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  • CLASSES

    Non-Nucleoside Reverse Transcriptase Inhibitor (NNRTI) and Nucleoside and Nucleotide Reverse Transcriptase Inhibitors (NRTI) Combinations

    BOXED WARNING

    Hepatic disease, hepatitis, hepatitis B and HIV coinfection, hepatitis B exacerbation

    Monitor liver function tests in all patients prior to and during treatment with doravirine; lamivudine; tenofovir disoproxil fumarate. Cases of elevated hepatic enzymes and increased bilirubin concentrations were observed in recipients of doravirine during clinical trials; use of the drug in patients with severe hepatic disease (Child-Pugh C) has not been studied. Doravirine; lamivudine; tenofovir disoproxil fumarate is not indicated for the treatment of chronic hepatitis B virus (HBV) infection; however, both the lamivudine and tenofovir components are active against the hepatitis B virus. Perform hepatitis B virus (HBV) screening in any patient who presents with HIV infection to assure appropriate treatment. Patients with hepatitis B and HIV coinfection should be started on a fully suppressive antiretroviral (ARV) regimen with activity against both viruses (regardless of CD4 counts and HBV DNA concentrations). HIV treatment guidelines recommend these patients receive an ARV regimen that contains a dual NRTI backbone of tenofovir alafenamide or tenofovir disoproxil fumarate with either emtricitabine or lamivudine. If tenofovir cannot be used, entecavir should be used in combination with a fully suppressive ARV regimen (note: entecavir should not be considered part of the ARV regimen). Avoid using single-drug therapy to treat HBV (i.e., lamivudine, emtricitabine, tenofovir, or entecavir as the only active agent) as this may result in HIV resistant strains. Further, HBV treatment regimens that include adefovir or telbivudine should also be avoided, as these regimens are associated with a higher incidence of toxicities and increased rates of HBV treatment failure. Most coinfected patients should continue treatment indefinitely with the goal of maximal HIV suppression and prevention of HBV relapse. Patients with coexisting HBV and HIV infections who discontinue lamivudine or tenofovir may experience severe acute hepatitis B exacerbation with some cases resulting in hepatic decompensation and hepatic failure. Therefore, close monitoring of transaminase concentrations (every 6 weeks for the first 3 months, and every 3 to 6 months thereafter) is recommended in coinfected patients who discontinue NRTI therapy. If appropriate, resumption of anti-hepatitis B treatment may be required. For patients who refuse a fully suppressive ARV regimen, but still require treatment for HBV, consider 48 weeks of peginterferon alfa; do not administer HIV-active medications in the absence of a fully suppressive ARV regimen. Instruct patients to avoid consuming alcohol, and offer vaccinations against hepatitis A and hepatitis B as appropriate. [34362] [46638] [63485]

    DEA CLASS

    Rx

    DESCRIPTION

    Fixed-dose combination tablet containing doravirine, an NNRTI, lamivudine, an NRTI, and tenofovir DF, an acyclic nucleotide reverse transcriptase inhibitor
    Used as a complete regimen to treat HIV-1 infection in treatment-naive adults and pediatric patients weighing at least 35 kg who are virologically stable on an antiretroviral regimen without history of treatment failure and no known resistance-associated substitutions to the individual drug components
    Severe acute exacerbations of hepatitis B virus (HBV) have been reported in patients coinfected with HIV-1 and HBV who have discontinued lamivudine or tenofovir DF

    COMMON BRAND NAMES

    DELSTRIGO

    HOW SUPPLIED

    DELSTRIGO Oral Tab: 100-300-300mg

    DOSAGE & INDICATIONS

    For the treatment of human immunodeficiency virus (HIV) infection in antiretroviral-naive and certain treatment-experienced patients.
    NOTE: Use in treatment-experienced patients is limited to those who have been virologically-suppressed (i.e., HIV RNA less than 50 copies/mL) on a stable antiretroviral regimen with no history of treatment failure and who are without known substitutions associated with resistance to the individual drug components.[63485]
    Oral dosage
    Adults

    1 tablet (doravirine 100 mg; lamivudine 300 mg; tenofovir disoproxil fumarate 300 mg) PO once daily.[63485]

    Children and Adolescents weighing 35 kg or more

    1 tablet (doravirine 100 mg; lamivudine 300 mg; tenofovir disoproxil fumarate 300 mg) PO once daily.[63485]

    MAXIMUM DOSAGE

    Adults

    1 tablet/day PO (doravirine 100 mg/day; lamivudine 300 mg/day; tenofovir disoproxil fumarate 300 mg/day).

    Geriatric

    1 tablet/day PO (doravirine 100 mg/day; lamivudine 300 mg/day; tenofovir disoproxil fumarate 300 mg/day).

    Adolescents

    weight 35 kg or more: 1 tablet/day PO (doravirine 100 mg/day; lamivudine 300 mg/day; tenofovir disoproxil fumarate 300 mg/day).
    weight less than 35 kg: Safety and efficacy have not been established.

    Children

    weight 35 kg or more: 1 tablet/day PO (doravirine 100 mg/day; lamivudine 300 mg/day; tenofovir disoproxil fumarate 300 mg/day).
    weight less than 35 kg: Safety and efficacy have not been established.

    Infants

    Safety and efficacy have not been established.

    Neonates

    Safety and efficacy have not been established.

    DOSING CONSIDERATIONS

    Hepatic Impairment

    No dosage adjustments are needed for patients with mild to moderate hepatic impairment (Child-Pugh A and B). Treatment has not been evaluated in patients with severe hepatic impairment (Child-Pugh C).

    Renal Impairment

    CrCl 50 mL/minute or more: No dosage adjustment is needed.
    CrCl less than 50 mL/minute: Not recommended.

    ADMINISTRATION

    Oral Administration

    Administer orally with or without food.

    STORAGE

    DELSTRIGO:
    - Protect from moisture
    - Store between 68 to 77 degrees F, excursions permitted 59 to 86 degrees F
    - Store in original container

    CONTRAINDICATIONS / PRECAUTIONS

    General Information

    Doravirine; lamivudine; tenofovir disoproxil fumarate is contraindicated for use in patients receiving strong CYP3A inducers (e.g., rifampin, St. John's wort); concurrent use of strong CYP3A inducers can lead to a significant decrease in plasma concentrations of doravirine, which may result in loss of therapeutic effect and viral resistance. Consider the potential for drug interactions prior to and during therapy; additional monitoring for efficacy and adverse reactions may be needed.[63485]
     
    Unplanned antiretroviral therapy interruption may be necessary for specific situations, such as serious drug toxicity, intercurrent illness or surgery precluding oral intake (e.g., gastroenteritis or pancreatitis), severe hyperemesis gravidarum unresponsive to antiemetics, or drug non-availability. If short-term treatment interruption (i.e., less than 1 to 2 days) is necessary, in general, it is recommended that all antiretroviral agents be discontinued simultaneously, especially if the interruption occurs in a pregnant patient or is because of a serious toxicity. However, if a short-term treatment interruption is anticipated in the case of elective surgery, the pharmacokinetic properties and food requirements of specific drugs should be considered; as stopping all simultaneously in a regimen containing drugs with differing half-lives may result in functional monotherapy of the drug with the longest half-life and may increase the risk for resistant mutations. Health care providers are advised to reinitiate a complete and effective antiretroviral regimen as soon as possible after an interruption of therapy. Planned long-term treatment interruptions are not recommended due to the potential for HIV disease progression (i.e., declining CD4 counts, viral rebound, acute viral syndrome), development of minor HIV-associated manifestations or serious non-AIDS complications, development of drug resistance, increased risk of HIV transmission, and increased risk for opportunistic infections. If therapy must be discontinued, counsel patient on the potential risks and closely monitor for any clinical or laboratory abnormalities. [46638] [42452]

    Human immunodeficiency virus (HIV) infection resistance

    Testing for human immunodeficiency virus (HIV) infection resistance is recommended in all antiretroviral treatment-naive patients at the time of HIV diagnosis, regardless of whether treatment will be initiated. Additionally, perform resistance testing before initiating or changing any HIV treatment regimen.[46638] [42452] Transmission of drug-resistant HIV strains has been both well documented and associated with suboptimal virologic response to initial antiretroviral therapy. In high-income countries (e.g., US, some European countries, Australia, Japan), approximately 10% to 17% of treatment-naive individuals have resistance mutations to at least 1 antiretroviral drug; up to 8% (but generally less than 5%) of transmitted viruses will exhibit resistance to drugs from more than 1 class. Therefore, resistance testing at baseline can help optimize treatment and, thus, virologic response. In the absence of therapy, resistant viruses may decline over time to less than the detection limit of standard resistance tests, but may still increase the risk of treatment failure when therapy is eventually initiated. Thus, if therapy is deferred, resistance testing should still be performed during acute HIV infection with the genotypic resistance test result kept in the patient's medical record until it becomes clinically useful. Additionally, because of the possibility of acquisition of another drug-resistant virus before treatment initiation, repeat resistance testing at the time therapy is initiated would be prudent. Lamivudine will not likely be effective in individuals who display antimicrobial resistance to emtricitabine, due to the similarities between the two drugs. Clinicians should not expect patients with the M184 mutation associated with emtricitabine to benefit from a lamivudine-containing regimen. The M184 mutation confers high-level resistance, and lamivudine, like emtricitabine, selects for the M184 mutation. It is important that persons with detectable viral load who plan to switch therapy from emtricitabine to lamivudine have genotypic testing performed to determine whether the M184 mutation is present. Also, cross-resistance may occur between tenofovir and other nucleoside reverse transcriptase inhibitors as well as doravirine and other non-nucleoside reverse transcriptase inhibitors.[46638] [63485]

    Hepatitis C and HIV coinfection, use with ribavirin

    HIV treatment guidelines recommend all patients presenting with HIV infection undergo testing for hepatitis C, with continued annual screening advised for those persons considered high risk for acquiring hepatitis C. If hepatitis C and HIV coinfection is identified, consider treating both viral infections concurrently. For most patients, the benefits of concurrent therapy outweigh the potential risks (i.e., drug-induced hepatic injury, complex drug interactions, overlapping toxicities); therefore, it is recommended to initiate a fully suppressive antiretroviral (ARV) therapy and a hepatitis C regimen in all coinfected patients regardless of CD4 count. However, for antiretroviral-naive patients with CD4 counts greater than 500 cells/mm3, consideration may be given to deferring ARV until the hepatitis C treatment regimen has been completed. Conversely, for patients with CD4 counts less than 200 cells/mm3, consider delaying initiation of the hepatitis C treatment regimen until the patient is stable on a fully suppressive ARV regimen. Instruct coinfected patients to avoid consuming alcohol, and offer vaccinations against hepatitis A and hepatitis B as appropriate.[46638] Patients receiving doravirine; lamivudine; tenofovir disoproxil fumarate in combination with hepatitis C treatment regimens containing ribavirin should be closely monitored. Ribavirin can reduce the phosphorylation of pyrimidine nucleoside analogs, such as lamivudine. Cell culture studies have shown lamivudine use with ribavirin decreases the anti-HIV-1 activity of lamivudine by 3.5-fold.[63485]

    Hepatic disease, hepatitis, hepatitis B and HIV coinfection, hepatitis B exacerbation

    Monitor liver function tests in all patients prior to and during treatment with doravirine; lamivudine; tenofovir disoproxil fumarate. Cases of elevated hepatic enzymes and increased bilirubin concentrations were observed in recipients of doravirine during clinical trials; use of the drug in patients with severe hepatic disease (Child-Pugh C) has not been studied. Doravirine; lamivudine; tenofovir disoproxil fumarate is not indicated for the treatment of chronic hepatitis B virus (HBV) infection; however, both the lamivudine and tenofovir components are active against the hepatitis B virus. Perform hepatitis B virus (HBV) screening in any patient who presents with HIV infection to assure appropriate treatment. Patients with hepatitis B and HIV coinfection should be started on a fully suppressive antiretroviral (ARV) regimen with activity against both viruses (regardless of CD4 counts and HBV DNA concentrations). HIV treatment guidelines recommend these patients receive an ARV regimen that contains a dual NRTI backbone of tenofovir alafenamide or tenofovir disoproxil fumarate with either emtricitabine or lamivudine. If tenofovir cannot be used, entecavir should be used in combination with a fully suppressive ARV regimen (note: entecavir should not be considered part of the ARV regimen). Avoid using single-drug therapy to treat HBV (i.e., lamivudine, emtricitabine, tenofovir, or entecavir as the only active agent) as this may result in HIV resistant strains. Further, HBV treatment regimens that include adefovir or telbivudine should also be avoided, as these regimens are associated with a higher incidence of toxicities and increased rates of HBV treatment failure. Most coinfected patients should continue treatment indefinitely with the goal of maximal HIV suppression and prevention of HBV relapse. Patients with coexisting HBV and HIV infections who discontinue lamivudine or tenofovir may experience severe acute hepatitis B exacerbation with some cases resulting in hepatic decompensation and hepatic failure. Therefore, close monitoring of transaminase concentrations (every 6 weeks for the first 3 months, and every 3 to 6 months thereafter) is recommended in coinfected patients who discontinue NRTI therapy. If appropriate, resumption of anti-hepatitis B treatment may be required. For patients who refuse a fully suppressive ARV regimen, but still require treatment for HBV, consider 48 weeks of peginterferon alfa; do not administer HIV-active medications in the absence of a fully suppressive ARV regimen. Instruct patients to avoid consuming alcohol, and offer vaccinations against hepatitis A and hepatitis B as appropriate. [34362] [46638] [63485]

    Hepatomegaly, hepatotoxicity or lactic acidosis, obesity

    Lactic acidosis and hepatomegaly with steatosis, including fatal cases, have been reported following use of lamivudine and tenofovir disoproxil fumarate (DF), both alone and in combination with other antiretroviral medications. Consider suspending treatment with doravirine; lamivudine; tenofovir DF in any patient who develops clinical or laboratory findings suggestive of hepatotoxicity or lactic acidosis, which may include hepatomegaly and steatosis even in the absence of marked elevated hepatic enzymes. Although these adverse events may occur in any drug recipient, some risk factors include impaired hepatic function, obesity, and prolonged nucleoside exposure. In addition, a majority of these cases have been in females; it is unknown if being pregnant augments the incidence of this syndrome in patients receiving nucleoside analogs. However, because being pregnant itself can mimic some of the early symptoms of the lactic acid and hepatic steatosis syndrome or be associated with other significant disorders of liver metabolism, clinicians need to be alert for early diagnosis of this syndrome. Pregnant women receiving nucleoside analogs should have LFTs and serum electrolytes assessed more frequently during the last trimester, and any new symptoms should be evaluated thoroughly.[46638] [63485]

    Autoimmune disease, Graves' disease, Guillain-Barre syndrome, immune reconstitution syndrome

    Immune reconstitution syndrome has been reported in patients treated with combination antiretroviral therapy. During the initial phase of HIV treatment, patients whose immune system responds to doravirine; lamivudine; tenofovir disoproxil fumarate therapy may develop an inflammatory response to indolent or residual opportunistic infections (such as progressive multifocal leukoencephalopathy (PML), mycobacterium avium complex (MAC), cytomegalovirus (CMV), Pneumocystis pneumonia, or tuberculosis (TB)), which may necessitate further evaluation and treatment.[34362] In addition, autoimmune disease (including Graves' disease, Guillain-Barre syndrome, autoimmune hepatitis, and polymyositis) may also develop; the time to onset is variable and may occur months after treatment initiation.[63485]

    Bone fractures, hypophosphatemia, renal disease, renal failure, renal impairment

    Lamivudine and tenofovir are principally eliminated by the kidney; use of doravirine; lamivudine; tenofovir disoproxil fumarate should be avoided in patients with impaired renal function (i.e., creatinine clearance less than 50 mL/min) and patients with end-stage renal disease requiring hemodialysis. Renal impairment, including acute renal failure and Fanconi syndrome (renal tubular injury with severe hypophosphatemia), has been associated with tenofovir disoproxil fumarate administration. The majority of such cases occurred in patients with underlying systemic or renal disease, or in patients taking nephrotoxic agents; some cases, however, occur in patients with no identifiable risk factors. The manufacturer recommends that an estimated creatinine clearance, urine glucose, and urine protein be assessed in all patients prior to treatment, and as indicated during treatment. Serum phosphorous concentrations should also be assessed prior to, and periodically during, treatment in patients with chronic kidney disease. In addition, closely evaluate the renal function of patients who experience persistent or worsening bone pain, pain in extremities, bone fractures, and muscle pain or weakness while receiving the drug as these may be manifestations of proximal renal tubulopathy. Avoid use of the drug concurrently with or recently after administration of a nephrotoxic agent, including high-dose or multiple non-steroidal antiinflammatory drugs (NSAIDS), as cases of acute renal failure requiring hospitalization and renal replacement therapy have been reported.[63485]

    Osteomalacia, osteopenia, osteoporosis

    Bone mineral density (BMD) monitoring should be considered for patients with HIV who have a history of pathologic bone fracture or are at substantial risk for osteopenia, osteoporosis, or osteomalacia. Cases of osteomalacia associated with proximal renal tubulopathy have been reported in association with the use of tenofovir disoproxil fumarate. In a postmarketing study comparing tenofovir with stavudine (each given in combination with lamivudine and efavirenz), decreases from baseline in BMD were seen at the lumbar spine and hip regions in both arms of the study. The clinical significance of the changes in BMD is unknown. Although the effect of supplementation with calcium and vitamin D was not studied, such supplementation may be considered for all patients. If bone abnormalities are suspected, appropriate consultation should be obtained.[28193] [63485]

    Peripheral neuropathy

    Patients with peripheral neuropathy may experience exacerbations during treatment with lamivudine-containing regimens.

