia and may lead to loss of glycemic control. The effects of thiazide diuretics on glycemic control appear to be dose-related and low doses can be instituted without deleterious effects on glycemic control. In addition, thiazide diuretics reduce the risk of stroke and cardiovascular disease in patients with diabetes. Patients receiving metformin should be monitored for changes in blood glucose control if any of these diuretics are added or deleted. Dosage adjustments may be necessary in some patients. (Moderate) Increased frequency of blood glucose monitoring may be required when a beta blocker is given with antidiabetic agents. Since beta blockers inhibit the release of catecholamines, these medications may hide symptoms of hypoglycemia such as tremor, tachycardia, and blood pressure changes. Other symptoms, like headache, dizziness, nervousness, mood changes, or hunger are not blunted. Beta-blockers also exert complex actions on the body's ability to regulate blood glucose. Some beta-blockers, particularly non-selective beta-blockers such as propranolol, have been noted to potentiate insulin-induced hypoglycemia and a delay in recovery of blood glucose to normal levels. Hyperglycemia has been reported as well and is possibly due to beta-2 receptor blockade in the beta cells of the pancreas. A selective beta-blocker may be preferred in patients with diabetes mellitus, if appropriate for the patient's condition. Selective beta-blockers, such as atenolol or metoprolol, do not appear to potentiate insulin-induced hypoglycemia. While beta-blockers may have negative effects on glycemic control, they reduce the risk of cardiovascular disease and stroke in patients with diabetes and their use should not be avoided in patients with compelling indications for beta-blocker therapy when no other contraindications are present.
    atypical antipsychotic: (Moderate) Atypical antipsychotic therapy may aggravate diabetes mellitus and cause metabolic changes such as hyperglycemia. Monitor patients on antidiabetic agents for worsening glycemic control. The atypical antipsychotics have been associated with metabolic changes, including hyperglycemia, diabetic ketoacidosis, hyperosmolar, hyperglycemic states, and diabetic coma. Aggravation of diabetes mellitus has been reported. Possible mechanisms include atypical antipsychotic-induced insulin resistance or direct beta-cell inhibition.
    Azilsartan: (Moderate) Angiotensin II receptor antagonists (ARBs) may enhance the hypoglycemic effects of metformin by improving insulin sensitivity. In addition, angiotensin II receptor antagonists have been associated with a reduced incidence in the development of new-onset diabetes in patients with hypertension or other cardiac disease. ARBs may rarely reduce renal function, a risk factor for reduced renal clearance of metformin. Patients receiving these drugs together should be monitored for changes in renal function and glycemic control. (Moderate) Patients receiving these drugs concomitantly should be monitored for changes in blood pressure, volume status, renal function, serum potassium and other electrolytes, and for glycemic control. When an SGLT2 inhibitor is initiated, mild diuresis and naturesis occurs, producing intravascular volume contraction. These effects may be additive to certain antihypertensive medications, such as the angiotensin II receptor antagonists (also known as angiotensin receptor blockers or ARBs). Patients with impaired renal function (eGFR less than 60 mL/minute/1.73 m2), low systolic blood pressure, or who are elderly may also be at a greater risk. Volume status should be assessed and corrected. In addition, some SGLT2 inhibitors, like canagliflozin, can increase serum potassium. Monitor serum potassium levels periodically and monitor for hyperkalemia. ARBs may also enhance the hypoglycemic effects of antidiabetic agents by improving insulin sensitivity.
    Azilsartan; Chlorthalidone: (Moderate) Angiotensin II receptor antagonists (ARBs) may enhance the hypoglycemic effects of metformin by improving insulin sensitivity. In addition, angiotensin II receptor antagonists have been associated with a reduced incidence in the development of new-onset diabetes in patients with hypertension or other cardiac disease. ARBs may rarely reduce renal function, a risk factor for reduced renal clearance of metformin. Patients receiving these drugs together should be monitored for changes in renal function and glycemic control. (Moderate) Certain drugs, such as thiazide diuretics, tend to produce hyperglycemia and may lead to loss of glycemic control. The effects of thiazide diuretics on glycemic control appear to be dose-related and low doses can be instituted without deleterious effects on glycemic control. In addition, thiazide diuretics reduce the risk of stroke and cardiovascular disease in patients with diabetes. Patients receiving metformin should be monitored for changes in blood glucose control if any of these diuretics are added or deleted. Dosage adjustments may be necessary in some patients. (Moderate) Patients receiving these drugs concomitantly should be monitored for changes in blood pressure, volume status, renal function, serum potassium and other electrolytes, and for glycemic control. When an SGLT2 inhibitor is initiated, mild diuresis and naturesis occurs, producing intravascular volume contraction. These effects may be additive to certain antihypertensive medications, such as the angiotensin II receptor antagonists (also known as angiotensin receptor blockers or ARBs). Patients with impaired renal function (eGFR less than 60 mL/minute/1.73 m2), low systolic blood pressure, or who are elderly may also be at a greater risk. Volume status should be assessed and corrected. In addition, some SGLT2 inhibitors, like canagliflozin, can increase serum potassium. Monitor serum potassium levels periodically and monitor for hyperkalemia. ARBs may also enhance the hypoglycemic effects of antidiabetic agents by improving insulin sensitivity.
    Benazepril: (Moderate) Angiotensin-converting enzyme (ACE) inhibitors may enhance the hypoglycemic effects of insulin or other antidiabetic agents by improving insulin sensitivity. Patients receiving antidiabetic agents can become hypoglycemic if ACE inhibitors are administered concomitantly. ACE inhibitors may rarely reduce renal function, a risk factor for reduced renal clearance of metformin. Patients receiving these drugs together should be monitored for changes in renal function and glycemic control. (Moderate) Patients receiving these drugs concomitantly should be monitored for changes in blood pressure, volume status, renal function, serum potassium, and glycemic control. When an SGLT2 inhibitor is initiated, mild diuresis and naturesis occurs, producing intravascular volume contraction. These effects may be additive to certain antihypertensive medications, such as the angiotensin-converting enzyme inhibitors (ACE inhibitors). Patients with impaired renal function (eGFR less than 60 mL/minute/1.73 m2), low systolic blood pressure, or who are elderly may also be at a greater risk. Volume status should be assessed and corrected. In addition, some SGLT2 inhibitors, like canagliflozin, can increase serum potassium. Monitor serum potassium levels periodically and monitor for hyperkalemia. ACE inhibitors may also enhance the hypoglycemic effects of antidiabetic agents by improving insulin sensitivity.
    Benazepril; Hydrochlorothiazide, HCTZ: (Moderate) Angiotensin-converting enzyme (ACE) inhibitors may enhance the hypoglycemic effects of insulin or other antidiabetic agents by improving insulin sensitivity. Patients receiving antidiabetic agents can become hypoglycemic if ACE inhibitors are administered concomitantly. ACE inhibitors may rarely reduce renal function, a risk factor for reduced renal clearance of metformin. Patients receiving these drugs together should be monitored for changes in renal function and glycemic control. (Moderate) Certain drugs, such as thiazide diuretics, tend to produce hyperglycemia and may lead to loss of glycemic control. The effects of thiazide diuretics on glycemic control appear to be dose-related and low doses can be instituted without deleterious effects on glycemic control. In addition, thiazide diuretics reduce the risk of stroke and cardiovascular disease in patients with diabetes. Patients receiving metformin should be monitored for changes in blood glucose control if any of these diuretics are added or deleted. Dosage adjustments may be necessary in some patients. (Moderate) Patients receiving these drugs concomitantly should be monitored for changes in blood pressure, volume status, renal function, serum potassium, and glycemic control. When an SGLT2 inhibitor is initiated, mild diuresis and naturesis occurs, producing intravascular volume contraction. These effects may be additive to certain antihypertensive medications, such as the angiotensin-converting enzyme inhibitors (ACE inhibitors). Patients with impaired renal function (eGFR less than 60 mL/minute/1.73 m2), low systolic blood pressure, or who are elderly may also be at a greater risk. Volume status should be assessed and corrected. In addition, some SGLT2 inhibitors, like canagliflozin, can increase serum potassium. Monitor serum potassium levels periodically and monitor for hyperkalemia. ACE inhibitors may also enhance the hypoglycemic effects of antidiabetic agents by improving insulin sensitivity.
    Bendroflumethiazide; Nadolol: (Moderate) Certain drugs, such as thiazide diuretics, tend to produce hyperglycemia and may lead to loss of glycemic control. The effects of thiazide diuretics on glycemic control appear to be dose-related and low doses can be instituted without deleterious effects on glycemic control. In addition, thiazide diuretics reduce the risk of stroke and cardiovascular disease in patients with diabetes. Patients receiving metformin should be monitored for changes in blood glucose control if any of these diuretics are added or deleted. Dosage adjustments may be necessary in some patients. (Moderate) Increased frequency of blood glucose monitoring may be required when a beta blocker is given with antidiabetic agents. Since beta blockers inhibit the release of catecholamines, these medications may hide symptoms of hypoglycemia such as tremor, tachycardia, and blood pressure changes. Other symptoms, like headache, dizziness, nervousness, mood changes, or hunger are not blunted. Beta-blockers also exert complex actions on the body's ability to regulate blood glucose. Some beta-blockers, particularly non-selective beta-blockers such as propranolol, have been noted to potentiate insulin-induced hypoglycemia and a delay in recovery of blood glucose to normal levels. Hyperglycemia has been reported as well and is possibly due to beta-2 receptor blockade in the beta cells of the pancreas. A selective beta-blocker may be preferred in patients with diabetes mellitus, if appropriate for the patient's condition. Selective beta-blockers, such as atenolol or metoprolol, do not appear to potentiate insulin-induced hypoglycemia. While beta-blockers may have negative effects on glycemic control, they reduce the risk of cardiovascular disease and stroke in patients with diabetes and their use should not be avoided in patients with compelling indications for beta-blocker therapy when no other contraindications are present.
    Benzphetamine: (Moderate) Sympathomimetic agents and adrenergic agonists tend to increase blood glucose concentrations when administered systemically. Monitor for loss of glycemic control when pseudoephedrine, phenylephrine, and other sympathomimetics are administered to patients taking antidiabetic agents. Epinephrine and other sympathomimetics, through stimulation of alpha- and beta- receptors, increase hepatic glucose production and glycogenolysis and inhibit insulin secretion. Also, adrenergic medications may decrease glucose uptake by muscle cells. For treatment of cold symptoms, nasal decongestants may be preferable for short term, limited use (1 to 3 days) as an alternative to systemic decongestants in patients taking medications for diabetes.
    Beta-blockers: (Moderate) Increased frequency of blood glucose monitoring may be required when a beta blocker is given with antidiabetic agents. Since beta blockers inhibit the release of catecholamines, these medications may hide symptoms of hypoglycemia such as tremor, tachycardia, and blood pressure changes. Other symptoms, like headache, dizziness, nervousness, mood changes, or hunger are not blunted. Beta-blockers also exert complex actions on the body's ability to regulate blood glucose. Some beta-blockers, particularly non-selective beta-blockers such as propranolol, have been noted to potentiate insulin-induced hypoglycemia and a delay in recovery of blood glucose to normal levels. Hyperglycemia has been reported as well and is possibly due to beta-2 receptor blockade in the beta cells of the pancreas. A selective beta-blocker may be preferred in patients with diabetes mellitus, if appropriate for the patient's condition. Selective beta-blockers, such as atenolol or metoprolol, do not appear to potentiate insulin-induced hypoglycemia. While beta-blockers may have negative effects on glycemic control, they reduce the risk of cardiovascular disease and stroke in patients with diabetes and their use should not be avoided in patients with compelling indications for beta-blocker therapy when no other contraindications are present.
    Betaxolol: (Moderate) Increased frequency of blood glucose monitoring may be required when a beta blocker is given with antidiabetic agents. Since beta blockers inhibit the release of catecholamines, these medications may hide symptoms of hypoglycemia such as tremor, tachycardia, and blood pressure changes. Other symptoms, like headache, dizziness, nervousness, mood changes, or hunger are not blunted. Beta-blockers also exert complex actions on the body's ability to regulate blood glucose. Some beta-blockers, particularly non-selective beta-blockers such as propranolol, have been noted to potentiate insulin-induced hypoglycemia and a delay in recovery of blood glucose to normal levels. Hyperglycemia has been reported as well and is possibly due to beta-2 receptor blockade in the beta cells of the pancreas. A selective beta-blocker may be preferred in patients with diabetes mellitus, if appropriate for the patient's condition. Selective beta-blockers, such as atenolol or metoprolol, do not appear to potentiate insulin-induced hypoglycemia. While beta-blockers may have negative effects on glycemic control, they reduce the risk of cardiovascular disease and stroke in patients with diabetes and their use should not be avoided in patients with compelling indications for beta-blocker therapy when no other contraindications are present.
    Bictegravir; Emtricitabine; Tenofovir Alafenamide: (Moderate) Caution is advised when administering bictegravir with metformin, as coadministration may increase exposure to metformin and increase the risk for hypoglycemia, gastrointestinal side effects, and potentially increase the risk for lactic acidosis. Close monitoring of blood glucose and patient clinical status is recommended. In drug interaction studies, bictegravir increased both the Cmax and AUC of metformin at a metformin dose of 500 mg PO twice daily. Bictegravir inhibits common renal tubular transport systems involved in the renal elimination of metformin (e.g., organic cationic transporter-2 [OCT2]/multidrug and toxin extrusion [MATE1]). (Moderate) Certain medications used concomitantly with metformin may increase the risk of lactic acidosis. Drugs that are eliminated by renal tubular secretion, such as emtricitabine, may decrease metformin elimination by competing for common renal tubular transport systems. Although such interactions remain theoretical, careful patient monitoring and dose adjustment of metformin and/or the interfering cationic drug are recommended.
    Bisoprolol: (Moderate) Increased frequency of blood glucose monitoring may be required when a beta blocker is given with antidiabetic agents. Since beta blockers inhibit the release of catecholamines, these medications may hide symptoms of hypoglycemia such as tremor, tachycardia, and blood pressure changes. Other symptoms, like headache, dizziness, nervousness, mood changes, or hunger are not blunted. Beta-blockers also exert complex actions on the body's ability to regulate blood glucose. Some beta-blockers, particularly non-selective beta-blockers such as propranolol, have been noted to potentiate insulin-induced hypoglycemia and a delay in recovery of blood glucose to normal levels. Hyperglycemia has been reported as well and is possibly due to beta-2 receptor blockade in the beta cells of the pancreas. A selective beta-blocker may be preferred in patients with diabetes mellitus, if appropriate for the patient's condition. Selective beta-blockers, such as atenolol or metoprolol, do not appear to potentiate insulin-induced hypoglycemia. While beta-blockers may have negative effects on glycemic control, they reduce the risk of cardiovascular disease and stroke in patients with diabetes and their use should not be avoided in patients with compelling indications for beta-blocker therapy when no other contraindications are present.
    Bisoprolol; Hydrochlorothiazide, HCTZ: (Moderate) Certain drugs, such as thiazide diuretics, tend to produce hyperglycemia and may lead to loss of glycemic control. The effects of thiazide diuretics on glycemic control appear to be dose-related and low doses can be instituted without deleterious effects on glycemic control. In addition, thiazide diuretics reduce the risk of stroke and cardiovascular disease in patients with diabetes. Patients receiving metformin should be monitored for changes in blood glucose control if any of these diuretics are added or deleted. Dosage adjustments may be necessary in some patients. (Moderate) Increased frequency of blood glucose monitoring may be required when a beta blocker is given with antidiabetic agents. Since beta blockers inhibit the release of catecholamines, these medications may hide symptoms of hypoglycemia such as tremor, tachycardia, and blood pressure changes. Other symptoms, like headache, dizziness, nervousness, mood changes, or hunger are not blunted. Beta-blockers also exert complex actions on the body's ability to regulate blood glucose. Some beta-blockers, particularly non-selective beta-blockers such as propranolol, have been noted to potentiate insulin-induced hypoglycemia and a delay in recovery of blood glucose to normal levels. Hyperglycemia has been reported as well and is possibly due to beta-2 receptor blockade in the beta cells of the pancreas. A selective beta-blocker may be preferred in patients with diabetes mellitus, if appropriate for the patient's condition. Selective beta-blockers, such as atenolol or metoprolol, do not appear to potentiate insulin-induced hypoglycemia. While beta-blockers may have negative effects on glycemic control, they reduce the risk of cardiovascular disease and stroke in patients with diabetes and their use should not be avoided in patients with compelling indications for beta-blocker therapy when no other contraindications are present.
    Bortezomib: (Moderate) During clinical trials of bortezomib, hypoglycemia and hyperglycemia were reported in diabetic patients receiving antidiabetic agents. Patients taking antidiabetic agents and receiving bortezomib treatment may require close monitoring of their blood glucose levels and dosage adjustment of their medication.
    Brigatinib: (Moderate) Consider the benefits and risks of concomitant therapy of brigatinib with metformin. Concomitant use of drugs that interfere with common renal tubular transport systems involved in the renal elimination of metformin (e.g., MATE inhibitors) could increase systemic exposure to metformin and increase the risk for lactic acidosis. Brigatinib inhibits MATE1 and MATE2K in vitro and may have the potential to increase concentrations of coadministered substrates of these transporters.
    Brimonidine; Timolol: (Moderate) Increased frequency of blood glucose monitoring may be required when a beta blocker is given with antidiabetic agents. Since beta blockers inhibit the release of catecholamines, these medications may hide symptoms of hypoglycemia such as tremor, tachycardia, and blood pressure changes. Other symptoms, like headache, dizziness, nervousness, mood changes, or hunger are not blunted. Beta-blockers also exert complex actions on the body's ability to regulate blood glucose. Some beta-blockers, particularly non-selective beta-blockers such as propranolol, have been noted to potentiate insulin-induced hypoglycemia and a delay in recovery of blood glucose to normal levels. Hyperglycemia has been reported as well and is possibly due to beta-2 receptor blockade in the beta cells of the pancreas. A selective beta-blocker may be preferred in patients with diabetes mellitus, if appropriate for the patient's condition. Selective beta-blockers, such as atenolol or metoprolol, do not appear to potentiate insulin-induced hypoglycemia. While beta-blockers may have negative effects on glycemic control, they reduce the risk of cardiovascular disease and stroke in patients with diabetes and their use should not be avoided in patients with compelling indications for beta-blocker therapy when no other contraindications are present.
    Brompheniramine; Carbetapentane; Phenylephrine: (Moderate) Sympathomimetic agents and adrenergic agonists tend to increase blood glucose concentrations when administered systemically. Monitor for loss of glycemic control when pseudoephedrine, phenylephrine, and other sympathomimetics are administered to patients taking antidiabetic agents. Epinephrine and other sympathomimetics, through stimulation of alpha- and beta- receptors, increase hepatic glucose production and glycogenolysis and inhibit insulin secretion. Also, adrenergic medications may decrease glucose uptake by muscle cells. For treatment of cold symptoms, nasal decongestants may be preferable for short term, limited use (1 to 3 days) as an alternative to systemic decongestants in patients taking medications for diabetes.
    Brompheniramine; Dextromethorphan; Phenylephrine: (Moderate) Sympathomimetic agents and adrenergic agonists tend to increase blood glucose concentrations when administered systemically. Monitor for loss of glycemic control when pseudoephedrine, phenylephrine, and other sympathomimetics are administered to patients taking antidiabetic agents. Epinephrine and other sympathomimetics, through stimulation of alpha- and beta- receptors, increase hepatic glucose production and glycogenolysis and inhibit insulin secretion. Also, adrenergic medications may decrease glucose uptake by muscle cells. For treatment of cold symptoms, nasal decongestants may be preferable for short term, limited use (1 to 3 days) as an alternative to systemic decongestants in patients taking medications for diabetes.
    Brompheniramine; Hydrocodone; Pseudoephedrine: (Moderate) Sympathomimetic agents and adrenergic agonists tend to increase blood glucose concentrations when administered systemically. Monitor for loss of glycemic control when pseudoephedrine, phenylephrine, and other sympathomimetics are administered to patients taking antidiabetic agents. Epinephrine and other sympathomimetics, through stimulation of alpha- and beta- receptors, increase hepatic glucose production and glycogenolysis and inhibit insulin secretion. Also, adrenergic medications may decrease glucose uptake by muscle cells. For treatment of cold symptoms, nasal decongestants may be preferable for short term, limited use (1 to 3 days) as an alternative to systemic decongestants in patients taking medications for diabetes.
    Brompheniramine; Phenylephrine: (Moderate) Sympathomimetic agents and adrenergic agonists tend to increase blood glucose concentrations when administered systemically. Monitor for loss of glycemic control when pseudoephedrine, phenylephrine, and other sympathomimetics are administered to patients taking antidiabetic agents. Epinephrine and other sympathomimetics, through stimulation of alpha- and beta- receptors, increase hepatic glucose production and glycogenolysis and inhibit insulin secretion. Also, adrenergic medications may decrease glucose uptake by muscle cells. For treatment of cold symptoms, nasal decongestants may be preferable for short term, limited use (1 to 3 days) as an alternative to systemic decongestants in patients taking medications for diabetes.
    Brompheniramine; Pseudoephedrine: (Moderate) Sympathomimetic agents and adrenergic agonists tend to increase blood glucose concentrations when administered systemically. Monitor for loss of glycemic control when pseudoephedrine, phenylephrine, and other sympathomimetics are administered to patients taking antidiabetic agents. Epinephrine and other sympathomimetics, through stimulation of alpha- and beta- receptors, increase hepatic glucose production and glycogenolysis and inhibit insulin secretion. Also, adrenergic medications may decrease glucose uptake by muscle cells. For treatment of cold symptoms, nasal decongestants may be preferable for short term, limited use (1 to 3 days) as an alternative to systemic decongestants in patients taking medications for diabetes.
    Brompheniramine; Pseudoephedrine; Dextromethorphan: (Moderate) Sympathomimetic agents and adrenergic agonists tend to increase blood glucose concentrations when administered systemically. Monitor for loss of glycemic control when pseudoephedrine, phenylephrine, and other sympathomimetics are administered to patients taking antidiabetic agents. Epinephrine and other sympathomimetics, through stimulation of alpha- and beta- receptors, increase hepatic glucose production and glycogenolysis and inhibit insulin secretion. Also, adrenergic medications may decrease glucose uptake by muscle cells. For treatment of cold symptoms, nasal decongestants may be preferable for short term, limited use (1 to 3 days) as an alternative to systemic decongestants in patients taking medications for diabetes.
    Budesonide; Glycopyrrolate; Formoterol: (Moderate) Coadministration of glycopyrrolate with metformin my increase metformin plasma concentrations, which may lead to increased metformin effects and possible adverse events. If coadministration is necessary, monitor clinical response to metformin and adjust metformin dose accordingly.
    Bumetanide: (Minor) Bumetanide has been associated with hyperglycemia, possibly due to potassium depletion, and, glycosuria has been reported. Because of this, a potential pharmacodynamic interaction exists between bumetanide and all antidiabetic agents. This interference can lead to a loss of diabetic control, so diabetic patients should be monitored closely.
    Calcium Carbonate; Famotidine; Magnesium Hydroxide: (Minor) Famotidine may decrease the renal clearance of metformin secondary to competition for renal tubular transport systems. Such an interaction has been observed when cimetidine was administered with metformin. The decrease in renal excretion led to a 40% increase in metformin AUC. Although interactions with cationic drugs remain theoretical (except for cimetidine), caution is warranted when famotidine and metformin are prescribed concurrently. Famotidine may be less likely to interact with metformin versus cimetidine or ranitidine because of less tubular excretion.
    Candesartan: (Moderate) Angiotensin II receptor antagonists (ARBs) may enhance the hypoglycemic effects of metformin by improving insulin sensitivity. In addition, angiotensin II receptor antagonists have been associated with a reduced incidence in the development of new-onset diabetes in patients with hypertension or other cardiac disease. ARBs may rarely reduce renal function, a risk factor for reduced renal clearance of metformin. Patients receiving these drugs together should be monitored for changes in renal function and glycemic control. (Moderate) Patients receiving these drugs concomitantly should be monitored for changes in blood pressure, volume status, renal function, serum potassium and other electrolytes, and for glycemic control. When an SGLT2 inhibitor is initiated, mild diuresis and naturesis occurs, producing intravascular volume contraction. These effects may be additive to certain antihypertensive medications, such as the angiotensin II receptor antagonists (also known as angiotensin receptor blockers or ARBs). Patients with impaired renal function (eGFR less than 60 mL/minute/1.73 m2), low systolic blood pressure, or who are elderly may also be at a greater risk. Volume status should be assessed and corrected. In addition, some SGLT2 inhibitors, like canagliflozin, can increase serum potassium. Monitor serum potassium levels periodically and monitor for hyperkalemia. ARBs may also enhance the hypoglycemic effects of antidiabetic agents by improving insulin sensitivity.
    Candesartan; Hydrochlorothiazide, HCTZ: (Moderate) Angiotensin II receptor antagonists (ARBs) may enhance the hypoglycemic effects of metformin by improving insulin sensitivity. In addition, angiotensin II receptor antagonists have been associated with a reduced incidence in the development of new-onset diabetes in patients with hypertension or other cardiac disease. ARBs may rarely reduce renal function, a risk factor for reduced renal clearance of metformin. Patients receiving these drugs together should be monitored for changes in renal function and glycemic control. (Moderate) Certain drugs, such as thiazide diuretics, tend to produce hyperglycemia and may lead to loss of glycemic control. The effects of thiazide diuretics on glycemic control appear to be dose-related and low doses can be instituted without deleterious effects on glycemic control. In addition, thiazide diuretics reduce the risk of stroke and cardiovascular disease in patients with diabetes. Patients receiving metformin should be monitored for changes in blood glucose control if any of these diuretics are added or deleted. Dosage adjustments may be necessary in some patients. (Moderate) Patients receiving these drugs concomitantly should be monitored for changes in blood pressure, volume status, renal function, serum potassium and other electrolytes, and for glycemic control. When an SGLT2 inhibitor is initiated, mild diuresis and naturesis occurs, producing intravascular volume contraction. These effects may be additive to certain antihypertensive medications, such as the angiotensin II receptor antagonists (also known as angiotensin receptor blockers or ARBs). Patients with impaired renal function (eGFR less than 60 mL/minute/1.73 m2), low systolic blood pressure, or who are elderly may also be at a greater risk. Volume status should be assessed and corrected. In addition, some SGLT2 inhibitors, like canagliflozin, can increase serum potassium. Monitor serum potassium levels periodically and monitor for hyperkalemia. ARBs may also enhance the hypoglycemic effects of antidiabetic agents by improving insulin sensitivity.
    Capmatinib: (Moderate) Monitor for an increased risk of metformin-related adverse reactions including lactic acidosis if coadministration with capmatinib is necessary; consider the benefits and risks of concomitant use. Metformin is a substrate of multidrug and toxin extrusion (MATE) and capmatinib is a MATE1 and MATE2K inhibitor. Coadministration may interfere with the renal elimination of metformin and increase metformin exposure.
    Captopril: (Moderate) Angiotensin-converting enzyme (ACE) inhibitors may enhance the hypoglycemic effects of insulin or other antidiabetic agents by improving insulin sensitivity. Patients receiving antidiabetic agents can become hypoglycemic if ACE inhibitors are administered concomitantly. ACE inhibitors may rarely reduce renal function, a risk factor for reduced renal clearance of metformin. Patients receiving these drugs together should be monitored for changes in renal function and glycemic control. (Moderate) Patients receiving these drugs concomitantly should be monitored for changes in blood pressure, volume status, renal function, serum potassium, and glycemic control. When an SGLT2 inhibitor is initiated, mild diuresis and naturesis occurs, producing intravascular volume contraction. These effects may be additive to certain antihypertensive medications, such as the angiotensin-converting enzyme inhibitors (ACE inhibitors). Patients with impaired renal function (eGFR less than 60 mL/minute/1.73 m2), low systolic blood pressure, or who are elderly may also be at a greater risk. Volume status should be assessed and corrected. In addition, some SGLT2 inhibitors, like canagliflozin, can increase serum potassium. Monitor serum potassium levels periodically and monitor for hyperkalemia. ACE inhibitors may also enhance the hypoglycemic effects of antidiabetic agents by improving insulin sensitivity.
    Captopril; Hydrochlorothiazide, HCTZ: (Moderate) Angiotensin-converting enzyme (ACE) inhibitors may enhance the hypoglycemic effects of insulin or other antidiabetic agents by improving insulin sensitivity. Patients receiving antidiabetic agents can become hypoglycemic if ACE inhibitors are administered concomitantly. ACE inhibitors may rarely reduce renal function, a risk factor for reduced renal clearance of metformin. Patients receiving these drugs together should be monitored for changes in renal function and glycemic control. (Moderate) Certain drugs, such as thiazide diuretics, tend to produce hyperglycemia and may lead to loss of glycemic control. The effects of thiazide diuretics on glycemic control appear to be dose-related and low doses can be instituted without deleterious effects on glycemic control. In addition, thiazide diuretics reduce the risk of stroke and cardiovascular disease in patients with diabetes. Patients receiving metformin should be monitored for changes in blood glucose control if any of these diuretics are added or deleted. Dosage adjustments may be necessary in some patients. (Moderate) Patients receiving these drugs concomitantly should be monitored for changes in blood pressure, volume status, renal function, serum potassium, and glycemic control. When an SGLT2 inhibitor is initiated, mild diuresis and naturesis occurs, producing intravascular volume contraction. These effects may be additive to certain antihypertensive medications, such as the angiotensin-converting enzyme inhibitors (ACE inhibitors). Patients with impaired renal function (eGFR less than 60 mL/minute/1.73 m2), low systolic blood pressure, or who are elderly may also be at a greater risk. Volume status should be assessed and corrected. In addition, some SGLT2 inhibitors, like canagliflozin, can increase serum potassium. Monitor serum potassium levels periodically and monitor for hyperkalemia. ACE inhibitors may also enhance the hypoglycemic effects of antidiabetic agents by improving insulin sensitivity.
    Carbetapentane; Chlorpheniramine; Phenylephrine: (Moderate) Sympathomimetic agents and adrenergic agonists tend to increase blood glucose concentrations when administered systemically. Monitor for loss of glycemic control when pseudoephedrine, phenylephrine, and other sympathomimetics are administered to patients taking antidiabetic agents. Epinephrine and other sympathomimetics, through stimulation of alpha- and beta- receptors, increase hepatic glucose production and glycogenolysis and inhibit insulin secretion. Also, adrenergic medications may decrease glucose uptake by muscle cells. For treatment of cold symptoms, nasal decongestants may be preferable for short term, limited use (1 to 3 days) as an alternative to systemic decongestants in patients taking medications for diabetes.
    Carbetapentane; Diphenhydramine; Phenylephrine: (Moderate) Sympathomimetic agents and adrenergic agonists tend to increase blood glucose concentrations when administered systemically. Monitor for loss of glycemic control when pseudoephedrine, phenylephrine, and other sympathomimetics are administered to patients taking antidiabetic agents. Epinephrine and other sympathomimetics, through stimulation of alpha- and beta- receptors, increase hepatic glucose production and glycogenolysis and inhibit insulin secretion. Also, adrenergic medications may decrease glucose uptake by muscle cells. For treatment of cold symptoms, nasal decongestants may be preferable for short term, limited use (1 to 3 days) as an alternative to systemic decongestants in patients taking medications for diabetes.
    Carbetapentane; Guaifenesin; Phenylephrine: (Moderate) Sympathomimetic agents and adrenergic agonists tend to increase blood glucose concentrations when administered systemically. Monitor for loss of glycemic control when pseudoephedrine, phenylephrine, and other sympathomimetics are administered to patients taking antidiabetic agents. Epinephrine and other sympathomimetics, through stimulation of alpha- and beta- receptors, increase hepatic glucose production and glycogenolysis and inhibit insulin secretion. Also, adrenergic medications may decrease glucose uptake by muscle cells. For treatment of cold symptoms, nasal decongestants may be preferable for short term, limited use (1 to 3 days) as an alternative to systemic decongestants in patients taking medications for diabetes.
    Carbetapentane; Phenylephrine: (Moderate) Sympathomimetic agents and adrenergic agonists tend to increase blood glucose concentrations when administered systemically. Monitor for loss of glycemic control when pseudoephedrine, phenylephrine, and other sympathomimetics are administered to patients taking antidiabetic agents. Epinephrine and other sympathomimetics, through stimulation of alpha- and beta- receptors, increase hepatic glucose production and glycogenolysis and inhibit insulin secretion. Also, adrenergic medications may decrease glucose uptake by muscle cells. For treatment of cold symptoms, nasal decongestants may be preferable for short term, limited use (1 to 3 days) as an alternative to systemic decongestants in patients taking medications for diabetes.