    Pregnancy

    Antiretroviral therapy should be provided to all women during pregnancy, regardless of HIV RNA concentrations or CD4 cell count. Using highly active antiretroviral combination therapy (HAART) to maximally suppress viral replication is the most effective strategy to prevent the development of resistance and to minimize the risk of perinatal transmission. In treatment-naive women, begin HAART as soon as pregnancy is recognized or HIV is diagnosed, without waiting for the results of resistance testing; subsequent modifications to the treatment regimen should be made once the test results are available. Women who are currently receiving antiretroviral treatment when pregnancy is recognized should continue their treatment regimen if it is currently effective in suppressing viral replication; consider resistance testing if HIV RNA concentrations are more than 500 copies/mL. For women not currently receiving HAART, but who have previously received treatment, obtain a complete and accurate history of all prior antiretroviral regimens used and results of prior resistance testing, and perform resistance testing if HIV RNA concentrations are more than 500 copies/mL; treatment should be initiated prior to receiving resistance test results. There are insufficient data to recommend the use of doravirine; lamivudine; tenofovir disoproxil fumarate (DF) in pregnant patients or patients who are trying to become pregnant. However, for virologically suppressed patients who become pregnant while receiving doravirine; lamivudine; tenofovir DF, consider whether to change to an alternative treatment option or continue the same regimen. If the decision is made with the patient to continue, viral loads should be monitored more frequently (i.e., every 1 to 2 months). The Antiretroviral Pregnancy Registry (APR) has monitored 4 patients treated with doravirine during the first trimester and 1 patient treated during the second and third trimesters. One infant with first trimester exposure was noted to have a birth defect. This information is insufficient to make conclusions regarding the safety of doravirine during pregnancy. Other data from the APR, which includes more than 5,430 first trimester exposures to lamivudine and more than 4,480 first trimester exposures to tenofovir DF, have shown no difference in the risk of overall major birth defects when compared to the 2.7% background rate among pregnant women in the US. When exposure occurred in the first trimester, prevalence of defects was 3.1% (95% CI: 2.7 to 3.6) for lamivudine and 2.4% (95% CI: 2 to 2.9) for tenofovir DF. Nucleoside reverse transcriptase inhibitors (NRTIs) are known to induce mitochondrial dysfunction. An association of mitochondrial dysfunction in infants and in-utero antiretroviral exposure has been suggested, but not established. While the development of severe or fatal mitochondrial disease in exposed infants appears to be extremely rare, more intensive monitoring of hematologic and electrolyte parameters during the first few weeks of life is advised. Nucleoside analogs have been associated with the development of lactic acidosis, especially during pregnancy. It is unclear if pregnancy augments the incidence of lactic acidosis/hepatic steatosis in patients receiving nucleoside analogs. However, because pregnancy itself can mimic some of the early symptoms of the lactic acid/hepatic steatosis syndrome or be associated with other significant disorders of liver metabolism, clinicians need to be alert for early diagnosis of this syndrome. Pregnant women receiving nucleoside analogs should have LFTs and serum electrolytes assessed more frequently during the last trimester of pregnancy, and any new symptoms should be evaluated thoroughly. Regular laboratory monitoring is recommended to determine antiretroviral efficacy. Monitor CD4 counts at the initial visit. Women who have been on HAART for at least 2 years and have consistent viral suppression and CD4 counts consistently greater than 300 cells/mm3 do not need CD4 counts monitored after the initial visit during the pregnancy. However, CD4 counts should be monitored every 3 months during pregnancy for women on HAART less than 2 years, women with CD4 count less than 300 cells/mm3, or women with inconsistent adherence or detectable viral loads. Monitor plasma HIV RNA at the initial visit, 2 to 4 weeks after initiating or changing therapy, monthly until undetectable, then at least every 3 months during pregnancy, and at 34 to 36 weeks gestation. Perform antiretroviral resistance assay (genotypic testing, and if indicated, phenotypic testing) at baseline in all women with HIV RNA concentrations greater than 500 copies/mL, unless they have already been tested for resistance. First trimester ultrasound is recommended to confirm gestational age and provide an accurate estimation of gestational age at delivery. A second trimester ultrasound can be used for both anatomical survey and determination of gestational age in those patients not seen until later in gestation. Perform standard glucose screening in women receiving antiretroviral therapy at 24 to 28 weeks gestation, although it should be noted that some experts would perform earlier screening with ongoing chronic protease inhibitor-based therapy initiated prior to pregnancy, similar to recommendations for women with high-risk factors for glucose intolerance. Liver function testing is recommended within 2 to 4 weeks after initiating or changing antiretroviral therapy, and approximately every 3 months thereafter during pregnancy (or as needed). All pregnant women should be counseled about the importance of adherence to their antiretroviral regimen to reduce the potential for the development of resistance and perinatal transmission. It is strongly recommended that antiretroviral therapy, once initiated, not be discontinued. If a woman decides to discontinue therapy, a consultation with an HIV specialist is recommended. There is a pregnancy exposure registry that monitors outcomes in pregnant patients exposed to doravirine; lamivudine; tenofovir disoproxil fumarate; information about the registry can be obtained at www.apregistry.com or by calling 1-800-258-4263.[27468] [23512] [46638] [63485]

    Breast-feeding

    To reduce the risk of postnatal transmission, mothers with HIV within the United States are advised by the Centers for Disease Control and Prevention to avoid breast-feeding. This recommendation applies to both untreated women and women who are receiving antiretroviral therapy, including doravirine; lamivudine; tenofovir disoproxil fumarate. If a mother with HIV opts to breast-feed, the infant should undergo immediate diagnostic and virologic HIV testing. Testing should continue throughout breast-feeding and up to 6 months after cessation of breast-feeding. For expert consultation, health care workers may contact the Perinatal HIV Hotline (888-448-8765).[42452] It is unknown if doravirine is present in human milk; however, both lamivudine and tenofovir have been shown to pass into human breast milk. Lamivudine was found to be secreted in human breast milk during a study involving 20 breast-feeding women with HIV who were administered either 300 mg of lamivudine twice daily as a single agent (n = 10) or lamivudine 150 mg twice daily in combination with zidovudine (n = 10). The mean breast milk concentrations of lamivudine in the respective groups were similar at 1.22 mg/L (range less than 0.5 to 6.09 mg/L) and 0.9 mg/L (range less than 0.5 to 8.2 mg/L). In another study, tenofovir exposure in exclusively breast-fed infants was found to be equivalent to approximately 4.2 micrograms per day. Other antiretroviral medications whose passage into human breast milk have been evaluated include efavirenz, nevirapine, zidovudine, lamivudine, and nelfinavir.[46774] [46675] [46688] [46679] [46680] [46682] [23512] [63485]

    ADVERSE REACTIONS

    Severe

    suicidal ideation / Delayed / 0-4.0
    bone fractures / Delayed / 1.3-1.3
    pancreatitis / Delayed / Incidence not known
    angioedema / Rapid / Incidence not known
    anaphylactoid reactions / Rapid / Incidence not known
    renal tubular necrosis / Delayed / Incidence not known
    Fanconi syndrome / Delayed / Incidence not known
    rhabdomyolysis / Delayed / Incidence not known
    diabetes insipidus / Delayed / Incidence not known
    renal failure (unspecified) / Delayed / Incidence not known
    interstitial nephritis / Delayed / Incidence not known
    hepatitis B exacerbation / Delayed / Incidence not known
    lactic acidosis / Delayed / Incidence not known

    Moderate

    depression / Delayed / 0-4.0
    elevated hepatic enzymes / Delayed / 0-4.0
    hyperbilirubinemia / Delayed / 0-1.0
    hypertriglyceridemia / Delayed / 0-1.0
    hypercholesterolemia / Delayed / 0-1.0
    hyperglycemia / Delayed / Incidence not known
    hypokalemia / Delayed / Incidence not known
    anemia / Delayed / Incidence not known
    lipodystrophy / Delayed / Incidence not known
    osteoporosis / Delayed / Incidence not known
    osteopenia / Delayed / Incidence not known
    osteomalacia / Delayed / Incidence not known
    hypophosphatemia / Delayed / Incidence not known
    myopathy / Delayed / Incidence not known
    proteinuria / Delayed / Incidence not known
    steatosis / Delayed / Incidence not known
    hepatomegaly / Delayed / Incidence not known
    dyspnea / Early / Incidence not known

    Mild

    dizziness / Early / 7.0-7.0
    nausea / Early / 5.0-5.0
    abnormal dreams / Early / 5.0-5.0
    nightmares / Early / 5.0-5.0
    diarrhea / Early / 4.0-4.0
    headache / Early / 4.0-4.0
    insomnia / Early / 4.0-4.0
    rash / Early / 2.0-2.0
    abdominal pain / Early / Incidence not known
    urticaria / Rapid / Incidence not known
    alopecia / Delayed / Incidence not known
    pruritus / Rapid / Incidence not known
    maculopapular rash / Early / Incidence not known
    weakness / Early / Incidence not known
    asthenia / Delayed / Incidence not known
    polyuria / Early / Incidence not known

    DRUG INTERACTIONS

    Abrocitinib: (Moderate) Coadministration of tenofovir disoproxil fumarate with abrocitinib may result in increased plasma concentrations of tenofovir, leading to an increase in tenofovir-related adverse effects. Tenofovir disoproxil fumarate is a P-gp substrate and abrocitinib is a P-gp inhibitor.
    Acalabrutinib: (Moderate) Coadministration of acalabrutinib and tenofovir disoproxil fumerate may increase may increase the absorption and plasma concentration of tenofovir disoproxil fumerate. Monitor patients for tenofovir-related adverse reactions and discontinue use in patients who experience an adverse reaction. Acalabrutinib is an inhibitor of the breast cancer resistance protein (BCRP) transporter in vitro; it may inhibit intestinal BCRP. Tenofovir disoproxil fumerate is a BCRP substrate.
    Acetaminophen; Aspirin, ASA; Caffeine: (Major) Renal impairment, which may include hypophosphatemia, has been reported with the use of tenofovir disoproxil fumarate with a majority of the cases occurring in patients who have underlying systemic or renal disease or who are concurrently taking nephrotoxic agents. Tenofovir should be avoided with concurrent or recent use of a nephrotoxic agent; patients receiving concomitant nephrotoxic agents, like salicylates should be carefully monitored for changes in serum creatinine and phosphorus.
    Acetaminophen; Caffeine; Magnesium Salicylate; Phenyltoloxamine: (Major) Renal impairment, which may include hypophosphatemia, has been reported with the use of tenofovir disoproxil fumarate with a majority of the cases occurring in patients who have underlying systemic or renal disease or who are concurrently taking nephrotoxic agents. Tenofovir should be avoided with concurrent or recent use of a nephrotoxic agent; patients receiving concomitant nephrotoxic agents, like salicylates should be carefully monitored for changes in serum creatinine and phosphorus.
    Acetaminophen; Caffeine; Phenyltoloxamine; Salicylamide: (Major) Renal impairment, which may include hypophosphatemia, has been reported with the use of tenofovir disoproxil fumarate with a majority of the cases occurring in patients who have underlying systemic or renal disease or who are concurrently taking nephrotoxic agents. Tenofovir should be avoided with concurrent or recent use of a nephrotoxic agent; patients receiving concomitant nephrotoxic agents, like salicylates should be carefully monitored for changes in serum creatinine and phosphorus.
    Acyclovir: (Moderate) Monitor for changes in serum creatinine and phosphorus if tenofovir disoproxil fumarate is administered in combination with nephrotoxic agents, such as acyclovir. Tenofovir is primarily excreted via the kidneys by a combination of glomerular filtration and active tubular secretion. Concurrent administration with drugs that decrease renal function may increase concentrations of tenofovir. In addition, use with drugs that are also eliminated by active tubular secretion may increase concentrations of the co-administered drug. Renal impairment, which may include hypophosphatemia, has been reported with the use of tenofovir disoproxil fumarate; a majority of the cases occurred in patients who had underlying systemic or renal disease or who are concurrently taking nephrotoxic agents. Tenofovir containing products should be avoided with concurrent or recent use of a nephrotoxic agent; patients receiving concomitant nephrotoxic agents should be carefully monitored for changes in serum creatinine and phosphorus, and urine glucose and protein.
    Adefovir: (Major) Avoid coadministration of tenofovir disoproxil fumarate with adefovir. Both tenofovir and adefovir are primarily excreted via the kidneys by a combination of glomerular filtration and active tubular secretion. Concurrent administration may increase concentrations of both drugs resulting in additive nephrotoxicity. Additionally, in the treatment of chronic hepatitis B, tenofovir should not be administered in combination with adefovir to avoid multi-drug resistance. If coadministration is necessary, patients should be carefully monitored for changes in serum creatinine and phosphorus, and urine glucose and protein. (Major) Patients who are concurrently taking adefovir with antiretrovirals (i.e., anti-retroviral nucleoside reverse transcriptase inhibitors (NRTIs)) are at risk of developing lactic acidosis and severe hepatomegaly with steatosis. Lactic acidosis and severe hepatomegaly with steatosis, including fatal cases, have been reported with the use of nucleoside analogs alone or in combination with antiretrovirals. A majority of these cases have been in women; obesity and prolonged nucleoside exposure may also be risk factors. Particular caution should be exercised when administering nucleoside analogs to any patient with known risk factors for hepatic disease; however, cases have also been reported in patients with no known risk factors. Suspend adefovir in any patient who develops clinical or laboratory findings suggestive of lactic acidosis or pronounced hepatotoxicity (which may include hepatomegaly and steatosis even in the absence of marked transaminase elevations).
    Alogliptin; Metformin: (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.
    Amikacin: (Moderate) Renal impairment, which may include hypophosphatemia, has been reported with the use of tenofovir with a majority of the cases occurring in patients who have underlying systemic or renal disease or who are concurrently taking nephrotoxic agents. Tenofovir should be avoided with concurrent or recent use of a nephrotoxic agent; patients receiving concomitant nephrotoxic agents should be carefully monitored for changes in serum creatinine and phosphorus.
    Amiloride: (Moderate) Drugs that are actively secreted via cationic tubular secretion, such as amiloride, should be co-administered with caution with lamivudine since they could increase lamivudine plasma concentrations, and therefore lamivudine associated adverse reactions, via potential competition for renal cationic secretion.
    Amiloride; Hydrochlorothiazide, HCTZ: (Moderate) Drugs that are actively secreted via cationic tubular secretion, such as amiloride, should be co-administered with caution with lamivudine since they could increase lamivudine plasma concentrations, and therefore lamivudine associated adverse reactions, via potential competition for renal cationic secretion.
    Aminoglycosides: (Moderate) Renal impairment, which may include hypophosphatemia, has been reported with the use of tenofovir with a majority of the cases occurring in patients who have underlying systemic or renal disease or who are concurrently taking nephrotoxic agents. Tenofovir should be avoided with concurrent or recent use of a nephrotoxic agent; patients receiving concomitant nephrotoxic agents should be carefully monitored for changes in serum creatinine and phosphorus.
    Aminosalicylate sodium, Aminosalicylic acid: (Major) Renal impairment, which may include hypophosphatemia, has been reported with the use of tenofovir disoproxil fumarate with a majority of the cases occurring in patients who have underlying systemic or renal disease or who are concurrently taking nephrotoxic agents. Tenofovir should be avoided with concurrent or recent use of a nephrotoxic agent; patients receiving concomitant nephrotoxic agents, like salicylates should be carefully monitored for changes in serum creatinine and phosphorus.
    Amiodarone: (Moderate) Caution is advised when administering tenofovir, PMPA, a P-glycoprotein (P-gp) substrate, concurrently with inhibitors of P-gp, such as amiodarone. Coadministration may result in increased absorption of tenofovir. Monitor for tenofovir-associated adverse reactions.
    Amlodipine; Celecoxib: (Moderate) Avoid administering tenofovir, PMPA concurrently with or recently after a nephrotoxic agent, such as high-dose or multiple nonsteroidal antiinflammatory drugs (NSAIDs). Cases of acute renal failure, some requiring hospitalization and renal replacement therapy, have been reported after high-dose or multiple NSAIDs were initiated in patients who appeared stable on tenofovir. Consider alternatives to NSAIDs in patients at risk for renal dysfunction. If these drugs must be coadministered, carefully monitor the estimated creatinine creatinine, serum phosphorus, urine glucose, and urine protein prior to, and periodically during, treatment.
    Amoxicillin; Clarithromycin; Omeprazole: (Moderate) Caution is advised when administering tenofovir, PMPA, a P-glycoprotein (P-gp) substrate, concurrently with inhibitors of P-gp, such as clarithromycin. Coadministration may result in increased absorption of tenofovir. Monitor for tenofovir-associated adverse reactions. (Minor) Coadministration of doravirine and clarithromycin may result in increased doravirine plasma concentrations. Doravirine is a CYP3A4 substrate; clarithromycin is a strong inhibitor. In drug interaction studies, concurrent use of strong CYP3A4 inhibitors increased doravirine exposure by more than 3-fold; however, this increase was not considered clinically significant.
    Amphotericin B cholesteryl sulfate complex (ABCD): (Minor) Additive nephrotoxicity can also occur if amphotericin B is given concomitantly with tenofovir. Tenofovir should be avoided with concurrent or recent use of a nephrotoxic agent; patients receiving concomitant nephrotoxic agents should be carefully monitored for changes in serum creatinine and phosphorus.
    Amphotericin B lipid complex (ABLC): (Minor) Additive nephrotoxicity can also occur if amphotericin B is given concomitantly with tenofovir. Tenofovir should be avoided with concurrent or recent use of a nephrotoxic agent; patients receiving concomitant nephrotoxic agents should be carefully monitored for changes in serum creatinine and phosphorus.
    Amphotericin B liposomal (LAmB): (Minor) Additive nephrotoxicity can also occur if amphotericin B is given concomitantly with tenofovir. Tenofovir should be avoided with concurrent or recent use of a nephrotoxic agent; patients receiving concomitant nephrotoxic agents should be carefully monitored for changes in serum creatinine and phosphorus.
    Amphotericin B: (Minor) Additive nephrotoxicity can also occur if amphotericin B is given concomitantly with tenofovir. Tenofovir should be avoided with concurrent or recent use of a nephrotoxic agent; patients receiving concomitant nephrotoxic agents should be carefully monitored for changes in serum creatinine and phosphorus.
    Apalutamide: (Contraindicated) Concurrent administration of doravirine and apalutamide is contraindicated due to decreased doravirine exposure, resulting in potential loss of virologic control. At least a 4-week cessation period is recommended before initiating treatment with doravirine. Doravirine is a CYP3A4 substrate; apalutamide is a strong CYP3A4 inducer.
    Armodafinil: (Minor) Concurrent administration of doravirine and armodafinil may result in decreased doravirine exposure, resulting in potential loss of virologic control. Doravirine is a CYP3A4 substrate; armodafinil is a weak CYP3A4 inducer.
    Aspirin, ASA: (Major) Renal impairment, which may include hypophosphatemia, has been reported with the use of tenofovir disoproxil fumarate with a majority of the cases occurring in patients who have underlying systemic or renal disease or who are concurrently taking nephrotoxic agents. Tenofovir should be avoided with concurrent or recent use of a nephrotoxic agent; patients receiving concomitant nephrotoxic agents, like salicylates should be carefully monitored for changes in serum creatinine and phosphorus.
    Aspirin, ASA; Butalbital; Caffeine: (Major) Renal impairment, which may include hypophosphatemia, has been reported with the use of tenofovir disoproxil fumarate with a majority of the cases occurring in patients who have underlying systemic or renal disease or who are concurrently taking nephrotoxic agents. Tenofovir should be avoided with concurrent or recent use of a nephrotoxic agent; patients receiving concomitant nephrotoxic agents, like salicylates should be carefully monitored for changes in serum creatinine and phosphorus. (Moderate) Concurrent administration of doravirine and butalbital may result in decreased doravirine exposure, resulting in potential loss of virologic control. Doravirine is a CYP3A4 substrate; butalbital is a moderate CYP3A4 inducer.
    Aspirin, ASA; Butalbital; Caffeine; Codeine: (Major) Renal impairment, which may include hypophosphatemia, has been reported with the use of tenofovir disoproxil fumarate with a majority of the cases occurring in patients who have underlying systemic or renal disease or who are concurrently taking nephrotoxic agents. Tenofovir should be avoided with concurrent or recent use of a nephrotoxic agent; patients receiving concomitant nephrotoxic agents, like salicylates should be carefully monitored for changes in serum creatinine and phosphorus. (Moderate) Concurrent administration of doravirine and butalbital may result in decreased doravirine exposure, resulting in potential loss of virologic control. Doravirine is a CYP3A4 substrate; butalbital is a moderate CYP3A4 inducer.
    Aspirin, ASA; Caffeine: (Major) Renal impairment, which may include hypophosphatemia, has been reported with the use of tenofovir disoproxil fumarate with a majority of the cases occurring in patients who have underlying systemic or renal disease or who are concurrently taking nephrotoxic agents. Tenofovir should be avoided with concurrent or recent use of a nephrotoxic agent; patients receiving concomitant nephrotoxic agents, like salicylates should be carefully monitored for changes in serum creatinine and phosphorus.
    Aspirin, ASA; Caffeine; Dihydrocodeine: (Major) Renal impairment, which may include hypophosphatemia, has been reported with the use of tenofovir disoproxil fumarate with a majority of the cases occurring in patients who have underlying systemic or renal disease or who are concurrently taking nephrotoxic agents. Tenofovir should be avoided with concurrent or recent use of a nephrotoxic agent; patients receiving concomitant nephrotoxic agents, like salicylates should be carefully monitored for changes in serum creatinine and phosphorus.
    Aspirin, ASA; Caffeine; Orphenadrine: (Major) Renal impairment, which may include hypophosphatemia, has been reported with the use of tenofovir disoproxil fumarate with a majority of the cases occurring in patients who have underlying systemic or renal disease or who are concurrently taking nephrotoxic agents. Tenofovir should be avoided with concurrent or recent use of a nephrotoxic agent; patients receiving concomitant nephrotoxic agents, like salicylates should be carefully monitored for changes in serum creatinine and phosphorus.
    Aspirin, ASA; Carisoprodol: (Major) Renal impairment, which may include hypophosphatemia, has been reported with the use of tenofovir disoproxil fumarate with a majority of the cases occurring in patients who have underlying systemic or renal disease or who are concurrently taking nephrotoxic agents. Tenofovir should be avoided with concurrent or recent use of a nephrotoxic agent; patients receiving concomitant nephrotoxic agents, like salicylates should be carefully monitored for changes in serum creatinine and phosphorus.
    Aspirin, ASA; Carisoprodol; Codeine: (Major) Renal impairment, which may include hypophosphatemia, has been reported with the use of tenofovir disoproxil fumarate with a majority of the cases occurring in patients who have underlying systemic or renal disease or who are concurrently taking nephrotoxic agents. Tenofovir should be avoided with concurrent or recent use of a nephrotoxic agent; patients receiving concomitant nephrotoxic agents, like salicylates should be carefully monitored for changes in serum creatinine and phosphorus.
    Aspirin, ASA; Citric Acid; Sodium Bicarbonate: (Major) Renal impairment, which may include hypophosphatemia, has been reported with the use of tenofovir disoproxil fumarate with a majority of the cases occurring in patients who have underlying systemic or renal disease or who are concurrently taking nephrotoxic agents. Tenofovir should be avoided with concurrent or recent use of a nephrotoxic agent; patients receiving concomitant nephrotoxic agents, like salicylates should be carefully monitored for changes in serum creatinine and phosphorus.
    Aspirin, ASA; Dipyridamole: (Major) Renal impairment, which may include hypophosphatemia, has been reported with the use of tenofovir disoproxil fumarate with a majority of the cases occurring in patients who have underlying systemic or renal disease or who are concurrently taking nephrotoxic agents. Tenofovir should be avoided with concurrent or recent use of a nephrotoxic agent; patients receiving concomitant nephrotoxic agents, like salicylates should be carefully monitored for changes in serum creatinine and phosphorus.
    Aspirin, ASA; Omeprazole: (Major) Renal impairment, which may include hypophosphatemia, has been reported with the use of tenofovir disoproxil fumarate with a majority of the cases occurring in patients who have underlying systemic or renal disease or who are concurrently taking nephrotoxic agents. Tenofovir should be avoided with concurrent or recent use of a nephrotoxic agent; patients receiving concomitant nephrotoxic agents, like salicylates should be carefully monitored for changes in serum creatinine and phosphorus.
    Aspirin, ASA; Oxycodone: (Major) Renal impairment, which may include hypophosphatemia, has been reported with the use of tenofovir disoproxil fumarate with a majority of the cases occurring in patients who have underlying systemic or renal disease or who are concurrently taking nephrotoxic agents. Tenofovir should be avoided with concurrent or recent use of a nephrotoxic agent; patients receiving concomitant nephrotoxic agents, like salicylates should be carefully monitored for changes in serum creatinine and phosphorus.
    Aspirin, ASA; Pravastatin: (Major) Renal impairment, which may include hypophosphatemia, has been reported with the use of tenofovir disoproxil fumarate with a majority of the cases occurring in patients who have underlying systemic or renal disease or who are concurrently taking nephrotoxic agents. Tenofovir should be avoided with concurrent or recent use of a nephrotoxic agent; patients receiving concomitant nephrotoxic agents, like salicylates should be carefully monitored for changes in serum creatinine and phosphorus.