    Carbetapentane; Phenylephrine; Pyrilamine: (Moderate) Sympathomimetic agents and adrenergic agonists tend to increase blood glucose concentrations when administered systemically. Monitor for loss of glycemic control when pseudoephedrine, phenylephrine, and other sympathomimetics are administered to patients taking antidiabetic agents. Epinephrine and other sympathomimetics, through stimulation of alpha- and beta- receptors, increase hepatic glucose production and glycogenolysis and inhibit insulin secretion. Also, adrenergic medications may decrease glucose uptake by muscle cells. For treatment of cold symptoms, nasal decongestants may be preferable for short term, limited use (1 to 3 days) as an alternative to systemic decongestants in patients taking medications for diabetes.
    Carbetapentane; Pseudoephedrine: (Moderate) Sympathomimetic agents and adrenergic agonists tend to increase blood glucose concentrations when administered systemically. Monitor for loss of glycemic control when pseudoephedrine, phenylephrine, and other sympathomimetics are administered to patients taking antidiabetic agents. Epinephrine and other sympathomimetics, through stimulation of alpha- and beta- receptors, increase hepatic glucose production and glycogenolysis and inhibit insulin secretion. Also, adrenergic medications may decrease glucose uptake by muscle cells. For treatment of cold symptoms, nasal decongestants may be preferable for short term, limited use (1 to 3 days) as an alternative to systemic decongestants in patients taking medications for diabetes.
    Carbinoxamine; Dextromethorphan; Pseudoephedrine: (Moderate) Sympathomimetic agents and adrenergic agonists tend to increase blood glucose concentrations when administered systemically. Monitor for loss of glycemic control when pseudoephedrine, phenylephrine, and other sympathomimetics are administered to patients taking antidiabetic agents. Epinephrine and other sympathomimetics, through stimulation of alpha- and beta- receptors, increase hepatic glucose production and glycogenolysis and inhibit insulin secretion. Also, adrenergic medications may decrease glucose uptake by muscle cells. For treatment of cold symptoms, nasal decongestants may be preferable for short term, limited use (1 to 3 days) as an alternative to systemic decongestants in patients taking medications for diabetes.
    Carbinoxamine; Hydrocodone; Phenylephrine: (Moderate) Sympathomimetic agents and adrenergic agonists tend to increase blood glucose concentrations when administered systemically. Monitor for loss of glycemic control when pseudoephedrine, phenylephrine, and other sympathomimetics are administered to patients taking antidiabetic agents. Epinephrine and other sympathomimetics, through stimulation of alpha- and beta- receptors, increase hepatic glucose production and glycogenolysis and inhibit insulin secretion. Also, adrenergic medications may decrease glucose uptake by muscle cells. For treatment of cold symptoms, nasal decongestants may be preferable for short term, limited use (1 to 3 days) as an alternative to systemic decongestants in patients taking medications for diabetes.
    Carbinoxamine; Hydrocodone; Pseudoephedrine: (Moderate) Sympathomimetic agents and adrenergic agonists tend to increase blood glucose concentrations when administered systemically. Monitor for loss of glycemic control when pseudoephedrine, phenylephrine, and other sympathomimetics are administered to patients taking antidiabetic agents. Epinephrine and other sympathomimetics, through stimulation of alpha- and beta- receptors, increase hepatic glucose production and glycogenolysis and inhibit insulin secretion. Also, adrenergic medications may decrease glucose uptake by muscle cells. For treatment of cold symptoms, nasal decongestants may be preferable for short term, limited use (1 to 3 days) as an alternative to systemic decongestants in patients taking medications for diabetes.
    Carbinoxamine; Phenylephrine: (Moderate) Sympathomimetic agents and adrenergic agonists tend to increase blood glucose concentrations when administered systemically. Monitor for loss of glycemic control when pseudoephedrine, phenylephrine, and other sympathomimetics are administered to patients taking antidiabetic agents. Epinephrine and other sympathomimetics, through stimulation of alpha- and beta- receptors, increase hepatic glucose production and glycogenolysis and inhibit insulin secretion. Also, adrenergic medications may decrease glucose uptake by muscle cells. For treatment of cold symptoms, nasal decongestants may be preferable for short term, limited use (1 to 3 days) as an alternative to systemic decongestants in patients taking medications for diabetes.
    Carbinoxamine; Pseudoephedrine: (Moderate) Sympathomimetic agents and adrenergic agonists tend to increase blood glucose concentrations when administered systemically. Monitor for loss of glycemic control when pseudoephedrine, phenylephrine, and other sympathomimetics are administered to patients taking antidiabetic agents. Epinephrine and other sympathomimetics, through stimulation of alpha- and beta- receptors, increase hepatic glucose production and glycogenolysis and inhibit insulin secretion. Also, adrenergic medications may decrease glucose uptake by muscle cells. For treatment of cold symptoms, nasal decongestants may be preferable for short term, limited use (1 to 3 days) as an alternative to systemic decongestants in patients taking medications for diabetes.
    Carbonic anhydrase inhibitors: (Minor) Carbonic anhydrase inhibitors may alter blood sugar. Both hyperglycemia and hypoglycemia have been described in patients treated with acetazolamide. This should be taken into consideration in patients with impaired glucose tolerance or diabetes mellitus who are receiving antidiabetic agents. Monitor blood glucose and for changes in glycemic control and be alert for evidence of an interaction.
    Carteolol: (Moderate) Increased frequency of blood glucose monitoring may be required when a beta blocker is given with antidiabetic agents. Since beta blockers inhibit the release of catecholamines, these medications may hide symptoms of hypoglycemia such as tremor, tachycardia, and blood pressure changes. Other symptoms, like headache, dizziness, nervousness, mood changes, or hunger are not blunted. Beta-blockers also exert complex actions on the body's ability to regulate blood glucose. Some beta-blockers, particularly non-selective beta-blockers such as propranolol, have been noted to potentiate insulin-induced hypoglycemia and a delay in recovery of blood glucose to normal levels. Hyperglycemia has been reported as well and is possibly due to beta-2 receptor blockade in the beta cells of the pancreas. A selective beta-blocker may be preferred in patients with diabetes mellitus, if appropriate for the patient's condition. Selective beta-blockers, such as atenolol or metoprolol, do not appear to potentiate insulin-induced hypoglycemia. While beta-blockers may have negative effects on glycemic control, they reduce the risk of cardiovascular disease and stroke in patients with diabetes and their use should not be avoided in patients with compelling indications for beta-blocker therapy when no other contraindications are present.
    Carvedilol: (Moderate) Increased frequency of blood glucose monitoring may be required when a beta blocker is given with antidiabetic agents. Since beta blockers inhibit the release of catecholamines, these medications may hide symptoms of hypoglycemia such as tremor, tachycardia, and blood pressure changes. Other symptoms, like headache, dizziness, nervousness, mood changes, or hunger are not blunted. Beta-blockers also exert complex actions on the body's ability to regulate blood glucose. Some beta-blockers, particularly non-selective beta-blockers such as propranolol, have been noted to potentiate insulin-induced hypoglycemia and a delay in recovery of blood glucose to normal levels. Hyperglycemia has been reported as well and is possibly due to beta-2 receptor blockade in the beta cells of the pancreas. A selective beta-blocker may be preferred in patients with diabetes mellitus, if appropriate for the patient's condition. Selective beta-blockers, such as atenolol or metoprolol, do not appear to potentiate insulin-induced hypoglycemia. While beta-blockers may have negative effects on glycemic control, they reduce the risk of cardiovascular disease and stroke in patients with diabetes and their use should not be avoided in patients with compelling indications for beta-blocker therapy when no other contraindications are present.
    Cephalexin: (Moderate) In healthy subjects given single 500 mg doses of cephalexin and metformin, plasma metformin Cmax and AUC increased by an average of 34% and 24%, respectively; metformin renal clearance decreased by an average of 14%. No information is available about the interaction of cephalexin and metformin following multiple dose administration.
    Cetirizine; Pseudoephedrine: (Moderate) Sympathomimetic agents and adrenergic agonists tend to increase blood glucose concentrations when administered systemically. Monitor for loss of glycemic control when pseudoephedrine, phenylephrine, and other sympathomimetics are administered to patients taking antidiabetic agents. Epinephrine and other sympathomimetics, through stimulation of alpha- and beta- receptors, increase hepatic glucose production and glycogenolysis and inhibit insulin secretion. Also, adrenergic medications may decrease glucose uptake by muscle cells. For treatment of cold symptoms, nasal decongestants may be preferable for short term, limited use (1 to 3 days) as an alternative to systemic decongestants in patients taking medications for diabetes.
    Chlophedianol; Dexchlorpheniramine; Pseudoephedrine: (Moderate) Sympathomimetic agents and adrenergic agonists tend to increase blood glucose concentrations when administered systemically. Monitor for loss of glycemic control when pseudoephedrine, phenylephrine, and other sympathomimetics are administered to patients taking antidiabetic agents. Epinephrine and other sympathomimetics, through stimulation of alpha- and beta- receptors, increase hepatic glucose production and glycogenolysis and inhibit insulin secretion. Also, adrenergic medications may decrease glucose uptake by muscle cells. For treatment of cold symptoms, nasal decongestants may be preferable for short term, limited use (1 to 3 days) as an alternative to systemic decongestants in patients taking medications for diabetes.
    Chlophedianol; Guaifenesin; Phenylephrine: (Moderate) Sympathomimetic agents and adrenergic agonists tend to increase blood glucose concentrations when administered systemically. Monitor for loss of glycemic control when pseudoephedrine, phenylephrine, and other sympathomimetics are administered to patients taking antidiabetic agents. Epinephrine and other sympathomimetics, through stimulation of alpha- and beta- receptors, increase hepatic glucose production and glycogenolysis and inhibit insulin secretion. Also, adrenergic medications may decrease glucose uptake by muscle cells. For treatment of cold symptoms, nasal decongestants may be preferable for short term, limited use (1 to 3 days) as an alternative to systemic decongestants in patients taking medications for diabetes.
    Chloroquine: (Major) Careful monitoring of blood glucose is recommended when chloroquine and antidiabetic agents, including metformin, are coadministered. A decreased dose of the antidiabetic agent may be necessary as severe hypoglycemia has been reported in patients treated concomitantly with chloroquine and an antidiabetic agent. (Major) Careful monitoring of blood glucose is recommended when chloroquine and antidiabetic agents, including the SGLT2 inhibitors, are coadministered. A decreased dose of the antidiabetic agent may be necessary as severe hypoglycemia has been reported in patients treated concomitantly with chloroquine and an antidiabetic agent.
    Chlorothiazide: (Moderate) Certain drugs, such as thiazide diuretics, tend to produce hyperglycemia and may lead to loss of glycemic control. The effects of thiazide diuretics on glycemic control appear to be dose-related and low doses can be instituted without deleterious effects on glycemic control. In addition, thiazide diuretics reduce the risk of stroke and cardiovascular disease in patients with diabetes. Patients receiving metformin should be monitored for changes in blood glucose control if any of these diuretics are added or deleted. Dosage adjustments may be necessary in some patients.
    Chlorpheniramine; Dextromethorphan; Phenylephrine: (Moderate) Sympathomimetic agents and adrenergic agonists tend to increase blood glucose concentrations when administered systemically. Monitor for loss of glycemic control when pseudoephedrine, phenylephrine, and other sympathomimetics are administered to patients taking antidiabetic agents. Epinephrine and other sympathomimetics, through stimulation of alpha- and beta- receptors, increase hepatic glucose production and glycogenolysis and inhibit insulin secretion. Also, adrenergic medications may decrease glucose uptake by muscle cells. For treatment of cold symptoms, nasal decongestants may be preferable for short term, limited use (1 to 3 days) as an alternative to systemic decongestants in patients taking medications for diabetes.
    Chlorpheniramine; Dextromethorphan; Pseudoephedrine: (Moderate) Sympathomimetic agents and adrenergic agonists tend to increase blood glucose concentrations when administered systemically. Monitor for loss of glycemic control when pseudoephedrine, phenylephrine, and other sympathomimetics are administered to patients taking antidiabetic agents. Epinephrine and other sympathomimetics, through stimulation of alpha- and beta- receptors, increase hepatic glucose production and glycogenolysis and inhibit insulin secretion. Also, adrenergic medications may decrease glucose uptake by muscle cells. For treatment of cold symptoms, nasal decongestants may be preferable for short term, limited use (1 to 3 days) as an alternative to systemic decongestants in patients taking medications for diabetes.
    Chlorpheniramine; Dihydrocodeine; Phenylephrine: (Moderate) Sympathomimetic agents and adrenergic agonists tend to increase blood glucose concentrations when administered systemically. Monitor for loss of glycemic control when pseudoephedrine, phenylephrine, and other sympathomimetics are administered to patients taking antidiabetic agents. Epinephrine and other sympathomimetics, through stimulation of alpha- and beta- receptors, increase hepatic glucose production and glycogenolysis and inhibit insulin secretion. Also, adrenergic medications may decrease glucose uptake by muscle cells. For treatment of cold symptoms, nasal decongestants may be preferable for short term, limited use (1 to 3 days) as an alternative to systemic decongestants in patients taking medications for diabetes.
    Chlorpheniramine; Dihydrocodeine; Pseudoephedrine: (Moderate) Sympathomimetic agents and adrenergic agonists tend to increase blood glucose concentrations when administered systemically. Monitor for loss of glycemic control when pseudoephedrine, phenylephrine, and other sympathomimetics are administered to patients taking antidiabetic agents. Epinephrine and other sympathomimetics, through stimulation of alpha- and beta- receptors, increase hepatic glucose production and glycogenolysis and inhibit insulin secretion. Also, adrenergic medications may decrease glucose uptake by muscle cells. For treatment of cold symptoms, nasal decongestants may be preferable for short term, limited use (1 to 3 days) as an alternative to systemic decongestants in patients taking medications for diabetes.
    Chlorpheniramine; Guaifenesin; Hydrocodone; Pseudoephedrine: (Moderate) Sympathomimetic agents and adrenergic agonists tend to increase blood glucose concentrations when administered systemically. Monitor for loss of glycemic control when pseudoephedrine, phenylephrine, and other sympathomimetics are administered to patients taking antidiabetic agents. Epinephrine and other sympathomimetics, through stimulation of alpha- and beta- receptors, increase hepatic glucose production and glycogenolysis and inhibit insulin secretion. Also, adrenergic medications may decrease glucose uptake by muscle cells. For treatment of cold symptoms, nasal decongestants may be preferable for short term, limited use (1 to 3 days) as an alternative to systemic decongestants in patients taking medications for diabetes.
    Chlorpheniramine; Hydrocodone; Phenylephrine: (Moderate) Sympathomimetic agents and adrenergic agonists tend to increase blood glucose concentrations when administered systemically. Monitor for loss of glycemic control when pseudoephedrine, phenylephrine, and other sympathomimetics are administered to patients taking antidiabetic agents. Epinephrine and other sympathomimetics, through stimulation of alpha- and beta- receptors, increase hepatic glucose production and glycogenolysis and inhibit insulin secretion. Also, adrenergic medications may decrease glucose uptake by muscle cells. For treatment of cold symptoms, nasal decongestants may be preferable for short term, limited use (1 to 3 days) as an alternative to systemic decongestants in patients taking medications for diabetes.
    Chlorpheniramine; Hydrocodone; Pseudoephedrine: (Moderate) Sympathomimetic agents and adrenergic agonists tend to increase blood glucose concentrations when administered systemically. Monitor for loss of glycemic control when pseudoephedrine, phenylephrine, and other sympathomimetics are administered to patients taking antidiabetic agents. Epinephrine and other sympathomimetics, through stimulation of alpha- and beta- receptors, increase hepatic glucose production and glycogenolysis and inhibit insulin secretion. Also, adrenergic medications may decrease glucose uptake by muscle cells. For treatment of cold symptoms, nasal decongestants may be preferable for short term, limited use (1 to 3 days) as an alternative to systemic decongestants in patients taking medications for diabetes.
    Chlorpheniramine; Ibuprofen; Pseudoephedrine: (Moderate) Sympathomimetic agents and adrenergic agonists tend to increase blood glucose concentrations when administered systemically. Monitor for loss of glycemic control when pseudoephedrine, phenylephrine, and other sympathomimetics are administered to patients taking antidiabetic agents. Epinephrine and other sympathomimetics, through stimulation of alpha- and beta- receptors, increase hepatic glucose production and glycogenolysis and inhibit insulin secretion. Also, adrenergic medications may decrease glucose uptake by muscle cells. For treatment of cold symptoms, nasal decongestants may be preferable for short term, limited use (1 to 3 days) as an alternative to systemic decongestants in patients taking medications for diabetes.
    Chlorpheniramine; Phenylephrine: (Moderate) Sympathomimetic agents and adrenergic agonists tend to increase blood glucose concentrations when administered systemically. Monitor for loss of glycemic control when pseudoephedrine, phenylephrine, and other sympathomimetics are administered to patients taking antidiabetic agents. Epinephrine and other sympathomimetics, through stimulation of alpha- and beta- receptors, increase hepatic glucose production and glycogenolysis and inhibit insulin secretion. Also, adrenergic medications may decrease glucose uptake by muscle cells. For treatment of cold symptoms, nasal decongestants may be preferable for short term, limited use (1 to 3 days) as an alternative to systemic decongestants in patients taking medications for diabetes.
    Chlorpheniramine; Pseudoephedrine: (Moderate) Sympathomimetic agents and adrenergic agonists tend to increase blood glucose concentrations when administered systemically. Monitor for loss of glycemic control when pseudoephedrine, phenylephrine, and other sympathomimetics are administered to patients taking antidiabetic agents. Epinephrine and other sympathomimetics, through stimulation of alpha- and beta- receptors, increase hepatic glucose production and glycogenolysis and inhibit insulin secretion. Also, adrenergic medications may decrease glucose uptake by muscle cells. For treatment of cold symptoms, nasal decongestants may be preferable for short term, limited use (1 to 3 days) as an alternative to systemic decongestants in patients taking medications for diabetes.
    Chlorpropamide: (Moderate) Use of metformin with a sulfonylurea may increase the risk of hypoglycemia. Sulfonylureas are known to cause hypoglycemia. To manage hypoglycemic risk, lower doses of the sulfonylurea may be needed. Monitor blood sugar.
    Chlorthalidone: (Moderate) Certain drugs, such as thiazide diuretics, tend to produce hyperglycemia and may lead to loss of glycemic control. The effects of thiazide diuretics on glycemic control appear to be dose-related and low doses can be instituted without deleterious effects on glycemic control. In addition, thiazide diuretics reduce the risk of stroke and cardiovascular disease in patients with diabetes. Patients receiving metformin should be monitored for changes in blood glucose control if any of these diuretics are added or deleted. Dosage adjustments may be necessary in some patients.
    Chlorthalidone; Clonidine: (Moderate) Certain drugs, such as thiazide diuretics, tend to produce hyperglycemia and may lead to loss of glycemic control. The effects of thiazide diuretics on glycemic control appear to be dose-related and low doses can be instituted without deleterious effects on glycemic control. In addition, thiazide diuretics reduce the risk of stroke and cardiovascular disease in patients with diabetes. Patients receiving metformin should be monitored for changes in blood glucose control if any of these diuretics are added or deleted. Dosage adjustments may be necessary in some patients. (Minor) Increased frequency of blood glucose monitoring may be required when clonidine is given with antidiabetic agents. Since clonidine inhibits the release of catecholamines, clonidine may hide symptoms of hypoglycemia such as tremor, tachycardia, and blood pressure changes. Other symptoms, like headache, dizziness, nervousness, mood changes, or hunger are not blunted. Clonidine does not appear to impair recovery from hypoglycemia, and has not been found to impair glucose tolerance in diabetic patients.
    Chromium: (Moderate) Chromium dietary supplements may lower blood glucose. As part of the glucose tolerance factor molecule, chromium appears to facilitate the binding of insulin to insulin receptors in tissues and to aid in glucose metabolism. Because blood glucose may be lowered by the use of chromium, patients who are on antidiabetic agents may need dose adjustments. Close monitoring of blood glucose is recommended.
    Cimetidine: (Moderate) Use with caution, as cimetidine inhibits renal elimination of metformin. Consider alternatives to cimetidine. Increased metformin exposure due to use of cimetidine may lead to gastrointestinal complaints, altered glycemic control, and a potential for an increased risk for lactic acidosis. If it is medically necessary to use cimetidine, carefully monitor. Metformin dose reduction may be needed. An interaction between metformin and oral cimetidine has been observed in normal healthy volunteers in both single- and multiple-dose drug interaction studies. Cimetidine caused a 60% increase in peak metformin concentrations and a 40% increase in metformin exposure (AUC). Cimetidine inhibits common renal tubular transport systems involved in the renal elimination of metformin (e.g., organic cationic transporter-2 [OCT2]/multidrug and toxin extrusion [MATE1 and MATE2k]).
    Cisapride: (Moderate) Because cisapride can enhance gastric emptying in diabetic patients, blood glucose can be affected, which, in turn, may affect the clinical response to antidiabetic agents. Monitor blood glucose and adjust if cliniically indicated.
    Clarithromycin: (Moderate) The concomitant use of clarithromycin and antidiabetic agents can result in significant hypoglycemia. Careful monitoring of blood glucose is recommended.
    Clofarabine: (Moderate) Concomitant use of clofarabine and metformin may result in altered clofarabine levels because both agents are a substrate of OCT1. Therefore, monitor for signs of clofarabine toxicity such as gastrointestinal toxicity (e.g., nausea, vomiting, diarrhea, mucosal inflammation), hematologic toxicity, and skin toxicity (e.g. hand and foot syndrome, rash, pruritus) in patients also receiving OCT1 substrates.
    Clonidine: (Minor) Increased frequency of blood glucose monitoring may be required when clonidine is given with antidiabetic agents. Since clonidine inhibits the release of catecholamines, clonidine may hide symptoms of hypoglycemia such as tremor, tachycardia, and blood pressure changes. Other symptoms, like headache, dizziness, nervousness, mood changes, or hunger are not blunted. Clonidine does not appear to impair recovery from hypoglycemia, and has not been found to impair glucose tolerance in diabetic patients.
    Cobicistat: (Moderate) Concurrent administration of metformin and cobicistat may increase the risk of lactic acidosis. Cobicistat is a potent inhibitor of the human multidrug and toxic extrusion 1 (MATE1) on proximal renal tubular cells; metformin is a MATE1 substrate. Inhibition of MATE1 by cobicistat may decrease metformin eliminiation by blocking renal tubular secretion. If these drugs are given together, closely monitor for signs of metformin toxicity; metformin dose adjustments may be needed.
    Codeine; Guaifenesin; Pseudoephedrine: (Moderate) Sympathomimetic agents and adrenergic agonists tend to increase blood glucose concentrations when administered systemically. Monitor for loss of glycemic control when pseudoephedrine, phenylephrine, and other sympathomimetics are administered to patients taking antidiabetic agents. Epinephrine and other sympathomimetics, through stimulation of alpha- and beta- receptors, increase hepatic glucose production and glycogenolysis and inhibit insulin secretion. Also, adrenergic medications may decrease glucose uptake by muscle cells. For treatment of cold symptoms, nasal decongestants may be preferable for short term, limited use (1 to 3 days) as an alternative to systemic decongestants in patients taking medications for diabetes.
    Codeine; Phenylephrine; Promethazine: (Moderate) Sympathomimetic agents and adrenergic agonists tend to increase blood glucose concentrations when administered systemically. Monitor for loss of glycemic control when pseudoephedrine, phenylephrine, and other sympathomimetics are administered to patients taking antidiabetic agents. Epinephrine and other sympathomimetics, through stimulation of alpha- and beta- receptors, increase hepatic glucose production and glycogenolysis and inhibit insulin secretion. Also, adrenergic medications may decrease glucose uptake by muscle cells. For treatment of cold symptoms, nasal decongestants may be preferable for short term, limited use (1 to 3 days) as an alternative to systemic decongestants in patients taking medications for diabetes.
    Colesevelam: (Moderate) The clinical response to metformin extended-release (metformin ER) should be monitored in patients receiving concomitant therapy with colesevelam. Be alert for changes in glycemic control, increased metformin side effects, such as gastrointestinal disturbances and a risk for lactic acidosis. Colesevelam increases the Cmax and AUC of metformin ER by approximately 8% and 44%, respectively. The mechanism of the interaction is not known. Colesevelam has no significant effect on the bioavailability of immediate-release metformin.
    Conjugated Estrogens: (Minor) Monitor blood glucose periodically in patients on metformin for changes in glycemic control when hormone therapy is instituted or discontinued. Estrogens can decrease the hypoglycemic effects of antidiabetic agents by impairing glucose tolerance. Changes in glucose tolerance occur more commonly in patients receiving 50 mcg or more of ethinyl estradiol (or equivalent) per day in combined oral contraceptives (COCs), which are not commonly used in practice since the marketing of lower dose COCs, patches, injections and rings. The presence or absence of a concomitant progestin may influence the significance of any hormonal effect on glucose homeostasis.
    Conjugated Estrogens; Bazedoxifene: (Minor) Monitor blood glucose periodically in patients on metformin for changes in glycemic control when hormone therapy is instituted or discontinued. Estrogens can decrease the hypoglycemic effects of antidiabetic agents by impairing glucose tolerance. Changes in glucose tolerance occur more commonly in patients receiving 50 mcg or more of ethinyl estradiol (or equivalent) per day in combined oral contraceptives (COCs), which are not commonly used in practice since the marketing of lower dose COCs, patches, injections and rings. The presence or absence of a concomitant progestin may influence the significance of any hormonal effect on glucose homeostasis.
    Conjugated Estrogens; Medroxyprogesterone: (Minor) Monitor blood glucose periodically in patients on metformin for changes in glycemic control when hormone therapy is instituted or discontinued. Estrogens can decrease the hypoglycemic effects of antidiabetic agents by impairing glucose tolerance. Changes in glucose tolerance occur more commonly in patients receiving 50 mcg or more of ethinyl estradiol (or equivalent) per day in combined oral contraceptives (COCs), which are not commonly used in practice since the marketing of lower dose COCs, patches, injections and rings. The presence or absence of a concomitant progestin may influence the significance of any hormonal effect on glucose homeostasis. (Minor) Patients receiving antidiabetic agents like metformin should be closely monitored for signs indicating changes in diabetic control when therapy with progestins is instituted or discontinued. Progestins can impair glucose tolerance.
    Corticosteroids: (Moderate) Monitor patients receiving antidiabetic agents closely for worsening glycemic control when corticosteroids are instituted and for signs of hypoglycemia when corticosteroids are discontinued. Systemic and inhaled corticosteroids are known to increase blood glucose and worsen glycemic control in patients taking antidiabetic agents. The main risk factors for impaired glucose tolerance due to corticosteroids are the dose of steroid and duration of treatment. Corticosteroids stimulate hepatic glucose production and inhibit peripheral glucose uptake into muscle and fatty tissues, producing insulin resistance. Decreased insulin production may occur in the pancreas due to a direct effect on pancreatic beta cells. (Moderate) Monitor patients receiving antidiabetic agents closely for worsening glycemic control when corticosteroids are instituted and for signs of hypoglycemia when corticosteroids are discontinued. Systemic and inhaled corticosteroids are known to increase blood glucose and worsen glycemic control in patients taking antidiabetic agents. The main risk factors for impaired glucose tolerance due to corticosteroids are the dose of steroid and duration of treatment. Corticosteroids stimulate hepatic glucose production and inhibit peripheral glucose uptake into muscle and fatty tissues, producing insulin resistance. Decreased insulin production may occur in the pancreas due to a direct effect on pancreatic beta cells.
    Cyanocobalamin, Vitamin B12: (Minor) Metformin may result in suboptimal oral vitamin B12 absorption by competitively blocking the calcium-dependent binding of the intrinsic factor-vitamin B12 complex to its receptor. Regular measurement of hematologic parameters is recommended in all patients on chronic metformin treatment; abnormalities should be investigated.
    Cyclosporine: (Moderate) Patients should be monitored for worsening glycemic control if therapy with cyclosporine is initiated in patients receiving antidiabetic agents. Cyclosporine has been reported to cause hyperglycemia or exacerbate diabetes mellitus; this effect appears to be dose-related and caused by direct beta-cell toxicity. Also, any drug that deteriorates the renal status of the patient is likely to alter metformin concentrations in the body, so renal function should be carefully monitored during the use of cyclosporine and metformin together.
    Daclatasvir: (Moderate) Closely monitor blood glucose levels if daclatasvir is administered with antidiabetic agents. Dose adjustments of the antidiabetic agents may be needed. Altered blood glucose control, resulting in serious symptomatic hypoglycemia, has been reported in diabetic patients receiving antidiabetic agents in combination with direct acting antivirals, such as daclatasvir.
    Danazol: (Moderate) Changes in insulin sensitivity or glycemic control may occur in patients treated with androgens. In diabetic patients, the metabolic effects of androgens may decrease blood glucose and, therefore, may decrease antidiabetic agent dosage requirements. Monitor blood glucose and HbA1C when these drugs are used together.
    Darunavir; Cobicistat: (Moderate) Concurrent administration of metformin and cobicistat may increase the risk of lactic acidosis. Cobicistat is a potent inhibitor of the human multidrug and toxic extrusion 1 (MATE1) on proximal renal tubular cells; metformin is a MATE1 substrate. Inhibition of MATE1 by cobicistat may decrease metformin eliminiation by blocking renal tubular secretion. If these drugs are given together, closely monitor for signs of metformin toxicity; metformin dose adjustments may be needed.
    Darunavir; Cobicistat; Emtricitabine; Tenofovir alafenamide: (Moderate) Certain medications used concomitantly with metformin may increase the risk of lactic acidosis. Drugs that are eliminated by renal tubular secretion, such as emtricitabine, may decrease metformin elimination by competing for common renal tubular transport systems. Although such interactions remain theoretical, careful patient monitoring and dose adjustment of metformin and/or the interfering cationic drug are recommended. (Moderate) Concurrent administration of metformin and cobicistat may increase the risk of lactic acidosis. Cobicistat is a potent inhibitor of the human multidrug and toxic extrusion 1 (MATE1) on proximal renal tubular cells; metformin is a MATE1 substrate. Inhibition of MATE1 by cobicistat may decrease metformin eliminiation by blocking renal tubular secretion. If these drugs are given together, closely monitor for signs of metformin toxicity; metformin dose adjustments may be needed.
    Dasabuvir; Ombitasvir; Paritaprevir; Ritonavir : (Moderate) Closely monitor blood glucose levels if dasabuvir; ombitasvir; paritaprevir; ritonavir is administered with antidiabetic agents. Dose adjustments of the antidiabetic agents may be needed. Altered blood glucose control, resulting in serious symptomatic hypoglycemia, has been reported in diabetic patients receiving antidiabetic agents in combination with direct acting antivirals, such as dasabuvir; ombitasvir; paritaprevir; ritonavir.
    Dasabuvir; Ombitasvir; Paritaprevir; Ritonavir: (Major) While no dosage adjustment of metformin is recommended in patients with normal hepatic or renal function, careful patient monitoring and dose adjustment of metformin and/or the potentially interfering drug is recommended with concurrent use. Monitor for signs of onset of lactic acidosis such as respiratory distress, somnolence, and non-specific abdominal distress or worsening renal function. Do not use metformin with paritaprevir in patients with renal insufficiency or hepatic impairment. Drugs that interfere with common renal tubular transport systems involved in the renal elimination of metformin could increase systemic exposure to metformin and may increase the risk for lactic acidosis. Paritaprevir is an inhibitor of the organic anion transporters OATP1B1 and OATP1B3. While initial drug-drug interaction studies of paritaprevir-containing hepatitis treatments have not noted an effect on metformin concentrations, more study is needed.
    Desloratadine; Pseudoephedrine: (Moderate) Sympathomimetic agents and adrenergic agonists tend to increase blood glucose concentrations when administered systemically. Monitor for loss of glycemic control when pseudoephedrine, phenylephrine, and other sympathomimetics are administered to patients taking antidiabetic agents. Epinephrine and other sympathomimetics, through stimulation of alpha- and beta- receptors, increase hepatic glucose production and glycogenolysis and inhibit insulin secretion. Also, adrenergic medications may decrease glucose uptake by muscle cells. For treatment of cold symptoms, nasal decongestants may be preferable for short term, limited use (1 to 3 days) as an alternative to systemic decongestants in patients taking medications for diabetes.
    Desogestrel; Ethinyl Estradiol: (Minor) Monitor blood glucose periodically in patients on metformin for changes in glycemic control when hormone therapy is instituted or discontinued. Estrogens can decrease the hypoglycemic effects of antidiabetic agents by impairing glucose tolerance. Changes in glucose tolerance occur more commonly in patients receiving 50 mcg or more of ethinyl estradiol (or equivalent) per day in combined oral contraceptives (COCs), which are not commonly used in practice since the marketing of lower dose COCs, patches, injections and rings. The presence or absence of a concomitant progestin may influence the significance of any hormonal effect on glucose homeostasis. (Minor) Patients receiving antidiabetic agents like metformin should be closely monitored for signs indicating changes in diabetic control when therapy with progestins is instituted or discontinued. Progestins can impair glucose tolerance.