    Atazanavir: (Moderate) Tenofovir decreases atazanavir AUC and Cmin. If atazanavir and tenofovir, PMPA are to be coadministered, it is recommended that atazanavir 300 mg be given with ritonavir 100 mg and tenofovir 300 mg once per day with food in patients >= 40 kg; atazanavir should not be coadministered with tenofovir without ritonavir. Data are insufficient to recommend atazanavir dosing in children < 40 kg who are also receiving concomitant tenofovir. In three post-marketing clinical trials, atazanavir AUC and Cmin were decreased by approximately 25% and 23 to 40%, respectively, when atazanavir was coadministered with tenofovir, PMPA as compared to atazanavir alone. Coadministration of atazanavir and tenofovir without ritonavir could lead to loss or lack of virologic response and possible resistance to atazanavir. In addition, atazanavir appears to increase tenofovir plasma concentrations, which could lead to adverse effects associated with tenofovir, including renal disorders. Increased tenofovir concentrations have been noted in the following combination regimens: tenofovir with ritonavir 'boosted' atazanavir; tenofovir, atazanavir, and lopinavir; ritonavir. Patients who receive tenofovir with atazanavir and any form/dose of ritonavir should be monitored for tenofovir-associated adverse events, with tenofovir being discontinued in patients who develop such adverse events. Although there are varying results in reports of an interaction between tenofovir and lopinavir; ritonavir, the clinical significance of an interaction is suspected to be insignificant. In treatment-experienced patients >= 40 kg receiving H2-antagonists and tenofovir, atazanavir should be dosed 400 mg with ritonavir 100 mg once daily with food. (Minor) Coadministration of doravirine and atazanavir may result in increased doravirine plasma concentrations. Doravirine is a CYP3A4 substrate; atazanavir is a strong inhibitor. In drug interaction studies, concurrent use of strong CYP3A4 inhibitors increased doravirine exposure by more than 3-fold; however, this increase was not considered clinically significant.
    Atazanavir; Cobicistat: (Moderate) Tenofovir decreases atazanavir AUC and Cmin. If atazanavir and tenofovir, PMPA are to be coadministered, it is recommended that atazanavir 300 mg be given with ritonavir 100 mg and tenofovir 300 mg once per day with food in patients >= 40 kg; atazanavir should not be coadministered with tenofovir without ritonavir. Data are insufficient to recommend atazanavir dosing in children < 40 kg who are also receiving concomitant tenofovir. In three post-marketing clinical trials, atazanavir AUC and Cmin were decreased by approximately 25% and 23 to 40%, respectively, when atazanavir was coadministered with tenofovir, PMPA as compared to atazanavir alone. Coadministration of atazanavir and tenofovir without ritonavir could lead to loss or lack of virologic response and possible resistance to atazanavir. In addition, atazanavir appears to increase tenofovir plasma concentrations, which could lead to adverse effects associated with tenofovir, including renal disorders. Increased tenofovir concentrations have been noted in the following combination regimens: tenofovir with ritonavir 'boosted' atazanavir; tenofovir, atazanavir, and lopinavir; ritonavir. Patients who receive tenofovir with atazanavir and any form/dose of ritonavir should be monitored for tenofovir-associated adverse events, with tenofovir being discontinued in patients who develop such adverse events. Although there are varying results in reports of an interaction between tenofovir and lopinavir; ritonavir, the clinical significance of an interaction is suspected to be insignificant. In treatment-experienced patients >= 40 kg receiving H2-antagonists and tenofovir, atazanavir should be dosed 400 mg with ritonavir 100 mg once daily with food. (Minor) Coadministration of doravirine and atazanavir may result in increased doravirine plasma concentrations. Doravirine is a CYP3A4 substrate; atazanavir is a strong inhibitor. In drug interaction studies, concurrent use of strong CYP3A4 inhibitors increased doravirine exposure by more than 3-fold; however, this increase was not considered clinically significant. (Minor) Coadministration of doravirine and cobicistat may result in increased doravirine plasma concentrations. Doravirine is a CYP3A4 substrate; cobicistat is a strong inhibitor. In drug interaction studies, concurrent use of strong CYP3A4 inhibitors increased doravirine exposure by more than 3-fold; however, this increase was not considered clinically significant.
    Atropine; Benzoic Acid; Hyoscyamine; Methenamine; Methylene Blue; Phenyl Salicylate: (Major) Renal impairment, which may include hypophosphatemia, has been reported with the use of tenofovir disoproxil fumarate with a majority of the cases occurring in patients who have underlying systemic or renal disease or who are concurrently taking nephrotoxic agents. Tenofovir should be avoided with concurrent or recent use of a nephrotoxic agent; patients receiving concomitant nephrotoxic agents, like salicylates should be carefully monitored for changes in serum creatinine and phosphorus.
    Bacitracin: (Moderate) Tenofovir-containing products should be avoided with concurrent or recent use of a nephrotoxic agent, such as bacitracin. Tenofovir is primarily excreted via the kidneys by a combination of glomerular filtration and active tubular secretion. Coadministration of tenofovir with drugs that are eliminated by active tubular secretion may increase concentrations of tenofovir and/or the co-administered drug. Drugs that decrease renal function may also increase concentrations of tenofovir. Renal impairment, which may include hypophosphatemia, has been reported with the use of tenofovir with a majority of the cases occurring in patients who have underlying systemic or renal disease or who are concurrently taking nephrotoxic agents. Monitor patients receiving concomitant nephrotoxic agents for changes in serum creatinine and phosphorus.
    Belladonna Alkaloids; Ergotamine; Phenobarbital: (Contraindicated) Concurrent administration of doravirine and phenobarbital is contraindicated due to decreased doravirine exposure, resulting in potential loss of virologic control. At least a 4-week cessation period is recommended before initiating treatment with doravirine. Doravirine is a CYP3A4 substrate; phenobarbital is a strong CYP3A4 inducer.
    Belzutifan: (Moderate) Concurrent administration of doravirine and belzutifan may result in decreased doravirine exposure, resulting in potential loss of virologic control. Doravirine is a CYP3A substrate; belzutifan is a weak CYP3A inducer.
    Benzoic Acid; Hyoscyamine; Methenamine; Methylene Blue; Phenyl Salicylate: (Major) Renal impairment, which may include hypophosphatemia, has been reported with the use of tenofovir disoproxil fumarate with a majority of the cases occurring in patients who have underlying systemic or renal disease or who are concurrently taking nephrotoxic agents. Tenofovir should be avoided with concurrent or recent use of a nephrotoxic agent; patients receiving concomitant nephrotoxic agents, like salicylates should be carefully monitored for changes in serum creatinine and phosphorus.
    Bepridil: (Moderate) Caution is advised when administering tenofovir, PMPA, a P-glycoprotein (P-gp) substrate, concurrently with inhibitors of P-gp, such as bepridil. Coadministration may result in increased absorption of tenofovir. Monitor for tenofovir-associated adverse reactions.
    Berotralstat: (Moderate) Coadministration of tenofovir disoproxil fumarate with berotralstat may result in increased plasma concentrations of tenofovir, leading to an increase in tenofovir-related adverse effects. Tenofovir disoproxil fumarate is a P-gp substrate and berotralstat is a P-gp inhibitor.
    Bexarotene: (Moderate) Concurrent administration of doravirine and bexarotene may result in decreased doravirine exposure, resulting in potential loss of virologic control. Doravirine is a CYP3A4 substrate; bexarotene is a moderate CYP3A4 inducer.
    Bictegravir; Emtricitabine; Tenofovir Alafenamide: (Major) Do not coadminister lamivudine, 3TC-containing products and emtricitabine-containing products due to similarities between emtricitabine and lamivudine.
    Bismuth Subsalicylate: (Major) Renal impairment, which may include hypophosphatemia, has been reported with the use of tenofovir disoproxil fumarate with a majority of the cases occurring in patients who have underlying systemic or renal disease or who are concurrently taking nephrotoxic agents. Tenofovir should be avoided with concurrent or recent use of a nephrotoxic agent; patients receiving concomitant nephrotoxic agents, like salicylates should be carefully monitored for changes in serum creatinine and phosphorus.
    Bismuth Subsalicylate; Metronidazole; Tetracycline: (Major) Renal impairment, which may include hypophosphatemia, has been reported with the use of tenofovir disoproxil fumarate with a majority of the cases occurring in patients who have underlying systemic or renal disease or who are concurrently taking nephrotoxic agents. Tenofovir should be avoided with concurrent or recent use of a nephrotoxic agent; patients receiving concomitant nephrotoxic agents, like salicylates should be carefully monitored for changes in serum creatinine and phosphorus.
    Boceprevir: (Moderate) Caution is advised when administering tenofovir, PMPA, a P-glycoprotein (P-gp) substrate, concurrently with inhibitors of P-gp, such as boceprevir. Coadministration may result in increased absorption of tenofovir. Monitor for tenofovir-associated adverse reactions.
    Bortezomib: (Minor) Monitor patients for the development of peripheral neuropathy when receiving bortezomib in combination with other drugs that can cause peripheral neuropathy like lamivudine; the risk of peripheral neuropathy may be additive.
    Bosentan: (Moderate) Concurrent administration of doravirine and bosentan may result in decreased doravirine exposure, resulting in potential loss of virologic control. Doravirine is a CYP3A4 substrate; bosentan is a moderate CYP3A4 inducer.
    Brigatinib: (Moderate) Monitor for an increase in tenofovir-related adverse reactions if coadministration with brigatinib is necessary. Tenofovir disoproxil fumarate is a substrate of P-glycoprotein (P-gp) and BCRP. Brigatinib inhibits both P-gp and BCRP in vitro and may have the potential to increase concentrations of substrates of these transporters. (Minor) Concurrent administration of doravirine and brigatinib may result in decreased doravirine exposure, resulting in potential loss of virologic control. Doravirine is a CYP3A4 substrate; brigatinib is a weak CYP3A4 inducer.
    Bupivacaine; Meloxicam: (Moderate) Avoid administering tenofovir, PMPA concurrently with or recently after a nephrotoxic agent, such as high-dose or multiple nonsteroidal antiinflammatory drugs (NSAIDs). Cases of acute renal failure, some requiring hospitalization and renal replacement therapy, have been reported after high-dose or multiple NSAIDs were initiated in patients who appeared stable on tenofovir. Consider alternatives to NSAIDs in patients at risk for renal dysfunction. If these drugs must be coadministered, carefully monitor the estimated creatinine creatinine, serum phosphorus, urine glucose, and urine protein prior to, and periodically during, treatment.
    Butabarbital: (Moderate) Concurrent administration of doravirine and butabarbital may result in decreased doravirine exposure, resulting in potential loss of virologic control. Doravirine is a CYP3A4 substrate; butabarbital is a moderate CYP3A4 inducer.
    Butalbital; Acetaminophen: (Moderate) Concurrent administration of doravirine and butalbital may result in decreased doravirine exposure, resulting in potential loss of virologic control. Doravirine is a CYP3A4 substrate; butalbital is a moderate CYP3A4 inducer.
    Butalbital; Acetaminophen; Caffeine: (Moderate) Concurrent administration of doravirine and butalbital may result in decreased doravirine exposure, resulting in potential loss of virologic control. Doravirine is a CYP3A4 substrate; butalbital is a moderate CYP3A4 inducer.
    Butalbital; Acetaminophen; Caffeine; Codeine: (Moderate) Concurrent administration of doravirine and butalbital may result in decreased doravirine exposure, resulting in potential loss of virologic control. Doravirine is a CYP3A4 substrate; butalbital is a moderate CYP3A4 inducer.
    Cabozantinib: (Minor) Monitor for an increase in both cabozantinib- and tenofovir-related adverse reactions if coadministration is necessary. Cabozantinib is a Multidrug Resistance Protein 2 (MRP2) substrate and tenofovir is an MRP2 inhibitor. MRP2 inhibitors have the potential to increase plasma concentrations of cabozantinib. Cabozantinib is also P-gp inhibitor and has the potential to increase plasma concentrations of P-gp substrates such as tenofovir. The clinical relevance of either of these interactions is unknown. (Minor) Monitor for an increase in cabozantinib-related adverse reactions if coadministration with lamivudine is necessary. Cabozantinib is a Multidrug Resistance Protein 2 (MRP2) substrate and lamivudine is an MRP2 inhibitor. MRP2 inhibitors have the potential to increase plasma concentrations of cabozantinib; however, the clinical relevance of this interaction is unknown.
    Canagliflozin; Metformin: (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.
    Cannabidiol: (Moderate) Coadministration of tenofovir disoproxil fumarate with cannabidiol may result in increased plasma concentrations of tenofovir, leading to an increase in tenofovir-related adverse effects. Tenofovir disoproxil fumarate is a P-gp substrate and cannabidiol is a P-gp inhibitor.
    Capmatinib: (Moderate) Coadministration of tenofovir disoproxil fumarate with capmatinib may result in increased plasma concentrations of tenofovir, leading to an increase in tenofovir-related adverse effects. Tenofovir disoproxil fumarate is a P-glycoprotein (P-gp) and BCRP substrate and capmatinib is a P-gp and BCRP inhibitor.
    Carbamazepine: (Contraindicated) Coadministration of carbamazepine and doravirine is contraindicated due to the potential for loss of virologic response and possible resistance to doravirine or the class of non-nucleoside reverse transcriptase inhibitors (NNRTIs). If doravirine use is necessary, discontinue carbamazepine at least 4-weeks prior to initiation. Doravirine is a CYP3A4 substrate and carbamazepine is a potent CYP3A4 inducer.
    Carboplatin: (Moderate) Tenofovir-containing products should be avoided with concurrent or recent use of a nephrotoxic agent, such as carboplatin. Tenofovir is primarily excreted via the kidneys by a combination of glomerular filtration and active tubular secretion. Coadministration of tenofovir with drugs that are eliminated by active tubular secretion may increase concentrations of tenofovir and/or the co-administered drug. Drugs that decrease renal function may also increase concentrations of tenofovir. Renal impairment, which may include hypophosphatemia, has been reported with the use of tenofovir with a majority of the cases occurring in patients who have underlying systemic or renal disease or who are concurrently taking nephrotoxic agents. Monitor patients receiving concomitant nephrotoxic agents for changes in serum creatinine and phosphorus.
    Carvedilol: (Moderate) Increased concentrations of tenofovir may occur if it is coadministered with carvedilol; exercise caution. Carvedilol is a P-glycoprotein (P-gp) inhibitor and tenofovir is a P-gp substrate.
    Celecoxib: (Moderate) Avoid administering tenofovir, PMPA concurrently with or recently after a nephrotoxic agent, such as high-dose or multiple nonsteroidal antiinflammatory drugs (NSAIDs). Cases of acute renal failure, some requiring hospitalization and renal replacement therapy, have been reported after high-dose or multiple NSAIDs were initiated in patients who appeared stable on tenofovir. Consider alternatives to NSAIDs in patients at risk for renal dysfunction. If these drugs must be coadministered, carefully monitor the estimated creatinine creatinine, serum phosphorus, urine glucose, and urine protein prior to, and periodically during, treatment.
    Celecoxib; Tramadol: (Moderate) Avoid administering tenofovir, PMPA concurrently with or recently after a nephrotoxic agent, such as high-dose or multiple nonsteroidal antiinflammatory drugs (NSAIDs). Cases of acute renal failure, some requiring hospitalization and renal replacement therapy, have been reported after high-dose or multiple NSAIDs were initiated in patients who appeared stable on tenofovir. Consider alternatives to NSAIDs in patients at risk for renal dysfunction. If these drugs must be coadministered, carefully monitor the estimated creatinine creatinine, serum phosphorus, urine glucose, and urine protein prior to, and periodically during, treatment.
    Cenobamate: (Moderate) Concurrent administration of doravirine and cenobamate may result in decreased doravirine exposure, resulting in potential loss of virologic control. Doravirine is a CYP3A4 substrate; cenobamate is a moderate CYP3A4 inducer.
    Ceritinib: (Minor) Monitor for an increase in doravirine-related adverse reactions if coadministration with ceritinib is necessary; increased doravirine plasma concentrations may occur. Doravirine is a CYP3A4 substrate; ceritinib is a strong inhibitor. In drug interaction studies, concurrent use of strong CYP3A4 inhibitors increased doravirine exposure by more than 3-fold; however, this increase was not considered clinically significant.
    Chloramphenicol: (Minor) Coadministration of doravirine and chloramphenicol may result in increased doravirine plasma concentrations. Doravirine is a CYP3A4 substrate; chloramphenicol is a strong inhibitor. In drug interaction studies, concurrent use of strong CYP3A4 inhibitors increased doravirine exposure by more than 3-fold; however, this increase was not considered clinically significant.
    Chlorpheniramine; Ibuprofen; Pseudoephedrine: (Moderate) Avoid administering tenofovir, PMPA concurrently with or recently after a nephrotoxic agent, such as high-dose or multiple nonsteroidal antiinflammatory drugs (NSAIDs). Cases of acute renal failure, some requiring hospitalization and renal replacement therapy, have been reported after high-dose or multiple NSAIDs were initiated in patients who appeared stable on tenofovir. Consider alternatives to NSAIDs in patients at risk for renal dysfunction. If these drugs must be coadministered, carefully monitor the estimated creatinine creatinine, serum phosphorus, urine glucose, and urine protein prior to, and periodically during, treatment.
    Choline Salicylate; Magnesium Salicylate: (Major) Renal impairment, which may include hypophosphatemia, has been reported with the use of tenofovir disoproxil fumarate with a majority of the cases occurring in patients who have underlying systemic or renal disease or who are concurrently taking nephrotoxic agents. Tenofovir should be avoided with concurrent or recent use of a nephrotoxic agent; patients receiving concomitant nephrotoxic agents, like salicylates should be carefully monitored for changes in serum creatinine and phosphorus.
    Cidofovir: (Moderate) Since tenofovir, PMPA is primarily eliminated by the kidneys, concurrent administration of tenofovir disoproxil with cidofovir may increase serum concentrations of tenofovir via competition for renal tubular secretion.
    Cisplatin: (Major) Avoid tenofovir administration with concurrent or recent treatment with cisplatin. Cisplatin can cause nephrotoxicity. Tenofovir is primarily eliminated by the kidneys; drugs that decrease renal function may increase concentrations of tenofovir. Also, cases of acute renal failure after initiation of other nephrotoxic drugs have been reported in HIV-infected patients with risk factors for renal dysfunction who appeared stable on tenofovir treatment; some patients required hospitalization and renal replacement therapy.
    Clarithromycin: (Moderate) Caution is advised when administering tenofovir, PMPA, a P-glycoprotein (P-gp) substrate, concurrently with inhibitors of P-gp, such as clarithromycin. Coadministration may result in increased absorption of tenofovir. Monitor for tenofovir-associated adverse reactions. (Minor) Coadministration of doravirine and clarithromycin may result in increased doravirine plasma concentrations. Doravirine is a CYP3A4 substrate; clarithromycin is a strong inhibitor. In drug interaction studies, concurrent use of strong CYP3A4 inhibitors increased doravirine exposure by more than 3-fold; however, this increase was not considered clinically significant.
    Clindamycin: (Moderate) Concomitant use of tenofovir and clindamycin may result in additive nephrotoxicity. Monitor for renal toxicity if concomitant use is required.
    Clobazam: (Minor) Concurrent administration of doravirine and clobazam may result in decreased doravirine exposure, resulting in potential loss of virologic control. Doravirine is a CYP3A4 substrate; clobazam is a weak CYP3A4 inducer.
    Clofarabine: (Major) Avoid the concomitant use of clofarabine and tenofovir; coadministration may result in additive nephrotoxicity. Additionally, taking these drugs together may alter clofarabine concentrations; clofarabine and tenofovir are both substrates of OAT1 and OAT3.
    Cobicistat: (Minor) Coadministration of doravirine and cobicistat may result in increased doravirine plasma concentrations. Doravirine is a CYP3A4 substrate; cobicistat is a strong inhibitor. In drug interaction studies, concurrent use of strong CYP3A4 inhibitors increased doravirine exposure by more than 3-fold; however, this increase was not considered clinically significant.
    Colchicine: (Moderate) Caution is advised when administering tenofovir, PMPA, a P-glycoprotein (P-gp) substrate, concurrently with inhibitors of P-gp, such as colchicine. Coadministration may result in increased absorption of tenofovir. Monitor for tenofovir-associated adverse reactions.
    Colistimethate, Colistin, Polymyxin E: (Moderate) Tenofovir-containing products should be avoided with concurrent or recent use of a nephrotoxic agent, such as colistimethate sodium. Tenofovir is primarily excreted via the kidneys by a combination of glomerular filtration and active tubular secretion. Coadministration of tenofovir with drugs that are eliminated by active tubular secretion may increase concentrations of tenofovir and/or the co-administered drug. Drugs that decrease renal function may also increase concentrations of tenofovir. Renal impairment, which may include hypophosphatemia, has been reported with the use of tenofovir with a majority of the cases occurring in patients who have underlying systemic or renal disease or who are concurrently taking nephrotoxic agents. Monitor patients receiving concomitant nephrotoxic agents for changes in serum creatinine and phosphorus, and urine glucose and protein.
    Colistin: (Moderate) Tenofovir-containing products should be avoided with concurrent or recent use of a nephrotoxic agent, such as colistimethate sodium. Tenofovir is primarily excreted via the kidneys by a combination of glomerular filtration and active tubular secretion. Coadministration of tenofovir with drugs that are eliminated by active tubular secretion may increase concentrations of tenofovir and/or the co-administered drug. Drugs that decrease renal function may also increase concentrations of tenofovir. Renal impairment, which may include hypophosphatemia, has been reported with the use of tenofovir with a majority of the cases occurring in patients who have underlying systemic or renal disease or who are concurrently taking nephrotoxic agents. Monitor patients receiving concomitant nephrotoxic agents for changes in serum creatinine and phosphorus, and urine glucose and protein.
    Conivaptan: (Moderate) Use caution when administering conivaptan and tenofovir concurrently. Conivaptan is an inhibitor of P-glycoprotein (P-gp). Co-administration of conivaptan with P-gp substrates, such as tenofovir, PMPA, can increase tenofovir exposure leading to increased or prolonged therapeutic effects and adverse events.
    Cyclosporine: (Major) Tenofovir should be avoided with concurrent or recent use of a nephrotoxic agent; patients receiving concomitant nephrotoxic agents, such as cyclosporine, should be carefully monitored for changes in serum creatinine and phosphorus.
    Dabrafenib: (Moderate) Concurrent administration of doravirine and dabrafenib may result in decreased doravirine exposure, resulting in potential loss of virologic control. Doravirine is a CYP3A4 substrate; dabrafenib is a moderate CYP3A4 inducer.
    Dapagliflozin; Metformin: (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.
    Darolutamide: (Moderate) Caution is advised with the coadministration of darolutamide and tenofovir disoproxil fumarate due to the potential for increased plasma concentrations of tenofovir disoproxil fumarate increasing the risk of adverse effects. Tenofovir disoproxil fumarate is a substrate of breast cancer resistance protein (BCRP) and darolutamide is a BCRP inhibitor.
    Darunavir: (Moderate) Pharmacokinetic parameters (AUC, Cmax, Cmin) of tenofovir, PMPA are elevated when administered in combination with darunavir and ritonavir. The clinical significance of this interaction has not been established, and dosage adjustments are not recommended. Monitor the patients closely for tenofovir-related adverse events. (Minor) Coadministration of doravirine and darunavir may result in increased doravirine plasma concentrations. Doravirine is a CYP3A4 substrate; darunavir is a strong inhibitor. In drug interaction studies, concurrent use of strong CYP3A4 inhibitors increased doravirine exposure by more than 3-fold; however, this increase was not considered clinically significant.
    Darunavir; Cobicistat: (Moderate) Pharmacokinetic parameters (AUC, Cmax, Cmin) of tenofovir, PMPA are elevated when administered in combination with darunavir and ritonavir. The clinical significance of this interaction has not been established, and dosage adjustments are not recommended. Monitor the patients closely for tenofovir-related adverse events. (Minor) Coadministration of doravirine and cobicistat may result in increased doravirine plasma concentrations. Doravirine is a CYP3A4 substrate; cobicistat is a strong inhibitor. In drug interaction studies, concurrent use of strong CYP3A4 inhibitors increased doravirine exposure by more than 3-fold; however, this increase was not considered clinically significant. (Minor) Coadministration of doravirine and darunavir may result in increased doravirine plasma concentrations. Doravirine is a CYP3A4 substrate; darunavir is a strong inhibitor. In drug interaction studies, concurrent use of strong CYP3A4 inhibitors increased doravirine exposure by more than 3-fold; however, this increase was not considered clinically significant.
    Darunavir; Cobicistat; Emtricitabine; Tenofovir alafenamide: (Major) Do not coadminister lamivudine, 3TC-containing products and emtricitabine-containing products due to similarities between emtricitabine and lamivudine. (Moderate) Pharmacokinetic parameters (AUC, Cmax, Cmin) of tenofovir, PMPA are elevated when administered in combination with darunavir and ritonavir. The clinical significance of this interaction has not been established, and dosage adjustments are not recommended. Monitor the patients closely for tenofovir-related adverse events. (Minor) Coadministration of doravirine and cobicistat may result in increased doravirine plasma concentrations. Doravirine is a CYP3A4 substrate; cobicistat is a strong inhibitor. In drug interaction studies, concurrent use of strong CYP3A4 inhibitors increased doravirine exposure by more than 3-fold; however, this increase was not considered clinically significant. (Minor) Coadministration of doravirine and darunavir may result in increased doravirine plasma concentrations. Doravirine is a CYP3A4 substrate; darunavir is a strong inhibitor. In drug interaction studies, concurrent use of strong CYP3A4 inhibitors increased doravirine exposure by more than 3-fold; however, this increase was not considered clinically significant.
    Dasabuvir; Ombitasvir; Paritaprevir; Ritonavir: (Moderate) Caution is advised when administering tenofovir, PMPA, a P-glycoprotein (P-gp) and breast cancer resistance protein (BCRP) substrate, concurrently with inhibitors of P-gp and BCRP, such as ritonavir. Coadministration may result in increased absorption of tenofovir. Monitor for tenofovir-associated adverse reactions. (Moderate) Concurrent administration of tenofovir, PMPA with dasabuvir; ombitasvir; paritaprevir; ritonavir may result in elevated tenofovir plasma concentrations. Tenofovir is a substrate for the breast cancer resistance protein (BCRP) and P-glycoprotein (P-gp). Dasabuvir, paritaprevir, and ritonavir are BCRP inhibitors, and ritonavir inhibits P-gp. Caution and close monitoring are advised if these drugs are administered together. (Minor) Coadministration of doravirine and ritonavir may result in increased doravirine plasma concentrations. Doravirine is a CYP3A4 substrate; ritonavir is a strong inhibitor. In a drug interaction study, concurrent use of ritonavir increased doravirine exposure by more than 3-fold; however, this increase was not considered clinically significant.
    Deferasirox: (Minor) Concurrent administration of doravirine and deferasirox may result in decreased doravirine exposure, resulting in potential loss of virologic control. Doravirine is a CYP3A4 substrate; deferasirox is a weak CYP3A4 inducer.
    Delavirdine: (Minor) Coadministration of doravirine and delavirdine may result in increased doravirine plasma concentrations. Doravirine is a CYP3A4 substrate; delavirdine is a strong inhibitor. In drug interaction studies, concurrent use of strong CYP3A4 inhibitors increased doravirine exposure by more than 3-fold; however, this increase was not considered clinically significant.
    Dexamethasone: (Moderate) Concurrent administration of doravirine and dexamethasone may result in decreased doravirine exposure, resulting in potential loss of virologic control. Doravirine is a CYP3A4 substrate; dexamethasone is a moderate CYP3A4 inducer.
    Dextromethorphan; Quinidine: (Moderate) Caution is advised when administering tenofovir, PMPA, a P-glycoprotein (P-gp) substrate, concurrently with inhibitors of P-gp, such as quinidine. Coadministration may result in increased absorption of tenofovir. Monitor for tenofovir-associated adverse reactions.
    Dichlorphenamide: (Major) Use of dichlorphenamide and tenofovir disoproxil fumarate is not recommended because of increased tenofovir exposure and a risk of tenofovir-related adverse effects. Monitor closely for signs of drug toxicity if coadministration cannot be avoided. For example, it is important to monitor renal and hepatic function for all patients during treatment with tenofovir, as the drug may cause hepatotoxicity or nephrotoxicity. Increased tenofovir exposure is possible. Tenofovir is a sensitive OAT1 substrate. Dichlorphenamide inhibits OAT1.
    Diclofenac: (Moderate) Avoid administering tenofovir, PMPA concurrently with or recently after a nephrotoxic agent, such as high-dose or multiple nonsteroidal antiinflammatory drugs (NSAIDs). Cases of acute renal failure, some requiring hospitalization and renal replacement therapy, have been reported after high-dose or multiple NSAIDs were initiated in patients who appeared stable on tenofovir. Consider alternatives to NSAIDs in patients at risk for renal dysfunction. If these drugs must be coadministered, carefully monitor the estimated creatinine creatinine, serum phosphorus, urine glucose, and urine protein prior to, and periodically during, treatment.
    Diclofenac; Misoprostol: (Moderate) Avoid administering tenofovir, PMPA concurrently with or recently after a nephrotoxic agent, such as high-dose or multiple nonsteroidal antiinflammatory drugs (NSAIDs). Cases of acute renal failure, some requiring hospitalization and renal replacement therapy, have been reported after high-dose or multiple NSAIDs were initiated in patients who appeared stable on tenofovir. Consider alternatives to NSAIDs in patients at risk for renal dysfunction. If these drugs must be coadministered, carefully monitor the estimated creatinine creatinine, serum phosphorus, urine glucose, and urine protein prior to, and periodically during, treatment.
    Didanosine, ddI: (Major) HIV guidelines recommend against concurrent use of tenofovir, PMPA and didanosine; however, these medications can be used together, if necessary, in patients with a creatinine clearance 60 mL/min or more if the didanosine dose is reduced; decrease the didanosine dose to 250 mg in patients weighing 60 kg or more and to 200 mg in patients weighing 25 to 59 kg. Concurrent administration of tenofovir, PMPA and didanosine, ddI increases the concentration of both didanosine and its active metabolite (dideoxyadenosine 5-triphosphate) which may cause or worsen didanosine-related clinical toxicities, including pancreatitis, symptomatic hyperlactatemia/lactic acidosis, and peripheral neuropathy. In addition, this combination has been associated with CD4 cell count decline despite viral suppression, high rates of early virologic failure, and rapid selection of resistance mutations. The mechanism of the interaction is not known, but the interaction occurs with both buffered and non-buffered didanosine formulations. When coadministered, tenofovir and didanosine EC may be taken under fasted conditions or with a light meal (under 400 kcal, containing 20% or less fat); coadministration of didanosine buffered tablet formulation with tenofovir should be under fasted conditions. Coadministration of tenofovir and didanosine should be undertaken with caution and patients receiving this combination should be monitored closely for didanosine-associated adverse events. Didanosine therapy should be suspended if signs or symptoms of pancreatitis, symptomatic hyperlactatemia, or lactic acidosis develop.
    Diflunisal: (Moderate) Avoid administering tenofovir, PMPA concurrently with or recently after a nephrotoxic agent, such as high-dose or multiple nonsteroidal antiinflammatory drugs (NSAIDs). Cases of acute renal failure, some requiring hospitalization and renal replacement therapy, have been reported after high-dose or multiple NSAIDs were initiated in patients who appeared stable on tenofovir. Consider alternatives to NSAIDs in patients at risk for renal dysfunction. If these drugs must be coadministered, carefully monitor the estimated creatinine creatinine, serum phosphorus, urine glucose, and urine protein prior to, and periodically during, treatment.
    Diphenhydramine; Ibuprofen: (Moderate) Avoid administering tenofovir, PMPA concurrently with or recently after a nephrotoxic agent, such as high-dose or multiple nonsteroidal antiinflammatory drugs (NSAIDs). Cases of acute renal failure, some requiring hospitalization and renal replacement therapy, have been reported after high-dose or multiple NSAIDs were initiated in patients who appeared stable on tenofovir. Consider alternatives to NSAIDs in patients at risk for renal dysfunction. If these drugs must be coadministered, carefully monitor the estimated creatinine creatinine, serum phosphorus, urine glucose, and urine protein prior to, and periodically during, treatment.
    Diphenhydramine; Naproxen: (Moderate) Avoid administering tenofovir, PMPA concurrently with or recently after a nephrotoxic agent, such as high-dose or multiple nonsteroidal antiinflammatory drugs (NSAIDs). Cases of acute renal failure, some requiring hospitalization and renal replacement therapy, have been reported after high-dose or multiple NSAIDs were initiated in patients who appeared stable on tenofovir. Consider alternatives to NSAIDs in patients at risk for renal dysfunction. If these drugs must be coadministered, carefully monitor the estimated creatinine creatinine, serum phosphorus, urine glucose, and urine protein prior to, and periodically during, treatment.
    Dofetilide: (Major) Dofetilide should be co-administered with tenofovir, PMPA 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. Increased concentrations of dofetilide may increase the risk for side effects including proarrhythmia. Careful patient monitoring and dose adjustment of dofetilide is recommended. (Moderate) Drugs that are actively secreted via cationic secretion, such as lamivudine, should be co-administered with dofetilide with caution since they could increase dofetilide plasma concentrations via potential competition for renal tubular secretion.
    Donepezil; Memantine: (Moderate) Memantine is excreted in part by renal tubular secretion. Competition of memantine for excretion with other drugs that are also eliminated by tubular secretion, such as lamivudine, could result in elevated serum concentrations of one or both drugs.
    Dronedarone: (Moderate) Caution is advised when administering tenofovir, PMPA, a P-glycoprotein (P-gp) substrate, concurrently with inhibitors of P-gp, such as dronedarone. Coadministration may result in increased absorption of tenofovir. Monitor for tenofovir-associated adverse reactions.
    Echinacea: (Moderate) Use Echinacea sp. with caution in patients taking medications for human immunodeficiency virus (HIV) infection. Some experts have suggested that Echinacea's effects on the immune system might cause problems for patients with HIV infection, particularly with long-term use. There may be less risk with short-term use (less than 2 weeks). A few pharmacokinetic studies have shown reductions in blood levels of some antiretroviral medications when Echinacea was given, presumably due to CYP induction. However, more study is needed for various HIV treatment regimens. Of the agents studied, the interactions do not appear to be significant or to require dose adjustments at the time of use. Although no dose adjustments are required, monitoring drug concentrations may give reassurance during co-administration. Monitor viral load and other parameters carefully during therapy.