    Dexbrompheniramine; Pseudoephedrine: (Moderate) Sympathomimetic agents and adrenergic agonists tend to increase blood glucose concentrations when administered systemically. Monitor for loss of glycemic control when pseudoephedrine, phenylephrine, and other sympathomimetics are administered to patients taking antidiabetic agents. Epinephrine and other sympathomimetics, through stimulation of alpha- and beta- receptors, increase hepatic glucose production and glycogenolysis and inhibit insulin secretion. Also, adrenergic medications may decrease glucose uptake by muscle cells. For treatment of cold symptoms, nasal decongestants may be preferable for short term, limited use (1 to 3 days) as an alternative to systemic decongestants in patients taking medications for diabetes.
    Dexchlorpheniramine; Dextromethorphan; Pseudoephedrine: (Moderate) Sympathomimetic agents and adrenergic agonists tend to increase blood glucose concentrations when administered systemically. Monitor for loss of glycemic control when pseudoephedrine, phenylephrine, and other sympathomimetics are administered to patients taking antidiabetic agents. Epinephrine and other sympathomimetics, through stimulation of alpha- and beta- receptors, increase hepatic glucose production and glycogenolysis and inhibit insulin secretion. Also, adrenergic medications may decrease glucose uptake by muscle cells. For treatment of cold symptoms, nasal decongestants may be preferable for short term, limited use (1 to 3 days) as an alternative to systemic decongestants in patients taking medications for diabetes.
    Dextroamphetamine: (Moderate) Sympathomimetic agents and adrenergic agonists tend to increase blood glucose concentrations when administered systemically. Monitor for loss of glycemic control when pseudoephedrine, phenylephrine, and other sympathomimetics are administered to patients taking antidiabetic agents. Epinephrine and other sympathomimetics, through stimulation of alpha- and beta- receptors, increase hepatic glucose production and glycogenolysis and inhibit insulin secretion. Also, adrenergic medications may decrease glucose uptake by muscle cells. For treatment of cold symptoms, nasal decongestants may be preferable for short term, limited use (1 to 3 days) as an alternative to systemic decongestants in patients taking medications for diabetes.
    Dextromethorphan; Diphenhydramine; Phenylephrine: (Moderate) Sympathomimetic agents and adrenergic agonists tend to increase blood glucose concentrations when administered systemically. Monitor for loss of glycemic control when pseudoephedrine, phenylephrine, and other sympathomimetics are administered to patients taking antidiabetic agents. Epinephrine and other sympathomimetics, through stimulation of alpha- and beta- receptors, increase hepatic glucose production and glycogenolysis and inhibit insulin secretion. Also, adrenergic medications may decrease glucose uptake by muscle cells. For treatment of cold symptoms, nasal decongestants may be preferable for short term, limited use (1 to 3 days) as an alternative to systemic decongestants in patients taking medications for diabetes.
    Dextromethorphan; Guaifenesin; Phenylephrine: (Moderate) Sympathomimetic agents and adrenergic agonists tend to increase blood glucose concentrations when administered systemically. Monitor for loss of glycemic control when pseudoephedrine, phenylephrine, and other sympathomimetics are administered to patients taking antidiabetic agents. Epinephrine and other sympathomimetics, through stimulation of alpha- and beta- receptors, increase hepatic glucose production and glycogenolysis and inhibit insulin secretion. Also, adrenergic medications may decrease glucose uptake by muscle cells. For treatment of cold symptoms, nasal decongestants may be preferable for short term, limited use (1 to 3 days) as an alternative to systemic decongestants in patients taking medications for diabetes.
    Dextromethorphan; Guaifenesin; Pseudoephedrine: (Moderate) Sympathomimetic agents and adrenergic agonists tend to increase blood glucose concentrations when administered systemically. Monitor for loss of glycemic control when pseudoephedrine, phenylephrine, and other sympathomimetics are administered to patients taking antidiabetic agents. Epinephrine and other sympathomimetics, through stimulation of alpha- and beta- receptors, increase hepatic glucose production and glycogenolysis and inhibit insulin secretion. Also, adrenergic medications may decrease glucose uptake by muscle cells. For treatment of cold symptoms, nasal decongestants may be preferable for short term, limited use (1 to 3 days) as an alternative to systemic decongestants in patients taking medications for diabetes.
    Diazoxide: (Minor) Diazoxide, when administered intravenously or orally, produces a prompt dose-related increase in blood glucose level, due primarily to an inhibition of insulin release from the pancreas, and also to an extrapancreatic effect. The hyperglycemic effect begins within an hour and generally lasts no more than 8 hours in the presence of normal renal function. The hyperglycemic effect of diazoxide is expected to be antagonized by certain antidiabetic agents (e.g., insulin or a sulfonylurea). Blood glucose should be closely monitored.
    Dichlorphenamide: (Moderate) Carbonic anhydrase inhibitors such as dichlorphenamide frequently cause a decrease in serum bicarbonate and induce non-anion gap, hyperchloremic metabolic acidosis. Concomitant use of dichlorphenamide with metformin may increase the risk for lactic acidosis; consider more frequent monitoring. Carbonic anhydrase inhibitors may also alter blood sugar; both hyperglycemia and hypoglycemia have been described. Monitor blood glucose and for changes in glycemic control and be alert for evidence of an interaction.
    Dienogest; Estradiol valerate: (Minor) Monitor blood glucose periodically in patients on metformin for changes in glycemic control when hormone therapy is instituted or discontinued. Estrogens can decrease the hypoglycemic effects of antidiabetic agents by impairing glucose tolerance. Changes in glucose tolerance occur more commonly in patients receiving 50 mcg or more of ethinyl estradiol (or equivalent) per day in combined oral contraceptives (COCs), which are not commonly used in practice since the marketing of lower dose COCs, patches, injections and rings. The presence or absence of a concomitant progestin may influence the significance of any hormonal effect on glucose homeostasis. (Minor) Patients receiving antidiabetic agents like metformin should be closely monitored for signs indicating changes in diabetic control when therapy with progestins is instituted or discontinued. Progestins can impair glucose tolerance.
    Diethylstilbestrol, DES: (Minor) Monitor blood glucose periodically in patients on metformin for changes in glycemic control when hormone therapy is instituted or discontinued. Estrogens can decrease the hypoglycemic effects of antidiabetic agents by impairing glucose tolerance. Changes in glucose tolerance occur more commonly in patients receiving 50 mcg or more of ethinyl estradiol (or equivalent) per day in combined oral contraceptives (COCs), which are not commonly used in practice since the marketing of lower dose COCs, patches, injections and rings. The presence or absence of a concomitant progestin may influence the significance of any hormonal effect on glucose homeostasis.
    Digoxin: (Moderate) Metformin may increase digoxin concentrations, but the magnitude is unclear. Measure serum digoxin concentrations before initiating metformin, and periodically after that. Monitor heart rate and other clinical parameters. Adjust digoxin dose as necessary.
    Dihydrocodeine; Guaifenesin; Pseudoephedrine: (Moderate) Sympathomimetic agents and adrenergic agonists tend to increase blood glucose concentrations when administered systemically. Monitor for loss of glycemic control when pseudoephedrine, phenylephrine, and other sympathomimetics are administered to patients taking antidiabetic agents. Epinephrine and other sympathomimetics, through stimulation of alpha- and beta- receptors, increase hepatic glucose production and glycogenolysis and inhibit insulin secretion. Also, adrenergic medications may decrease glucose uptake by muscle cells. For treatment of cold symptoms, nasal decongestants may be preferable for short term, limited use (1 to 3 days) as an alternative to systemic decongestants in patients taking medications for diabetes.
    Diphenhydramine; Hydrocodone; Phenylephrine: (Moderate) Sympathomimetic agents and adrenergic agonists tend to increase blood glucose concentrations when administered systemically. Monitor for loss of glycemic control when pseudoephedrine, phenylephrine, and other sympathomimetics are administered to patients taking antidiabetic agents. Epinephrine and other sympathomimetics, through stimulation of alpha- and beta- receptors, increase hepatic glucose production and glycogenolysis and inhibit insulin secretion. Also, adrenergic medications may decrease glucose uptake by muscle cells. For treatment of cold symptoms, nasal decongestants may be preferable for short term, limited use (1 to 3 days) as an alternative to systemic decongestants in patients taking medications for diabetes.
    Diphenhydramine; Phenylephrine: (Moderate) Sympathomimetic agents and adrenergic agonists tend to increase blood glucose concentrations when administered systemically. Monitor for loss of glycemic control when pseudoephedrine, phenylephrine, and other sympathomimetics are administered to patients taking antidiabetic agents. Epinephrine and other sympathomimetics, through stimulation of alpha- and beta- receptors, increase hepatic glucose production and glycogenolysis and inhibit insulin secretion. Also, adrenergic medications may decrease glucose uptake by muscle cells. For treatment of cold symptoms, nasal decongestants may be preferable for short term, limited use (1 to 3 days) as an alternative to systemic decongestants in patients taking medications for diabetes.
    Disopyramide: (Moderate) Disopyramide may enhance the hypoglycemic effects of antidiabetic agents. Patients receiving disopyramide concomitantly with antidiabetic agents should be monitored for changes in glycemic control.
    Dofetilide: (Major) Dofetilide should be co-administered with metformin with caution since both drugs are actively secreted via cationic secretion and could compete for common renal tubular transport systems. This results in a possible increase in plasma concentrations of either drug. Reduced clearance of metformin may increase the risk for lactic acidosis; increased concentrations of dofetilide may increase the risk for side effects including proarrhythmia. Careful patient monitoring and dose adjustment of metformin and dofetilide is recommended.
    Dolutegravir: (Major) If these drugs are used in combination, the total daily dose of metformin must not exceed 1,000 mg/day. Dolutegravir may increase exposure to metformin. Increased exposure to metformin may increase the risk for hypoglycemia, gastrointestinal side effects, and potentially increase the risk for lactic acidosis. Consider the benefits and risks of concomitant use of dolutegravir with metformin. Close monitoring of blood glucose and patient clinical status (gastrointestinal side effects, renal function, electrolytes and acid-base balance) is recommended. When stopping dolutegravir, the metformin dose may need to be adjusted. In drug interaction studies, dolutegravir increased both the Cmax and AUC of metformin when metformin 500 mg PO twice daily was coadministered. Dolutegravir inhibits common renal tubular transport systems involved in the renal elimination of metformin (e.g., organic cationic transporter-2 [OCT2]/multidrug and toxin extrusion [MATE1 and MATE2k]).
    Dolutegravir; Lamivudine: (Major) If these drugs are used in combination, the total daily dose of metformin must not exceed 1,000 mg/day. Dolutegravir may increase exposure to metformin. Increased exposure to metformin may increase the risk for hypoglycemia, gastrointestinal side effects, and potentially increase the risk for lactic acidosis. Consider the benefits and risks of concomitant use of dolutegravir with metformin. Close monitoring of blood glucose and patient clinical status (gastrointestinal side effects, renal function, electrolytes and acid-base balance) is recommended. When stopping dolutegravir, the metformin dose may need to be adjusted. In drug interaction studies, dolutegravir increased both the Cmax and AUC of metformin when metformin 500 mg PO twice daily was coadministered. Dolutegravir inhibits common renal tubular transport systems involved in the renal elimination of metformin (e.g., organic cationic transporter-2 [OCT2]/multidrug and toxin extrusion [MATE1 and MATE2k]). (Moderate) Certain medications used concomitantly with metformin may increase the risk of lactic acidosis. Cationic drugs that are eliminated by renal tubular secretion, such as lamivudine, may decrease metformin elimination by competing for common renal tubular transport systems.
    Dolutegravir; Rilpivirine: (Major) If these drugs are used in combination, the total daily dose of metformin must not exceed 1,000 mg/day. Dolutegravir may increase exposure to metformin. Increased exposure to metformin may increase the risk for hypoglycemia, gastrointestinal side effects, and potentially increase the risk for lactic acidosis. Consider the benefits and risks of concomitant use of dolutegravir with metformin. Close monitoring of blood glucose and patient clinical status (gastrointestinal side effects, renal function, electrolytes and acid-base balance) is recommended. When stopping dolutegravir, the metformin dose may need to be adjusted. In drug interaction studies, dolutegravir increased both the Cmax and AUC of metformin when metformin 500 mg PO twice daily was coadministered. Dolutegravir inhibits common renal tubular transport systems involved in the renal elimination of metformin (e.g., organic cationic transporter-2 [OCT2]/multidrug and toxin extrusion [MATE1 and MATE2k]).
    Donepezil; Memantine: (Moderate) Certain medications used concomitantly with metformin may increase the risk of lactic acidosis. Drugs that are eliminated by renal tubular secretion (e.g., memantine) may decrease metformin elimination by competing for common renal tubular transport systems. It should be noted that in a pharmacokinetic study in which memantine and glyburide; metformin (Glucovance) were coadministered, the pharmacokinetics of memantine, metformin, or glyburide were not altered. Regardless, careful patient monitoring is recommended.
    Doravirine; Lamivudine; Tenofovir disoproxil fumarate: (Moderate) Certain medications used concomitantly with metformin may increase the risk of lactic acidosis. Cationic drugs that are eliminated by renal tubular secretion, such as lamivudine, may decrease metformin elimination by competing for common renal tubular transport systems. (Moderate) Certain medications used concomitantly with metformin may increase the risk of lactic acidosis. Drugs that are eliminated by renal tubular secretion, such as tenofovir, PMPA may decrease metformin elimination by competing for common renal tubular transport systems. Although such interactions remain theoretical, careful patient monitoring and dose adjustment of metformin and/or the interfering cationic drug are recommended.
    Dorzolamide; Timolol: (Moderate) Increased frequency of blood glucose monitoring may be required when a beta blocker is given with antidiabetic agents. Since beta blockers inhibit the release of catecholamines, these medications may hide symptoms of hypoglycemia such as tremor, tachycardia, and blood pressure changes. Other symptoms, like headache, dizziness, nervousness, mood changes, or hunger are not blunted. Beta-blockers also exert complex actions on the body's ability to regulate blood glucose. Some beta-blockers, particularly non-selective beta-blockers such as propranolol, have been noted to potentiate insulin-induced hypoglycemia and a delay in recovery of blood glucose to normal levels. Hyperglycemia has been reported as well and is possibly due to beta-2 receptor blockade in the beta cells of the pancreas. A selective beta-blocker may be preferred in patients with diabetes mellitus, if appropriate for the patient's condition. Selective beta-blockers, such as atenolol or metoprolol, do not appear to potentiate insulin-induced hypoglycemia. While beta-blockers may have negative effects on glycemic control, they reduce the risk of cardiovascular disease and stroke in patients with diabetes and their use should not be avoided in patients with compelling indications for beta-blocker therapy when no other contraindications are present.
    Drospirenone: (Minor) Patients receiving antidiabetic agents like metformin should be closely monitored for signs indicating changes in diabetic control when therapy with progestins is instituted or discontinued. Progestins can impair glucose tolerance.
    Drospirenone; Estetrol: (Minor) Monitor blood glucose periodically in patients on metformin for changes in glycemic control when hormone therapy is instituted or discontinued. Estrogens can decrease the hypoglycemic effects of antidiabetic agents by impairing glucose tolerance. Changes in glucose tolerance occur more commonly in patients receiving 50 mcg or more of ethinyl estradiol (or equivalent) per day in combined oral contraceptives (COCs), which are not commonly used in practice since the marketing of lower dose COCs, patches, injections and rings. The presence or absence of a concomitant progestin may influence the significance of any hormonal effect on glucose homeostasis. (Minor) Patients receiving antidiabetic agents like metformin should be closely monitored for signs indicating changes in diabetic control when therapy with progestins is instituted or discontinued. Progestins can impair glucose tolerance.
    Drospirenone; Estradiol: (Minor) Monitor blood glucose periodically in patients on metformin for changes in glycemic control when hormone therapy is instituted or discontinued. Estrogens can decrease the hypoglycemic effects of antidiabetic agents by impairing glucose tolerance. Changes in glucose tolerance occur more commonly in patients receiving 50 mcg or more of ethinyl estradiol (or equivalent) per day in combined oral contraceptives (COCs), which are not commonly used in practice since the marketing of lower dose COCs, patches, injections and rings. The presence or absence of a concomitant progestin may influence the significance of any hormonal effect on glucose homeostasis. (Minor) Patients receiving antidiabetic agents like metformin should be closely monitored for signs indicating changes in diabetic control when therapy with progestins is instituted or discontinued. Progestins can impair glucose tolerance.
    Drospirenone; Ethinyl Estradiol: (Minor) Monitor blood glucose periodically in patients on metformin for changes in glycemic control when hormone therapy is instituted or discontinued. Estrogens can decrease the hypoglycemic effects of antidiabetic agents by impairing glucose tolerance. Changes in glucose tolerance occur more commonly in patients receiving 50 mcg or more of ethinyl estradiol (or equivalent) per day in combined oral contraceptives (COCs), which are not commonly used in practice since the marketing of lower dose COCs, patches, injections and rings. The presence or absence of a concomitant progestin may influence the significance of any hormonal effect on glucose homeostasis. (Minor) Patients receiving antidiabetic agents like metformin should be closely monitored for signs indicating changes in diabetic control when therapy with progestins is instituted or discontinued. Progestins can impair glucose tolerance.
    Drospirenone; Ethinyl Estradiol; Levomefolate: (Minor) Levomefolate and metformin should be used together cautiously. Plasma concentrations of levomefolate may be reduced during treatment of type 2 diabetes with metformin. Monitor patients for decreased efficacy of levomefolate if these agents are used together. (Minor) Monitor blood glucose periodically in patients on metformin for changes in glycemic control when hormone therapy is instituted or discontinued. Estrogens can decrease the hypoglycemic effects of antidiabetic agents by impairing glucose tolerance. Changes in glucose tolerance occur more commonly in patients receiving 50 mcg or more of ethinyl estradiol (or equivalent) per day in combined oral contraceptives (COCs), which are not commonly used in practice since the marketing of lower dose COCs, patches, injections and rings. The presence or absence of a concomitant progestin may influence the significance of any hormonal effect on glucose homeostasis. (Minor) Patients receiving antidiabetic agents like metformin should be closely monitored for signs indicating changes in diabetic control when therapy with progestins is instituted or discontinued. Progestins can impair glucose tolerance.
    Efavirenz; Emtricitabine; Tenofovir: (Moderate) Certain medications used concomitantly with metformin may increase the risk of lactic acidosis. Drugs that are eliminated by renal tubular secretion, such as emtricitabine, may decrease metformin elimination by competing for common renal tubular transport systems. Although such interactions remain theoretical, careful patient monitoring and dose adjustment of metformin and/or the interfering cationic drug are recommended. (Moderate) Certain medications used concomitantly with metformin may increase the risk of lactic acidosis. Drugs that are eliminated by renal tubular secretion, such as tenofovir, PMPA may decrease metformin elimination by competing for common renal tubular transport systems. Although such interactions remain theoretical, careful patient monitoring and dose adjustment of metformin and/or the interfering cationic drug are recommended.
    Efavirenz; Lamivudine; Tenofovir Disoproxil Fumarate: (Moderate) Certain medications used concomitantly with metformin may increase the risk of lactic acidosis. Cationic drugs that are eliminated by renal tubular secretion, such as lamivudine, may decrease metformin elimination by competing for common renal tubular transport systems. (Moderate) Certain medications used concomitantly with metformin may increase the risk of lactic acidosis. Drugs that are eliminated by renal tubular secretion, such as tenofovir, PMPA may decrease metformin elimination by competing for common renal tubular transport systems. Although such interactions remain theoretical, careful patient monitoring and dose adjustment of metformin and/or the interfering cationic drug are recommended.
    Elagolix; Estradiol; Norethindrone acetate: (Minor) Monitor blood glucose periodically in patients on metformin for changes in glycemic control when hormone therapy is instituted or discontinued. Estrogens can decrease the hypoglycemic effects of antidiabetic agents by impairing glucose tolerance. Changes in glucose tolerance occur more commonly in patients receiving 50 mcg or more of ethinyl estradiol (or equivalent) per day in combined oral contraceptives (COCs), which are not commonly used in practice since the marketing of lower dose COCs, patches, injections and rings. The presence or absence of a concomitant progestin may influence the significance of any hormonal effect on glucose homeostasis. (Minor) Patients receiving antidiabetic agents like metformin should be closely monitored for signs indicating changes in diabetic control when therapy with progestins is instituted or discontinued. Progestins can impair glucose tolerance.
    Elbasvir; Grazoprevir: (Moderate) Closely monitor blood glucose levels if elbasvir is administered with antidiabetic agents. Dose adjustments of the antidiabetic agents may be needed. Altered blood glucose control, resulting in serious symptomatic hypoglycemia, has been reported in diabetic patients receiving antidiabetic agents in combination with direct acting antivirals, such as elbasvir.
    Elvitegravir; Cobicistat; Emtricitabine; Tenofovir Alafenamide: (Moderate) Certain medications used concomitantly with metformin may increase the risk of lactic acidosis. Drugs that are eliminated by renal tubular secretion, such as emtricitabine, may decrease metformin elimination by competing for common renal tubular transport systems. Although such interactions remain theoretical, careful patient monitoring and dose adjustment of metformin and/or the interfering cationic drug are recommended. (Moderate) Concurrent administration of metformin and cobicistat may increase the risk of lactic acidosis. Cobicistat is a potent inhibitor of the human multidrug and toxic extrusion 1 (MATE1) on proximal renal tubular cells; metformin is a MATE1 substrate. Inhibition of MATE1 by cobicistat may decrease metformin eliminiation by blocking renal tubular secretion. If these drugs are given together, closely monitor for signs of metformin toxicity; metformin dose adjustments may be needed.
    Elvitegravir; Cobicistat; Emtricitabine; Tenofovir Disoproxil Fumarate: (Moderate) Certain medications used concomitantly with metformin may increase the risk of lactic acidosis. Drugs that are eliminated by renal tubular secretion, such as emtricitabine, may decrease metformin elimination by competing for common renal tubular transport systems. Although such interactions remain theoretical, careful patient monitoring and dose adjustment of metformin and/or the interfering cationic drug are recommended. (Moderate) Certain medications used concomitantly with metformin may increase the risk of lactic acidosis. Drugs that are eliminated by renal tubular secretion, such as tenofovir, PMPA may decrease metformin elimination by competing for common renal tubular transport systems. Although such interactions remain theoretical, careful patient monitoring and dose adjustment of metformin and/or the interfering cationic drug are recommended. (Moderate) Concurrent administration of metformin and cobicistat may increase the risk of lactic acidosis. Cobicistat is a potent inhibitor of the human multidrug and toxic extrusion 1 (MATE1) on proximal renal tubular cells; metformin is a MATE1 substrate. Inhibition of MATE1 by cobicistat may decrease metformin eliminiation by blocking renal tubular secretion. If these drugs are given together, closely monitor for signs of metformin toxicity; metformin dose adjustments may be needed.
    Emtricitabine: (Moderate) Certain medications used concomitantly with metformin may increase the risk of lactic acidosis. Drugs that are eliminated by renal tubular secretion, such as emtricitabine, may decrease metformin elimination by competing for common renal tubular transport systems. Although such interactions remain theoretical, careful patient monitoring and dose adjustment of metformin and/or the interfering cationic drug are recommended.
    Emtricitabine; Rilpivirine; Tenofovir alafenamide: (Moderate) Certain medications used concomitantly with metformin may increase the risk of lactic acidosis. Drugs that are eliminated by renal tubular secretion, such as emtricitabine, may decrease metformin elimination by competing for common renal tubular transport systems. Although such interactions remain theoretical, careful patient monitoring and dose adjustment of metformin and/or the interfering cationic drug are recommended.
    Emtricitabine; Rilpivirine; Tenofovir disoproxil fumarate: (Moderate) Certain medications used concomitantly with metformin may increase the risk of lactic acidosis. Drugs that are eliminated by renal tubular secretion, such as emtricitabine, may decrease metformin elimination by competing for common renal tubular transport systems. Although such interactions remain theoretical, careful patient monitoring and dose adjustment of metformin and/or the interfering cationic drug are recommended. (Moderate) Certain medications used concomitantly with metformin may increase the risk of lactic acidosis. Drugs that are eliminated by renal tubular secretion, such as tenofovir, PMPA may decrease metformin elimination by competing for common renal tubular transport systems. Although such interactions remain theoretical, careful patient monitoring and dose adjustment of metformin and/or the interfering cationic drug are recommended.
    Emtricitabine; Tenofovir alafenamide: (Moderate) Certain medications used concomitantly with metformin may increase the risk of lactic acidosis. Drugs that are eliminated by renal tubular secretion, such as emtricitabine, may decrease metformin elimination by competing for common renal tubular transport systems. Although such interactions remain theoretical, careful patient monitoring and dose adjustment of metformin and/or the interfering cationic drug are recommended.
    Emtricitabine; Tenofovir disoproxil fumarate: (Moderate) Certain medications used concomitantly with metformin may increase the risk of lactic acidosis. Drugs that are eliminated by renal tubular secretion, such as emtricitabine, may decrease metformin elimination by competing for common renal tubular transport systems. Although such interactions remain theoretical, careful patient monitoring and dose adjustment of metformin and/or the interfering cationic drug are recommended. (Moderate) Certain medications used concomitantly with metformin may increase the risk of lactic acidosis. Drugs that are eliminated by renal tubular secretion, such as tenofovir, PMPA may decrease metformin elimination by competing for common renal tubular transport systems. Although such interactions remain theoretical, careful patient monitoring and dose adjustment of metformin and/or the interfering cationic drug are recommended.
    Enalapril, Enalaprilat: (Moderate) Angiotensin-converting enzyme (ACE) inhibitors may enhance the hypoglycemic effects of insulin or other antidiabetic agents by improving insulin sensitivity. Patients receiving antidiabetic agents can become hypoglycemic if ACE inhibitors are administered concomitantly. ACE inhibitors may rarely reduce renal function, a risk factor for reduced renal clearance of metformin. Patients receiving these drugs together should be monitored for changes in renal function and glycemic control. (Moderate) Patients receiving these drugs concomitantly should be monitored for changes in blood pressure, volume status, renal function, serum potassium, and glycemic control. When an SGLT2 inhibitor is initiated, mild diuresis and naturesis occurs, producing intravascular volume contraction. These effects may be additive to certain antihypertensive medications, such as the angiotensin-converting enzyme inhibitors (ACE inhibitors). Patients with impaired renal function (eGFR less than 60 mL/minute/1.73 m2), low systolic blood pressure, or who are elderly may also be at a greater risk. Volume status should be assessed and corrected. In addition, some SGLT2 inhibitors, like canagliflozin, can increase serum potassium. Monitor serum potassium levels periodically and monitor for hyperkalemia. ACE inhibitors may also enhance the hypoglycemic effects of antidiabetic agents by improving insulin sensitivity.
    Enalapril; Felodipine: (Moderate) Angiotensin-converting enzyme (ACE) inhibitors may enhance the hypoglycemic effects of insulin or other antidiabetic agents by improving insulin sensitivity. Patients receiving antidiabetic agents can become hypoglycemic if ACE inhibitors are administered concomitantly. ACE inhibitors may rarely reduce renal function, a risk factor for reduced renal clearance of metformin. Patients receiving these drugs together should be monitored for changes in renal function and glycemic control. (Moderate) Patients receiving these drugs concomitantly should be monitored for changes in blood pressure, volume status, renal function, serum potassium, and glycemic control. When an SGLT2 inhibitor is initiated, mild diuresis and naturesis occurs, producing intravascular volume contraction. These effects may be additive to certain antihypertensive medications, such as the angiotensin-converting enzyme inhibitors (ACE inhibitors). Patients with impaired renal function (eGFR less than 60 mL/minute/1.73 m2), low systolic blood pressure, or who are elderly may also be at a greater risk. Volume status should be assessed and corrected. In addition, some SGLT2 inhibitors, like canagliflozin, can increase serum potassium. Monitor serum potassium levels periodically and monitor for hyperkalemia. ACE inhibitors may also enhance the hypoglycemic effects of antidiabetic agents by improving insulin sensitivity.
    Enalapril; Hydrochlorothiazide, HCTZ: (Moderate) Angiotensin-converting enzyme (ACE) inhibitors may enhance the hypoglycemic effects of insulin or other antidiabetic agents by improving insulin sensitivity. Patients receiving antidiabetic agents can become hypoglycemic if ACE inhibitors are administered concomitantly. ACE inhibitors may rarely reduce renal function, a risk factor for reduced renal clearance of metformin. Patients receiving these drugs together should be monitored for changes in renal function and glycemic control. (Moderate) Certain drugs, such as thiazide diuretics, tend to produce hyperglycemia and may lead to loss of glycemic control. The effects of thiazide diuretics on glycemic control appear to be dose-related and low doses can be instituted without deleterious effects on glycemic control. In addition, thiazide diuretics reduce the risk of stroke and cardiovascular disease in patients with diabetes. Patients receiving metformin should be monitored for changes in blood glucose control if any of these diuretics are added or deleted. Dosage adjustments may be necessary in some patients. (Moderate) Patients receiving these drugs concomitantly should be monitored for changes in blood pressure, volume status, renal function, serum potassium, and glycemic control. When an SGLT2 inhibitor is initiated, mild diuresis and naturesis occurs, producing intravascular volume contraction. These effects may be additive to certain antihypertensive medications, such as the angiotensin-converting enzyme inhibitors (ACE inhibitors). Patients with impaired renal function (eGFR less than 60 mL/minute/1.73 m2), low systolic blood pressure, or who are elderly may also be at a greater risk. Volume status should be assessed and corrected. In addition, some SGLT2 inhibitors, like canagliflozin, can increase serum potassium. Monitor serum potassium levels periodically and monitor for hyperkalemia. ACE inhibitors may also enhance the hypoglycemic effects of antidiabetic agents by improving insulin sensitivity.
    Entecavir: (Moderate) Certain medications used concomitantly with metformin may increase the risk of lactic acidosis. Cationic drugs that are eliminated by renal tubular secretion (e.g., entecavir) may decrease metformin elimination by competing for common renal tubular transport systems. Although such interactions remain theoretical, careful patient monitoring and dose adjustment of metformin and/or the interfering cationic drug are recommended.
    Ephedrine: (Moderate) Sympathomimetic agents and adrenergic agonists tend to increase blood glucose concentrations when administered systemically. Monitor for loss of glycemic control when pseudoephedrine, phenylephrine, and other sympathomimetics are administered to patients taking antidiabetic agents. Epinephrine and other sympathomimetics, through stimulation of alpha- and beta- receptors, increase hepatic glucose production and glycogenolysis and inhibit insulin secretion. Also, adrenergic medications may decrease glucose uptake by muscle cells. For treatment of cold symptoms, nasal decongestants may be preferable for short term, limited use (1 to 3 days) as an alternative to systemic decongestants in patients taking medications for diabetes.
    Ephedrine; Guaifenesin: (Moderate) Sympathomimetic agents and adrenergic agonists tend to increase blood glucose concentrations when administered systemically. Monitor for loss of glycemic control when pseudoephedrine, phenylephrine, and other sympathomimetics are administered to patients taking antidiabetic agents. Epinephrine and other sympathomimetics, through stimulation of alpha- and beta- receptors, increase hepatic glucose production and glycogenolysis and inhibit insulin secretion. Also, adrenergic medications may decrease glucose uptake by muscle cells. For treatment of cold symptoms, nasal decongestants may be preferable for short term, limited use (1 to 3 days) as an alternative to systemic decongestants in patients taking medications for diabetes.
    Eprosartan: (Moderate) Angiotensin II receptor antagonists (ARBs) may enhance the hypoglycemic effects of metformin by improving insulin sensitivity. In addition, angiotensin II receptor antagonists have been associated with a reduced incidence in the development of new-onset diabetes in patients with hypertension or other cardiac disease. ARBs may rarely reduce renal function, a risk factor for reduced renal clearance of metformin. Patients receiving these drugs together should be monitored for changes in renal function and glycemic control. (Moderate) Patients receiving these drugs concomitantly should be monitored for changes in blood pressure, volume status, renal function, serum potassium and other electrolytes, and for glycemic control. When an SGLT2 inhibitor is initiated, mild diuresis and naturesis occurs, producing intravascular volume contraction. These effects may be additive to certain antihypertensive medications, such as the angiotensin II receptor antagonists (also known as angiotensin receptor blockers or ARBs). Patients with impaired renal function (eGFR less than 60 mL/minute/1.73 m2), low systolic blood pressure, or who are elderly may also be at a greater risk. Volume status should be assessed and corrected. In addition, some SGLT2 inhibitors, like canagliflozin, can increase serum potassium. Monitor serum potassium levels periodically and monitor for hyperkalemia. ARBs may also enhance the hypoglycemic effects of antidiabetic agents by improving insulin sensitivity.
    Eprosartan; Hydrochlorothiazide, HCTZ: (Moderate) Angiotensin II receptor antagonists (ARBs) may enhance the hypoglycemic effects of metformin by improving insulin sensitivity. In addition, angiotensin II receptor antagonists have been associated with a reduced incidence in the development of new-onset diabetes in patients with hypertension or other cardiac disease. ARBs may rarely reduce renal function, a risk factor for reduced renal clearance of metformin. Patients receiving these drugs together should be monitored for changes in renal function and glycemic control. (Moderate) Certain drugs, such as thiazide diuretics, tend to produce hyperglycemia and may lead to loss of glycemic control. The effects of thiazide diuretics on glycemic control appear to be dose-related and low doses can be instituted without deleterious effects on glycemic control. In addition, thiazide diuretics reduce the risk of stroke and cardiovascular disease in patients with diabetes. Patients receiving metformin should be monitored for changes in blood glucose control if any of these diuretics are added or deleted. Dosage adjustments may be necessary in some patients. (Moderate) Patients receiving these drugs concomitantly should be monitored for changes in blood pressure, volume status, renal function, serum potassium and other electrolytes, and for glycemic control. When an SGLT2 inhibitor is initiated, mild diuresis and naturesis occurs, producing intravascular volume contraction. These effects may be additive to certain antihypertensive medications, such as the angiotensin II receptor antagonists (also known as angiotensin receptor blockers or ARBs). Patients with impaired renal function (eGFR less than 60 mL/minute/1.73 m2), low systolic blood pressure, or who are elderly may also be at a greater risk. Volume status should be assessed and corrected. In addition, some SGLT2 inhibitors, like canagliflozin, can increase serum potassium. Monitor serum potassium levels periodically and monitor for hyperkalemia. ARBs may also enhance the hypoglycemic effects of antidiabetic agents by improving insulin sensitivity.
    Erdafitinib: (Moderate) Consider the benefits and risks of concomitant treatment with metformin and erdafitinib. Metformin is a substrate of organic cationic transporter-2 (OCT2). Erdafitinib is an OCT2 inhibitor. Coadministration with OCT2 inhibitors could increase systemic exposure to metformin and increase the risk for lactic acidosis.
    Erythromycin; Sulfisoxazole: (Moderate) Sulfonamides may enhance the hypoglycemic action of antidiabetic agents; patients with diabetes mellitus should be closely monitored during sulfonamide treatment. Sulfonamides may induce hypoglycemia in some patients by increasing the secretion of insulin from the pancreas. Patients at risk include those with compromised renal function, those fasting for prolonged periods, those that are malnourished, and those receiving high or excessive doses of sulfonamides.
    Esmolol: (Moderate) Increased frequency of blood glucose monitoring may be required when a beta blocker is given with antidiabetic agents. Since beta blockers inhibit the release of catecholamines, these medications may hide symptoms of hypoglycemia such as tremor, tachycardia, and blood pressure changes. Other symptoms, like headache, dizziness, nervousness, mood changes, or hunger are not blunted. Beta-blockers also exert complex actions on the body's ability to regulate blood glucose. Some beta-blockers, particularly non-selective beta-blockers such as propranolol, have been noted to potentiate insulin-induced hypoglycemia and a delay in recovery of blood glucose to normal levels. Hyperglycemia has been reported as well and is possibly due to beta-2 receptor blockade in the beta cells of the pancreas. A selective beta-blocker may be preferred in patients with diabetes mellitus, if appropriate for the patient's condition. Selective beta-blockers, such as atenolol or metoprolol, do not appear to potentiate insulin-induced hypoglycemia. While beta-blockers may have negative effects on glycemic control, they reduce the risk of cardiovascular disease and stroke in patients with diabetes and their use should not be avoided in patients with compelling indications for beta-blocker therapy when no other contraindications are present.
    Esterified Estrogens: (Minor) Monitor blood glucose periodically in patients on metformin for changes in glycemic control when hormone therapy is instituted or discontinued. Estrogens can decrease the hypoglycemic effects of antidiabetic agents by impairing glucose tolerance. Changes in glucose tolerance occur more commonly in patients receiving 50 mcg or more of ethinyl estradiol (or equivalent) per day in combined oral contraceptives (COCs), which are not commonly used in practice since the marketing of lower dose COCs, patches, injections and rings. The presence or absence of a concomitant progestin may influence the significance of any hormonal effect on glucose homeostasis.
    Esterified Estrogens; Methyltestosterone: (Moderate) Changes in insulin sensitivity or glycemic control may occur in patients treated with androgens. In diabetic patients, the metabolic effects of androgens may decrease blood glucose and, therefore, may decrease antidiabetic agent dosage requirements. Monitor blood glucose and HbA1C when these drugs are used together. (Minor) Monitor blood glucose periodically in patients on metformin for changes in glycemic control when hormone therapy is instituted or discontinued. Estrogens can decrease the hypoglycemic effects of antidiabetic agents by impairing glucose tolerance. Changes in glucose tolerance occur more commonly in patients receiving 50 mcg or more of ethinyl estradiol (or equivalent) per day in combined oral contraceptives (COCs), which are not commonly used in practice since the marketing of lower dose COCs, patches, injections and rings. The presence or absence of a concomitant progestin may influence the significance of any hormonal effect on glucose homeostasis.
    Estradiol Cypionate; Medroxyprogesterone: (Minor) Monitor blood glucose periodically in patients on metformin for changes in glycemic control when hormone therapy is instituted or discontinued. Estrogens can decrease the hypoglycemic effects of antidiabetic agents by impairing glucose tolerance. Changes in glucose tolerance occur more commonly in patients receiving 50 mcg or more of ethinyl estradiol (or equivalent) per day in combined oral contraceptives (COCs), which are not commonly used in practice since the marketing of lower dose COCs, patches, injections and rings. The presence or absence of a concomitant progestin may influence the significance of any hormonal effect on glucose homeostasis. (Minor) Patients receiving antidiabetic agents like metformin should be closely monitored for signs indicating changes in diabetic control when therapy with progestins is instituted or discontinued. Progestins can impair glucose tolerance.
    Estradiol: (Minor) Monitor blood glucose periodically in patients on metformin for changes in glycemic control when hormone therapy is instituted or discontinued. Estrogens can decrease the hypoglycemic effects of antidiabetic agents by impairing glucose tolerance. Changes in glucose tolerance occur more commonly in patients receiving 50 mcg or more of ethinyl estradiol (or equivalent) per day in combined oral contraceptives (COCs), which are not commonly used in practice since the marketing of lower dose COCs, patches, injections and rings. The presence or absence of a concomitant progestin may influence the significance of any hormonal effect on glucose homeostasis.
    Estradiol; Levonorgestrel: (Minor) Monitor blood glucose periodically in patients on metformin for changes in glycemic control when hormone therapy is instituted or discontinued. Estrogens can decrease the hypoglycemic effects of antidiabetic agents by impairing glucose tolerance. Changes in glucose tolerance occur more commonly in patients receiving 50 mcg or more of ethinyl estradiol (or equivalent) per day in combined oral contraceptives (COCs), which are not commonly used in practice since the marketing of lower dose COCs, patches, injections and rings. The presence or absence of a concomitant progestin may influence the significance of any hormonal effect on glucose homeostasis. (Minor) Patients receiving antidiabetic agents like metformin should be closely monitored for signs indicating changes in diabetic control when therapy with progestins is instituted or discontinued. Progestins can impair glucose tolerance.
    Estradiol; Norethindrone: (Minor) Monitor blood glucose periodically in patients on metformin for changes in glycemic control when hormone therapy is instituted or discontinued. Estrogens can decrease the hypoglycemic effects of antidiabetic agents by impairing glucose tolerance. Changes in glucose tolerance occur more commonly in patients receiving 50 mcg or more of ethinyl estradiol (or equivalent) per day in combined oral contraceptives (COCs), which are not commonly used in practice since the marketing of lower dose COCs, patches, injections and rings. The presence or absence of a concomitant progestin may influence the significance of any hormonal effect on glucose homeostasis. (Minor) Patients receiving antidiabetic agents like metformin should be closely monitored for signs indicating changes in diabetic control when therapy with progestins is instituted or discontinued. Progestins can impair glucose tolerance.
    Estradiol; Norgestimate: (Minor) Monitor blood glucose periodically in patients on metformin for changes in glycemic control when hormone therapy is instituted or discontinued. Estrogens can decrease the hypoglycemic effects of antidiabetic agents by impairing glucose tolerance. Changes in glucose tolerance occur more commonly in patients receiving 50 mcg or more of ethinyl estradiol (or equivalent) per day in combined oral contraceptives (COCs), which are not commonly used in practice since the marketing of lower dose COCs, patches, injections and rings. The presence or absence of a concomitant progestin may influence the significance of any hormonal effect on glucose homeostasis. (Minor) Patients receiving antidiabetic agents like metformin should be closely monitored for signs indicating changes in diabetic control when therapy with progestins is instituted or discontinued. Progestins can impair glucose tolerance.
    Estradiol; Progesterone: (Minor) Monitor blood glucose periodically in patients on metformin for changes in glycemic control when hormone therapy is instituted or discontinued. Estrogens can decrease the hypoglycemic effects of antidiabetic agents by impairing glucose tolerance. Changes in glucose tolerance occur more commonly in patients receiving 50 mcg or more of ethinyl estradiol (or equivalent) per day in combined oral contraceptives (COCs), which are not commonly used in practice since the marketing of lower dose COCs, patches, injections and rings. The presence or absence of a concomitant progestin may influence the significance of any hormonal effect on glucose homeostasis. (Minor) Patients receiving antidiabetic agents like metformin should be closely monitored for signs indicating changes in diabetic control when therapy with progestins is instituted or discontinued. Progestins can impair glucose tolerance.
    Estramustine: (Minor) Estramustine should be used cautiously in patients receiving metformin. Patients should routinely monitor their blood glucose as indicated. Estramustine may decrease glucose tolerance leading to hyperglycemia.
    Estrogens: (Minor) Monitor blood glucose periodically in patients on metformin for changes in glycemic control when hormone therapy is instituted or discontinued. Estrogens can decrease the hypoglycemic effects of antidiabetic agents by impairing glucose tolerance. Changes in glucose tolerance occur more commonly in patients receiving 50 mcg or more of ethinyl estradiol (or equivalent) per day in combined oral contraceptives (COCs), which are not commonly used in practice since the marketing of lower dose COCs, patches, injections and rings. The presence or absence of a concomitant progestin may influence the significance of any hormonal effect on glucose homeostasis. (Minor) Patients receiving antidiabetic agents should be periodically monitored for changes in glycemic control when hormone therapy is instituted or discontinued. Estrogens can decrease the hypoglycemic effects of antidiabetic agents by impairing glucose tolerance. Changes in glucose tolerance occur more commonly in patients receiving 50 mcg or more of ethinyl estradiol (or equivalent) per day in combined oral contraceptives (COCs), which are not commonly used in practice since the marketing of lower dose COCs, patches, injections and rings. The presence or absence of a concomitant progestin may influence the significance of any hormonal effect on glucose homeostasis.
    Estropipate: (Minor) Monitor blood glucose periodically in patients on metformin for changes in glycemic control when hormone therapy is instituted or discontinued. Estrogens can decrease the hypoglycemic effects of antidiabetic agents by impairing glucose tolerance. Changes in glucose tolerance occur more commonly in patients receiving 50 mcg or more of ethinyl estradiol (or equivalent) per day in combined oral contraceptives (COCs), which are not commonly used in practice since the marketing of lower dose COCs, patches, injections and rings. The presence or absence of a concomitant progestin may influence the significance of any hormonal effect on glucose homeostasis.
    Ethacrynic Acid: (Moderate) Loop diuretics can decrease the hypoglycemic effects of antidiabetic agents by producing an increase in blood glucose concentrations.Patients receiving antidiabetic agents should be monitored for changes in blood glucose control if such diuretics are added or deleted. Dosage adjustments may be necessary.
    Ethanol: (Moderate) Patients should be advised to limit alcohol (ethanol) ingestion when treated with an antidiabetic agent. Ethanol inhibits gluconeogenesis, which can contribute to or increase the risk for hypoglycemia. In some patients, hypoglycemia can be prolonged. If a patient with diabetes ingests alcohol, they should be counselled to to avoid ingestion of alcohol on an empty stomach, which increases risk for low blood sugar. Patients should also be aware of the carbohydrate intake provided by certain types of alcohol in the diet, which can contribute to poor glycemic control. If a patient chooses to ingest alcohol, they should monitor their blood glucose frequently. Many non-prescription drug products may be formulated with alcohol; instruct patients to scrutinize product labels prior to consumption. (Moderate) Patients should be advised to limit alcohol ingestion when treated with an antidiabetic agent. Alcohol inhibits gluconeogenesis, which can contribute to or increase the risk for hypoglycemia. In some patients, hypoglycemia can be prolonged. If a patient with diabetes ingests alcohol, they should be counselled to to avoid ingestion of alcohol on an empty stomach, which increases risk for low blood sugar. Patients should also be aware of the carbohydrate intake provided by certain types of alcohol in the diet, which can contribute to poor glycemic control. If a patient chooses to ingest alcohol, they should monitor their blood glucose frequently. Many non-prescription drug products may be formulated with alcohol; instruct patients to scrutinize product labels prior to consumption. (Moderate) Patients taking metformin should be advised to limit their use of alcohol. Blood lactate concentrations and the lactate to pyruvate ratio are increased during excessive (acute or chronic) intake of alcohol with metformin. Elevated lactic acid concentrations are associated with increased morbidity rates as the risk for lactic acidosis is increased. In patients with diabetes, alcohol intake can also cause hypoglycemia or worsen glycemic control as it provides a source of additional calories. Many non-prescription drug products may be formulated with alcohol; have patients scrutinize product labels prior to consumption.
    Ethinyl Estradiol: (Minor) Monitor blood glucose periodically in patients on metformin for changes in glycemic control when hormone therapy is instituted or discontinued. Estrogens can decrease the hypoglycemic effects of antidiabetic agents by impairing glucose tolerance. Changes in glucose tolerance occur more commonly in patients receiving 50 mcg or more of ethinyl estradiol (or equivalent) per day in combined oral contraceptives (COCs), which are not commonly used in practice since the marketing of lower dose COCs, patches, injections and rings. The presence or absence of a concomitant progestin may influence the significance of any hormonal effect on glucose homeostasis.
    Ethinyl Estradiol; Levonorgestrel; Folic Acid; Levomefolate: (Minor) Levomefolate and metformin should be used together cautiously. Plasma concentrations of levomefolate may be reduced during treatment of type 2 diabetes with metformin. Monitor patients for decreased efficacy of levomefolate if these agents are used together. (Minor) Monitor blood glucose periodically in patients on metformin for changes in glycemic control when hormone therapy is instituted or discontinued. Estrogens can decrease the hypoglycemic effects of antidiabetic agents by impairing glucose tolerance. Changes in glucose tolerance occur more commonly in patients receiving 50 mcg or more of ethinyl estradiol (or equivalent) per day in combined oral contraceptives (COCs), which are not commonly used in practice since the marketing of lower dose COCs, patches, injections and rings. The presence or absence of a concomitant progestin may influence the significance of any hormonal effect on glucose homeostasis. (Minor) Patients receiving antidiabetic agents like metformin should be closely monitored for signs indicating changes in diabetic control when therapy with progestins is instituted or discontinued. Progestins can impair glucose tolerance.
    Ethinyl Estradiol; Norelgestromin: (Minor) Monitor blood glucose periodically in patients on metformin for changes in glycemic control when hormone therapy is instituted or discontinued. Estrogens can decrease the hypoglycemic effects of antidiabetic agents by impairing glucose tolerance. Changes in glucose tolerance occur more commonly in patients receiving 50 mcg or more of ethinyl estradiol (or equivalent) per day in combined oral contraceptives (COCs), which are not commonly used in practice since the marketing of lower dose COCs, patches, injections and rings. The presence or absence of a concomitant progestin may influence the significance of any hormonal effect on glucose homeostasis. (Minor) Patients receiving antidiabetic agents like metformin should be closely monitored for signs indicating changes in diabetic control when therapy with progestins is instituted or discontinued. Progestins can impair glucose tolerance.
    Ethinyl Estradiol; Norethindrone Acetate: (Minor) Monitor blood glucose periodically in patients on metformin for changes in glycemic control when hormone therapy is instituted or discontinued. Estrogens can decrease the hypoglycemic effects of antidiabetic agents by impairing glucose tolerance. Changes in glucose tolerance occur more commonly in patients receiving 50 mcg or more of ethinyl estradiol (or equivalent) per day in combined oral contraceptives (COCs), which are not commonly used in practice since the marketing of lower dose COCs, patches, injections and rings. The presence or absence of a concomitant progestin may influence the significance of any hormonal effect on glucose homeostasis. (Minor) Patients receiving antidiabetic agents like metformin should be closely monitored for signs indicating changes in diabetic control when therapy with progestins is instituted or discontinued. Progestins can impair glucose tolerance.
    Ethinyl Estradiol; Norgestrel: (Minor) Monitor blood glucose periodically in patients on metformin for changes in glycemic control when hormone therapy is instituted or discontinued. Estrogens can decrease the hypoglycemic effects of antidiabetic agents by impairing glucose tolerance. Changes in glucose tolerance occur more commonly in patients receiving 50 mcg or more of ethinyl estradiol (or equivalent) per day in combined oral contraceptives (COCs), which are not commonly used in practice since the marketing of lower dose COCs, patches, injections and rings. The presence or absence of a concomitant progestin may influence the significance of any hormonal effect on glucose homeostasis. (Minor) Patients receiving antidiabetic agents like metformin should be closely monitored for signs indicating changes in diabetic control when therapy with progestins is instituted or discontinued. Progestins can impair glucose tolerance.
    Ethotoin: (Minor) Ethotoin and other hydantoins have the potential to increase blood glucose and thus interact with antidiabetic agents pharmacodynamically. Monitor blood glucose for changes in glycemic control. Dosage adjustments may be necessary in some patients.
    Ethynodiol Diacetate; Ethinyl Estradiol: (Minor) Monitor blood glucose periodically in patients on metformin for changes in glycemic control when hormone therapy is instituted or discontinued. Estrogens can decrease the hypoglycemic effects of antidiabetic agents by impairing glucose tolerance. Changes in glucose tolerance occur more commonly in patients receiving 50 mcg or more of ethinyl estradiol (or equivalent) per day in combined oral contraceptives (COCs), which are not commonly used in practice since the marketing of lower dose COCs, patches, injections and rings. The presence or absence of a concomitant progestin may influence the significance of any hormonal effect on glucose homeostasis. (Minor) Patients receiving antidiabetic agents like metformin should be closely monitored for signs indicating changes in diabetic control when therapy with progestins is instituted or discontinued. Progestins can impair glucose tolerance.
    Etonogestrel: (Minor) Patients receiving antidiabetic agents like metformin should be closely monitored for signs indicating changes in diabetic control when therapy with progestins is instituted or discontinued. Progestins can impair glucose tolerance.
    Etonogestrel; Ethinyl Estradiol: (Minor) Monitor blood glucose periodically in patients on metformin for changes in glycemic control when hormone therapy is instituted or discontinued. Estrogens can decrease the hypoglycemic effects of antidiabetic agents by impairing glucose tolerance. Changes in glucose tolerance occur more commonly in patients receiving 50 mcg or more of ethinyl estradiol (or equivalent) per day in combined oral contraceptives (COCs), which are not commonly used in practice since the marketing of lower dose COCs, patches, injections and rings. The presence or absence of a concomitant progestin may influence the significance of any hormonal effect on glucose homeostasis. (Minor) Patients receiving antidiabetic agents like metformin should be closely monitored for signs indicating changes in diabetic control when therapy with progestins is instituted or discontinued. Progestins can impair glucose tolerance.
    Famotidine: (Minor) Famotidine may decrease the renal clearance of metformin secondary to competition for renal tubular transport systems. Such an interaction has been observed when cimetidine was administered with metformin. The decrease in renal excretion led to a 40% increase in metformin AUC. Although interactions with cationic drugs remain theoretical (except for cimetidine), caution is warranted when famotidine and metformin are prescribed concurrently. Famotidine may be less likely to interact with metformin versus cimetidine or ranitidine because of less tubular excretion.
    Famotidine; Ibuprofen: (Minor) Famotidine may decrease the renal clearance of metformin secondary to competition for renal tubular transport systems. Such an interaction has been observed when cimetidine was administered with metformin. The decrease in renal excretion led to a 40% increase in metformin AUC. Although interactions with cationic drugs remain theoretical (except for cimetidine), caution is warranted when famotidine and metformin are prescribed concurrently. Famotidine may be less likely to interact with metformin versus cimetidine or ranitidine because of less tubular excretion.
    Fedratinib: (Moderate) Concurrent use of metformin and fedratinib may produce unpredictable effects. Concomitant administration may increase the risk for metformin adverse events (e.g., lactic acidosis) or reduce metformin's efficacy. If these drugs are given together, monitor for metformin toxicity and efficacy; metformin dose adjustments may be needed. Fedratinib inhibits the common renal tubular transport systems involved in the renal elimination of metformin (e.g., OCT2/MATE1 and MATE2). In a drug interaction study, fedratinib was observed to have no clinically meaningful effect on metformin overall exposure; however, the renal clearance of metformin was decreased by 36% and the glucose lowering effect of metformin appeared to be reduced. The baseline adjusted glucose exposure was about 50% higher in response to an oral glucose challenge when these drugs were administered together.
    Fenofibrate: (Moderate) Dose reductions and increased frequency of glucose monitoring may be required when antidiabetic agents are administered with fibric acid derivatives (e.g., clofibrate, fenofibric acid, fenofibrate, gemfibrozil). Fibric acid derivatives may enhance the hypoglycemic effects of antidiabetic agents through increased insulin sensitivity and decreased glucagon secretion.
    Fenofibric Acid: (Moderate) Dose reductions and increased frequency of glucose monitoring may be required when antidiabetic agents are administered with fibric acid derivatives (e.g., clofibrate, fenofibric acid, fenofibrate, gemfibrozil). Fibric acid derivatives may enhance the hypoglycemic effects of antidiabetic agents through increased insulin sensitivity and decreased glucagon secretion.
    Fexofenadine; Pseudoephedrine: (Moderate) Sympathomimetic agents and adrenergic agonists tend to increase blood glucose concentrations when administered systemically. Monitor for loss of glycemic control when pseudoephedrine, phenylephrine, and other sympathomimetics are administered to patients taking antidiabetic agents. Epinephrine and other sympathomimetics, through stimulation of alpha- and beta- receptors, increase hepatic glucose production and glycogenolysis and inhibit insulin secretion. Also, adrenergic medications may decrease glucose uptake by muscle cells. For treatment of cold symptoms, nasal decongestants may be preferable for short term, limited use (1 to 3 days) as an alternative to systemic decongestants in patients taking medications for diabetes.
    Fibric acid derivatives: (Moderate) Dose reductions and increased frequency of glucose monitoring may be required when antidiabetic agents are administered with fibric acid derivatives (e.g., clofibrate, fenofibric acid, fenofibrate, gemfibrozil). Fibric acid derivatives may enhance the hypoglycemic effects of antidiabetic agents through increased insulin sensitivity and decreased glucagon secretion.
    Fluoxetine: (Moderate) In patients with diabetes mellitus, fluoxetine may alter glycemic control. Hypoglycemia has occurred during fluoxetine therapy. Hyperglycemia has developed in patients with diabetes mellitus following discontinuation of the drug. The dosage of insulin and/or other antidiabetic agents may need to be adjusted when therapy with fluoxetine is instituted or discontinued.
    Fluoxymesterone: (Moderate) Changes in insulin sensitivity or glycemic control may occur in patients treated with androgens. In diabetic patients, the metabolic effects of androgens may decrease blood glucose and, therefore, may decrease antidiabetic agent dosage requirements. Monitor blood glucose and HbA1C when these drugs are used together.
    Fosinopril: (Moderate) Angiotensin-converting enzyme (ACE) inhibitors may enhance the hypoglycemic effects of insulin or other antidiabetic agents by improving insulin sensitivity. Patients receiving antidiabetic agents can become hypoglycemic if ACE inhibitors are administered concomitantly. ACE inhibitors may rarely reduce renal function, a risk factor for reduced renal clearance of metformin. Patients receiving these drugs together should be monitored for changes in renal function and glycemic control. (Moderate) Patients receiving these drugs concomitantly should be monitored for changes in blood pressure, volume status, renal function, serum potassium, and glycemic control. When an SGLT2 inhibitor is initiated, mild diuresis and naturesis occurs, producing intravascular volume contraction. These effects may be additive to certain antihypertensive medications, such as the angiotensin-converting enzyme inhibitors (ACE inhibitors). Patients with impaired renal function (eGFR less than 60 mL/minute/1.73 m2), low systolic blood pressure, or who are elderly may also be at a greater risk. Volume status should be assessed and corrected. In addition, some SGLT2 inhibitors, like canagliflozin, can increase serum potassium. Monitor serum potassium levels periodically and monitor for hyperkalemia. ACE inhibitors may also enhance the hypoglycemic effects of antidiabetic agents by improving insulin sensitivity.
    Fosinopril; Hydrochlorothiazide, HCTZ: (Moderate) Angiotensin-converting enzyme (ACE) inhibitors may enhance the hypoglycemic effects of insulin or other antidiabetic agents by improving insulin sensitivity. Patients receiving antidiabetic agents can become hypoglycemic if ACE inhibitors are administered concomitantly. ACE inhibitors may rarely reduce renal function, a risk factor for reduced renal clearance of metformin. Patients receiving these drugs together should be monitored for changes in renal function and glycemic control. (Moderate) Certain drugs, such as thiazide diuretics, tend to produce hyperglycemia and may lead to loss of glycemic control. The effects of thiazide diuretics on glycemic control appear to be dose-related and low doses can be instituted without deleterious effects on glycemic control. In addition, thiazide diuretics reduce the risk of stroke and cardiovascular disease in patients with diabetes. Patients receiving metformin should be monitored for changes in blood glucose control if any of these diuretics are added or deleted. Dosage adjustments may be necessary in some patients. (Moderate) Patients receiving these drugs concomitantly should be monitored for changes in blood pressure, volume status, renal function, serum potassium, and glycemic control. When an SGLT2 inhibitor is initiated, mild diuresis and naturesis occurs, producing intravascular volume contraction. These effects may be additive to certain antihypertensive medications, such as the angiotensin-converting enzyme inhibitors (ACE inhibitors). Patients with impaired renal function (eGFR less than 60 mL/minute/1.73 m2), low systolic blood pressure, or who are elderly may also be at a greater risk. Volume status should be assessed and corrected. In addition, some SGLT2 inhibitors, like canagliflozin, can increase serum potassium. Monitor serum potassium levels periodically and monitor for hyperkalemia. ACE inhibitors may also enhance the hypoglycemic effects of antidiabetic agents by improving insulin sensitivity.
    Fosphenytoin: (Minor) Fosphenytoin and other hydantoins have the potential to increase blood glucose and thus interact with antidiabetic agents pharmacodynamically. Monitor blood glucose for changes in glycemic control. Dosage adjustments may be necessary in some patients.
    Furosemide: (Minor) Furosemide may cause hyperglycemia and glycosuria in patients with diabetes mellitus, probably due to diuretic-induced hypokalemia.
    Garlic, Allium sativum: (Moderate) Patients receiving antidiabetic agents should use dietary supplements of Garlic, Allium sativum with caution. Constituents in garlic might have some antidiabetic activity, and may increase serum insulin levels and increase glycogen storage in the liver. Monitor blood glucose and glycemic control. Patients with diabetes should inform their health care professionals of their intent to ingest garlic dietary supplements. Some patients may require adjustment to their hypoglycemic medications over time. One study stated that additional garlic supplementation (0.05 to 1.5 grams PO per day) contributed to improved blood glucose control in patients with type 2 diabetes mellitus within 1 to 2 weeks, and had positive effects on total cholesterol and high/low density lipoprotein regulation over time. It is unclear if hemoglobin A1C is improved or if improvements are sustained with continued treatment beyond 24 weeks. Other reviews suggest that garlic may provide modest improvements in blood lipids, but few studies demonstrate decreases in blood glucose in diabetic and non-diabetic patients. More controlled trials are needed to discern if garlic has an effect on blood glucose in patients with diabetes. When garlic is used in foods or as a seasoning, or at doses of 50 mg/day or less, it is unlikely that blood glucose levels are affected to any clinically significant degree.
    Gemfibrozil: (Moderate) Dose reductions and increased frequency of glucose monitoring may be required when antidiabetic agents are administered with fibric acid derivatives (e.g., clofibrate, fenofibric acid, fenofibrate, gemfibrozil). Fibric acid derivatives may enhance the hypoglycemic effects of antidiabetic agents through increased insulin sensitivity and decreased glucagon secretion.
    Glecaprevir; Pibrentasvir: (Moderate) Closely monitor blood glucose levels if glecaprevir is administered with antidiabetic agents. Dose adjustments of the antidiabetic agents may be needed. Altered blood glucose control, resulting in serious symptomatic hypoglycemia, has been reported in diabetic patients receiving antidiabetic agents in combination with direct acting antivirals, such as glecaprevir. (Moderate) Closely monitor blood glucose levels if pibrentasvir is administered with antidiabetic agents. Dose adjustments of the antidiabetic agents may be needed. Altered blood glucose control, resulting in serious symptomatic hypoglycemia, has been reported in diabetic patients receiving antidiabetic agents in combination with direct acting antivirals, such as pibrentasvir.
    Glimepiride: (Moderate) Use of metformin with a sulfonylurea may increase the risk of hypoglycemia. Sulfonylureas are known to cause hypoglycemia. To manage hypoglycemic risk, lower doses of the sulfonylurea may be needed. Monitor blood sugar.
    Glimepiride; Rosiglitazone: (Moderate) Use of metformin with a sulfonylurea may increase the risk of hypoglycemia. Sulfonylureas are known to cause hypoglycemia. To manage hypoglycemic risk, lower doses of the sulfonylurea may be needed. Monitor blood sugar.
    Glipizide: (Moderate) Use of metformin with a sulfonylurea may increase the risk of hypoglycemia. Sulfonylureas are known to cause hypoglycemia. To manage hypoglycemic risk, lower doses of the sulfonylurea may be needed. Monitor blood sugar.
    Glipizide; Metformin: (Moderate) Use of metformin with a sulfonylurea may increase the risk of hypoglycemia. Sulfonylureas are known to cause hypoglycemia. To manage hypoglycemic risk, lower doses of the sulfonylurea may be needed. Monitor blood sugar.
    Glyburide: (Moderate) Use of metformin with a sulfonylurea may increase the risk of hypoglycemia. Sulfonylureas are known to cause hypoglycemia. To manage hypoglycemic risk, lower doses of the sulfonylurea may be needed. Monitor blood sugar.
    Glyburide; Metformin: (Moderate) Use of metformin with a sulfonylurea may increase the risk of hypoglycemia. Sulfonylureas are known to cause hypoglycemia. To manage hypoglycemic risk, lower doses of the sulfonylurea may be needed. Monitor blood sugar.
    Glycopyrrolate: (Moderate) Coadministration of glycopyrrolate with metformin my increase metformin plasma concentrations, which may lead to increased metformin effects and possible adverse events. If coadministration is necessary, monitor clinical response to metformin and adjust metformin dose accordingly.
    Glycopyrrolate; Formoterol: (Moderate) Coadministration of glycopyrrolate with metformin my increase metformin plasma concentrations, which may lead to increased metformin effects and possible adverse events. If coadministration is necessary, monitor clinical response to metformin and adjust metformin dose accordingly.
    Green Tea: (Moderate) Green tea catechins have been shown to decrease serum glucose concentrations in vitro. Patients with diabetes mellitus taking antidiabetic agents should be monitored closely for hypoglycemia if consuming green tea products.
    Guaifenesin; Hydrocodone; Pseudoephedrine: (Moderate) Sympathomimetic agents and adrenergic agonists tend to increase blood glucose concentrations when administered systemically. Monitor for loss of glycemic control when pseudoephedrine, phenylephrine, and other sympathomimetics are administered to patients taking antidiabetic agents. Epinephrine and other sympathomimetics, through stimulation of alpha- and beta- receptors, increase hepatic glucose production and glycogenolysis and inhibit insulin secretion. Also, adrenergic medications may decrease glucose uptake by muscle cells. For treatment of cold symptoms, nasal decongestants may be preferable for short term, limited use (1 to 3 days) as an alternative to systemic decongestants in patients taking medications for diabetes.
    Guaifenesin; Phenylephrine: (Moderate) Sympathomimetic agents and adrenergic agonists tend to increase blood glucose concentrations when administered systemically. Monitor for loss of glycemic control when pseudoephedrine, phenylephrine, and other sympathomimetics are administered to patients taking antidiabetic agents. Epinephrine and other sympathomimetics, through stimulation of alpha- and beta- receptors, increase hepatic glucose production and glycogenolysis and inhibit insulin secretion. Also, adrenergic medications may decrease glucose uptake by muscle cells. For treatment of cold symptoms, nasal decongestants may be preferable for short term, limited use (1 to 3 days) as an alternative to systemic decongestants in patients taking medications for diabetes.