    Efavirenz: (Contraindicated) Concurrent treatment with efavirenz and doravirine is not recommended. Both medications are non-nucleoside reverse transcriptase inhibitors (NNRTIs), and using these drugs together would represent duplicate therapy. In addition, taking these drugs together results in decreased doravirine exposure. Doravirine is a CYP3A4 substrate; efavirenz is a CYP3A4 inducer.
    Efavirenz; Emtricitabine; Tenofovir: (Contraindicated) Concurrent treatment with efavirenz and doravirine is not recommended. Both medications are non-nucleoside reverse transcriptase inhibitors (NNRTIs), and using these drugs together would represent duplicate therapy. In addition, taking these drugs together results in decreased doravirine exposure. Doravirine is a CYP3A4 substrate; efavirenz is a CYP3A4 inducer. (Major) Do not coadminister lamivudine, 3TC-containing products and emtricitabine-containing products due to similarities between emtricitabine and lamivudine.
    Efavirenz; Lamivudine; Tenofovir Disoproxil Fumarate: (Contraindicated) Concurrent treatment with efavirenz and doravirine is not recommended. Both medications are non-nucleoside reverse transcriptase inhibitors (NNRTIs), and using these drugs together would represent duplicate therapy. In addition, taking these drugs together results in decreased doravirine exposure. Doravirine is a CYP3A4 substrate; efavirenz is a CYP3A4 inducer.
    Elagolix: (Moderate) Concurrent administration of doravirine and elagolix may result in decreased doravirine exposure, resulting in potential loss of virologic control. Doravirine is a CYP3A4 substrate; elagolix is a weak to moderate CYP3A4 inducer.
    Elagolix; Estradiol; Norethindrone acetate: (Moderate) Concurrent administration of doravirine and elagolix may result in decreased doravirine exposure, resulting in potential loss of virologic control. Doravirine is a CYP3A4 substrate; elagolix is a weak to moderate CYP3A4 inducer.
    Elexacaftor; tezacaftor; ivacaftor: (Moderate) Caution is advised when administering tenofovir, PMPA, a P-glycoprotein (P-gp) substrate, concurrently with inhibitors of P-gp, such as ivacaftor. Coadministration may result in increased absorption of tenofovir. Monitor for tenofovir-associated adverse reactions.
    Eliglustat: (Moderate) Coadministration of tenofovir, PMPA and eliglustat may result in increased concentrations of tenofovir. Monitor patients closely for tenofovir-related adverse effects including nausea, diarrhea, headache, asthenia, and nephrotoxicity. Tenofovir is a P-glycoprotein (P-gp) substrate; eliglustat is a P-gp inhibitor. For coadministration with P-gp substrates, eliglustat's product labeling recommends monitoring therapeutic drug concentrations of the P-gp substrate, if possible, or consideration of a dosage reduction and titrating to clinical effect.
    Elvitegravir; Cobicistat; Emtricitabine; Tenofovir Alafenamide: (Major) Do not coadminister lamivudine, 3TC-containing products and emtricitabine-containing products due to similarities between emtricitabine and lamivudine. (Minor) Coadministration of doravirine and cobicistat may result in increased doravirine plasma concentrations. Doravirine is a CYP3A4 substrate; cobicistat is a strong inhibitor. In drug interaction studies, concurrent use of strong CYP3A4 inhibitors increased doravirine exposure by more than 3-fold; however, this increase was not considered clinically significant.
    Elvitegravir; Cobicistat; Emtricitabine; Tenofovir Disoproxil Fumarate: (Major) Do not coadminister lamivudine, 3TC-containing products and emtricitabine-containing products due to similarities between emtricitabine and lamivudine. (Minor) Coadministration of doravirine and cobicistat may result in increased doravirine plasma concentrations. Doravirine is a CYP3A4 substrate; cobicistat is a strong inhibitor. In drug interaction studies, concurrent use of strong CYP3A4 inhibitors increased doravirine exposure by more than 3-fold; however, this increase was not considered clinically significant.
    Empagliflozin; Linagliptin; Metformin: (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.
    Empagliflozin; Metformin: (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.
    Emtricitabine: (Major) Do not coadminister lamivudine, 3TC-containing products and emtricitabine-containing products due to similarities between emtricitabine and lamivudine.
    Emtricitabine; Rilpivirine; Tenofovir alafenamide: (Major) Do not coadminister lamivudine, 3TC-containing products and emtricitabine-containing products due to similarities between emtricitabine and lamivudine.
    Emtricitabine; Rilpivirine; Tenofovir disoproxil fumarate: (Major) Do not coadminister lamivudine, 3TC-containing products and emtricitabine-containing products due to similarities between emtricitabine and lamivudine.
    Emtricitabine; Tenofovir alafenamide: (Major) Do not coadminister lamivudine, 3TC-containing products and emtricitabine-containing products due to similarities between emtricitabine and lamivudine.
    Emtricitabine; Tenofovir disoproxil fumarate: (Major) Do not coadminister lamivudine, 3TC-containing products and emtricitabine-containing products due to similarities between emtricitabine and lamivudine.
    Enasidenib: (Moderate) Coadministration of tenofovir disoproxil fumarate with enasidenib may result in increased plasma concentrations of tenofovir, leading to an increase in tenofovir-related adverse effects. Tenofovir disoproxil fumarate is a P-gp and BCRP substrate and enasidenib is a P-gp and BCRP inhibitor.
    Enzalutamide: (Contraindicated) Concurrent administration of doravirine and enzalutamide is contraindicated due to decreased doravirine exposure, resulting in potential loss of virologic control. At least a 4-week cessation period is recommended before initiating treatment with doravirine. Doravirine is a CYP3A4 substrate; enzalutamide is a strong CYP3A4 inducer.
    Ertugliflozin; Metformin: (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.
    Erythromycin: (Moderate) Caution is advised when administering tenofovir, PMPA, a P-glycoprotein (P-gp) substrate, concurrently with inhibitors of P-gp, such as erythromycin. Coadministration may result in increased absorption of tenofovir. Monitor for tenofovir-associated adverse reactions.
    Erythromycin; Sulfisoxazole: (Moderate) Caution is advised when administering tenofovir, PMPA, a P-glycoprotein (P-gp) substrate, concurrently with inhibitors of P-gp, such as erythromycin. Coadministration may result in increased absorption of tenofovir. Monitor for tenofovir-associated adverse reactions.
    Eslicarbazepine: (Moderate) Concurrent administration of doravirine and eslicarbazepine may result in decreased doravirine exposure, resulting in potential loss of virologic control. Doravirine is a CYP3A4 substrate; eslicarbazepine is a moderate CYP3A4 inducer.
    Ethiodized Oil: (Moderate) Tenofovir-containing products should be avoided with concurrent or recent use of a nephrotoxic agent, such as radiopaque contrast agents. Tenofovir is primarily excreted via the kidneys by a combination of glomerular filtration and active tubular secretion. Coadministration of tenofovir with drugs that are eliminated by active tubular secretion may increase concentrations of tenofovir and/or the co-administered drug. Drugs that decrease renal function may also increase concentrations of tenofovir. Renal impairment, which may include hypophosphatemia, has been reported with the use of tenofovir with a majority of the cases occurring in patients who have underlying systemic or renal disease or who are concurrently taking nephrotoxic agents. Monitor patients receiving concomitant nephrotoxic agents for changes in serum creatinine and phosphorus.
    Etodolac: (Moderate) Avoid administering tenofovir, PMPA concurrently with or recently after a nephrotoxic agent, such as high-dose or multiple nonsteroidal antiinflammatory drugs (NSAIDs). Cases of acute renal failure, some requiring hospitalization and renal replacement therapy, have been reported after high-dose or multiple NSAIDs were initiated in patients who appeared stable on tenofovir. Consider alternatives to NSAIDs in patients at risk for renal dysfunction. If these drugs must be coadministered, carefully monitor the estimated creatinine creatinine, serum phosphorus, urine glucose, and urine protein prior to, and periodically during, treatment.
    Etravirine: (Contraindicated) Concurrent treatment with etravirine and doravirine is not recommended. Both medications are non-nucleoside reverse transcriptase inhibitors (NNRTIs), and using these drugs together would represent duplicate therapy. In addition, taking these drugs together may result in decreased doravirine exposure. Doravirine is a CYP3A4 substrate; etravirine is a CYP3A4 inducer. (Moderate) Caution is advised when administering tenofovir, PMPA, a P-glycoprotein (P-gp) substrate, concurrently with inhibitors of P-gp, such as etravirine. Coadministration may result in increased absorption of tenofovir. Monitor for tenofovir-associated adverse reactions.
    Famotidine; Ibuprofen: (Moderate) Avoid administering tenofovir, PMPA concurrently with or recently after a nephrotoxic agent, such as high-dose or multiple nonsteroidal antiinflammatory drugs (NSAIDs). Cases of acute renal failure, some requiring hospitalization and renal replacement therapy, have been reported after high-dose or multiple NSAIDs were initiated in patients who appeared stable on tenofovir. Consider alternatives to NSAIDs in patients at risk for renal dysfunction. If these drugs must be coadministered, carefully monitor the estimated creatinine creatinine, serum phosphorus, urine glucose, and urine protein prior to, and periodically during, treatment.
    Fenoprofen: (Moderate) Avoid administering tenofovir, PMPA concurrently with or recently after a nephrotoxic agent, such as high-dose or multiple nonsteroidal antiinflammatory drugs (NSAIDs). Cases of acute renal failure, some requiring hospitalization and renal replacement therapy, have been reported after high-dose or multiple NSAIDs were initiated in patients who appeared stable on tenofovir. Consider alternatives to NSAIDs in patients at risk for renal dysfunction. If these drugs must be coadministered, carefully monitor the estimated creatinine creatinine, serum phosphorus, urine glucose, and urine protein prior to, and periodically during, treatment.
    Flurbiprofen: (Moderate) Avoid administering tenofovir, PMPA concurrently with or recently after a nephrotoxic agent, such as high-dose or multiple nonsteroidal antiinflammatory drugs (NSAIDs). Cases of acute renal failure, some requiring hospitalization and renal replacement therapy, have been reported after high-dose or multiple NSAIDs were initiated in patients who appeared stable on tenofovir. Consider alternatives to NSAIDs in patients at risk for renal dysfunction. If these drugs must be coadministered, carefully monitor the estimated creatinine creatinine, serum phosphorus, urine glucose, and urine protein prior to, and periodically during, treatment.
    Food: (Moderate) The pharmacokinetic parameters of anti-retroviral medications (anti-retroviral non-nucleoside reverse transcriptase inhibitors (NNRTIs), anti-retroviral nucleoside reverse transcriptase inhibitors (NRTIs), anti-retroviral nucleotide reverse transcriptase inhibitors, and anti-retroviral protease inhibitors) metabolized through the CYP isoenzyme system are slightly altered by smoked and oral marijuana. Despite this interaction, marijuana is not expected to adversely affect anti-retroviral efficacy. However, the incidence of marijuana associated adverse effects may change following coadministration with anti-retroviral drugs. Many anti-retrovirals are inhibitors of CYP3A4, an isoenzyme partially responsible for the metabolism of marijuana's most psychoactive compound, delta-9-tetrahydrocannabinol (Delta-9-THC). When given concurrently with anti-retrovirals, the amount of Delta-9-THC converted to the active metabolite 11-hydroxy-delta-9-tetrahydrocannabinol (11-OH-THC) may be reduced. These changes in Delta-9-THC and 11-OH-THC plasma concentrations may result in an altered marijuana adverse event profile. (Moderate) The pharmacokinetic parameters of anti-retroviral medications (anti-retroviral non-nucleoside reverse transcriptase inhibitors (NNRTIs), anti-retroviral nucleoside reverse transcriptase inhibitors (NRTIs), anti-retroviral nucleotide reverse transcriptase inhibitors, and anti-retroviral protease inhibitors) metabolized through the CYP isoenzyme system are slightly altered by smoked and oral marijuana. Despite this interaction, marijuana is not expected to adversely affect anti-retroviral efficacy.However, the incidence of marijuana associated adverse effects may change following coadministration with anti-retroviral drugs. Many anti-retrovirals are inhibitors of CYP3A4, an isoenzyme partially responsible for the metabolism of marijuana's most psychoactive compound, delta-9-tetrahydrocannabinol (Delta-9-THC). When given concurrently with anti-retrovirals, the amount of Delta-9-THC converted to the active metabolite 11-hydroxy-delta-9-tetrahydrocannabinol (11-OH-THC) may be reduced. These changes in Delta-9-THC and 11-OH-THC plasma concentrations may result in an altered marijuana adverse event profile.
    Fosamprenavir: (Minor) Coadministration of doravirine and fosamprenavir may result in increased doravirine plasma concentrations. Doravirine is a CYP3A4 substrate; fosamprenavir is a strong inhibitor. In drug interaction studies, concurrent use of strong CYP3A4 inhibitors increased doravirine exposure by more than 3-fold; however, this increase was not considered clinically significant.
    Foscarnet: (Moderate) Monitor for changes in serum creatinine and phosphorus if tenofovir is administered in combination with nephrotoxic agents, such as foscarnet. Tenofovir is primarily excreted via the kidneys by a combination of glomerular filtration and active tubular secretion. While no drug interactions due to competition for renal excretion have been observed, coadministration of tenofovir with drugs that are eliminated by active tubular secretion may increase concentrations of tenofovir, and/or the co-administered drug. Drugs that decrease renal function may increase concentrations of tenofovir. Renal impairment, which may include hypophosphatemia, has been reported with the use of tenofovir; a majority of the cases occurred in patients who had underlying systemic or renal disease or who are concurrently taking nephrotoxic agents. Tenofovir containing products should be avoided with concurrent or recent use of a nephrotoxic agent; patients receiving concomitant nephrotoxic agents should be carefully monitored for changes in serum creatinine and phosphorus.
    Fosphenytoin: (Contraindicated) Concurrent administration of doravirine and fosphenytoin is contraindicated due to decreased doravirine exposure, resulting in potential loss of virologic control. At least a 4-week cessation period is recommended before initiating treatment with doravirine. Doravirine is a CYP3A4 substrate; phenytoin (the active metabolite of fosphenytoin) is a strong CYP3A4 inducer.
    Fostamatinib: (Moderate) Monitor for tenofovir toxicities that may require tenofovir disoproxil dose reduction if given concurrently with fostamatinib. Concomitant use of fostamatinib with a BCRP or P-gp substrate may increase the concentration of the BCRP or P-gp substrate. Fostamatinib is a P-gp inhibitor, and the active metabolite of fostamatinib, R406, is a BCRP inhibitor; tenofovir disoproxil is a substrate for BCRP and P-gp. Coadministration of fostamatinib with another BCRP substrate increased the substrate AUC by 95% and Cmax by 88%. Coadministration of fostamatinib with another P-gp substrate increased the substrate AUC by 37% and Cmax by 70%.
    Ganciclovir: (Moderate) Concurrent use of nephrotoxic agents with ganciclovir should be done cautiously to avoid additive nephrotoxicity. Other nephrotoxic agents include tenofovir.
    Gentamicin: (Moderate) Renal impairment, which may include hypophosphatemia, has been reported with the use of tenofovir with a majority of the cases occurring in patients who have underlying systemic or renal disease or who are concurrently taking nephrotoxic agents. Tenofovir should be avoided with concurrent or recent use of a nephrotoxic agent; patients receiving concomitant nephrotoxic agents should be carefully monitored for changes in serum creatinine and phosphorus.
    Gilteritinib: (Moderate) Coadministration of tenofovir disoproxil fumarate with gilteritinib may result in increased plasma concentrations of tenofovir, leading to an increase in tenofovir-related adverse effects. Tenofovir disoproxil fumarate is a substrate of P-gp and BCRP and gilteritinib is a P-gp and BCRP inhibitor.
    Glipizide; Metformin: (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.
    Glyburide; Metformin: (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.
    Grapefruit juice: (Moderate) Caution is advised when administering tenofovir, PMPA, a P-glycoprotein (P-gp) substrate, concurrently with inhibitors of P-gp, such as grapefruit juice. Coadministration may result in increased absorption of tenofovir. Monitor for tenofovir-associated adverse reactions. (Minor) Instruct patients that consuming grapefruit or grapefruit juice while taking doravirine may result in increased doravirine plasma concentrations. Doravirine is a CYP3A4 substrate; grapefruit is a strong inhibitor. In drug interaction studies, concurrent use of strong CYP3A4 inhibitors increased doravirine exposure by more than 3-fold; however, this increase was not considered clinically significant.
    Hydrocodone; Ibuprofen: (Moderate) Avoid administering tenofovir, PMPA concurrently with or recently after a nephrotoxic agent, such as high-dose or multiple nonsteroidal antiinflammatory drugs (NSAIDs). Cases of acute renal failure, some requiring hospitalization and renal replacement therapy, have been reported after high-dose or multiple NSAIDs were initiated in patients who appeared stable on tenofovir. Consider alternatives to NSAIDs in patients at risk for renal dysfunction. If these drugs must be coadministered, carefully monitor the estimated creatinine creatinine, serum phosphorus, urine glucose, and urine protein prior to, and periodically during, treatment.