    Guaifenesin; Pseudoephedrine: (Moderate) Sympathomimetic agents and adrenergic agonists tend to increase blood glucose concentrations when administered systemically. Monitor for loss of glycemic control when pseudoephedrine, phenylephrine, and other sympathomimetics are administered to patients taking antidiabetic agents. Epinephrine and other sympathomimetics, through stimulation of alpha- and beta- receptors, increase hepatic glucose production and glycogenolysis and inhibit insulin secretion. Also, adrenergic medications may decrease glucose uptake by muscle cells. For treatment of cold symptoms, nasal decongestants may be preferable for short term, limited use (1 to 3 days) as an alternative to systemic decongestants in patients taking medications for diabetes.
    Hydralazine; Hydrochlorothiazide, HCTZ: (Moderate) Certain drugs, such as thiazide diuretics, tend to produce hyperglycemia and may lead to loss of glycemic control. The effects of thiazide diuretics on glycemic control appear to be dose-related and low doses can be instituted without deleterious effects on glycemic control. In addition, thiazide diuretics reduce the risk of stroke and cardiovascular disease in patients with diabetes. Patients receiving metformin should be monitored for changes in blood glucose control if any of these diuretics are added or deleted. Dosage adjustments may be necessary in some patients.
    Hydrochlorothiazide, HCTZ: (Moderate) Certain drugs, such as thiazide diuretics, tend to produce hyperglycemia and may lead to loss of glycemic control. The effects of thiazide diuretics on glycemic control appear to be dose-related and low doses can be instituted without deleterious effects on glycemic control. In addition, thiazide diuretics reduce the risk of stroke and cardiovascular disease in patients with diabetes. Patients receiving metformin should be monitored for changes in blood glucose control if any of these diuretics are added or deleted. Dosage adjustments may be necessary in some patients.
    Hydrochlorothiazide, HCTZ; Methyldopa: (Moderate) Certain drugs, such as thiazide diuretics, tend to produce hyperglycemia and may lead to loss of glycemic control. The effects of thiazide diuretics on glycemic control appear to be dose-related and low doses can be instituted without deleterious effects on glycemic control. In addition, thiazide diuretics reduce the risk of stroke and cardiovascular disease in patients with diabetes. Patients receiving metformin should be monitored for changes in blood glucose control if any of these diuretics are added or deleted. Dosage adjustments may be necessary in some patients.
    Hydrochlorothiazide, HCTZ; Moexipril: (Moderate) Angiotensin-converting enzyme (ACE) inhibitors may enhance the hypoglycemic effects of insulin or other antidiabetic agents by improving insulin sensitivity. Patients receiving antidiabetic agents can become hypoglycemic if ACE inhibitors are administered concomitantly. ACE inhibitors may rarely reduce renal function, a risk factor for reduced renal clearance of metformin. Patients receiving these drugs together should be monitored for changes in renal function and glycemic control. (Moderate) Certain drugs, such as thiazide diuretics, tend to produce hyperglycemia and may lead to loss of glycemic control. The effects of thiazide diuretics on glycemic control appear to be dose-related and low doses can be instituted without deleterious effects on glycemic control. In addition, thiazide diuretics reduce the risk of stroke and cardiovascular disease in patients with diabetes. Patients receiving metformin should be monitored for changes in blood glucose control if any of these diuretics are added or deleted. Dosage adjustments may be necessary in some patients. (Moderate) Patients receiving these drugs concomitantly should be monitored for changes in blood pressure, volume status, renal function, serum potassium, and glycemic control. When an SGLT2 inhibitor is initiated, mild diuresis and naturesis occurs, producing intravascular volume contraction. These effects may be additive to certain antihypertensive medications, such as the angiotensin-converting enzyme inhibitors (ACE inhibitors). Patients with impaired renal function (eGFR less than 60 mL/minute/1.73 m2), low systolic blood pressure, or who are elderly may also be at a greater risk. Volume status should be assessed and corrected. In addition, some SGLT2 inhibitors, like canagliflozin, can increase serum potassium. Monitor serum potassium levels periodically and monitor for hyperkalemia. ACE inhibitors may also enhance the hypoglycemic effects of antidiabetic agents by improving insulin sensitivity.
    Hydrocodone; Phenylephrine: (Moderate) Sympathomimetic agents and adrenergic agonists tend to increase blood glucose concentrations when administered systemically. Monitor for loss of glycemic control when pseudoephedrine, phenylephrine, and other sympathomimetics are administered to patients taking antidiabetic agents. Epinephrine and other sympathomimetics, through stimulation of alpha- and beta- receptors, increase hepatic glucose production and glycogenolysis and inhibit insulin secretion. Also, adrenergic medications may decrease glucose uptake by muscle cells. For treatment of cold symptoms, nasal decongestants may be preferable for short term, limited use (1 to 3 days) as an alternative to systemic decongestants in patients taking medications for diabetes.
    Hydrocodone; Potassium Guaiacolsulfonate; Pseudoephedrine: (Moderate) Sympathomimetic agents and adrenergic agonists tend to increase blood glucose concentrations when administered systemically. Monitor for loss of glycemic control when pseudoephedrine, phenylephrine, and other sympathomimetics are administered to patients taking antidiabetic agents. Epinephrine and other sympathomimetics, through stimulation of alpha- and beta- receptors, increase hepatic glucose production and glycogenolysis and inhibit insulin secretion. Also, adrenergic medications may decrease glucose uptake by muscle cells. For treatment of cold symptoms, nasal decongestants may be preferable for short term, limited use (1 to 3 days) as an alternative to systemic decongestants in patients taking medications for diabetes.
    Hydrocodone; Pseudoephedrine: (Moderate) Sympathomimetic agents and adrenergic agonists tend to increase blood glucose concentrations when administered systemically. Monitor for loss of glycemic control when pseudoephedrine, phenylephrine, and other sympathomimetics are administered to patients taking antidiabetic agents. Epinephrine and other sympathomimetics, through stimulation of alpha- and beta- receptors, increase hepatic glucose production and glycogenolysis and inhibit insulin secretion. Also, adrenergic medications may decrease glucose uptake by muscle cells. For treatment of cold symptoms, nasal decongestants may be preferable for short term, limited use (1 to 3 days) as an alternative to systemic decongestants in patients taking medications for diabetes.
    Hydroxychloroquine: (Moderate) Careful monitoring of blood glucose is recommended when hydroxychloroquine and antidiabetic agents, including metformin, are coadministered. A decreased dose of the antidiabetic agent may be necessary as severe hypoglycemia has been reported in patients treated concomitantly with hydroxychloroquine and an antidiabetic agent. (Moderate) Careful monitoring of blood glucose is recommended when hydroxychloroquine and antidiabetic agents, including the SGLT2 inhibitors, are coadministered. A decreased dose of the antidiabetic agent may be necessary as severe hypoglycemia has been reported in patients treated concomitantly with hydroxychloroquine and an antidiabetic agent.
    Hydroxyprogesterone: (Minor) Progestins, like hydroxyprogesterone, can impair glucose tolerance. Patients receiving antidiabetic agents should be closely monitored for signs indicating changes in diabetic control when therapy with progestins is instituted or discontinued.
    Ibuprofen; Pseudoephedrine: (Moderate) Sympathomimetic agents and adrenergic agonists tend to increase blood glucose concentrations when administered systemically. Monitor for loss of glycemic control when pseudoephedrine, phenylephrine, and other sympathomimetics are administered to patients taking antidiabetic agents. Epinephrine and other sympathomimetics, through stimulation of alpha- and beta- receptors, increase hepatic glucose production and glycogenolysis and inhibit insulin secretion. Also, adrenergic medications may decrease glucose uptake by muscle cells. For treatment of cold symptoms, nasal decongestants may be preferable for short term, limited use (1 to 3 days) as an alternative to systemic decongestants in patients taking medications for diabetes.
    Indacaterol; Glycopyrrolate: (Moderate) Coadministration of glycopyrrolate with metformin my increase metformin plasma concentrations, which may lead to increased metformin effects and possible adverse events. If coadministration is necessary, monitor clinical response to metformin and adjust metformin dose accordingly.
    Indapamide: (Moderate) A potential pharmacodynamic interaction exists between indapamide and antidiabetic agents, like metformin. Indapamide can decrease insulin sensitivity thereby leading to glucose intolerance and hyperglycemia. Diuretic-induced hypokalemia may also lead to hyperglycemia.
    Insulin Aspart: (Moderate) Coadministration of metformin with an insulin may increase the risk of hypoglycemia. Insulins are known to cause hypoglycemia. To manage hypoglycemic risk, lower doses of insulin may be needed. Monitor blood sugar and adjust insulin dosage as clinically indicated.
    Insulin Aspart; Insulin Aspart Protamine: (Moderate) Coadministration of metformin with an insulin may increase the risk of hypoglycemia. Insulins are known to cause hypoglycemia. To manage hypoglycemic risk, lower doses of insulin may be needed. Monitor blood sugar and adjust insulin dosage as clinically indicated.
    Insulin Degludec: (Moderate) Coadministration of metformin with an insulin may increase the risk of hypoglycemia. Insulins are known to cause hypoglycemia. To manage hypoglycemic risk, lower doses of insulin may be needed. Monitor blood sugar and adjust insulin dosage as clinically indicated.
    Insulin Degludec; Liraglutide: (Moderate) Coadministration of metformin with an insulin may increase the risk of hypoglycemia. Insulins are known to cause hypoglycemia. To manage hypoglycemic risk, lower doses of insulin may be needed. Monitor blood sugar and adjust insulin dosage as clinically indicated.
    Insulin Detemir: (Moderate) Coadministration of metformin with an insulin may increase the risk of hypoglycemia. Insulins are known to cause hypoglycemia. To manage hypoglycemic risk, lower doses of insulin may be needed. Monitor blood sugar and adjust insulin dosage as clinically indicated.
    Insulin Glargine: (Moderate) Coadministration of metformin with an insulin may increase the risk of hypoglycemia. Insulins are known to cause hypoglycemia. To manage hypoglycemic risk, lower doses of insulin may be needed. Monitor blood sugar and adjust insulin dosage as clinically indicated.
    Insulin Glargine; Lixisenatide: (Moderate) Coadministration of metformin with an insulin may increase the risk of hypoglycemia. Insulins are known to cause hypoglycemia. To manage hypoglycemic risk, lower doses of insulin may be needed. Monitor blood sugar and adjust insulin dosage as clinically indicated.
    Insulin Glulisine: (Moderate) Coadministration of metformin with an insulin may increase the risk of hypoglycemia. Insulins are known to cause hypoglycemia. To manage hypoglycemic risk, lower doses of insulin may be needed. Monitor blood sugar and adjust insulin dosage as clinically indicated.
    Insulin Lispro: (Moderate) Coadministration of metformin with an insulin may increase the risk of hypoglycemia. Insulins are known to cause hypoglycemia. To manage hypoglycemic risk, lower doses of insulin may be needed. Monitor blood sugar and adjust insulin dosage as clinically indicated.
    Insulin Lispro; Insulin Lispro Protamine: (Moderate) Coadministration of metformin with an insulin may increase the risk of hypoglycemia. Insulins are known to cause hypoglycemia. To manage hypoglycemic risk, lower doses of insulin may be needed. Monitor blood sugar and adjust insulin dosage as clinically indicated.
    Insulin, Inhaled: (Moderate) Coadministration of metformin with an insulin may increase the risk of hypoglycemia. Insulins are known to cause hypoglycemia. To manage hypoglycemic risk, lower doses of insulin may be needed. Monitor blood sugar and adjust insulin dosage as clinically indicated.
    Insulins: (Moderate) Coadministration of metformin with an insulin may increase the risk of hypoglycemia. Insulins are known to cause hypoglycemia. To manage hypoglycemic risk, lower doses of insulin may be needed. Monitor blood sugar and adjust insulin dosage as clinically indicated.
    Iodipamide Meglumine: (Contraindicated) Metformin and combination products containing metformin should be temporarily discontinued prior to the administration of iodinated contrast media. Metformin should be held for at least 48 hours after contrast administration and not restarted until renal function returns to normal post-procedure. Lactic acidosis has been reported in patients taking metformin that experience nephrotoxicity after use of iodinated contrast media.
    Ionic Contrast Media: (Contraindicated) Metformin and combination products containing metformin should be temporarily discontinued prior to the administration of iodinated contrast media. Metformin should be held for at least 48 hours after contrast administration and not restarted until renal function returns to normal post-procedure. Lactic acidosis has been reported in patients taking metformin that experience nephrotoxicity after use of iodinated contrast media.
    Ioxaglate Meglumine; Ioxaglate Sodium: (Contraindicated) Metformin and combination products containing metformin should be temporarily discontinued prior to the administration of iodinated contrast media. Metformin should be held for at least 48 hours after contrast administration and not restarted until renal function returns to normal post-procedure. Lactic acidosis has been reported in patients taking metformin that experience nephrotoxicity after use of iodinated contrast media.
    Irbesartan: (Moderate) Angiotensin II receptor antagonists (ARBs) may enhance the hypoglycemic effects of metformin by improving insulin sensitivity. In addition, angiotensin II receptor antagonists have been associated with a reduced incidence in the development of new-onset diabetes in patients with hypertension or other cardiac disease. ARBs may rarely reduce renal function, a risk factor for reduced renal clearance of metformin. Patients receiving these drugs together should be monitored for changes in renal function and glycemic control. (Moderate) Patients receiving these drugs concomitantly should be monitored for changes in blood pressure, volume status, renal function, serum potassium and other electrolytes, and for glycemic control. When an SGLT2 inhibitor is initiated, mild diuresis and naturesis occurs, producing intravascular volume contraction. These effects may be additive to certain antihypertensive medications, such as the angiotensin II receptor antagonists (also known as angiotensin receptor blockers or ARBs). Patients with impaired renal function (eGFR less than 60 mL/minute/1.73 m2), low systolic blood pressure, or who are elderly may also be at a greater risk. Volume status should be assessed and corrected. In addition, some SGLT2 inhibitors, like canagliflozin, can increase serum potassium. Monitor serum potassium levels periodically and monitor for hyperkalemia. ARBs may also enhance the hypoglycemic effects of antidiabetic agents by improving insulin sensitivity.
    Irbesartan; Hydrochlorothiazide, HCTZ: (Moderate) Angiotensin II receptor antagonists (ARBs) may enhance the hypoglycemic effects of metformin by improving insulin sensitivity. In addition, angiotensin II receptor antagonists have been associated with a reduced incidence in the development of new-onset diabetes in patients with hypertension or other cardiac disease. ARBs may rarely reduce renal function, a risk factor for reduced renal clearance of metformin. Patients receiving these drugs together should be monitored for changes in renal function and glycemic control. (Moderate) Certain drugs, such as thiazide diuretics, tend to produce hyperglycemia and may lead to loss of glycemic control. The effects of thiazide diuretics on glycemic control appear to be dose-related and low doses can be instituted without deleterious effects on glycemic control. In addition, thiazide diuretics reduce the risk of stroke and cardiovascular disease in patients with diabetes. Patients receiving metformin should be monitored for changes in blood glucose control if any of these diuretics are added or deleted. Dosage adjustments may be necessary in some patients. (Moderate) Patients receiving these drugs concomitantly should be monitored for changes in blood pressure, volume status, renal function, serum potassium and other electrolytes, and for glycemic control. When an SGLT2 inhibitor is initiated, mild diuresis and naturesis occurs, producing intravascular volume contraction. These effects may be additive to certain antihypertensive medications, such as the angiotensin II receptor antagonists (also known as angiotensin receptor blockers or ARBs). Patients with impaired renal function (eGFR less than 60 mL/minute/1.73 m2), low systolic blood pressure, or who are elderly may also be at a greater risk. Volume status should be assessed and corrected. In addition, some SGLT2 inhibitors, like canagliflozin, can increase serum potassium. Monitor serum potassium levels periodically and monitor for hyperkalemia. ARBs may also enhance the hypoglycemic effects of antidiabetic agents by improving insulin sensitivity.
    Isocarboxazid: (Moderate) Serum glucose should be monitored closely when monoamine oxidase inhibitors (MAOIs) are added to any regimen containing antidiabetic agents, including ertugliflozin. Inhibitors of MAO type A have been shown to prolong the hypoglycemic response to insulin and other antidiabetic agents.
    Isophane Insulin (NPH): (Moderate) Coadministration of metformin with an insulin may increase the risk of hypoglycemia. Insulins are known to cause hypoglycemia. To manage hypoglycemic risk, lower doses of insulin may be needed. Monitor blood sugar and adjust insulin dosage as clinically indicated.
    Ketoconazole: (Moderate) Concomitant administration of metformin and ketoconazole may increase metformin exposure and increase the risk for lactic acidosis. During dosage titration, monitor blood sugar, kidney function, and Vitamin B12 as per the metformin prescribing information and adjust metformin dosage if needed. Metformin is a human organic cationic transporter-2 (OCT2) and multidrug and toxic extrusion 1 (MATE1) substrate. Ketoconazole is a an OCT2 and MATE1 inhibitor. OCT2 and MATE inhibitors may decrease metformin elimination by blocking renal tubular secretion.
    Labetalol: (Moderate) Increased frequency of blood glucose monitoring may be required when a beta blocker is given with antidiabetic agents. Since beta blockers inhibit the release of catecholamines, these medications may hide symptoms of hypoglycemia such as tremor, tachycardia, and blood pressure changes. Other symptoms, like headache, dizziness, nervousness, mood changes, or hunger are not blunted. Beta-blockers also exert complex actions on the body's ability to regulate blood glucose. Some beta-blockers, particularly non-selective beta-blockers such as propranolol, have been noted to potentiate insulin-induced hypoglycemia and a delay in recovery of blood glucose to normal levels. Hyperglycemia has been reported as well and is possibly due to beta-2 receptor blockade in the beta cells of the pancreas. A selective beta-blocker may be preferred in patients with diabetes mellitus, if appropriate for the patient's condition. Selective beta-blockers, such as atenolol or metoprolol, do not appear to potentiate insulin-induced hypoglycemia. While beta-blockers may have negative effects on glycemic control, they reduce the risk of cardiovascular disease and stroke in patients with diabetes and their use should not be avoided in patients with compelling indications for beta-blocker therapy when no other contraindications are present.
    Lamivudine, 3TC: (Moderate) Certain medications used concomitantly with metformin may increase the risk of lactic acidosis. Cationic drugs that are eliminated by renal tubular secretion, such as lamivudine, may decrease metformin elimination by competing for common renal tubular transport systems.
    Lamivudine, 3TC; Zidovudine, ZDV: (Moderate) Certain medications used concomitantly with metformin may increase the risk of lactic acidosis. Cationic drugs that are eliminated by renal tubular secretion, such as lamivudine, may decrease metformin elimination by competing for common renal tubular transport systems.
    Lamivudine; Tenofovir Disoproxil Fumarate: (Moderate) Certain medications used concomitantly with metformin may increase the risk of lactic acidosis. Cationic drugs that are eliminated by renal tubular secretion, such as lamivudine, may decrease metformin elimination by competing for common renal tubular transport systems. (Moderate) Certain medications used concomitantly with metformin may increase the risk of lactic acidosis. Drugs that are eliminated by renal tubular secretion, such as tenofovir, PMPA may decrease metformin elimination by competing for common renal tubular transport systems. Although such interactions remain theoretical, careful patient monitoring and dose adjustment of metformin and/or the interfering cationic drug are recommended.
    Lamotrigine: (Moderate) Coadministration of metformin and lamotrigine may decrease metformin clearance, resulting in increased plasma concentrations and the potential for adverse events, including a risk for lactic acidosis. Lamotrigine is an inhibitor of renal tubular secretion via organic cationic transporter 2 (OCT2) proteins, and metformin is excreted via this route.
    Lanreotide: (Moderate) Monitor blood glucose levels regularly in patients with diabetes, especially when lanreotide treatment is initiated or when the dose is altered. Adjust treatment with antidiabetic agents as clinically indicated. Lanreotide inhibits the secretion of insulin and glucagon. Patients treated with lanreotide may experience either hypoglycemia or hyperglycemia.
    Lansoprazole; Amoxicillin; Clarithromycin: (Moderate) The concomitant use of clarithromycin and antidiabetic agents can result in significant hypoglycemia. Careful monitoring of blood glucose is recommended.
    Ledipasvir; Sofosbuvir: (Moderate) Closely monitor blood glucose levels if ledipasvir is administered with antidiabetic agents. Dose adjustments of the antidiabetic agent(s) may be needed. Altered blood glucose control, resulting in serious symptomatic hypoglycemia, has been reported in diabetic patients receiving antidiabetic agents in combination with direct acting antivirals, such as ledipasvir. (Moderate) Closely monitor blood glucose levels if sofosbuvir is administered with antidiabetic agents. Dose adjustments of the antidiabetic agents may be needed. Altered blood glucose control, resulting in serious symptomatic hypoglycemia, has been reported in diabetic patients receiving antidiabetic agents in combination with direct acting antivirals, such as sofosbuvir.
    Lente Insulin: (Moderate) Coadministration of metformin with an insulin may increase the risk of hypoglycemia. Insulins are known to cause hypoglycemia. To manage hypoglycemic risk, lower doses of insulin may be needed. Monitor blood sugar and adjust insulin dosage as clinically indicated.
    Leuprolide; Norethindrone: (Minor) Patients receiving antidiabetic agents like metformin should be closely monitored for signs indicating changes in diabetic control when therapy with progestins is instituted or discontinued. Progestins can impair glucose tolerance.
    Levobetaxolol: (Moderate) Increased frequency of blood glucose monitoring may be required when a beta blocker is given with antidiabetic agents. Since beta blockers inhibit the release of catecholamines, these medications may hide symptoms of hypoglycemia such as tremor, tachycardia, and blood pressure changes. Other symptoms, like headache, dizziness, nervousness, mood changes, or hunger are not blunted. Beta-blockers also exert complex actions on the body's ability to regulate blood glucose. Some beta-blockers, particularly non-selective beta-blockers such as propranolol, have been noted to potentiate insulin-induced hypoglycemia and a delay in recovery of blood glucose to normal levels. Hyperglycemia has been reported as well and is possibly due to beta-2 receptor blockade in the beta cells of the pancreas. A selective beta-blocker may be preferred in patients with diabetes mellitus, if appropriate for the patient's condition. Selective beta-blockers, such as atenolol or metoprolol, do not appear to potentiate insulin-induced hypoglycemia. While beta-blockers may have negative effects on glycemic control, they reduce the risk of cardiovascular disease and stroke in patients with diabetes and their use should not be avoided in patients with compelling indications for beta-blocker therapy when no other contraindications are present.
    Levobunolol: (Moderate) Increased frequency of blood glucose monitoring may be required when a beta blocker is given with antidiabetic agents. Since beta blockers inhibit the release of catecholamines, these medications may hide symptoms of hypoglycemia such as tremor, tachycardia, and blood pressure changes. Other symptoms, like headache, dizziness, nervousness, mood changes, or hunger are not blunted. Beta-blockers also exert complex actions on the body's ability to regulate blood glucose. Some beta-blockers, particularly non-selective beta-blockers such as propranolol, have been noted to potentiate insulin-induced hypoglycemia and a delay in recovery of blood glucose to normal levels. Hyperglycemia has been reported as well and is possibly due to beta-2 receptor blockade in the beta cells of the pancreas. A selective beta-blocker may be preferred in patients with diabetes mellitus, if appropriate for the patient's condition. Selective beta-blockers, such as atenolol or metoprolol, do not appear to potentiate insulin-induced hypoglycemia. While beta-blockers may have negative effects on glycemic control, they reduce the risk of cardiovascular disease and stroke in patients with diabetes and their use should not be avoided in patients with compelling indications for beta-blocker therapy when no other contraindications are present.
    Levoketoconazole: (Moderate) Concomitant administration of metformin and ketoconazole may increase metformin exposure and increase the risk for lactic acidosis. During dosage titration, monitor blood sugar, kidney function, and Vitamin B12 as per the metformin prescribing information and adjust metformin dosage if needed. Metformin is a human organic cationic transporter-2 (OCT2) and multidrug and toxic extrusion 1 (MATE1) substrate. Ketoconazole is a an OCT2 and MATE1 inhibitor. OCT2 and MATE inhibitors may decrease metformin elimination by blocking renal tubular secretion.
    Levomefolate: (Minor) Levomefolate and metformin should be used together cautiously. Plasma concentrations of levomefolate may be reduced during treatment of type 2 diabetes with metformin. Monitor patients for decreased efficacy of levomefolate if these agents are used together.
    Levonorgestrel: (Minor) Patients receiving antidiabetic agents like metformin should be closely monitored for signs indicating changes in diabetic control when therapy with progestins is instituted or discontinued. Progestins can impair glucose tolerance.
    Levonorgestrel; Ethinyl Estradiol: (Minor) Monitor blood glucose periodically in patients on metformin for changes in glycemic control when hormone therapy is instituted or discontinued. Estrogens can decrease the hypoglycemic effects of antidiabetic agents by impairing glucose tolerance. Changes in glucose tolerance occur more commonly in patients receiving 50 mcg or more of ethinyl estradiol (or equivalent) per day in combined oral contraceptives (COCs), which are not commonly used in practice since the marketing of lower dose COCs, patches, injections and rings. The presence or absence of a concomitant progestin may influence the significance of any hormonal effect on glucose homeostasis. (Minor) Patients receiving antidiabetic agents like metformin should be closely monitored for signs indicating changes in diabetic control when therapy with progestins is instituted or discontinued. Progestins can impair glucose tolerance.
    Levonorgestrel; Ethinyl Estradiol; Ferrous Bisglycinate: (Minor) Monitor blood glucose periodically in patients on metformin for changes in glycemic control when hormone therapy is instituted or discontinued. Estrogens can decrease the hypoglycemic effects of antidiabetic agents by impairing glucose tolerance. Changes in glucose tolerance occur more commonly in patients receiving 50 mcg or more of ethinyl estradiol (or equivalent) per day in combined oral contraceptives (COCs), which are not commonly used in practice since the marketing of lower dose COCs, patches, injections and rings. The presence or absence of a concomitant progestin may influence the significance of any hormonal effect on glucose homeostasis. (Minor) Patients receiving antidiabetic agents like metformin should be closely monitored for signs indicating changes in diabetic control when therapy with progestins is instituted or discontinued. Progestins can impair glucose tolerance.
    Levothyroxine: (Minor) Thyroid hormone use may result in increased blood sugar and a loss of glycemic control in some patients. Interactions may or may not be clinically significant at usual replacement doses. Monitor blood sugars carefully when thyroid therapy is added, changed, or discontinued in patients receiving metformin.
    Levothyroxine; Liothyronine (Porcine): (Minor) Thyroid hormone use may result in increased blood sugar and a loss of glycemic control in some patients. Interactions may or may not be clinically significant at usual replacement doses. Monitor blood sugars carefully when thyroid therapy is added, changed, or discontinued in patients receiving metformin.
    Levothyroxine; Liothyronine (Synthetic): (Minor) Thyroid hormone use may result in increased blood sugar and a loss of glycemic control in some patients. Interactions may or may not be clinically significant at usual replacement doses. Monitor blood sugars carefully when thyroid therapy is added, changed, or discontinued in patients receiving metformin.
    Linezolid: (Moderate) Hypoglycemia, including symptomatic episodes, has been noted in post-marketing reports with linezolid in patients with diabetes mellitus receiving therapy with antidiabetic agents, such as insulin and oral hypoglycemic agents. Diabetic patients should be monitored for potential hypoglycemic reactions while on linezolid. If hypoglycemia occurs, discontinue or decrease the dose of the antidiabetic agent or discontinue the linezolid therapy. Linezolid is a reversible, nonselective MAO inhibitor and other MAO inhibitors have been associated with hypoglycemic episodes in diabetic patients receiving insulin or oral hypoglycemic agents.
    Liothyronine: (Minor) Thyroid hormone use may result in increased blood sugar and a loss of glycemic control in some patients. Interactions may or may not be clinically significant at usual replacement doses. Monitor blood sugars carefully when thyroid therapy is added, changed, or discontinued in patients receiving metformin.
    Lisdexamfetamine: (Moderate) Sympathomimetic agents and adrenergic agonists tend to increase blood glucose concentrations when administered systemically. Monitor for loss of glycemic control when pseudoephedrine, phenylephrine, and other sympathomimetics are administered to patients taking antidiabetic agents. Epinephrine and other sympathomimetics, through stimulation of alpha- and beta- receptors, increase hepatic glucose production and glycogenolysis and inhibit insulin secretion. Also, adrenergic medications may decrease glucose uptake by muscle cells. For treatment of cold symptoms, nasal decongestants may be preferable for short term, limited use (1 to 3 days) as an alternative to systemic decongestants in patients taking medications for diabetes.
    Lisinopril: (Moderate) Angiotensin-converting enzyme (ACE) inhibitors may enhance the hypoglycemic effects of insulin or other antidiabetic agents by improving insulin sensitivity. Patients receiving antidiabetic agents can become hypoglycemic if ACE inhibitors are administered concomitantly. ACE inhibitors may rarely reduce renal function, a risk factor for reduced renal clearance of metformin. Patients receiving these drugs together should be monitored for changes in renal function and glycemic control. (Moderate) Patients receiving these drugs concomitantly should be monitored for changes in blood pressure, volume status, renal function, serum potassium, and glycemic control. When an SGLT2 inhibitor is initiated, mild diuresis and naturesis occurs, producing intravascular volume contraction. These effects may be additive to certain antihypertensive medications, such as the angiotensin-converting enzyme inhibitors (ACE inhibitors). Patients with impaired renal function (eGFR less than 60 mL/minute/1.73 m2), low systolic blood pressure, or who are elderly may also be at a greater risk. Volume status should be assessed and corrected. In addition, some SGLT2 inhibitors, like canagliflozin, can increase serum potassium. Monitor serum potassium levels periodically and monitor for hyperkalemia. ACE inhibitors may also enhance the hypoglycemic effects of antidiabetic agents by improving insulin sensitivity.
    Lisinopril; Hydrochlorothiazide, HCTZ: (Moderate) Angiotensin-converting enzyme (ACE) inhibitors may enhance the hypoglycemic effects of insulin or other antidiabetic agents by improving insulin sensitivity. Patients receiving antidiabetic agents can become hypoglycemic if ACE inhibitors are administered concomitantly. ACE inhibitors may rarely reduce renal function, a risk factor for reduced renal clearance of metformin. Patients receiving these drugs together should be monitored for changes in renal function and glycemic control. (Moderate) Certain drugs, such as thiazide diuretics, tend to produce hyperglycemia and may lead to loss of glycemic control. The effects of thiazide diuretics on glycemic control appear to be dose-related and low doses can be instituted without deleterious effects on glycemic control. In addition, thiazide diuretics reduce the risk of stroke and cardiovascular disease in patients with diabetes. Patients receiving metformin should be monitored for changes in blood glucose control if any of these diuretics are added or deleted. Dosage adjustments may be necessary in some patients. (Moderate) Patients receiving these drugs concomitantly should be monitored for changes in blood pressure, volume status, renal function, serum potassium, and glycemic control. When an SGLT2 inhibitor is initiated, mild diuresis and naturesis occurs, producing intravascular volume contraction. These effects may be additive to certain antihypertensive medications, such as the angiotensin-converting enzyme inhibitors (ACE inhibitors). Patients with impaired renal function (eGFR less than 60 mL/minute/1.73 m2), low systolic blood pressure, or who are elderly may also be at a greater risk. Volume status should be assessed and corrected. In addition, some SGLT2 inhibitors, like canagliflozin, can increase serum potassium. Monitor serum potassium levels periodically and monitor for hyperkalemia. ACE inhibitors may also enhance the hypoglycemic effects of antidiabetic agents by improving insulin sensitivity.
    Lithium: (Moderate) Lithium may cause variable effects on glycemic control when used in patients receiving antidiabetic agents. Monitor blood glucose concentrations closely if lithium is coadministered with antidiabetic agents. Dosage adjustments of antidiabetic agents may be necessary.
    Lonapegsomatropin: (Moderate) Patients with diabetes mellitus should be monitored closely during somatropin (recombinant rhGH) therapy. Antidiabetic drugs (e.g., insulin or oral agents) may require adjustment when somatropin therapy is instituted in these patients. Growth hormones, such as somatropin, may decrease insulin sensitivity, leading to glucose intolerance and loss of blood glucose control. Therefore, glucose levels should be monitored periodically in all patients treated with somatropin, especially in those with risk factors for diabetes mellitus.
    Loratadine; Pseudoephedrine: (Moderate) Sympathomimetic agents and adrenergic agonists tend to increase blood glucose concentrations when administered systemically. Monitor for loss of glycemic control when pseudoephedrine, phenylephrine, and other sympathomimetics are administered to patients taking antidiabetic agents. Epinephrine and other sympathomimetics, through stimulation of alpha- and beta- receptors, increase hepatic glucose production and glycogenolysis and inhibit insulin secretion. Also, adrenergic medications may decrease glucose uptake by muscle cells. For treatment of cold symptoms, nasal decongestants may be preferable for short term, limited use (1 to 3 days) as an alternative to systemic decongestants in patients taking medications for diabetes.
    Lorcaserin: (Moderate) In general, weight reduction may increase the risk of hypoglycemia in patients with type 2 diabetes mellitus treated with antidiabetic agents, such as insulin and/or insulin secretagogues (e.g., sulfonylureas). In clinical trials, lorcaserin use was associated with reports of hypoglycemia. Blood glucose monitoring is warranted in patients with type 2 diabetes prior to starting and during lorcaserin treatment. Dosage adjustments of anti-diabetic medications should be considered. If a patient develops hypoglycemia during treatment, adjust anti-diabetic drug regimen accordingly. Of note, lorcaserin has not been studied in combination with insulin.
    Losartan: (Moderate) Angiotensin II receptor antagonists (ARBs) may enhance the hypoglycemic effects of metformin by improving insulin sensitivity. In addition, angiotensin II receptor antagonists have been associated with a reduced incidence in the development of new-onset diabetes in patients with hypertension or other cardiac disease. ARBs may rarely reduce renal function, a risk factor for reduced renal clearance of metformin. Patients receiving these drugs together should be monitored for changes in renal function and glycemic control. (Moderate) Patients receiving these drugs concomitantly should be monitored for changes in blood pressure, volume status, renal function, serum potassium and other electrolytes, and for glycemic control. When an SGLT2 inhibitor is initiated, mild diuresis and naturesis occurs, producing intravascular volume contraction. These effects may be additive to certain antihypertensive medications, such as the angiotensin II receptor antagonists (also known as angiotensin receptor blockers or ARBs). Patients with impaired renal function (eGFR less than 60 mL/minute/1.73 m2), low systolic blood pressure, or who are elderly may also be at a greater risk. Volume status should be assessed and corrected. In addition, some SGLT2 inhibitors, like canagliflozin, can increase serum potassium. Monitor serum potassium levels periodically and monitor for hyperkalemia. ARBs may also enhance the hypoglycemic effects of antidiabetic agents by improving insulin sensitivity.
    Losartan; Hydrochlorothiazide, HCTZ: (Moderate) Angiotensin II receptor antagonists (ARBs) may enhance the hypoglycemic effects of metformin by improving insulin sensitivity. In addition, angiotensin II receptor antagonists have been associated with a reduced incidence in the development of new-onset diabetes in patients with hypertension or other cardiac disease. ARBs may rarely reduce renal function, a risk factor for reduced renal clearance of metformin. Patients receiving these drugs together should be monitored for changes in renal function and glycemic control. (Moderate) Certain drugs, such as thiazide diuretics, tend to produce hyperglycemia and may lead to loss of glycemic control. The effects of thiazide diuretics on glycemic control appear to be dose-related and low doses can be instituted without deleterious effects on glycemic control. In addition, thiazide diuretics reduce the risk of stroke and cardiovascular disease in patients with diabetes. Patients receiving metformin should be monitored for changes in blood glucose control if any of these diuretics are added or deleted. Dosage adjustments may be necessary in some patients. (Moderate) Patients receiving these drugs concomitantly should be monitored for changes in blood pressure, volume status, renal function, serum potassium and other electrolytes, and for glycemic control. When an SGLT2 inhibitor is initiated, mild diuresis and naturesis occurs, producing intravascular volume contraction. These effects may be additive to certain antihypertensive medications, such as the angiotensin II receptor antagonists (also known as angiotensin receptor blockers or ARBs). Patients with impaired renal function (eGFR less than 60 mL/minute/1.73 m2), low systolic blood pressure, or who are elderly may also be at a greater risk. Volume status should be assessed and corrected. In addition, some SGLT2 inhibitors, like canagliflozin, can increase serum potassium. Monitor serum potassium levels periodically and monitor for hyperkalemia. ARBs may also enhance the hypoglycemic effects of antidiabetic agents by improving insulin sensitivity.
    Lovastatin; Niacin: (Moderate) Niacin (nicotinic acid) interferes with glucose metabolism and can result in hyperglycemia. Changes in glycemic control can usually be corrected through modification of hypoglycemic therapy. Monitor patients taking antidiabetic agents for changes in glycemic control if niacin (nicotinic acid) is added or deleted to the medication regimen. Dosage adjustments may be necessary. (Moderate) Niacin interferes with glucose metabolism and can result in hyperglycemia. Changes in glycemic control can usually be corrected through modification of hypoglycemic therapy. Monitor patients taking antidiabetic agents for changes in glycemic control if niacin is added or deleted to the medication regimen. Dosage adjustments may be necessary.
    Mecasermin rinfabate: (Moderate) Use caution in combining mecasermin, recombinant, rh-IGF-1 or mecasermin rinfabate (rh-IGF-1/rh-IGFBP-3) with antidiabetic agents. Patients should be advised to eat within 20 minutes of mecasermin administration. Glucose monitoring is important when initializing or adjusting mecasermin therapies, when adjusting concomitant antidiabetic therapy, and in the event of hypoglycemic symptoms. An increased risk for hypoglycemia is possible. The hypoglycemic effect induced by IGF-1 activity may be exacerbated. The amino acid sequence of mecasermin (rh-IGF-1) is approximately 50 percent homologous to insulin and cross binding with either receptor is possible. Treatment with mecasermin has been shown to improve insulin sensitivity and to improve glycemic control in patients with either Type 1 or Type 2 diabetes mellitus when used alone or in conjunction with insulins.
    Mecasermin, Recombinant, rh-IGF-1: (Moderate) Use caution in combining mecasermin, recombinant, rh-IGF-1 or mecasermin rinfabate (rh-IGF-1/rh-IGFBP-3) with antidiabetic agents. Patients should be advised to eat within 20 minutes of mecasermin administration. Glucose monitoring is important when initializing or adjusting mecasermin therapies, when adjusting concomitant antidiabetic therapy, and in the event of hypoglycemic symptoms. An increased risk for hypoglycemia is possible. The hypoglycemic effect induced by IGF-1 activity may be exacerbated. The amino acid sequence of mecasermin (rh-IGF-1) is approximately 50 percent homologous to insulin and cross binding with either receptor is possible. Treatment with mecasermin has been shown to improve insulin sensitivity and to improve glycemic control in patients with either Type 1 or Type 2 diabetes mellitus when used alone or in conjunction with insulins.
    Medroxyprogesterone: (Minor) Patients receiving antidiabetic agents like metformin should be closely monitored for signs indicating changes in diabetic control when therapy with progestins is instituted or discontinued. Progestins can impair glucose tolerance.
    Meglitinides: (Moderate) Use of metformin with a meglitinide ("glinide") may increase the risk of hypoglycemia. Meglitinides are insulin secretagogues and are known to cause hypoglycemia. To manage hypoglycemic risk, lower doses of the meglitinide may be needed. Monitor blood sugar.
    Memantine: (Moderate) Certain medications used concomitantly with metformin may increase the risk of lactic acidosis. Drugs that are eliminated by renal tubular secretion (e.g., memantine) may decrease metformin elimination by competing for common renal tubular transport systems. It should be noted that in a pharmacokinetic study in which memantine and glyburide; metformin (Glucovance) were coadministered, the pharmacokinetics of memantine, metformin, or glyburide were not altered. Regardless, careful patient monitoring is recommended.
    Mestranol; Norethindrone: (Minor) Monitor blood glucose periodically in patients on metformin for changes in glycemic control when hormone therapy is instituted or discontinued. Estrogens can decrease the hypoglycemic effects of antidiabetic agents by impairing glucose tolerance. Changes in glucose tolerance occur more commonly in patients receiving 50 mcg or more of ethinyl estradiol (or equivalent) per day in combined oral contraceptives (COCs), which are not commonly used in practice since the marketing of lower dose COCs, patches, injections and rings. The presence or absence of a concomitant progestin may influence the significance of any hormonal effect on glucose homeostasis. (Minor) Patients receiving antidiabetic agents like metformin should be closely monitored for signs indicating changes in diabetic control when therapy with progestins is instituted or discontinued. Progestins can impair glucose tolerance.
    Metformin; Repaglinide: (Moderate) Use of metformin with a meglitinide ("glinide") may increase the risk of hypoglycemia. Meglitinides are insulin secretagogues and are known to cause hypoglycemia. To manage hypoglycemic risk, lower doses of the meglitinide may be needed. Monitor blood sugar.
    Methamphetamine: (Moderate) Sympathomimetic agents and adrenergic agonists tend to increase blood glucose concentrations when administered systemically. Monitor for loss of glycemic control when pseudoephedrine, phenylephrine, and other sympathomimetics are administered to patients taking antidiabetic agents. Epinephrine and other sympathomimetics, through stimulation of alpha- and beta- receptors, increase hepatic glucose production and glycogenolysis and inhibit insulin secretion. Also, adrenergic medications may decrease glucose uptake by muscle cells. For treatment of cold symptoms, nasal decongestants may be preferable for short term, limited use (1 to 3 days) as an alternative to systemic decongestants in patients taking medications for diabetes.
    Methazolamide: (Moderate) Carbonic anhydrase inhibitors such as methazolamide frequently cause a decrease in serum bicarbonate and induce non-anion gap, hyperchloremic metabolic acidosis. Concomitant use of methazolamide with metformin may increase the risk for lactic acidosis; consider more frequent monitoring. Carbonic anhydrase inhibitors may also alter blood sugar; both hyperglycemia and hypoglycemia have been described. Monitor blood glucose and for changes in glycemic control and be alert for evidence of an interaction. (Minor) Carbonic anhydrase inhibitors may alter blood sugar. Both hyperglycemia and hypoglycemia have been described in patients treated with acetazolamide. This should be taken into consideration in patients with impaired glucose tolerance or diabetes mellitus who are receiving antidiabetic agents. Monitor blood glucose and for changes in glycemic control and be alert for evidence of an interaction.
    Methyclothiazide: (Moderate) Certain drugs, such as thiazide diuretics, tend to produce hyperglycemia and may lead to loss of glycemic control. The effects of thiazide diuretics on glycemic control appear to be dose-related and low doses can be instituted without deleterious effects on glycemic control. In addition, thiazide diuretics reduce the risk of stroke and cardiovascular disease in patients with diabetes. Patients receiving metformin should be monitored for changes in blood glucose control if any of these diuretics are added or deleted. Dosage adjustments may be necessary in some patients.
    Methyltestosterone: (Moderate) Changes in insulin sensitivity or glycemic control may occur in patients treated with androgens. In diabetic patients, the metabolic effects of androgens may decrease blood glucose and, therefore, may decrease antidiabetic agent dosage requirements. Monitor blood glucose and HbA1C when these drugs are used together.
    Metolazone: (Moderate) Certain drugs, such as thiazide diuretics, tend to produce hyperglycemia and may lead to loss of glycemic control. The effects of thiazide diuretics on glycemic control appear to be dose-related and low doses can be instituted without deleterious effects on glycemic control. In addition, thiazide diuretics reduce the risk of stroke and cardiovascular disease in patients with diabetes. Patients receiving metformin should be monitored for changes in blood glucose control if any of these diuretics are added or deleted. Dosage adjustments may be necessary in some patients.
    Metoprolol: (Moderate) Increased frequency of blood glucose monitoring may be required when a beta blocker is given with antidiabetic agents. Since beta blockers inhibit the release of catecholamines, these medications may hide symptoms of hypoglycemia such as tremor, tachycardia, and blood pressure changes. Other symptoms, like headache, dizziness, nervousness, mood changes, or hunger are not blunted. Beta-blockers also exert complex actions on the body's ability to regulate blood glucose. Some beta-blockers, particularly non-selective beta-blockers such as propranolol, have been noted to potentiate insulin-induced hypoglycemia and a delay in recovery of blood glucose to normal levels. Hyperglycemia has been reported as well and is possibly due to beta-2 receptor blockade in the beta cells of the pancreas. A selective beta-blocker may be preferred in patients with diabetes mellitus, if appropriate for the patient's condition. Selective beta-blockers, such as atenolol or metoprolol, do not appear to potentiate insulin-induced hypoglycemia. While beta-blockers may have negative effects on glycemic control, they reduce the risk of cardiovascular disease and stroke in patients with diabetes and their use should not be avoided in patients with compelling indications for beta-blocker therapy when no other contraindications are present.
    Metoprolol; Hydrochlorothiazide, HCTZ: (Moderate) Certain drugs, such as thiazide diuretics, tend to produce hyperglycemia and may lead to loss of glycemic control. The effects of thiazide diuretics on glycemic control appear to be dose-related and low doses can be instituted without deleterious effects on glycemic control. In addition, thiazide diuretics reduce the risk of stroke and cardiovascular disease in patients with diabetes. Patients receiving metformin should be monitored for changes in blood glucose control if any of these diuretics are added or deleted. Dosage adjustments may be necessary in some patients. (Moderate) Increased frequency of blood glucose monitoring may be required when a beta blocker is given with antidiabetic agents. Since beta blockers inhibit the release of catecholamines, these medications may hide symptoms of hypoglycemia such as tremor, tachycardia, and blood pressure changes. Other symptoms, like headache, dizziness, nervousness, mood changes, or hunger are not blunted. Beta-blockers also exert complex actions on the body's ability to regulate blood glucose. Some beta-blockers, particularly non-selective beta-blockers such as propranolol, have been noted to potentiate insulin-induced hypoglycemia and a delay in recovery of blood glucose to normal levels. Hyperglycemia has been reported as well and is possibly due to beta-2 receptor blockade in the beta cells of the pancreas. A selective beta-blocker may be preferred in patients with diabetes mellitus, if appropriate for the patient's condition. Selective beta-blockers, such as atenolol or metoprolol, do not appear to potentiate insulin-induced hypoglycemia. While beta-blockers may have negative effects on glycemic control, they reduce the risk of cardiovascular disease and stroke in patients with diabetes and their use should not be avoided in patients with compelling indications for beta-blocker therapy when no other contraindications are present.
    Metyrapone: (Moderate) In patients taking insulin or other antidiabetic agents, the signs and symptoms of acute metyrapone toxicity (e.g., symptoms of acute adrenal insufficiency) may be aggravated or modified.
    Midodrine: (Moderate) Certain medications used concomitantly with metformin may increase the risk of lactic acidosis. Cationic drugs that are eliminated by renal tubular secretion, like midodrine, may decrease metformin elimination by competing for common renal tubular transport systems. Careful patient monitoring and dose adjustment of metformin and/or midodrine is recommended.
    Moexipril: (Moderate) Angiotensin-converting enzyme (ACE) inhibitors may enhance the hypoglycemic effects of insulin or other antidiabetic agents by improving insulin sensitivity. Patients receiving antidiabetic agents can become hypoglycemic if ACE inhibitors are administered concomitantly. ACE inhibitors may rarely reduce renal function, a risk factor for reduced renal clearance of metformin. Patients receiving these drugs together should be monitored for changes in renal function and glycemic control. (Moderate) Patients receiving these drugs concomitantly should be monitored for changes in blood pressure, volume status, renal function, serum potassium, and glycemic control. When an SGLT2 inhibitor is initiated, mild diuresis and naturesis occurs, producing intravascular volume contraction. These effects may be additive to certain antihypertensive medications, such as the angiotensin-converting enzyme inhibitors (ACE inhibitors). Patients with impaired renal function (eGFR less than 60 mL/minute/1.73 m2), low systolic blood pressure, or who are elderly may also be at a greater risk. Volume status should be assessed and corrected. In addition, some SGLT2 inhibitors, like canagliflozin, can increase serum potassium. Monitor serum potassium levels periodically and monitor for hyperkalemia. ACE inhibitors may also enhance the hypoglycemic effects of antidiabetic agents by improving insulin sensitivity.
    Monoamine oxidase inhibitors: (Moderate) Serum glucose should be monitored closely when monoamine oxidase inhibitors (MAOIs) are added to any regimen containing antidiabetic agents, including ertugliflozin. Inhibitors of MAO type A have been shown to prolong the hypoglycemic response to insulin and other antidiabetic agents. (Moderate) Serum glucose should be monitored closely when monoamine oxidase inhibitors (MAOIs) are added to any regimen containing antidiabetic agents, including metformin. Inhibitors of MAO type A have been shown to prolong the hypoglycemic response to insulin and other antidiabetic agents.
    Nadolol: (Moderate) Increased frequency of blood glucose monitoring may be required when a beta blocker is given with antidiabetic agents. Since beta blockers inhibit the release of catecholamines, these medications may hide symptoms of hypoglycemia such as tremor, tachycardia, and blood pressure changes. Other symptoms, like headache, dizziness, nervousness, mood changes, or hunger are not blunted. Beta-blockers also exert complex actions on the body's ability to regulate blood glucose. Some beta-blockers, particularly non-selective beta-blockers such as propranolol, have been noted to potentiate insulin-induced hypoglycemia and a delay in recovery of blood glucose to normal levels. Hyperglycemia has been reported as well and is possibly due to beta-2 receptor blockade in the beta cells of the pancreas. A selective beta-blocker may be preferred in patients with diabetes mellitus, if appropriate for the patient's condition. Selective beta-blockers, such as atenolol or metoprolol, do not appear to potentiate insulin-induced hypoglycemia. While beta-blockers may have negative effects on glycemic control, they reduce the risk of cardiovascular disease and stroke in patients with diabetes and their use should not be avoided in patients with compelling indications for beta-blocker therapy when no other contraindications are present.
    Nandrolone Decanoate: (Moderate) Changes in insulin sensitivity or glycemic control may occur in patients treated with androgens. In diabetic patients, the metabolic effects of androgens may decrease blood glucose and, therefore, may decrease antidiabetic agent dosage requirements. Monitor blood glucose and HbA1C when these drugs are used together.
    Naproxen; Pseudoephedrine: (Moderate) Sympathomimetic agents and adrenergic agonists tend to increase blood glucose concentrations when administered systemically. Monitor for loss of glycemic control when pseudoephedrine, phenylephrine, and other sympathomimetics are administered to patients taking antidiabetic agents. Epinephrine and other sympathomimetics, through stimulation of alpha- and beta- receptors, increase hepatic glucose production and glycogenolysis and inhibit insulin secretion. Also, adrenergic medications may decrease glucose uptake by muscle cells. For treatment of cold symptoms, nasal decongestants may be preferable for short term, limited use (1 to 3 days) as an alternative to systemic decongestants in patients taking medications for diabetes.
    Nateglinide: (Moderate) Use of metformin with a meglitinide ("glinide") may increase the risk of hypoglycemia. Meglitinides are insulin secretagogues and are known to cause hypoglycemia. To manage hypoglycemic risk, lower doses of the meglitinide may be needed. Monitor blood sugar.
    Nebivolol: (Moderate) Increased frequency of blood glucose monitoring may be required when a beta blocker is given with antidiabetic agents. Since beta blockers inhibit the release of catecholamines, these medications may hide symptoms of hypoglycemia such as tremor, tachycardia, and blood pressure changes. Other symptoms, like headache, dizziness, nervousness, mood changes, or hunger are not blunted. Beta-blockers also exert complex actions on the body's ability to regulate blood glucose. Some beta-blockers, particularly non-selective beta-blockers such as propranolol, have been noted to potentiate insulin-induced hypoglycemia and a delay in recovery of blood glucose to normal levels. Hyperglycemia has been reported as well and is possibly due to beta-2 receptor blockade in the beta cells of the pancreas. A selective beta-blocker may be preferred in patients with diabetes mellitus, if appropriate for the patient's condition. Selective beta-blockers, such as atenolol or metoprolol, do not appear to potentiate insulin-induced hypoglycemia. While beta-blockers may have negative effects on glycemic control, they reduce the risk of cardiovascular disease and stroke in patients with diabetes and their use should not be avoided in patients with compelling indications for beta-blocker therapy when no other contraindications are present.
    Nebivolol; Valsartan: (Moderate) Angiotensin II receptor antagonists (ARBs) may enhance the hypoglycemic effects of metformin by improving insulin sensitivity. In addition, angiotensin II receptor antagonists have been associated with a reduced incidence in the development of new-onset diabetes in patients with hypertension or other cardiac disease. ARBs may rarely reduce renal function, a risk factor for reduced renal clearance of metformin. Patients receiving these drugs together should be monitored for changes in renal function and glycemic control. (Moderate) Increased frequency of blood glucose monitoring may be required when a beta blocker is given with antidiabetic agents. Since beta blockers inhibit the release of catecholamines, these medications may hide symptoms of hypoglycemia such as tremor, tachycardia, and blood pressure changes. Other symptoms, like headache, dizziness, nervousness, mood changes, or hunger are not blunted. Beta-blockers also exert complex actions on the body's ability to regulate blood glucose. Some beta-blockers, particularly non-selective beta-blockers such as propranolol, have been noted to potentiate insulin-induced hypoglycemia and a delay in recovery of blood glucose to normal levels. Hyperglycemia has been reported as well and is possibly due to beta-2 receptor blockade in the beta cells of the pancreas. A selective beta-blocker may be preferred in patients with diabetes mellitus, if appropriate for the patient's condition. Selective beta-blockers, such as atenolol or metoprolol, do not appear to potentiate insulin-induced hypoglycemia. While beta-blockers may have negative effects on glycemic control, they reduce the risk of cardiovascular disease and stroke in patients with diabetes and their use should not be avoided in patients with compelling indications for beta-blocker therapy when no other contraindications are present. (Moderate) Patients receiving these drugs concomitantly should be monitored for changes in blood pressure, volume status, renal function, serum potassium and other electrolytes, and for glycemic control. When an SGLT2 inhibitor is initiated, mild diuresis and naturesis occurs, producing intravascular volume contraction. These effects may be additive to certain antihypertensive medications, such as the angiotensin II receptor antagonists (also known as angiotensin receptor blockers or ARBs). Patients with impaired renal function (eGFR less than 60 mL/minute/1.73 m2), low systolic blood pressure, or who are elderly may also be at a greater risk. Volume status should be assessed and corrected. In addition, some SGLT2 inhibitors, like canagliflozin, can increase serum potassium. Monitor serum potassium levels periodically and monitor for hyperkalemia. ARBs may also enhance the hypoglycemic effects of antidiabetic agents by improving insulin sensitivity.
    Niacin, Niacinamide: (Moderate) Niacin (nicotinic acid) interferes with glucose metabolism and can result in hyperglycemia. Changes in glycemic control can usually be corrected through modification of hypoglycemic therapy. Monitor patients taking antidiabetic agents for changes in glycemic control if niacin (nicotinic acid) is added or deleted to the medication regimen. Dosage adjustments may be necessary. (Moderate) Niacin interferes with glucose metabolism and can result in hyperglycemia. Changes in glycemic control can usually be corrected through modification of hypoglycemic therapy. Monitor patients taking antidiabetic agents for changes in glycemic control if niacin is added or deleted to the medication regimen. Dosage adjustments may be necessary.
    Niacin; Simvastatin: (Moderate) Niacin (nicotinic acid) interferes with glucose metabolism and can result in hyperglycemia. Changes in glycemic control can usually be corrected through modification of hypoglycemic therapy. Monitor patients taking antidiabetic agents for changes in glycemic control if niacin (nicotinic acid) is added or deleted to the medication regimen. Dosage adjustments may be necessary. (Moderate) Niacin interferes with glucose metabolism and can result in hyperglycemia. Changes in glycemic control can usually be corrected through modification of hypoglycemic therapy. Monitor patients taking antidiabetic agents for changes in glycemic control if niacin is added or deleted to the medication regimen. Dosage adjustments may be necessary.
    Nicotine: (Minor) Blood glucose concentrations should be monitored more closely whenever a change in either nicotine intake or smoking status occurs; dosage adjustments of metformin may be needed. Nicotine may increase plasma glucose; tobacco smoking is known to aggravate insulin resistance. The cessation of nicotine therapy or tobacco smoking may result in a decrease in blood glucose.
    Nifedipine: (Minor) Nifedipine may increase the plasma metformin Cmax and AUC and increase the amount of metformin excreted in the urine. Metformin half-life is unaffected. Nifedipine appears to enhance the absorption of metformin.
    Non-Ionic Contrast Media: (Major) Discontinue metformin at the time of, or before, administration of non-ionic contrast media to patients with an eGFR of 30 to 60 mL/minute/1.73 m2, history of liver disease, alcoholism, or heart failure, or who will be administered intra-arterial iodinated contrast. Reevaluate eGFR 48 hours after the imaging procedure; restart metformin if renal function is stable. Iodinated contrast agents appear to increase the risk of metformin-induced lactic acidosis, possibly as a result of worsening renal function.
    Norethindrone Acetate; Ethinyl Estradiol; Ferrous fumarate: (Minor) Monitor blood glucose periodically in patients on metformin for changes in glycemic control when hormone therapy is instituted or discontinued. Estrogens can decrease the hypoglycemic effects of antidiabetic agents by impairing glucose tolerance. Changes in glucose tolerance occur more commonly in patients receiving 50 mcg or more of ethinyl estradiol (or equivalent) per day in combined oral contraceptives (COCs), which are not commonly used in practice since the marketing of lower dose COCs, patches, injections and rings. The presence or absence of a concomitant progestin may influence the significance of any hormonal effect on glucose homeostasis. (Minor) Patients receiving antidiabetic agents like metformin should be closely monitored for signs indicating changes in diabetic control when therapy with progestins is instituted or discontinued. Progestins can impair glucose tolerance.
    Norethindrone: (Minor) Patients receiving antidiabetic agents like metformin should be closely monitored for signs indicating changes in diabetic control when therapy with progestins is instituted or discontinued. Progestins can impair glucose tolerance.
    Norethindrone; Ethinyl Estradiol: (Minor) Monitor blood glucose periodically in patients on metformin for changes in glycemic control when hormone therapy is instituted or discontinued. Estrogens can decrease the hypoglycemic effects of antidiabetic agents by impairing glucose tolerance. Changes in glucose tolerance occur more commonly in patients receiving 50 mcg or more of ethinyl estradiol (or equivalent) per day in combined oral contraceptives (COCs), which are not commonly used in practice since the marketing of lower dose COCs, patches, injections and rings. The presence or absence of a concomitant progestin may influence the significance of any hormonal effect on glucose homeostasis. (Minor) Patients receiving antidiabetic agents like metformin should be closely monitored for signs indicating changes in diabetic control when therapy with progestins is instituted or discontinued. Progestins can impair glucose tolerance.
    Norethindrone; Ethinyl Estradiol; Ferrous fumarate: (Minor) Monitor blood glucose periodically in patients on metformin for changes in glycemic control when hormone therapy is instituted or discontinued. Estrogens can decrease the hypoglycemic effects of antidiabetic agents by impairing glucose tolerance. Changes in glucose tolerance occur more commonly in patients receiving 50 mcg or more of ethinyl estradiol (or equivalent) per day in combined oral contraceptives (COCs), which are not commonly used in practice since the marketing of lower dose COCs, patches, injections and rings. The presence or absence of a concomitant progestin may influence the significance of any hormonal effect on glucose homeostasis. (Minor) Patients receiving antidiabetic agents like metformin should be closely monitored for signs indicating changes in diabetic control when therapy with progestins is instituted or discontinued. Progestins can impair glucose tolerance.
    Norgestimate; Ethinyl Estradiol: (Minor) Monitor blood glucose periodically in patients on metformin for changes in glycemic control when hormone therapy is instituted or discontinued. Estrogens can decrease the hypoglycemic effects of antidiabetic agents by impairing glucose tolerance. Changes in glucose tolerance occur more commonly in patients receiving 50 mcg or more of ethinyl estradiol (or equivalent) per day in combined oral contraceptives (COCs), which are not commonly used in practice since the marketing of lower dose COCs, patches, injections and rings. The presence or absence of a concomitant progestin may influence the significance of any hormonal effect on glucose homeostasis. (Minor) Patients receiving antidiabetic agents like metformin should be closely monitored for signs indicating changes in diabetic control when therapy with progestins is instituted or discontinued. Progestins can impair glucose tolerance.
    Norgestrel: (Minor) Patients receiving antidiabetic agents like metformin should be closely monitored for signs indicating changes in diabetic control when therapy with progestins is instituted or discontinued. Progestins can impair glucose tolerance.
    Octreotide: (Moderate) Monitor patients receiving octreotide concomitantly with insulin or other antidiabetic agents for changes in glycemic control and adjust doses of these medications accordingly. Octreotide alters the balance between the counter-regulatory hormones of insulin, glucagon, and growth hormone, which may result in hypoglycemia or hyperglycemia. The hypoglycemia or hyperglycemia which occurs during octreotide acetate therapy is usually mild but may result in overt diabetes mellitus or necessitate dose changes in insulin or other hypoglycemic agents. In patients with concomitant type1 diabetes mellitus, octreotide is likely to affect glucose regulation, and insulin requirements may be reduced. Symptomatic hypoglycemia, which may be severe, has been reported in type 1 diabetic patients. In Type 2 diabetes patients with partially intact insulin reserves, octreotide administration may result in decreases in plasma insulin levels and hyperglycemia.
    Olanzapine; Fluoxetine: (Moderate) In patients with diabetes mellitus, fluoxetine may alter glycemic control. Hypoglycemia has occurred during fluoxetine therapy. Hyperglycemia has developed in patients with diabetes mellitus following discontinuation of the drug. The dosage of insulin and/or other antidiabetic agents may need to be adjusted when therapy with fluoxetine is instituted or discontinued.
    Olmesartan: (Moderate) Angiotensin II receptor antagonists (ARBs) may enhance the hypoglycemic effects of metformin by improving insulin sensitivity. In addition, angiotensin II receptor antagonists have been associated with a reduced incidence in the development of new-onset diabetes in patients with hypertension or other cardiac disease. ARBs may rarely reduce renal function, a risk factor for reduced renal clearance of metformin. Patients receiving these drugs together should be monitored for changes in renal function and glycemic control. (Moderate) Patients receiving these drugs concomitantly should be monitored for changes in blood pressure, volume status, renal function, serum potassium and other electrolytes, and for glycemic control. When an SGLT2 inhibitor is initiated, mild diuresis and naturesis occurs, producing intravascular volume contraction. These effects may be additive to certain antihypertensive medications, such as the angiotensin II receptor antagonists (also known as angiotensin receptor blockers or ARBs). Patients with impaired renal function (eGFR less than 60 mL/minute/1.73 m2), low systolic blood pressure, or who are elderly may also be at a greater risk. Volume status should be assessed and corrected. In addition, some SGLT2 inhibitors, like canagliflozin, can increase serum potassium. Monitor serum potassium levels periodically and monitor for hyperkalemia. ARBs may also enhance the hypoglycemic effects of antidiabetic agents by improving insulin sensitivity.
    Olmesartan; Amlodipine; Hydrochlorothiazide, HCTZ: (Moderate) Angiotensin II receptor antagonists (ARBs) may enhance the hypoglycemic effects of metformin by improving insulin sensitivity. In addition, angiotensin II receptor antagonists have been associated with a reduced incidence in the development of new-onset diabetes in patients with hypertension or other cardiac disease. ARBs may rarely reduce renal function, a risk factor for reduced renal clearance of metformin. Patients receiving these drugs together should be monitored for changes in renal function and glycemic control. (Moderate) Certain drugs, such as thiazide diuretics, tend to produce hyperglycemia and may lead to loss of glycemic control. The effects of thiazide diuretics on glycemic control appear to be dose-related and low doses can be instituted without deleterious effects on glycemic control. In addition, thiazide diuretics reduce the risk of stroke and cardiovascular disease in patients with diabetes. Patients receiving metformin should be monitored for changes in blood glucose control if any of these diuretics are added or deleted. Dosage adjustments may be necessary in some patients. (Moderate) Patients receiving these drugs concomitantly should be monitored for changes in blood pressure, volume status, renal function, serum potassium and other electrolytes, and for glycemic control. When an SGLT2 inhibitor is initiated, mild diuresis and naturesis occurs, producing intravascular volume contraction. These effects may be additive to certain antihypertensive medications, such as the angiotensin II receptor antagonists (also known as angiotensin receptor blockers or ARBs). Patients with impaired renal function (eGFR less than 60 mL/minute/1.73 m2), low systolic blood pressure, or who are elderly may also be at a greater risk. Volume status should be assessed and corrected. In addition, some SGLT2 inhibitors, like canagliflozin, can increase serum potassium. Monitor serum potassium levels periodically and monitor for hyperkalemia. ARBs may also enhance the hypoglycemic effects of antidiabetic agents by improving insulin sensitivity.
    Olmesartan; Hydrochlorothiazide, HCTZ: (Moderate) Angiotensin II receptor antagonists (ARBs) may enhance the hypoglycemic effects of metformin by improving insulin sensitivity. In addition, angiotensin II receptor antagonists have been associated with a reduced incidence in the development of new-onset diabetes in patients with hypertension or other cardiac disease. ARBs may rarely reduce renal function, a risk factor for reduced renal clearance of metformin. Patients receiving these drugs together should be monitored for changes in renal function and glycemic control. (Moderate) Certain drugs, such as thiazide diuretics, tend to produce hyperglycemia and may lead to loss of glycemic control. The effects of thiazide diuretics on glycemic control appear to be dose-related and low doses can be instituted without deleterious effects on glycemic control. In addition, thiazide diuretics reduce the risk of stroke and cardiovascular disease in patients with diabetes. Patients receiving metformin should be monitored for changes in blood glucose control if any of these diuretics are added or deleted. Dosage adjustments may be necessary in some patients. (Moderate) Patients receiving these drugs concomitantly should be monitored for changes in blood pressure, volume status, renal function, serum potassium and other electrolytes, and for glycemic control. When an SGLT2 inhibitor is initiated, mild diuresis and naturesis occurs, producing intravascular volume contraction. These effects may be additive to certain antihypertensive medications, such as the angiotensin II receptor antagonists (also known as angiotensin receptor blockers or ARBs). Patients with impaired renal function (eGFR less than 60 mL/minute/1.73 m2), low systolic blood pressure, or who are elderly may also be at a greater risk. Volume status should be assessed and corrected. In addition, some SGLT2 inhibitors, like canagliflozin, can increase serum potassium. Monitor serum potassium levels periodically and monitor for hyperkalemia. ARBs may also enhance the hypoglycemic effects of antidiabetic agents by improving insulin sensitivity.