    Hyoscyamine; Methenamine; Methylene Blue; Phenyl Salicylate; Sodium Biphosphate: (Major) Renal impairment, which may include hypophosphatemia, has been reported with the use of tenofovir disoproxil fumarate with a majority of the cases occurring in patients who have underlying systemic or renal disease or who are concurrently taking nephrotoxic agents. Tenofovir should be avoided with concurrent or recent use of a nephrotoxic agent; patients receiving concomitant nephrotoxic agents, like salicylates should be carefully monitored for changes in serum creatinine and phosphorus.
    Ibuprofen: (Moderate) Avoid administering tenofovir, PMPA concurrently with or recently after a nephrotoxic agent, such as high-dose or multiple nonsteroidal antiinflammatory drugs (NSAIDs). Cases of acute renal failure, some requiring hospitalization and renal replacement therapy, have been reported after high-dose or multiple NSAIDs were initiated in patients who appeared stable on tenofovir. Consider alternatives to NSAIDs in patients at risk for renal dysfunction. If these drugs must be coadministered, carefully monitor the estimated creatinine creatinine, serum phosphorus, urine glucose, and urine protein prior to, and periodically during, treatment.
    Ibuprofen; Oxycodone: (Moderate) Avoid administering tenofovir, PMPA concurrently with or recently after a nephrotoxic agent, such as high-dose or multiple nonsteroidal antiinflammatory drugs (NSAIDs). Cases of acute renal failure, some requiring hospitalization and renal replacement therapy, have been reported after high-dose or multiple NSAIDs were initiated in patients who appeared stable on tenofovir. Consider alternatives to NSAIDs in patients at risk for renal dysfunction. If these drugs must be coadministered, carefully monitor the estimated creatinine creatinine, serum phosphorus, urine glucose, and urine protein prior to, and periodically during, treatment.
    Ibuprofen; Pseudoephedrine: (Moderate) Avoid administering tenofovir, PMPA concurrently with or recently after a nephrotoxic agent, such as high-dose or multiple nonsteroidal antiinflammatory drugs (NSAIDs). Cases of acute renal failure, some requiring hospitalization and renal replacement therapy, have been reported after high-dose or multiple NSAIDs were initiated in patients who appeared stable on tenofovir. Consider alternatives to NSAIDs in patients at risk for renal dysfunction. If these drugs must be coadministered, carefully monitor the estimated creatinine creatinine, serum phosphorus, urine glucose, and urine protein prior to, and periodically during, treatment.
    Idelalisib: (Minor) Coadministration of doravirine and idelalisib may result in increased doravirine plasma concentrations. Doravirine is a CYP3A4 substrate; idelalisib is a strong inhibitor. In drug interaction studies, concurrent use of strong CYP3A4 inhibitors increased doravirine exposure by more than 3-fold; however, this increase was not considered clinically significant.
    Indinavir: (Minor) Coadministration of doravirine and indinavir may result in increased doravirine plasma concentrations. Doravirine is a CYP3A4 substrate; indinavir is a strong inhibitor. In drug interaction studies, concurrent use of strong CYP3A4 inhibitors increased doravirine exposure by more than 3-fold; however, this increase was not considered clinically significant.
    Indomethacin: (Moderate) Avoid administering tenofovir, PMPA concurrently with or recently after a nephrotoxic agent, such as high-dose or multiple nonsteroidal antiinflammatory drugs (NSAIDs). Cases of acute renal failure, some requiring hospitalization and renal replacement therapy, have been reported after high-dose or multiple NSAIDs were initiated in patients who appeared stable on tenofovir. Consider alternatives to NSAIDs in patients at risk for renal dysfunction. If these drugs must be coadministered, carefully monitor the estimated creatinine creatinine, serum phosphorus, urine glucose, and urine protein prior to, and periodically during, treatment.
    Interferon Alfa-2b; Ribavirin: (Moderate) Use lamivudine with ribavirin and interferon with caution and closely monitor for hepatic decompensation and anemia. Dose reduction or discontinuation of interferon, ribavirin, or both should be considered if worsening clinical toxicities are observed, including hepatic decompensation (e.g., Child-Pugh greater than 6). Hepatic decompensation (some fatal) has occurred in HCV/HIV coinfected patients who received both ribavirin/interferon and anti-retroviral nucleoside reverse transcriptase inhibitors (NRTIs) therapies. In addition, ribavirin has been shown in cell culture to inhibit phosphorylation of lamivudine, which could lead to decreased antiretroviral activity; however, while ribavirin inhibits the phosphorylation reactions required to activate lamivudine, no evidence of a pharmacokinetic or pharmacodynamic interaction has been observed.
    Interferons: (Moderate) Monitor for treatment-associated toxicities, especially hepatic decompensation, during coadministration of interferons (with or without ribavirin) and lamivudine. Dose reduction or discontinuation of interferon, ribavirin, or both should be considered if worsening clinical toxicities are observed, including hepatic decompensation (e.g., Child-Pugh score greater than 6).
    Iodixanol: (Moderate) Tenofovir-containing products should be avoided with concurrent or recent use of a nephrotoxic agent, such as radiopaque contrast agents. Tenofovir is primarily excreted via the kidneys by a combination of glomerular filtration and active tubular secretion. Coadministration of tenofovir with drugs that are eliminated by active tubular secretion may increase concentrations of tenofovir and/or the co-administered drug. Drugs that decrease renal function may also increase concentrations of tenofovir. Renal impairment, which may include hypophosphatemia, has been reported with the use of tenofovir with a majority of the cases occurring in patients who have underlying systemic or renal disease or who are concurrently taking nephrotoxic agents. Monitor patients receiving concomitant nephrotoxic agents for changes in serum creatinine and phosphorus.
    Iohexol: (Moderate) Tenofovir-containing products should be avoided with concurrent or recent use of a nephrotoxic agent, such as radiopaque contrast agents. Tenofovir is primarily excreted via the kidneys by a combination of glomerular filtration and active tubular secretion. Coadministration of tenofovir with drugs that are eliminated by active tubular secretion may increase concentrations of tenofovir and/or the co-administered drug. Drugs that decrease renal function may also increase concentrations of tenofovir. Renal impairment, which may include hypophosphatemia, has been reported with the use of tenofovir with a majority of the cases occurring in patients who have underlying systemic or renal disease or who are concurrently taking nephrotoxic agents. Monitor patients receiving concomitant nephrotoxic agents for changes in serum creatinine and phosphorus.
    Iopamidol: (Moderate) Tenofovir-containing products should be avoided with concurrent or recent use of a nephrotoxic agent, such as radiopaque contrast agents. Tenofovir is primarily excreted via the kidneys by a combination of glomerular filtration and active tubular secretion. Coadministration of tenofovir with drugs that are eliminated by active tubular secretion may increase concentrations of tenofovir and/or the co-administered drug. Drugs that decrease renal function may also increase concentrations of tenofovir. Renal impairment, which may include hypophosphatemia, has been reported with the use of tenofovir with a majority of the cases occurring in patients who have underlying systemic or renal disease or who are concurrently taking nephrotoxic agents. Monitor patients receiving concomitant nephrotoxic agents for changes in serum creatinine and phosphorus.
    Iopromide: (Moderate) Tenofovir-containing products should be avoided with concurrent or recent use of a nephrotoxic agent, such as radiopaque contrast agents. Tenofovir is primarily excreted via the kidneys by a combination of glomerular filtration and active tubular secretion. Coadministration of tenofovir with drugs that are eliminated by active tubular secretion may increase concentrations of tenofovir and/or the co-administered drug. Drugs that decrease renal function may also increase concentrations of tenofovir. Renal impairment, which may include hypophosphatemia, has been reported with the use of tenofovir with a majority of the cases occurring in patients who have underlying systemic or renal disease or who are concurrently taking nephrotoxic agents. Monitor patients receiving concomitant nephrotoxic agents for changes in serum creatinine and phosphorus.
    Ioversol: (Moderate) Tenofovir-containing products should be avoided with concurrent or recent use of a nephrotoxic agent, such as radiopaque contrast agents. Tenofovir is primarily excreted via the kidneys by a combination of glomerular filtration and active tubular secretion. Coadministration of tenofovir with drugs that are eliminated by active tubular secretion may increase concentrations of tenofovir and/or the co-administered drug. Drugs that decrease renal function may also increase concentrations of tenofovir. Renal impairment, which may include hypophosphatemia, has been reported with the use of tenofovir with a majority of the cases occurring in patients who have underlying systemic or renal disease or who are concurrently taking nephrotoxic agents. Monitor patients receiving concomitant nephrotoxic agents for changes in serum creatinine and phosphorus.
    Isoniazid, INH; Pyrazinamide, PZA; Rifampin: (Contraindicated) Concurrent administration of doravirine and rifampin is contraindicated due to decreased doravirine exposure, resulting in potential loss of virologic control. At least a 4-week cessation period is recommended before initiating treatment with doravirine. Doravirine is a CYP3A4 substrate; rifampin is a strong CYP3A4 inducer.
    Isoniazid, INH; Rifampin: (Contraindicated) Concurrent administration of doravirine and rifampin is contraindicated due to decreased doravirine exposure, resulting in potential loss of virologic control. At least a 4-week cessation period is recommended before initiating treatment with doravirine. Doravirine is a CYP3A4 substrate; rifampin is a strong CYP3A4 inducer.
    Isosulfan Blue: (Moderate) Tenofovir-containing products should be avoided with concurrent or recent use of a nephrotoxic agent, such as radiopaque contrast agents. Tenofovir is primarily excreted via the kidneys by a combination of glomerular filtration and active tubular secretion. Coadministration of tenofovir with drugs that are eliminated by active tubular secretion may increase concentrations of tenofovir and/or the co-administered drug. Drugs that decrease renal function may also increase concentrations of tenofovir. Renal impairment, which may include hypophosphatemia, has been reported with the use of tenofovir with a majority of the cases occurring in patients who have underlying systemic or renal disease or who are concurrently taking nephrotoxic agents. Monitor patients receiving concomitant nephrotoxic agents for changes in serum creatinine and phosphorus.
    Istradefylline: (Moderate) Monitor for an increase in tenofovir-related adverse reactions if coadministration with istradefylline is necessary as concurrent use may increase tenofovir exposure. Tenofovir is a P-gp substrate and istradefylline is a P-gp inhibitor.
    Itraconazole: (Moderate) Caution is advised when administering tenofovir, PMPA, a P-glycoprotein (P-gp) and breast cancer resistance protein (BCRP) substrate, concurrently with inhibitors of P-gp and BCRP, such as itraconazole. Coadministration may result in increased absorption of tenofovir. Monitor for tenofovir-associated adverse reactions. (Minor) Coadministration of doravirine and itraconazole may result in increased doravirine plasma concentrations. Doravirine is a CYP3A4 substrate; itraconazole is a strong inhibitor. In drug interaction studies, concurrent use of strong CYP3A4 inhibitors increased doravirine exposure by more than 3-fold; however, this increase was not considered clinically significant.
    Ivacaftor: (Moderate) Caution is advised when administering tenofovir, PMPA, a P-glycoprotein (P-gp) substrate, concurrently with inhibitors of P-gp, such as ivacaftor. Coadministration may result in increased absorption of tenofovir. Monitor for tenofovir-associated adverse reactions.
    Kanamycin: (Moderate) Renal impairment, which may include hypophosphatemia, has been reported with the use of tenofovir with a majority of the cases occurring in patients who have underlying systemic or renal disease or who are concurrently taking nephrotoxic agents. Tenofovir should be avoided with concurrent or recent use of a nephrotoxic agent; patients receiving concomitant nephrotoxic agents should be carefully monitored for changes in serum creatinine and phosphorus.
    Ketoconazole: (Moderate) Caution is advised when administering tenofovir, PMPA, a P-glycoprotein (P-gp) substrate, concurrently with inhibitors of P-gp, such as ketoconazole. Coadministration may result in increased absorption of tenofovir. Monitor for tenofovir-associated adverse reactions. (Minor) Coadministration of doravirine and ketoconazole may result in increased doravirine plasma concentrations. Doravirine is a CYP3A4 substrate; ketoconazole is a strong inhibitor. In a drug interaction study, concurrent use of ketoconazole increased doravirine exposure by more than 3-fold; however, this increase was not considered clinically significant.
    Ketoprofen: (Moderate) Avoid administering tenofovir, PMPA concurrently with or recently after a nephrotoxic agent, such as high-dose or multiple nonsteroidal antiinflammatory drugs (NSAIDs). Cases of acute renal failure, some requiring hospitalization and renal replacement therapy, have been reported after high-dose or multiple NSAIDs were initiated in patients who appeared stable on tenofovir. Consider alternatives to NSAIDs in patients at risk for renal dysfunction. If these drugs must be coadministered, carefully monitor the estimated creatinine creatinine, serum phosphorus, urine glucose, and urine protein prior to, and periodically during, treatment.
    Ketorolac: (Moderate) Avoid administering tenofovir, PMPA concurrently with or recently after a nephrotoxic agent, such as high-dose or multiple nonsteroidal antiinflammatory drugs (NSAIDs). Cases of acute renal failure, some requiring hospitalization and renal replacement therapy, have been reported after high-dose or multiple NSAIDs were initiated in patients who appeared stable on tenofovir. Consider alternatives to NSAIDs in patients at risk for renal dysfunction. If these drugs must be coadministered, carefully monitor the estimated creatinine creatinine, serum phosphorus, urine glucose, and urine protein prior to, and periodically during, treatment.
    Lansoprazole; Amoxicillin; Clarithromycin: (Moderate) Caution is advised when administering tenofovir, PMPA, a P-glycoprotein (P-gp) substrate, concurrently with inhibitors of P-gp, such as clarithromycin. Coadministration may result in increased absorption of tenofovir. Monitor for tenofovir-associated adverse reactions. (Minor) Coadministration of doravirine and clarithromycin may result in increased doravirine plasma concentrations. Doravirine is a CYP3A4 substrate; clarithromycin is a strong inhibitor. In drug interaction studies, concurrent use of strong CYP3A4 inhibitors increased doravirine exposure by more than 3-fold; however, this increase was not considered clinically significant.
    Lansoprazole; Naproxen: (Moderate) Avoid administering tenofovir, PMPA concurrently with or recently after a nephrotoxic agent, such as high-dose or multiple nonsteroidal antiinflammatory drugs (NSAIDs). Cases of acute renal failure, some requiring hospitalization and renal replacement therapy, have been reported after high-dose or multiple NSAIDs were initiated in patients who appeared stable on tenofovir. Consider alternatives to NSAIDs in patients at risk for renal dysfunction. If these drugs must be coadministered, carefully monitor the estimated creatinine creatinine, serum phosphorus, urine glucose, and urine protein prior to, and periodically during, treatment.
    Lapatinib: (Moderate) Monitor for an increase in tenofovir-related adverse reactions if coadministration with lapatinib is necessary. Tenofovir is a P-glycoprotein (P-gp) substrate and lapatinib is a P-gp inhibitor. Increased plasma concentrations of tenofovir may occur.
    Ledipasvir; Sofosbuvir: (Moderate) Closely monitor for tenofovir-associated adverse reactions if ledipasvir is administered with tenofovir disoproxil fumarate. In addition, because safety has not been established, avoid use of ledipasvir in combination with HIV regimens that contain tenofovir disoproxil fumarate and HIV protease inhibitors boosted with ritonavir. Consider use of tenofovir alafenamide in place of tenofovir disoproxil fumarate. If coadministration is deemed necessary, closely monitor for tenofovir adverse effects. Plasma concentrations of tenofovir may increase when administered with ledipasvir. Tenofovir is a substrate of the drug transporters P-glycoprotein (P-gp) and breast cancer resistance protein (BCRP); ledipasvir is an inhibitor of both P-gp and BCRP.
    Lesinurad: (Minor) Concurrent administration of doravirine and lesinurad may result in decreased doravirine exposure, resulting in potential loss of virologic control. Doravirine is a CYP3A4 substrate; lesinurad is a weak CYP3A4 inducer.
    Lesinurad; Allopurinol: (Minor) Concurrent administration of doravirine and lesinurad may result in decreased doravirine exposure, resulting in potential loss of virologic control. Doravirine is a CYP3A4 substrate; lesinurad is a weak CYP3A4 inducer.
    Levoketoconazole: (Moderate) Caution is advised when administering tenofovir, PMPA, a P-glycoprotein (P-gp) substrate, concurrently with inhibitors of P-gp, such as ketoconazole. Coadministration may result in increased absorption of tenofovir. Monitor for tenofovir-associated adverse reactions. (Minor) Coadministration of doravirine and ketoconazole may result in increased doravirine plasma concentrations. Doravirine is a CYP3A4 substrate; ketoconazole is a strong inhibitor. In a drug interaction study, concurrent use of ketoconazole increased doravirine exposure by more than 3-fold; however, this increase was not considered clinically significant.
    Linagliptin; Metformin: (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.