    Ombitasvir; Paritaprevir; Ritonavir: (Major) While no dosage adjustment of metformin is recommended in patients with normal hepatic or renal function, careful patient monitoring and dose adjustment of metformin and/or the potentially interfering drug is recommended with concurrent use. Monitor for signs of onset of lactic acidosis such as respiratory distress, somnolence, and non-specific abdominal distress or worsening renal function. Do not use metformin with paritaprevir in patients with renal insufficiency or hepatic impairment. Drugs that interfere with common renal tubular transport systems involved in the renal elimination of metformin could increase systemic exposure to metformin and may increase the risk for lactic acidosis. Paritaprevir is an inhibitor of the organic anion transporters OATP1B1 and OATP1B3. While initial drug-drug interaction studies of paritaprevir-containing hepatitis treatments have not noted an effect on metformin concentrations, more study is needed.
    Orlistat: (Minor) Weight-loss may affect glycemic control in patients with diabetes mellitus. In many patients, glycemic control may improve. A reduction in dose of oral hypoglycemic medications may be required in some patients taking orlistat. Monitor blood glucose and glycemic control and adjust therapy as clinically indicated.
    Oxandrolone: (Moderate) Changes in insulin sensitivity or glycemic control may occur in patients treated with androgens. In diabetic patients, the metabolic effects of androgens may decrease blood glucose and, therefore, may decrease antidiabetic agent dosage requirements. Monitor blood glucose and HbA1C when these drugs are used together.
    Oxymetholone: (Moderate) Changes in insulin sensitivity or glycemic control may occur in patients treated with androgens. In diabetic patients, the metabolic effects of androgens may decrease blood glucose and, therefore, may decrease antidiabetic agent dosage requirements. Monitor blood glucose and HbA1C when these drugs are used together.
    Pasireotide: (Moderate) Monitor blood glucose levels regularly in patients with diabetes, especially when pasireotide treatment is initiated or when the dose is altered. Adjust treatment with antidiabetic agents as clinically indicated. Pasireotide inhibits the secretion of insulin and glucagon. Patients treated with pasireotide may experience either hypoglycemia or hyperglycemia.
    Pegvisomant: (Moderate) Monitor blood glucose levels regularly in patients with diabetes, especially when pegvisomant treatment is initiated or when the dose is altered. Adjust treatment with antidiabetic agents as clinically indicated. Pegvisomant increases sensitivity to insulin by lowering the activity of growth hormone, and in some patients glucose tolerance improves with treatment. Patients with diabetes treated with pegvisomant and antidiabetic agents may be more likely to experience hypoglycemia.
    Penbutolol: (Moderate) Increased frequency of blood glucose monitoring may be required when a beta blocker is given with antidiabetic agents. Since beta blockers inhibit the release of catecholamines, these medications may hide symptoms of hypoglycemia such as tremor, tachycardia, and blood pressure changes. Other symptoms, like headache, dizziness, nervousness, mood changes, or hunger are not blunted. Beta-blockers also exert complex actions on the body's ability to regulate blood glucose. Some beta-blockers, particularly non-selective beta-blockers such as propranolol, have been noted to potentiate insulin-induced hypoglycemia and a delay in recovery of blood glucose to normal levels. Hyperglycemia has been reported as well and is possibly due to beta-2 receptor blockade in the beta cells of the pancreas. A selective beta-blocker may be preferred in patients with diabetes mellitus, if appropriate for the patient's condition. Selective beta-blockers, such as atenolol or metoprolol, do not appear to potentiate insulin-induced hypoglycemia. While beta-blockers may have negative effects on glycemic control, they reduce the risk of cardiovascular disease and stroke in patients with diabetes and their use should not be avoided in patients with compelling indications for beta-blocker therapy when no other contraindications are present.
    Pentamidine: (Moderate) Pentamidine can be harmful to pancreatic cells. This effect may lead to hypoglycemia acutely, followed by hyperglycemia with prolonged pentamidine therapy. Patients on antidiabetic agents should be monitored for the need for dosage adjustments during the use of pentamidine.
    Pentoxifylline: (Moderate) Pentoxiphylline has been used concurrently with antidiabetic agents without observed problems, but it may enhance the hypoglycemic action of antidiabetic agents. Patients should be monitored for changes in glycemic control while receiving pentoxifylline in combination with antidiabetic agents.
    Perindopril: (Moderate) Angiotensin-converting enzyme (ACE) inhibitors may enhance the hypoglycemic effects of insulin or other antidiabetic agents by improving insulin sensitivity. Patients receiving antidiabetic agents can become hypoglycemic if ACE inhibitors are administered concomitantly. ACE inhibitors may rarely reduce renal function, a risk factor for reduced renal clearance of metformin. Patients receiving these drugs together should be monitored for changes in renal function and glycemic control. (Moderate) Patients receiving these drugs concomitantly should be monitored for changes in blood pressure, volume status, renal function, serum potassium, and glycemic control. When an SGLT2 inhibitor is initiated, mild diuresis and naturesis occurs, producing intravascular volume contraction. These effects may be additive to certain antihypertensive medications, such as the angiotensin-converting enzyme inhibitors (ACE inhibitors). Patients with impaired renal function (eGFR less than 60 mL/minute/1.73 m2), low systolic blood pressure, or who are elderly may also be at a greater risk. Volume status should be assessed and corrected. In addition, some SGLT2 inhibitors, like canagliflozin, can increase serum potassium. Monitor serum potassium levels periodically and monitor for hyperkalemia. ACE inhibitors may also enhance the hypoglycemic effects of antidiabetic agents by improving insulin sensitivity.
    Perindopril; Amlodipine: (Moderate) Angiotensin-converting enzyme (ACE) inhibitors may enhance the hypoglycemic effects of insulin or other antidiabetic agents by improving insulin sensitivity. Patients receiving antidiabetic agents can become hypoglycemic if ACE inhibitors are administered concomitantly. ACE inhibitors may rarely reduce renal function, a risk factor for reduced renal clearance of metformin. Patients receiving these drugs together should be monitored for changes in renal function and glycemic control. (Moderate) Patients receiving these drugs concomitantly should be monitored for changes in blood pressure, volume status, renal function, serum potassium, and glycemic control. When an SGLT2 inhibitor is initiated, mild diuresis and naturesis occurs, producing intravascular volume contraction. These effects may be additive to certain antihypertensive medications, such as the angiotensin-converting enzyme inhibitors (ACE inhibitors). Patients with impaired renal function (eGFR less than 60 mL/minute/1.73 m2), low systolic blood pressure, or who are elderly may also be at a greater risk. Volume status should be assessed and corrected. In addition, some SGLT2 inhibitors, like canagliflozin, can increase serum potassium. Monitor serum potassium levels periodically and monitor for hyperkalemia. ACE inhibitors may also enhance the hypoglycemic effects of antidiabetic agents by improving insulin sensitivity.
    Phenelzine: (Moderate) Serum glucose should be monitored closely when monoamine oxidase inhibitors (MAOIs) are added to any regimen containing antidiabetic agents, including ertugliflozin. Inhibitors of MAO type A have been shown to prolong the hypoglycemic response to insulin and other antidiabetic agents.
    Phenothiazines: (Minor) Phenothiazines, especially chlorpromazine, may increase blood glucose concentrations. Hyperglycemia and glycosuria have been reported. Patients who are taking antidiabetic agents should be closely monitored for worsening glycemic control when any of these antipsychotics is instituted. (Minor) Phenothiazines, especially chlorpromazine, may increase blood glucose concentrations. Hyperglycemia and glycosuria have been reported. When such drugs are administered to a patient receiving metformin, observe the patient closely for loss of blood glucose control. When such drugs are withdrawn from a patient receiving metformin, observe the patient closely for hypoglycemia.
    Phentermine; Topiramate: (Major) Extended-release topiramate is contraindicated in patients with metabolic acidosis who are taking concomitant metformin because topiramate can frequently cause metabolic acidosis, a condition for which metformin use is contraindicated. Consider more frequent monitoring of patients taking immediate-release topiramate with metformin. In healthy volunteers, metformin Cmax and AUC increased by 17% and 25%, respectively, when topiramate was added, and oral plasma clearance of topiramate appears to be reduced when administered with metformin. However, the clinical significance of these pharmacokinetic effects is unclear.
    Phenylephrine: (Moderate) Sympathomimetic agents and adrenergic agonists tend to increase blood glucose concentrations when administered systemically. Monitor for loss of glycemic control when pseudoephedrine, phenylephrine, and other sympathomimetics are administered to patients taking antidiabetic agents. Epinephrine and other sympathomimetics, through stimulation of alpha- and beta- receptors, increase hepatic glucose production and glycogenolysis and inhibit insulin secretion. Also, adrenergic medications may decrease glucose uptake by muscle cells. For treatment of cold symptoms, nasal decongestants may be preferable for short term, limited use (1 to 3 days) as an alternative to systemic decongestants in patients taking medications for diabetes.
    Phenytoin: (Minor) Phenytoin and other hydantoins have the potential to increase blood glucose and thus interact with antidiabetic agents pharmacodynamically. Monitor blood glucose for changes in glycemic control. Dosage adjustments may be necessary in some patients.
    Pindolol: (Moderate) Increased frequency of blood glucose monitoring may be required when a beta blocker is given with antidiabetic agents. Since beta blockers inhibit the release of catecholamines, these medications may hide symptoms of hypoglycemia such as tremor, tachycardia, and blood pressure changes. Other symptoms, like headache, dizziness, nervousness, mood changes, or hunger are not blunted. Beta-blockers also exert complex actions on the body's ability to regulate blood glucose. Some beta-blockers, particularly non-selective beta-blockers such as propranolol, have been noted to potentiate insulin-induced hypoglycemia and a delay in recovery of blood glucose to normal levels. Hyperglycemia has been reported as well and is possibly due to beta-2 receptor blockade in the beta cells of the pancreas. A selective beta-blocker may be preferred in patients with diabetes mellitus, if appropriate for the patient's condition. Selective beta-blockers, such as atenolol or metoprolol, do not appear to potentiate insulin-induced hypoglycemia. While beta-blockers may have negative effects on glycemic control, they reduce the risk of cardiovascular disease and stroke in patients with diabetes and their use should not be avoided in patients with compelling indications for beta-blocker therapy when no other contraindications are present.
    Pioglitazone; Glimepiride: (Moderate) Use of metformin with a sulfonylurea may increase the risk of hypoglycemia. Sulfonylureas are known to cause hypoglycemia. To manage hypoglycemic risk, lower doses of the sulfonylurea may be needed. Monitor blood sugar.
    Prasterone, Dehydroepiandrosterone, DHEA (Dietary Supplements): (Moderate) Changes in insulin sensitivity or glycemic control may occur in patients treated with androgens. In diabetic patients, the metabolic effects of androgens may decrease blood glucose and, therefore, may decrease antidiabetic agent dosage requirements. Monitor blood glucose and HbA1C when these drugs are used together.
    Prasterone, Dehydroepiandrosterone, DHEA (FDA-approved): (Moderate) Changes in insulin sensitivity or glycemic control may occur in patients treated with androgens. In diabetic patients, the metabolic effects of androgens may decrease blood glucose and, therefore, may decrease antidiabetic agent dosage requirements. Monitor blood glucose and HbA1C when these drugs are used together.
    Progesterone: (Minor) Patients receiving antidiabetic agents like metformin should be closely monitored for signs indicating changes in diabetic control when therapy with progestins is instituted or discontinued. Progestins can impair glucose tolerance.
    Progestins: (Minor) Patients receiving antidiabetic agents like metformin should be closely monitored for signs indicating changes in diabetic control when therapy with progestins is instituted or discontinued. Progestins can impair glucose tolerance. (Minor) Progestins can impair glucose tolerance. Patients receiving antidiabetic agents should be closely monitored for signs indicating changes in diabetic control when therapy with progestins is instituted or discontinued.
    Promethazine; Phenylephrine: (Moderate) Sympathomimetic agents and adrenergic agonists tend to increase blood glucose concentrations when administered systemically. Monitor for loss of glycemic control when pseudoephedrine, phenylephrine, and other sympathomimetics are administered to patients taking antidiabetic agents. Epinephrine and other sympathomimetics, through stimulation of alpha- and beta- receptors, increase hepatic glucose production and glycogenolysis and inhibit insulin secretion. Also, adrenergic medications may decrease glucose uptake by muscle cells. For treatment of cold symptoms, nasal decongestants may be preferable for short term, limited use (1 to 3 days) as an alternative to systemic decongestants in patients taking medications for diabetes.
    Propantheline: (Moderate) Propantheline slows GI motility, which may increase the absorption of metformin from the small intestine. A 19% increase in metformin AUC has been reported in studies of this interaction in healthy volunteers. However, no serious side effects resulted.
    Propoxyphene: (Moderate) Propoxyphene may enhance the hypoglycemic action of antidiabetic agents. Patients should be closely monitored for changes in glycemic control while receiving propoxyphene in combination with antidiabetic agents.
    Propranolol: (Moderate) Increased frequency of blood glucose monitoring may be required when a beta blocker is given with antidiabetic agents. Since beta blockers inhibit the release of catecholamines, these medications may hide symptoms of hypoglycemia such as tremor, tachycardia, and blood pressure changes. Other symptoms, like headache, dizziness, nervousness, mood changes, or hunger are not blunted. Beta-blockers also exert complex actions on the body's ability to regulate blood glucose. Some beta-blockers, particularly non-selective beta-blockers such as propranolol, have been noted to potentiate insulin-induced hypoglycemia and a delay in recovery of blood glucose to normal levels. Hyperglycemia has been reported as well and is possibly due to beta-2 receptor blockade in the beta cells of the pancreas. A selective beta-blocker may be preferred in patients with diabetes mellitus, if appropriate for the patient's condition. Selective beta-blockers, such as atenolol or metoprolol, do not appear to potentiate insulin-induced hypoglycemia. While beta-blockers may have negative effects on glycemic control, they reduce the risk of cardiovascular disease and stroke in patients with diabetes and their use should not be avoided in patients with compelling indications for beta-blocker therapy when no other contraindications are present.
    Propranolol; Hydrochlorothiazide, HCTZ: (Moderate) Certain drugs, such as thiazide diuretics, tend to produce hyperglycemia and may lead to loss of glycemic control. The effects of thiazide diuretics on glycemic control appear to be dose-related and low doses can be instituted without deleterious effects on glycemic control. In addition, thiazide diuretics reduce the risk of stroke and cardiovascular disease in patients with diabetes. Patients receiving metformin should be monitored for changes in blood glucose control if any of these diuretics are added or deleted. Dosage adjustments may be necessary in some patients. (Moderate) Increased frequency of blood glucose monitoring may be required when a beta blocker is given with antidiabetic agents. Since beta blockers inhibit the release of catecholamines, these medications may hide symptoms of hypoglycemia such as tremor, tachycardia, and blood pressure changes. Other symptoms, like headache, dizziness, nervousness, mood changes, or hunger are not blunted. Beta-blockers also exert complex actions on the body's ability to regulate blood glucose. Some beta-blockers, particularly non-selective beta-blockers such as propranolol, have been noted to potentiate insulin-induced hypoglycemia and a delay in recovery of blood glucose to normal levels. Hyperglycemia has been reported as well and is possibly due to beta-2 receptor blockade in the beta cells of the pancreas. A selective beta-blocker may be preferred in patients with diabetes mellitus, if appropriate for the patient's condition. Selective beta-blockers, such as atenolol or metoprolol, do not appear to potentiate insulin-induced hypoglycemia. While beta-blockers may have negative effects on glycemic control, they reduce the risk of cardiovascular disease and stroke in patients with diabetes and their use should not be avoided in patients with compelling indications for beta-blocker therapy when no other contraindications are present.
    Protease inhibitors: (Moderate) New onset diabetes mellitus, exacerbation of diabetes mellitus, and hyperglycemia due to insulin resistance have been reported with use of anti-retroviral protease inhibitors. Another possible mechanism is impairment of beta-cell function. Onset averaged approximately 63 days after initiating protease inhibitor therapy, but has occurred as early as 4 days after beginning therapy. Diabetic ketoacidosis has occurred in some patients including patients who were not diabetic prior to protease inhibitor treatment. Patients taking antidiabetic therapy should be closely monitored for changes in glycemic control, specifically hyperglycemia, if protease inhibitor therapy is initiated.
    Pseudoephedrine: (Moderate) Sympathomimetic agents and adrenergic agonists tend to increase blood glucose concentrations when administered systemically. Monitor for loss of glycemic control when pseudoephedrine, phenylephrine, and other sympathomimetics are administered to patients taking antidiabetic agents. Epinephrine and other sympathomimetics, through stimulation of alpha- and beta- receptors, increase hepatic glucose production and glycogenolysis and inhibit insulin secretion. Also, adrenergic medications may decrease glucose uptake by muscle cells. For treatment of cold symptoms, nasal decongestants may be preferable for short term, limited use (1 to 3 days) as an alternative to systemic decongestants in patients taking medications for diabetes.
    Pseudoephedrine; Triprolidine: (Moderate) Sympathomimetic agents and adrenergic agonists tend to increase blood glucose concentrations when administered systemically. Monitor for loss of glycemic control when pseudoephedrine, phenylephrine, and other sympathomimetics are administered to patients taking antidiabetic agents. Epinephrine and other sympathomimetics, through stimulation of alpha- and beta- receptors, increase hepatic glucose production and glycogenolysis and inhibit insulin secretion. Also, adrenergic medications may decrease glucose uptake by muscle cells. For treatment of cold symptoms, nasal decongestants may be preferable for short term, limited use (1 to 3 days) as an alternative to systemic decongestants in patients taking medications for diabetes.
    Pyrimethamine; Sulfadoxine: (Moderate) Sulfonamides may enhance the hypoglycemic action of antidiabetic agents; patients with diabetes mellitus should be closely monitored during sulfonamide treatment. Sulfonamides may induce hypoglycemia in some patients by increasing the secretion of insulin from the pancreas. Patients at risk include those with compromised renal function, those fasting for prolonged periods, those that are malnourished, and those receiving high or excessive doses of sulfonamides.
    Quinapril: (Moderate) Angiotensin-converting enzyme (ACE) inhibitors may enhance the hypoglycemic effects of insulin or other antidiabetic agents by improving insulin sensitivity. Patients receiving antidiabetic agents can become hypoglycemic if ACE inhibitors are administered concomitantly. ACE inhibitors may rarely reduce renal function, a risk factor for reduced renal clearance of metformin. Patients receiving these drugs together should be monitored for changes in renal function and glycemic control. (Moderate) Patients receiving these drugs concomitantly should be monitored for changes in blood pressure, volume status, renal function, serum potassium, and glycemic control. When an SGLT2 inhibitor is initiated, mild diuresis and naturesis occurs, producing intravascular volume contraction. These effects may be additive to certain antihypertensive medications, such as the angiotensin-converting enzyme inhibitors (ACE inhibitors). Patients with impaired renal function (eGFR less than 60 mL/minute/1.73 m2), low systolic blood pressure, or who are elderly may also be at a greater risk. Volume status should be assessed and corrected. In addition, some SGLT2 inhibitors, like canagliflozin, can increase serum potassium. Monitor serum potassium levels periodically and monitor for hyperkalemia. ACE inhibitors may also enhance the hypoglycemic effects of antidiabetic agents by improving insulin sensitivity.
    Quinapril; Hydrochlorothiazide, HCTZ: (Moderate) Angiotensin-converting enzyme (ACE) inhibitors may enhance the hypoglycemic effects of insulin or other antidiabetic agents by improving insulin sensitivity. Patients receiving antidiabetic agents can become hypoglycemic if ACE inhibitors are administered concomitantly. ACE inhibitors may rarely reduce renal function, a risk factor for reduced renal clearance of metformin. Patients receiving these drugs together should be monitored for changes in renal function and glycemic control. (Moderate) Certain drugs, such as thiazide diuretics, tend to produce hyperglycemia and may lead to loss of glycemic control. The effects of thiazide diuretics on glycemic control appear to be dose-related and low doses can be instituted without deleterious effects on glycemic control. In addition, thiazide diuretics reduce the risk of stroke and cardiovascular disease in patients with diabetes. Patients receiving metformin should be monitored for changes in blood glucose control if any of these diuretics are added or deleted. Dosage adjustments may be necessary in some patients. (Moderate) Patients receiving these drugs concomitantly should be monitored for changes in blood pressure, volume status, renal function, serum potassium, and glycemic control. When an SGLT2 inhibitor is initiated, mild diuresis and naturesis occurs, producing intravascular volume contraction. These effects may be additive to certain antihypertensive medications, such as the angiotensin-converting enzyme inhibitors (ACE inhibitors). Patients with impaired renal function (eGFR less than 60 mL/minute/1.73 m2), low systolic blood pressure, or who are elderly may also be at a greater risk. Volume status should be assessed and corrected. In addition, some SGLT2 inhibitors, like canagliflozin, can increase serum potassium. Monitor serum potassium levels periodically and monitor for hyperkalemia. ACE inhibitors may also enhance the hypoglycemic effects of antidiabetic agents by improving insulin sensitivity.
    Quinolones: (Moderate) Monitor blood glucose carefully when systemic quinolones and antidiabetic agents, including metformin, are coadministered. Discontinue the quinolone if a hypoglycemic reaction occurs and initiate appropriate therapy immediately. Disturbances of blood glucose, including hyperglycemia and hypoglycemia, have been reported in patients treated concomitantly with quinolones and an antidiabetic agent. Hypoglycemia, sometimes resulting in coma, can occur. (Moderate) Monitor blood glucose carefully when systemic quinolones and antidiabetic agents, including SGLT2 inhibitors, are coadministered. Discontinue the quinolone if a hypoglycemic reaction occurs and initiate appropriate therapy immediately. Disturbances of blood glucose, including hyperglycemia and hypoglycemia, have been reported in patients treated concomitantly with quinolones and an antidiabetic agent. Hypoglycemia, sometimes resulting in coma, can occur.
    Ramipril: (Moderate) Angiotensin-converting enzyme (ACE) inhibitors may enhance the hypoglycemic effects of insulin or other antidiabetic agents by improving insulin sensitivity. Patients receiving antidiabetic agents can become hypoglycemic if ACE inhibitors are administered concomitantly. ACE inhibitors may rarely reduce renal function, a risk factor for reduced renal clearance of metformin. Patients receiving these drugs together should be monitored for changes in renal function and glycemic control. (Moderate) Patients receiving these drugs concomitantly should be monitored for changes in blood pressure, volume status, renal function, serum potassium, and glycemic control. When an SGLT2 inhibitor is initiated, mild diuresis and naturesis occurs, producing intravascular volume contraction. These effects may be additive to certain antihypertensive medications, such as the angiotensin-converting enzyme inhibitors (ACE inhibitors). Patients with impaired renal function (eGFR less than 60 mL/minute/1.73 m2), low systolic blood pressure, or who are elderly may also be at a greater risk. Volume status should be assessed and corrected. In addition, some SGLT2 inhibitors, like canagliflozin, can increase serum potassium. Monitor serum potassium levels periodically and monitor for hyperkalemia. ACE inhibitors may also enhance the hypoglycemic effects of antidiabetic agents by improving insulin sensitivity.
    Ranolazine: (Major) Limit the dose of metformin to 1,700 mg/day in adults if coadministered with ranolazine 1,000 mg twice daily. Coadministration of metformin with ranolazine 1,000 mg twice daily results in increased exposure to metformin. There is potential for an increased risk for lactic acidosis, which is associated with high metformin concentrations. Doses of metformin do not require reduction if coadministered with ranolazine 500 mg twice daily, as metformin exposure was not significantly increased with this lower dose of ranolazine. Ranolazine inhibits common renal tubular transport systems involved in the renal elimination of metformin (e.g., organic cationic transporter-2 [OCT2]/multidrug and toxin extrusion [MATE1 and MATE2k]). Consider the benefits and risks of concomitant use of ranolazine with metformin. Monitor blood sugar and for gastrointestinal side effects, and increase monitoring for a risk for lactic acidosis, including renal function and electrolytes/acid-base balance.
    Regular Insulin: (Moderate) Coadministration of metformin with an insulin may increase the risk of hypoglycemia. Insulins are known to cause hypoglycemia. To manage hypoglycemic risk, lower doses of insulin may be needed. Monitor blood sugar and adjust insulin dosage as clinically indicated.
    Regular Insulin; Isophane Insulin (NPH): (Moderate) Coadministration of metformin with an insulin may increase the risk of hypoglycemia. Insulins are known to cause hypoglycemia. To manage hypoglycemic risk, lower doses of insulin may be needed. Monitor blood sugar and adjust insulin dosage as clinically indicated.
    Relugolix; Estradiol; Norethindrone acetate: (Minor) Monitor blood glucose periodically in patients on metformin for changes in glycemic control when hormone therapy is instituted or discontinued. Estrogens can decrease the hypoglycemic effects of antidiabetic agents by impairing glucose tolerance. Changes in glucose tolerance occur more commonly in patients receiving 50 mcg or more of ethinyl estradiol (or equivalent) per day in combined oral contraceptives (COCs), which are not commonly used in practice since the marketing of lower dose COCs, patches, injections and rings. The presence or absence of a concomitant progestin may influence the significance of any hormonal effect on glucose homeostasis. (Minor) Patients receiving antidiabetic agents like metformin should be closely monitored for signs indicating changes in diabetic control when therapy with progestins is instituted or discontinued. Progestins can impair glucose tolerance.
    Repaglinide: (Moderate) Use of metformin with a meglitinide ("glinide") may increase the risk of hypoglycemia. Meglitinides are insulin secretagogues and are known to cause hypoglycemia. To manage hypoglycemic risk, lower doses of the meglitinide may be needed. Monitor blood sugar.
    Reserpine: (Moderate) Reserpine may mask the signs and symptoms of hypoglycemia. Patients receiving these drugs concomitantly should be monitored for changes in glycemic control.
    Risdiplam: (Moderate) Concomitant administration of metformin and risdiplam may increase metformin exposure and increase the risk for lactic acidosis. If these drugs are given together, monitor for signs of metformin toxicity; metformin dose adjustments may be needed. Metformin is a human multidrug and toxic extrusion 1 (MATE1) substrate and risdiplam is a an MATE1/2-K inhibitor. MATE inhibitors may decrease metformin elimination by blocking renal tubular secretion.
    Sacubitril; Valsartan: (Moderate) Angiotensin II receptor antagonists (ARBs) may enhance the hypoglycemic effects of metformin by improving insulin sensitivity. In addition, angiotensin II receptor antagonists have been associated with a reduced incidence in the development of new-onset diabetes in patients with hypertension or other cardiac disease. ARBs may rarely reduce renal function, a risk factor for reduced renal clearance of metformin. Patients receiving these drugs together should be monitored for changes in renal function and glycemic control. (Moderate) Patients receiving these drugs concomitantly should be monitored for changes in blood pressure, volume status, renal function, serum potassium and other electrolytes, and for glycemic control. When an SGLT2 inhibitor is initiated, mild diuresis and naturesis occurs, producing intravascular volume contraction. These effects may be additive to certain antihypertensive medications, such as the angiotensin II receptor antagonists (also known as angiotensin receptor blockers or ARBs). Patients with impaired renal function (eGFR less than 60 mL/minute/1.73 m2), low systolic blood pressure, or who are elderly may also be at a greater risk. Volume status should be assessed and corrected. In addition, some SGLT2 inhibitors, like canagliflozin, can increase serum potassium. Monitor serum potassium levels periodically and monitor for hyperkalemia. ARBs may also enhance the hypoglycemic effects of antidiabetic agents by improving insulin sensitivity.
    Salicylates: (Moderate) Large doses of salicylates may enhance hypoglycemia in diabetic patients via inhibition of prostaglandin synthesis. If these agents are administered or discontinued in patients receiving oral antidiabetic agents, patients should be monitored for hypoglycemia or loss of blood glucose control.
    Segesterone Acetate; Ethinyl Estradiol: (Minor) Monitor blood glucose periodically in patients on metformin for changes in glycemic control when hormone therapy is instituted or discontinued. Estrogens can decrease the hypoglycemic effects of antidiabetic agents by impairing glucose tolerance. Changes in glucose tolerance occur more commonly in patients receiving 50 mcg or more of ethinyl estradiol (or equivalent) per day in combined oral contraceptives (COCs), which are not commonly used in practice since the marketing of lower dose COCs, patches, injections and rings. The presence or absence of a concomitant progestin may influence the significance of any hormonal effect on glucose homeostasis. (Minor) Patients receiving antidiabetic agents like metformin should be closely monitored for signs indicating changes in diabetic control when therapy with progestins is instituted or discontinued. Progestins can impair glucose tolerance.
    Sofosbuvir: (Moderate) Closely monitor blood glucose levels if sofosbuvir is administered with antidiabetic agents. Dose adjustments of the antidiabetic agents may be needed. Altered blood glucose control, resulting in serious symptomatic hypoglycemia, has been reported in diabetic patients receiving antidiabetic agents in combination with direct acting antivirals, such as sofosbuvir.
    Sofosbuvir; Velpatasvir: (Moderate) Closely monitor blood glucose levels if sofosbuvir is administered with antidiabetic agents. Dose adjustments of the antidiabetic agents may be needed. Altered blood glucose control, resulting in serious symptomatic hypoglycemia, has been reported in diabetic patients receiving antidiabetic agents in combination with direct acting antivirals, such as sofosbuvir. (Moderate) Closely monitor blood glucose levels if velpatasvir is administered with antidiabetic agents. Dose adjustments of the antidiabetic agents may be needed. Altered blood glucose control, resulting in serious symptomatic hypoglycemia, has been reported in diabetic patients receiving antidiabetic agents in combination with direct acting antivirals, such as velpatasvir.
    Sofosbuvir; Velpatasvir; Voxilaprevir: (Moderate) Closely monitor blood glucose levels if sofosbuvir is administered with antidiabetic agents. Dose adjustments of the antidiabetic agents may be needed. Altered blood glucose control, resulting in serious symptomatic hypoglycemia, has been reported in diabetic patients receiving antidiabetic agents in combination with direct acting antivirals, such as sofosbuvir. (Moderate) Closely monitor blood glucose levels if velpatasvir is administered with antidiabetic agents. Dose adjustments of the antidiabetic agents may be needed. Altered blood glucose control, resulting in serious symptomatic hypoglycemia, has been reported in diabetic patients receiving antidiabetic agents in combination with direct acting antivirals, such as velpatasvir. (Moderate) Closely monitor blood glucose levels if voxilaprevir is administered with antidiabetic agents. Dose adjustments of the antidiabetic agents may be needed. Altered blood glucose control, resulting in serious symptomatic hypoglycemia, has been reported in diabetic patients receiving antidiabetic agents in combination with direct acting antivirals, such as voxilaprevir.
    Somatropin, rh-GH: (Moderate) Patients with diabetes mellitus should be monitored closely during somatropin (recombinant rhGH) therapy. Antidiabetic drugs (e.g., insulin or oral agents) may require adjustment when somatropin therapy is instituted in these patients. Growth hormones, such as somatropin, may decrease insulin sensitivity, leading to glucose intolerance and loss of blood glucose control. Therefore, glucose levels should be monitored periodically in all patients treated with somatropin, especially in those with risk factors for diabetes mellitus.
    Sotalol: (Moderate) Increased frequency of blood glucose monitoring may be required when a beta blocker is given with antidiabetic agents. Since beta blockers inhibit the release of catecholamines, these medications may hide symptoms of hypoglycemia such as tremor, tachycardia, and blood pressure changes. Other symptoms, like headache, dizziness, nervousness, mood changes, or hunger are not blunted. Beta-blockers also exert complex actions on the body's ability to regulate blood glucose. Some beta-blockers, particularly non-selective beta-blockers such as propranolol, have been noted to potentiate insulin-induced hypoglycemia and a delay in recovery of blood glucose to normal levels. Hyperglycemia has been reported as well and is possibly due to beta-2 receptor blockade in the beta cells of the pancreas. A selective beta-blocker may be preferred in patients with diabetes mellitus, if appropriate for the patient's condition. Selective beta-blockers, such as atenolol or metoprolol, do not appear to potentiate insulin-induced hypoglycemia. While beta-blockers may have negative effects on glycemic control, they reduce the risk of cardiovascular disease and stroke in patients with diabetes and their use should not be avoided in patients with compelling indications for beta-blocker therapy when no other contraindications are present.
    Spironolactone; Hydrochlorothiazide, HCTZ: (Moderate) Certain drugs, such as thiazide diuretics, tend to produce hyperglycemia and may lead to loss of glycemic control. The effects of thiazide diuretics on glycemic control appear to be dose-related and low doses can be instituted without deleterious effects on glycemic control. In addition, thiazide diuretics reduce the risk of stroke and cardiovascular disease in patients with diabetes. Patients receiving metformin should be monitored for changes in blood glucose control if any of these diuretics are added or deleted. Dosage adjustments may be necessary in some patients.
    Sulfadiazine: (Moderate) Sulfonamides may enhance the hypoglycemic action of antidiabetic agents; patients with diabetes mellitus should be closely monitored during sulfonamide treatment. Sulfonamides may induce hypoglycemia in some patients by increasing the secretion of insulin from the pancreas. Patients at risk include those with compromised renal function, those fasting for prolonged periods, those that are malnourished, and those receiving high or excessive doses of sulfonamides.
    Sulfamethoxazole; Trimethoprim, SMX-TMP, Cotrimoxazole: (Moderate) Sulfonamides may enhance the hypoglycemic action of antidiabetic agents; patients with diabetes mellitus should be closely monitored during sulfonamide treatment. Sulfonamides may induce hypoglycemia in some patients by increasing the secretion of insulin from the pancreas. Patients at risk include those with compromised renal function, those fasting for prolonged periods, those that are malnourished, and those receiving high or excessive doses of sulfonamides.
    Sulfasalazine: (Moderate) Sulfonamides may enhance the hypoglycemic action of antidiabetic agents; patients with diabetes mellitus should be closely monitored during sulfonamide treatment. Sulfonamides may induce hypoglycemia in some patients by increasing the secretion of insulin from the pancreas. Patients at risk include those with compromised renal function, those fasting for prolonged periods, those that are malnourished, and those receiving high or excessive doses of sulfonamides.
    Sulfisoxazole: (Moderate) Sulfonamides may enhance the hypoglycemic action of antidiabetic agents; patients with diabetes mellitus should be closely monitored during sulfonamide treatment. Sulfonamides may induce hypoglycemia in some patients by increasing the secretion of insulin from the pancreas. Patients at risk include those with compromised renal function, those fasting for prolonged periods, those that are malnourished, and those receiving high or excessive doses of sulfonamides.
    Sulfonamides: (Moderate) Sulfonamides may enhance the hypoglycemic action of antidiabetic agents; patients with diabetes mellitus should be closely monitored during sulfonamide treatment. Sulfonamides may induce hypoglycemia in some patients by increasing the secretion of insulin from the pancreas. Patients at risk include those with compromised renal function, those fasting for prolonged periods, those that are malnourished, and those receiving high or excessive doses of sulfonamides.
    Sulfonylureas: (Moderate) Use of metformin with a sulfonylurea may increase the risk of hypoglycemia. Sulfonylureas are known to cause hypoglycemia. To manage hypoglycemic risk, lower doses of the sulfonylurea may be needed. Monitor blood sugar.
    Sympathomimetics: (Moderate) Sympathomimetic agents and adrenergic agonists tend to increase blood glucose concentrations when administered systemically. Monitor for loss of glycemic control when pseudoephedrine, phenylephrine, and other sympathomimetics are administered to patients taking antidiabetic agents. Epinephrine and other sympathomimetics, through stimulation of alpha- and beta- receptors, increase hepatic glucose production and glycogenolysis and inhibit insulin secretion. Also, adrenergic medications may decrease glucose uptake by muscle cells. For treatment of cold symptoms, nasal decongestants may be preferable for short term, limited use (1 to 3 days) as an alternative to systemic decongestants in patients taking medications for diabetes.
    Tacrolimus: (Moderate) Tacrolimus has been reported to cause hyperglycemia. Furthermore, tacrolimus has been implicated in causing insulin-dependent diabetes mellitus in patients after renal transplantation. Tacrolimus may have direct beta-cell toxicity. Patients should be monitored for worsening of glycemic control if Tacrolimus is initiated in patients receiving antidiabetic agents.
    Tafenoquine: (Moderate) Consider the benefits and risks of coadministration of tafenoquine and metformin due to the potential for increased metformin concentrations and lactic acidosis. If coadministration cannot be avoided, monitor for metformin-related toxicities, and consider metformin dosage reduction, if needed. The effect of coadministration of tafenoquine on the pharmacokinetics of OCT2 and MATE substrates, like metformin, in humans is unknown; however, in vitro observations suggest the potential for increased concentrations of OCT2 and MATE substrates. Tafenoquine may interfere with these common renal tubular transport systems involved in the renal elimination of metformin.
    Tegaserod: (Moderate) Because tegaserod can enhance gastric emptying in diabetic patients, blood glucose can be affected, which, in turn, may affect the clinical response to antidiabetic agents. The dosing of antidiabetic agents may require adjustment in patients who receive GI prokinetic agents concomitantly.
    Telmisartan: (Moderate) Angiotensin II receptor antagonists (ARBs) may enhance the hypoglycemic effects of metformin by improving insulin sensitivity. In addition, angiotensin II receptor antagonists have been associated with a reduced incidence in the development of new-onset diabetes in patients with hypertension or other cardiac disease. ARBs may rarely reduce renal function, a risk factor for reduced renal clearance of metformin. Patients receiving these drugs together should be monitored for changes in renal function and glycemic control. (Moderate) Patients receiving these drugs concomitantly should be monitored for changes in blood pressure, volume status, renal function, serum potassium and other electrolytes, and for glycemic control. When an SGLT2 inhibitor is initiated, mild diuresis and naturesis occurs, producing intravascular volume contraction. These effects may be additive to certain antihypertensive medications, such as the angiotensin II receptor antagonists (also known as angiotensin receptor blockers or ARBs). Patients with impaired renal function (eGFR less than 60 mL/minute/1.73 m2), low systolic blood pressure, or who are elderly may also be at a greater risk. Volume status should be assessed and corrected. In addition, some SGLT2 inhibitors, like canagliflozin, can increase serum potassium. Monitor serum potassium levels periodically and monitor for hyperkalemia. ARBs may also enhance the hypoglycemic effects of antidiabetic agents by improving insulin sensitivity.
    Telmisartan; Amlodipine: (Moderate) Angiotensin II receptor antagonists (ARBs) may enhance the hypoglycemic effects of metformin by improving insulin sensitivity. In addition, angiotensin II receptor antagonists have been associated with a reduced incidence in the development of new-onset diabetes in patients with hypertension or other cardiac disease. ARBs may rarely reduce renal function, a risk factor for reduced renal clearance of metformin. Patients receiving these drugs together should be monitored for changes in renal function and glycemic control. (Moderate) Patients receiving these drugs concomitantly should be monitored for changes in blood pressure, volume status, renal function, serum potassium and other electrolytes, and for glycemic control. When an SGLT2 inhibitor is initiated, mild diuresis and naturesis occurs, producing intravascular volume contraction. These effects may be additive to certain antihypertensive medications, such as the angiotensin II receptor antagonists (also known as angiotensin receptor blockers or ARBs). Patients with impaired renal function (eGFR less than 60 mL/minute/1.73 m2), low systolic blood pressure, or who are elderly may also be at a greater risk. Volume status should be assessed and corrected. In addition, some SGLT2 inhibitors, like canagliflozin, can increase serum potassium. Monitor serum potassium levels periodically and monitor for hyperkalemia. ARBs may also enhance the hypoglycemic effects of antidiabetic agents by improving insulin sensitivity.
    Telmisartan; Hydrochlorothiazide, HCTZ: (Moderate) Angiotensin II receptor antagonists (ARBs) may enhance the hypoglycemic effects of metformin by improving insulin sensitivity. In addition, angiotensin II receptor antagonists have been associated with a reduced incidence in the development of new-onset diabetes in patients with hypertension or other cardiac disease. ARBs may rarely reduce renal function, a risk factor for reduced renal clearance of metformin. Patients receiving these drugs together should be monitored for changes in renal function and glycemic control. (Moderate) Certain drugs, such as thiazide diuretics, tend to produce hyperglycemia and may lead to loss of glycemic control. The effects of thiazide diuretics on glycemic control appear to be dose-related and low doses can be instituted without deleterious effects on glycemic control. In addition, thiazide diuretics reduce the risk of stroke and cardiovascular disease in patients with diabetes. Patients receiving metformin should be monitored for changes in blood glucose control if any of these diuretics are added or deleted. Dosage adjustments may be necessary in some patients. (Moderate) Patients receiving these drugs concomitantly should be monitored for changes in blood pressure, volume status, renal function, serum potassium and other electrolytes, and for glycemic control. When an SGLT2 inhibitor is initiated, mild diuresis and naturesis occurs, producing intravascular volume contraction. These effects may be additive to certain antihypertensive medications, such as the angiotensin II receptor antagonists (also known as angiotensin receptor blockers or ARBs). Patients with impaired renal function (eGFR less than 60 mL/minute/1.73 m2), low systolic blood pressure, or who are elderly may also be at a greater risk. Volume status should be assessed and corrected. In addition, some SGLT2 inhibitors, like canagliflozin, can increase serum potassium. Monitor serum potassium levels periodically and monitor for hyperkalemia. ARBs may also enhance the hypoglycemic effects of antidiabetic agents by improving insulin sensitivity.
    Tenofovir Alafenamide: (Moderate) According to the manufacturer, interactions are not expected when metformin is administered with tenofovir alafenamide; however, because tenofovir and metformin can compete for elimination through the kidneys, use of these medications together may increase the risk for side effects, such as lactic acidosis. Drugs that are eliminated by renal tubular secretion, such as tenofovir alafenamide, may decrease metformin elimination by competing for common renal tubular transport systems. Although such interactions remain theoretical, careful patient monitoring and dose adjustment of metformin and/or the interfering cationic drug are recommended.
    Tenofovir, PMPA: (Moderate) Certain medications used concomitantly with metformin may increase the risk of lactic acidosis. Drugs that are eliminated by renal tubular secretion, such as tenofovir, PMPA may decrease metformin elimination by competing for common renal tubular transport systems. Although such interactions remain theoretical, careful patient monitoring and dose adjustment of metformin and/or the interfering cationic drug are recommended.
    Testosterone: (Moderate) Changes in insulin sensitivity or glycemic control may occur in patients treated with androgens. In diabetic patients, the metabolic effects of androgens may decrease blood glucose and, therefore, may decrease antidiabetic agent dosage requirements. Monitor blood glucose and HbA1C when these drugs are used together.
    Thiazide diuretics: (Moderate) Certain drugs, such as thiazide diuretics, tend to produce hyperglycemia and may lead to loss of glycemic control. The effects of thiazide diuretics on glycemic control appear to be dose-related and low doses can be instituted without deleterious effects on glycemic control. In addition, thiazide diuretics reduce the risk of stroke and cardiovascular disease in patients with diabetes. Patients receiving metformin should be monitored for changes in blood glucose control if any of these diuretics are added or deleted. Dosage adjustments may be necessary in some patients.
    Thyroid hormones: (Minor) Thyroid hormone use may result in increased blood sugar and a loss of glycemic control in some patients. Interactions may or may not be clinically significant at usual replacement doses. Monitor blood sugars carefully when thyroid therapy is added, changed, or discontinued in patients receiving metformin.
    Timolol: (Moderate) Increased frequency of blood glucose monitoring may be required when a beta blocker is given with antidiabetic agents. Since beta blockers inhibit the release of catecholamines, these medications may hide symptoms of hypoglycemia such as tremor, tachycardia, and blood pressure changes. Other symptoms, like headache, dizziness, nervousness, mood changes, or hunger are not blunted. Beta-blockers also exert complex actions on the body's ability to regulate blood glucose. Some beta-blockers, particularly non-selective beta-blockers such as propranolol, have been noted to potentiate insulin-induced hypoglycemia and a delay in recovery of blood glucose to normal levels. Hyperglycemia has been reported as well and is possibly due to beta-2 receptor blockade in the beta cells of the pancreas. A selective beta-blocker may be preferred in patients with diabetes mellitus, if appropriate for the patient's condition. Selective beta-blockers, such as atenolol or metoprolol, do not appear to potentiate insulin-induced hypoglycemia. While beta-blockers may have negative effects on glycemic control, they reduce the risk of cardiovascular disease and stroke in patients with diabetes and their use should not be avoided in patients with compelling indications for beta-blocker therapy when no other contraindications are present.
    Tobacco: (Moderate) Tobacco smoking is known to aggravate insulin resistance. The cessation of tobacco smoking may result in a decrease in blood glucose. Blood glucose concentrations should be monitored more closely whenever a change in either smoking status occurs; dosage adjustments in antidiabetic agents may be needed. (Minor) Tobacco smoking is known to aggravate insulin resistance. The cessation of tobacco smoking may result in a decrease in blood glucose. Blood glucose concentrations should be monitored more closely whenever a change in either smoking status occurs; dosage adjustments in antidiabetic agents may be needed.
    Tolazamide: (Moderate) Use of metformin with a sulfonylurea may increase the risk of hypoglycemia. Sulfonylureas are known to cause hypoglycemia. To manage hypoglycemic risk, lower doses of the sulfonylurea may be needed. Monitor blood sugar.
    Tolbutamide: (Moderate) Use of metformin with a sulfonylurea may increase the risk of hypoglycemia. Sulfonylureas are known to cause hypoglycemia. To manage hypoglycemic risk, lower doses of the sulfonylurea may be needed. Monitor blood sugar.
    Topiramate: (Major) Extended-release topiramate is contraindicated in patients with metabolic acidosis who are taking concomitant metformin because topiramate can frequently cause metabolic acidosis, a condition for which metformin use is contraindicated. Consider more frequent monitoring of patients taking immediate-release topiramate with metformin. In healthy volunteers, metformin Cmax and AUC increased by 17% and 25%, respectively, when topiramate was added, and oral plasma clearance of topiramate appears to be reduced when administered with metformin. However, the clinical significance of these pharmacokinetic effects is unclear.
    Torsemide: (Minor) Hyperglycemia has been detected during torsemide therapy, but the incidence is low. Because of this, a potential pharmacodynamic interaction exists between torsemide and all antidiabetic agents, including metformin. Monitor blood glucose.
    Trandolapril: (Moderate) Angiotensin-converting enzyme (ACE) inhibitors may enhance the hypoglycemic effects of insulin or other antidiabetic agents by improving insulin sensitivity. Patients receiving antidiabetic agents can become hypoglycemic if ACE inhibitors are administered concomitantly. ACE inhibitors may rarely reduce renal function, a risk factor for reduced renal clearance of metformin. Patients receiving these drugs together should be monitored for changes in renal function and glycemic control. (Moderate) Patients receiving these drugs concomitantly should be monitored for changes in blood pressure, volume status, renal function, serum potassium, and glycemic control. When an SGLT2 inhibitor is initiated, mild diuresis and naturesis occurs, producing intravascular volume contraction. These effects may be additive to certain antihypertensive medications, such as the angiotensin-converting enzyme inhibitors (ACE inhibitors). Patients with impaired renal function (eGFR less than 60 mL/minute/1.73 m2), low systolic blood pressure, or who are elderly may also be at a greater risk. Volume status should be assessed and corrected. In addition, some SGLT2 inhibitors, like canagliflozin, can increase serum potassium. Monitor serum potassium levels periodically and monitor for hyperkalemia. ACE inhibitors may also enhance the hypoglycemic effects of antidiabetic agents by improving insulin sensitivity.
    Trandolapril; Verapamil: (Moderate) Angiotensin-converting enzyme (ACE) inhibitors may enhance the hypoglycemic effects of insulin or other antidiabetic agents by improving insulin sensitivity. Patients receiving antidiabetic agents can become hypoglycemic if ACE inhibitors are administered concomitantly. ACE inhibitors may rarely reduce renal function, a risk factor for reduced renal clearance of metformin. Patients receiving these drugs together should be monitored for changes in renal function and glycemic control. (Moderate) Patients receiving these drugs concomitantly should be monitored for changes in blood pressure, volume status, renal function, serum potassium, and glycemic control. When an SGLT2 inhibitor is initiated, mild diuresis and naturesis occurs, producing intravascular volume contraction. These effects may be additive to certain antihypertensive medications, such as the angiotensin-converting enzyme inhibitors (ACE inhibitors). Patients with impaired renal function (eGFR less than 60 mL/minute/1.73 m2), low systolic blood pressure, or who are elderly may also be at a greater risk. Volume status should be assessed and corrected. In addition, some SGLT2 inhibitors, like canagliflozin, can increase serum potassium. Monitor serum potassium levels periodically and monitor for hyperkalemia. ACE inhibitors may also enhance the hypoglycemic effects of antidiabetic agents by improving insulin sensitivity.
    Tranylcypromine: (Moderate) Serum glucose should be monitored closely when monoamine oxidase inhibitors (MAOIs) are added to any regimen containing antidiabetic agents, including ertugliflozin. Inhibitors of MAO type A have been shown to prolong the hypoglycemic response to insulin and other antidiabetic agents.
    Triamterene; Hydrochlorothiazide, HCTZ: (Moderate) Certain drugs, such as thiazide diuretics, tend to produce hyperglycemia and may lead to loss of glycemic control. The effects of thiazide diuretics on glycemic control appear to be dose-related and low doses can be instituted without deleterious effects on glycemic control. In addition, thiazide diuretics reduce the risk of stroke and cardiovascular disease in patients with diabetes. Patients receiving metformin should be monitored for changes in blood glucose control if any of these diuretics are added or deleted. Dosage adjustments may be necessary in some patients.
    Trilaciclib: (Moderate) Concomitant administration of metformin and trilaciclib may increase metformin exposure and increase the risk for lactic acidosis. If these drugs are given together, monitor for signs of metformin toxicity; metformin dose adjustments may be needed. Metformin is an OCT2 and MATE substrate; trilaciclib is an OCT2 and MATE inhibitor that may decrease metformin elimination by blocking renal tubular secretion.
    Trospium: (Moderate) Trospium, if used concomitantly with metformin, may increase the risk of lactic acidosis. Cationic drugs that are eliminated by renal tubular secretion like trospium may decrease metformin elimination by competing for common renal tubular transport systems.
    Trovafloxacin, Alatrofloxacin: (Moderate) Careful monitoring of blood glucose is recommended when other quinolones andantidiabetic agents, including the sodium-glucose co-transporter 2 (SGLT2) inhibitors, are coadministered. Disturbances of blood glucose, including hyperglycemia and hypoglycemia, have been reported in patients treated concomitantly with quinolones and an antidiabetic agent.
    Ultralente Insulin: (Moderate) Coadministration of metformin with an insulin may increase the risk of hypoglycemia. Insulins are known to cause hypoglycemia. To manage hypoglycemic risk, lower doses of insulin may be needed. Monitor blood sugar and adjust insulin dosage as clinically indicated.
    Valsartan: (Moderate) Angiotensin II receptor antagonists (ARBs) may enhance the hypoglycemic effects of metformin by improving insulin sensitivity. In addition, angiotensin II receptor antagonists have been associated with a reduced incidence in the development of new-onset diabetes in patients with hypertension or other cardiac disease. ARBs may rarely reduce renal function, a risk factor for reduced renal clearance of metformin. Patients receiving these drugs together should be monitored for changes in renal function and glycemic control. (Moderate) Patients receiving these drugs concomitantly should be monitored for changes in blood pressure, volume status, renal function, serum potassium and other electrolytes, and for glycemic control. When an SGLT2 inhibitor is initiated, mild diuresis and naturesis occurs, producing intravascular volume contraction. These effects may be additive to certain antihypertensive medications, such as the angiotensin II receptor antagonists (also known as angiotensin receptor blockers or ARBs). Patients with impaired renal function (eGFR less than 60 mL/minute/1.73 m2), low systolic blood pressure, or who are elderly may also be at a greater risk. Volume status should be assessed and corrected. In addition, some SGLT2 inhibitors, like canagliflozin, can increase serum potassium. Monitor serum potassium levels periodically and monitor for hyperkalemia. ARBs may also enhance the hypoglycemic effects of antidiabetic agents by improving insulin sensitivity.
    Valsartan; Hydrochlorothiazide, HCTZ: (Moderate) Angiotensin II receptor antagonists (ARBs) may enhance the hypoglycemic effects of metformin by improving insulin sensitivity. In addition, angiotensin II receptor antagonists have been associated with a reduced incidence in the development of new-onset diabetes in patients with hypertension or other cardiac disease. ARBs may rarely reduce renal function, a risk factor for reduced renal clearance of metformin. Patients receiving these drugs together should be monitored for changes in renal function and glycemic control. (Moderate) Certain drugs, such as thiazide diuretics, tend to produce hyperglycemia and may lead to loss of glycemic control. The effects of thiazide diuretics on glycemic control appear to be dose-related and low doses can be instituted without deleterious effects on glycemic control. In addition, thiazide diuretics reduce the risk of stroke and cardiovascular disease in patients with diabetes. Patients receiving metformin should be monitored for changes in blood glucose control if any of these diuretics are added or deleted. Dosage adjustments may be necessary in some patients. (Moderate) Patients receiving these drugs concomitantly should be monitored for changes in blood pressure, volume status, renal function, serum potassium and other electrolytes, and for glycemic control. When an SGLT2 inhibitor is initiated, mild diuresis and naturesis occurs, producing intravascular volume contraction. These effects may be additive to certain antihypertensive medications, such as the angiotensin II receptor antagonists (also known as angiotensin receptor blockers or ARBs). Patients with impaired renal function (eGFR less than 60 mL/minute/1.73 m2), low systolic blood pressure, or who are elderly may also be at a greater risk. Volume status should be assessed and corrected. In addition, some SGLT2 inhibitors, like canagliflozin, can increase serum potassium. Monitor serum potassium levels periodically and monitor for hyperkalemia. ARBs may also enhance the hypoglycemic effects of antidiabetic agents by improving insulin sensitivity.
    Vandetanib: (Moderate) Vandetanib could increase systemic exposure to metformin and may increase the risk for lactic acidosis. Vandetanib increased the plasma concentrations of metformin, which is transported by the renal organic cation transporter type 2 (OCT2). Use caution and closely monitor for toxicities when administering vendetanib with metformin.
    Zonisamide: (Moderate) Carbonic anhydrase inhibitors such as zonisamide frequently cause a decrease in serum bicarbonate and induce non-anion gap, hyperchloremic metabolic acidosis. Use of zonisamide with metformin may increase the risk for lactic acidosis; consider more frequent monitoring. Carbonic anhydrase inhibitors may also alter blood sugar; both hyperglycemia and hypoglycemia have been described. Monitor blood glucose and for changes in glycemic control and be alert for evidence of an interaction.

    PREGNANCY AND LACTATION

    Pregnancy

    Due to the potential for serious adverse reactions in a nursing infant, breast-feeding during use of ertugliflozin; metformin is not recommended. There are no data available regarding the presence of ertugliflozin or ertugliflozin; metformin in human milk, the effects on a breast-fed infant, or the effects on milk production. However, since ertugliflozin is present in the milk of lactating rats and human kidney maturation occurs in utero and during the first 2 years of life when lactational exposure may occur, there may be risk to the developing human kidney. Metformin monotherapy may be an option during lactation. Small studies indicate that metformin is excreted in human breast milk. Infant hypoglycemia or other side effects are a possibility; however, adverse effects on infant plasma glucose have not been reported in human studies. Furthermore, the use of metformin 2,550 mg/day by mothers breast-feeding their infants for 6 months does not affect growth, motor, or social development; the effects beyond 6 months are not known. In all of these studies, the estimated weight-adjusted infant exposure to metformin ranged from 0.11% to 1.08% of the mother's dose. While the manufacturers of metformin recommend that a decision should be made to discontinue breast-feeding or discontinue the drug, the results of these studies indicate that maternal ingestion of metformin during breast-feeding is probably safe to the infant. However, a risk and benefit analysis should be made for each mother and her infant; if patients elect to continue metformin monotherapy while breast-feeding, the mother should be aware of the potential risks to the infant. Other oral hypoglycemics may be considered as possible alternatives during breast-feeding. Because acarbose has limited systemic absorption, which results in minimal maternal plasma concentrations, clinically significant exposure via breast milk is not expected. Tolbutamide is usually considered compatible with breast-feeding. Glyburide may be a suitable alternative since it was not detected in the breast milk of lactating women who received single and multiple doses of glyburide. If any oral hypoglycemics are used during breast-feeding, the nursing infant should be monitored for signs of hypoglycemia, such as increased fussiness or somnolence. Consider the benefits of breast-feeding, the risk of potential infant drug exposure, and the risk of an untreated or inadequately treated condition. If a breast-feeding infant experiences an adverse effect related to a maternally ingested drug, healthcare providers are encouraged to report the adverse effect to the FDA.

    MECHANISM OF ACTION

    Combination products containing ertugliflozin and metformin are used to improve glycemic control in type 2 diabetes mellitus. Clinicians may wish to consult the individual monographs for more information about each agent.
     
    Ertugliflozin: Ertugliflozin is an inhibitor of sodium-glucose co-transporter 2 (SGLT2), the transporter responsible for reabsorbing most of the glucose filtered by the tubular lumen in the kidney. SGLT2 is expressed in the proximal renal tubules. By inhibiting SGLT2, ertugliflozin reduces reabsorption of filtered glucose and lowers the renal threshold for glucose (RTG), and thereby increases urinary glucose excretion, improving blood glucose control. Dose-dependent increases in the amount of glucose excreted in the urine were observed in patients with Type 2 Diabetes Mellitus following single- and multiple-dose administration of ertugliflozin. Dose-response modeling indicates that ertugliflozin 5 mg and 15 mg results in near maximum urinary glucose excretion (UGE); enhanced UGE is maintained after multiple doses. This UGE with ertugliflozin also results in increased urinary volume.
    Metformin: Metformin decreases hepatic gluconeogenesis production, decreases intestinal absorption of glucose, and improves insulin sensitivity by increasing peripheral glucose uptake and utilization; insulin secretion remains unchanged while fasting insulin levels and day-long plasma insulin response may actually decrease. Metformin improves glucose utilization in skeletal muscle and adipose tissue by increasing cell membrane glucose transport. This effect may be due to improved binding of insulin to insulin receptors since metformin is not effective in diabetics without some residual functioning pancreatic islet cells. Metformin causes a 10% to 20% decrease in fatty-acid oxidation and a slight increase in glucose oxidation. Unlike phenformin, metformin does not inhibit the mitochondrial oxidation of lactate unless its plasma concentrations become excessive (i.e., in patients with renal failure) and/or hypoxia is present. Clinically, metformin lowers fasting and postprandial hyperglycemia. The decrease in fasting plasma glucose is approximately 25% to 30%. Unlike oral sulfonylureas, it rarely causes hypoglycemia. Thus, metformin demonstrates more of an antihyperglycemic action than a hypoglycemic action. Metformin does not cause weight gain and in fact, may cause a modest weight loss due to drug-induced anorexia. Metformin also decreases plasma VLDL triglycerides resulting in modest decreases in plasma triglycerides and total cholesterol. Patients receiving metformin show a significant improvement in A1C, and a tendency toward improvement in the lipid profile, especially when baseline values are abnormally elevated.

    PHARMACOKINETICS

    Ertugliflozin; metformin is administered orally.
    Ertugliflozin: The mean steady state volume of distribution of ertugliflozin following an intravenous (IV) dose is 85.5 L. Ertugliflozin is approximately 94% protein bound. Protein binding is independent of ertugliflozin plasma concentrations. The blood-to-plasma concentration ratio of ertugliflozin is 0.66. Ertugliflozin is mainly metabolized via O-glucuronidation by UGT1A9 and UGT2B7 to 2 glucuronides that are pharmacologically inactive at relevant concentrations. CYP-mediated (oxidative) metabolism of ertugliflozin is minimal (12%). Following oral administration, approximately 50% and 41% of the dose is excreted in the urine and feces, respectively. In the urine, only 1.5% of the dose is excreted as the parent drug. In the feces, approximately 34% of the dose is excreted as the parent drug. This is likely due to biliary excretion of glucuronides metabolites and subsequent hydrolysis to parent. The mean elimination half-life of ertugliflozin is approximately 17 hours. Steady state is reached after 4 to 6 days of once-daily dosing. Ertugliflozin does not exhibit time-dependent pharmacokinetics and accumulates in plasma up to 10% to 40% following multiple dosing.
    Metformin: Metformin is distributed rapidly into peripheral body tissues and fluids and appears to distribute slowly into erythrocytes and to a deep tissue compartment (most likely GI tissues). The highest concentrations of metformin are found in the GI tract (10 times the concentrations in the plasma) and lower concentrations in the kidney, liver, and salivary gland tissue. Metformin is negligibly bound to plasma proteins. The apparent volume of distribution (V/F) of metformin following a single, 850 mg dose is 654 +/- 358 L. Steady-state concentrations of metformin are reached within 1 to 2 days and are generally less than 1 mcg/mL. Metformin is not metabolized by the liver and this fact may explain why the risk of lactic acidosis is much less for metformin than for phenformin (i.e., approximately 10% of patients have an inherited defect in the ability to metabolize phenformin). The drug is excreted by the kidneys, largely unchanged, through an active tubular process; tubular secretion may be altered by many cationic drugs. Approximately 10% of an oral dose is excreted in the feces, presumably as unabsorbed metformin, and about 90% of a dose is excreted by the kidneys within 24 hours. Biliary excretion does not occur. Although the average elimination half-life in the plasma is 6.2 hours in patients with normal renal function, metformin accumulates in red blood cells, which leads to a much longer elimination half-life in the blood (17.6 hours).
     
    Affected cytochrome P450 (CYP450) isoenzymes and drug transporters: Organic cationic transporter-2 (OCT2), multidrug and toxin extrusion (MATE1 and MATE2k)
    Ertugliflozin: Ertugliflozin and ertugliflozin glucuronides did not inhibit CYP1A2, CYP2C9, CYP2C19, CYP2C8, CYP2B6, CYP2D6, or CYP3A4, and did not induce CYP1A2, CYP2B6, or CYP3A4 based on in vitro studies. Ertugliflozin also did not inhibit UGT1A6, 1A9, or 2B7 and was a weak inhibitor of UGT1A1 and 1A4. Overall, ertugliflozin is unlikely to affect the pharmacokinetics of concurrently administered medications that are eliminated by these enzymes. Ertugliflozin is a substrate of P-glycoprotein (P-gp) and breast cancer resistance protein (BCRP) drug transporters. Ertugliflozin and ertugliflozin glucuronides do not meaningful inhibit P-gp, OCT2, OAT1, OAT3 transporters, or OATP1B1 and OATP1B3 at clinically relevant concentrations. Overall, ertugliflozin is unlikely to affect the pharmacokinetics of concurrently administered medications that are substrates of these transporters.
    Metformin: Drugs that interfere with common renal tubular transport systems involved in the renal elimination of metformin (e.g., organic cationic transporter-2 [OCT2]/multidrug and toxin extrusion [MATE1 and MATE2k] inhibitors such as ranolazine, vandetanib, dolutegravir, and cimetidine) could increase systemic exposure to metformin. An interaction between metformin and oral cimetidine has been observed, with a 60% increase in peak metformin plasma and whole blood concentrations and a 40% increase in plasma and whole blood metformin AUC, but no change in metformin elimination half-life. Careful patient monitoring and dose adjustment of metformin and/or the potentially interfering drug is recommended with concurrent use.

    Oral Route

    The effects of a high-fat meal on the pharmacokinetics of ertugliflozin; metformin are comparable to those reported for the individual components. Food had no meaningful effect on AUC of ertugliflozin and metformin, but reduced mean ertugliflozin Cmax by approximately 41% and metformin Cmax by approximately 29% compared to the fasted condition. The combination product is given with meals/food.
    Ertugliflozin: Following single-dose administration of 5 mg and 15 mg of ertugliflozin, peak plasma concentrations (Tmax) occur at 1 hour postdose under fasted conditions. The Cmax and AUC values increase dose proportionally with increases in ertugliflozin dose. The absolute bioavailability of ertugliflozin following administration of a 15 mg dose is approximately 100%. Administration of ertugliflozin with a high-fat, high calorie meal decreases Cmax by 29% and prolongs the Tmax by 1 hour compared with the fasted state; however, the AUC is unaffected. These effects of food on ertugliflozin pharmacokinetics are not considered clinically significant.
    Metformin: The absolute bioavailability of a metformin hydrochloride 500 mg tablet given under fasting conditions is approximately 50% to 60%. Studies using single oral doses of metformin hydrochloride tablets 500 mg to 1,500 mg, and 850 mg to 2,550 mg (approximately 1.3 times the maximum recommended daily dosage), indicate that there is a lack of dose proportionality with increasing doses, which is due to decreased absorption rather than an alternation in elimination. Food decreases the extent of and slightly delays the absorption of metformin, as shown by approximately a 40% lower Cmax, a 25% lower AUC, and a 35-minute prolongation of Tmax following administration of a single 850-mg tablet of metformin with food, compared to the same tablet strength administered fasting. The clinical relevance of these decreases is unknown.