    Lonafarnib: (Moderate) Coadministration of tenofovir disoproxil fumarate with lonafarnib may result in increased plasma concentrations of tenofovir, leading to an increase in tenofovir-related adverse effects. Tenofovir disoproxil fumarate is a P-glycoprotein (P-gp) substrate and lonafarnib is a P-gp inhibitor. (Minor) Coadministration of doravirine and lonafarnib may result in increased doravirine plasma concentrations. Doravirine is a CYP3A4 substrate; lonafarnib is a strong inhibitor. In drug interaction studies, concurrent use of strong CYP3A4 inhibitors increased doravirine exposure by more than 3-fold; however, this increase was not considered clinically significant.
    Lopinavir; Ritonavir: (Moderate) Caution is advised when administering tenofovir, PMPA, a P-glycoprotein (P-gp) and breast cancer resistance protein (BCRP) substrate, concurrently with inhibitors of P-gp and BCRP, such as ritonavir. Coadministration may result in increased absorption of tenofovir. Monitor for tenofovir-associated adverse reactions. (Minor) Coadministration of doravirine and ritonavir may result in increased doravirine plasma concentrations. Doravirine is a CYP3A4 substrate; ritonavir is a strong inhibitor. In a drug interaction study, concurrent use of ritonavir increased doravirine exposure by more than 3-fold; however, this increase was not considered clinically significant. (Minor) There are varying results in reports of an interaction between tenofovir and lopinavir; ritonavir. In one report, the concurrent administration of tenofovir with lopinavir; ritonavir increased tenofovir Cmax 31%, AUC 34%, and Cmin 29%, with slight (15%) decreases in lopinavir Cmax and AUC; the alterations may be a food effect rather than a drug-drug interaction. In another report, lopinavir; ritonavir (400 mg; 100 mg PO twice daily for 14 days) increased the tenofovir (300 mg/day PO) Cmin 51% and AUC 32%, with no effect seen on lopinavir; ritonavir pharmacokinetics. While the clinical significance of this interaction is unknown, and is suspected to be insignificant, patients receiving lopinavir; ritonavir with tenofovir should be monitored for tenofovir-associated adverse events.
    Lorlatinib: (Moderate) Concurrent administration of doravirine and lorlatinib may result in decreased doravirine exposure, resulting in potential loss of virologic control. Doravirine is a CYP3A4 substrate; lorlatinib is a moderate CYP3A4 inducer.
    Lumacaftor; Ivacaftor: (Contraindicated) Concurrent administration of doravirine and lumacaftor; ivacaftor is contraindicated due to decreased doravirine exposure, resulting in potential loss of virologic control. At least a 4-week cessation period is recommended before initiating treatment with doravirine. Doravirine is a CYP3A4 substrate; lumacaftor is a strong CYP3A4 inducer. (Moderate) Caution is advised when administering tenofovir, PMPA, a P-glycoprotein (P-gp) substrate, concurrently with inhibitors of P-gp, such as ivacaftor. Coadministration may result in increased absorption of tenofovir. Monitor for tenofovir-associated adverse reactions.
    Lumacaftor; Ivacaftor: (Contraindicated) Concurrent administration of doravirine and lumacaftor; ivacaftor is contraindicated due to decreased doravirine exposure, resulting in potential loss of virologic control. At least a 4-week cessation period is recommended before initiating treatment with doravirine. Doravirine is a CYP3A4 substrate; lumacaftor is a strong CYP3A4 inducer.
    Magnesium Salicylate: (Major) Renal impairment, which may include hypophosphatemia, has been reported with the use of tenofovir disoproxil fumarate with a majority of the cases occurring in patients who have underlying systemic or renal disease or who are concurrently taking nephrotoxic agents. Tenofovir should be avoided with concurrent or recent use of a nephrotoxic agent; patients receiving concomitant nephrotoxic agents, like salicylates should be carefully monitored for changes in serum creatinine and phosphorus.
    Maribavir: (Moderate) Coadministration of tenofovir disoproxil fumarate with maribavir may result in increased plasma concentrations of tenofovir, leading to an increase in tenofovir-related adverse effects. Tenofovir disoproxil fumarate is a P-gp and BCRP substrate and maribavir is a P-gp and BCRP inhibitor.
    Meclofenamate Sodium: (Moderate) Avoid administering tenofovir, PMPA concurrently with or recently after a nephrotoxic agent, such as high-dose or multiple nonsteroidal antiinflammatory drugs (NSAIDs). Cases of acute renal failure, some requiring hospitalization and renal replacement therapy, have been reported after high-dose or multiple NSAIDs were initiated in patients who appeared stable on tenofovir. Consider alternatives to NSAIDs in patients at risk for renal dysfunction. If these drugs must be coadministered, carefully monitor the estimated creatinine creatinine, serum phosphorus, urine glucose, and urine protein prior to, and periodically during, treatment.
    Mefenamic Acid: (Moderate) Avoid administering tenofovir, PMPA concurrently with or recently after a nephrotoxic agent, such as high-dose or multiple nonsteroidal antiinflammatory drugs (NSAIDs). Cases of acute renal failure, some requiring hospitalization and renal replacement therapy, have been reported after high-dose or multiple NSAIDs were initiated in patients who appeared stable on tenofovir. Consider alternatives to NSAIDs in patients at risk for renal dysfunction. If these drugs must be coadministered, carefully monitor the estimated creatinine creatinine, serum phosphorus, urine glucose, and urine protein prior to, and periodically during, treatment.
    Mefloquine: (Moderate) Caution is advised when administering tenofovir, PMPA, a P-glycoprotein (P-gp) substrate, concurrently with inhibitors of P-gp, such as mefloquine. Coadministration may result in increased absorption of tenofovir. Monitor for tenofovir-associated adverse reactions.
    Meloxicam: (Moderate) Avoid administering tenofovir, PMPA concurrently with or recently after a nephrotoxic agent, such as high-dose or multiple nonsteroidal antiinflammatory drugs (NSAIDs). Cases of acute renal failure, some requiring hospitalization and renal replacement therapy, have been reported after high-dose or multiple NSAIDs were initiated in patients who appeared stable on tenofovir. Consider alternatives to NSAIDs in patients at risk for renal dysfunction. If these drugs must be coadministered, carefully monitor the estimated creatinine creatinine, serum phosphorus, urine glucose, and urine protein prior to, and periodically during, treatment.
    Memantine: (Moderate) Memantine is excreted in part by renal tubular secretion. Competition of memantine for excretion with other drugs that are also eliminated by tubular secretion, such as lamivudine, could result in elevated serum concentrations of one or both drugs.
    Metformin: (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.
    Metformin; Repaglinide: (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.
    Metformin; Rosiglitazone: (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.
    Metformin; Saxagliptin: (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.
    Metformin; Sitagliptin: (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.
    Methotrexate: (Major) Avoid concomitant use of methotrexate with tenofovir disoproxil fumarate due to the risk of additive nephrotoxicity as well as an increased risk of severe methotrexate-related adverse reactions. If concomitant use is unavoidable, closely monitor for adverse reactions. Tenofovir disoproxil fumarate and methotrexate are both nephrotoxic drugs; methotrexate is also renally eliminated. Coadministration of methotrexate with tenofovir disoproxil fumarate may result in decreased renal function as well as increased methotrexate plasma concentrations.
    Midostaurin: (Moderate) Coadministration of tenofovir disoproxil fumarate with midostaurin may result in increased plasma concentrations of tenofovir, leading to an increase in tenofovir-related adverse effects. Tenofovir disoproxil fumarate is a BCRP substrate and midostaurin is a BCRP inhibitor.
    Mifepristone: (Moderate) Caution is advised when administering tenofovir, PMPA, a P-glycoprotein (P-gp) substrate, concurrently with inhibitors of P-gp, such as mifepristone. Coadministration may result in increased absorption of tenofovir. Monitor for tenofovir-associated adverse reactions. (Minor) Coadministration of doravirine and chronic mifepristone therapy may result in increased doravirine plasma concentrations. Doravirine is a CYP3A4 substrate; mifepristone is a strong inhibitor. In drug interaction studies, concurrent use of strong CYP3A4 inhibitors increased doravirine exposure by more than 3-fold; however, this increase was not considered clinically significant. The clinical significance of CYP450 inhibition with short-term use of mifepristone for termination of pregnancy is unknown.
    Mitapivat: (Moderate) Coadministration of tenofovir disoproxil fumarate with mitapivat may result in increased plasma concentrations of tenofovir, leading to an increase in tenofovir-related adverse effects. Tenofovir disoproxil fumarate is a P-gp substrate and mitapivat is a P-gp inhibitor. (Moderate) Concurrent administration of doravirine and mitapivat may result in decreased doravirine exposure, resulting in potential loss of virologic control. Doravirine is a CYP3A substrate; mitapivat is a weak CYP3A inducer.
    Mitotane: (Contraindicated) Concurrent administration of doravirine and mitotane is contraindicated due to decreased doravirine exposure, resulting in potential loss of virologic control. At least a 4-week cessation period is recommended before initiating treatment with doravirine. Doravirine is a CYP3A4 substrate; mitotane is a strong CYP3A4 inducer.
    Mobocertinib: (Moderate) Concurrent administration of doravirine and mobocertinib may result in decreased doravirine exposure, resulting in potential loss of virologic control. Doravirine is a CYP3A substrate; mobocertinib is a weak CYP3A inducer.
    Modafinil: (Moderate) Concurrent administration of doravirine and modafinil may result in decreased doravirine exposure, resulting in potential loss of virologic control. Doravirine is a CYP3A4 substrate; modafinil is a moderate CYP3A4 inducer.
    Nabumetone: (Moderate) Avoid administering tenofovir, PMPA concurrently with or recently after a nephrotoxic agent, such as high-dose or multiple nonsteroidal antiinflammatory drugs (NSAIDs). Cases of acute renal failure, some requiring hospitalization and renal replacement therapy, have been reported after high-dose or multiple NSAIDs were initiated in patients who appeared stable on tenofovir. Consider alternatives to NSAIDs in patients at risk for renal dysfunction. If these drugs must be coadministered, carefully monitor the estimated creatinine creatinine, serum phosphorus, urine glucose, and urine protein prior to, and periodically during, treatment.
    Nafcillin: (Moderate) Concurrent administration of doravirine and nafcillin may result in decreased doravirine exposure, resulting in potential loss of virologic control. Doravirine is a CYP3A4 substrate; nafcillin is a moderate CYP3A4 inducer.
    Naproxen: (Moderate) Avoid administering tenofovir, PMPA concurrently with or recently after a nephrotoxic agent, such as high-dose or multiple nonsteroidal antiinflammatory drugs (NSAIDs). Cases of acute renal failure, some requiring hospitalization and renal replacement therapy, have been reported after high-dose or multiple NSAIDs were initiated in patients who appeared stable on tenofovir. Consider alternatives to NSAIDs in patients at risk for renal dysfunction. If these drugs must be coadministered, carefully monitor the estimated creatinine creatinine, serum phosphorus, urine glucose, and urine protein prior to, and periodically during, treatment.
    Naproxen; Esomeprazole: (Moderate) Avoid administering tenofovir, PMPA concurrently with or recently after a nephrotoxic agent, such as high-dose or multiple nonsteroidal antiinflammatory drugs (NSAIDs). Cases of acute renal failure, some requiring hospitalization and renal replacement therapy, have been reported after high-dose or multiple NSAIDs were initiated in patients who appeared stable on tenofovir. Consider alternatives to NSAIDs in patients at risk for renal dysfunction. If these drugs must be coadministered, carefully monitor the estimated creatinine creatinine, serum phosphorus, urine glucose, and urine protein prior to, and periodically during, treatment.
    Naproxen; Pseudoephedrine: (Moderate) Avoid administering tenofovir, PMPA concurrently with or recently after a nephrotoxic agent, such as high-dose or multiple nonsteroidal antiinflammatory drugs (NSAIDs). Cases of acute renal failure, some requiring hospitalization and renal replacement therapy, have been reported after high-dose or multiple NSAIDs were initiated in patients who appeared stable on tenofovir. Consider alternatives to NSAIDs in patients at risk for renal dysfunction. If these drugs must be coadministered, carefully monitor the estimated creatinine creatinine, serum phosphorus, urine glucose, and urine protein prior to, and periodically during, treatment.
    Nefazodone: (Minor) Coadministration of doravirine and nefazodone may result in increased doravirine plasma concentrations. Doravirine is a CYP3A4 substrate; nefazodone is a strong inhibitor. In drug interaction studies, concurrent use of strong CYP3A4 inhibitors increased doravirine exposure by more than 3-fold; however, this increase was not considered clinically significant.
    Nelfinavir: (Moderate) Caution is advised when administering tenofovir, PMPA, a P-glycoprotein (P-gp) substrate, concurrently with inhibitors of P-gp, such as nelfinavir. Coadministration may result in increased absorption of tenofovir. Monitor for tenofovir-associated adverse reactions. (Minor) Coadministration of doravirine and nelfinavir may result in increased doravirine plasma concentrations. Doravirine is a CYP3A4 substrate; nelfinavir is a strong inhibitor. In drug interaction studies, concurrent use of strong CYP3A4 inhibitors increased doravirine exposure by more than 3-fold; however, this increase was not considered clinically significant.
    Neratinib: (Moderate) Coadministration of tenofovir disoproxil fumarate with neratinib may result in increased plasma concentrations of tenofovir, leading to an increase in tenofovir-related adverse effects. Tenofovir disoproxil fumarate is a P-glycoprotein (P-gp) substrate and neratinib is a P-gp inhibitor.
    Nevirapine: (Contraindicated) Concurrent treatment with nevirapine and doravirine is not recommended. Both medications are non-nucleoside reverse transcriptase inhibitors (NNRTIs), and using these drugs together would represent duplicate therapy. In addition, taking these drugs together may result in decreased doravirine exposure. Doravirine is a CYP3A4 substrate; nevirapine is a CYP3A4 inducer.
    Nirmatrelvir; Ritonavir: (Moderate) Caution is advised when administering tenofovir, PMPA, a P-glycoprotein (P-gp) and breast cancer resistance protein (BCRP) substrate, concurrently with inhibitors of P-gp and BCRP, such as ritonavir. Coadministration may result in increased absorption of tenofovir. Monitor for tenofovir-associated adverse reactions. (Minor) Coadministration of doravirine and ritonavir may result in increased doravirine plasma concentrations. Doravirine is a CYP3A4 substrate; ritonavir is a strong inhibitor. In a drug interaction study, concurrent use of ritonavir increased doravirine exposure by more than 3-fold; however, this increase was not considered clinically significant.
    Non-Ionic Contrast Media: (Moderate) Tenofovir-containing products should be avoided with concurrent or recent use of a nephrotoxic agent, such as radiopaque contrast agents. Tenofovir is primarily excreted via the kidneys by a combination of glomerular filtration and active tubular secretion. Coadministration of tenofovir with drugs that are eliminated by active tubular secretion may increase concentrations of tenofovir and/or the co-administered drug. Drugs that decrease renal function may also increase concentrations of tenofovir. Renal impairment, which may include hypophosphatemia, has been reported with the use of tenofovir with a majority of the cases occurring in patients who have underlying systemic or renal disease or who are concurrently taking nephrotoxic agents. Monitor patients receiving concomitant nephrotoxic agents for changes in serum creatinine and phosphorus.
    Nonsteroidal antiinflammatory drugs: (Moderate) Avoid administering tenofovir, PMPA concurrently with or recently after a nephrotoxic agent, such as high-dose or multiple nonsteroidal antiinflammatory drugs (NSAIDs). Cases of acute renal failure, some requiring hospitalization and renal replacement therapy, have been reported after high-dose or multiple NSAIDs were initiated in patients who appeared stable on tenofovir. Consider alternatives to NSAIDs in patients at risk for renal dysfunction. If these drugs must be coadministered, carefully monitor the estimated creatinine creatinine, serum phosphorus, urine glucose, and urine protein prior to, and periodically during, treatment.
    Odevixibat: (Moderate) Concurrent administration of doravirine and odevixibat may result in decreased doravirine exposure, resulting in potential loss of virologic control. Doravirine is a CYP3A substrate; odevixibat is a weak CYP3A inducer.
    Ombitasvir; Paritaprevir; Ritonavir: (Moderate) Caution is advised when administering tenofovir, PMPA, a P-glycoprotein (P-gp) and breast cancer resistance protein (BCRP) substrate, concurrently with inhibitors of P-gp and BCRP, such as ritonavir. Coadministration may result in increased absorption of tenofovir. Monitor for tenofovir-associated adverse reactions. (Moderate) Concurrent administration of tenofovir, PMPA with dasabuvir; ombitasvir; paritaprevir; ritonavir may result in elevated tenofovir plasma concentrations. Tenofovir is a substrate for the breast cancer resistance protein (BCRP) and P-glycoprotein (P-gp). Dasabuvir, paritaprevir, and ritonavir are BCRP inhibitors, and ritonavir inhibits P-gp. Caution and close monitoring are advised if these drugs are administered together. (Minor) Coadministration of doravirine and ritonavir may result in increased doravirine plasma concentrations. Doravirine is a CYP3A4 substrate; ritonavir is a strong inhibitor. In a drug interaction study, concurrent use of ritonavir increased doravirine exposure by more than 3-fold; however, this increase was not considered clinically significant.
    Omeprazole; Amoxicillin; Rifabutin: (Major) Increase the doravirine dose to 100 mg PO twice daily (approximately 12 hours apart) if coadministered with rifabutin. Concurrent use decreases doravirine exposure, resulting in potential loss of virologic control. Doravirine is a CYP3A4 substrate and rifabutin is a moderate CYP3A4 inducer.
    Oritavancin: (Minor) Concurrent administration of doravirine and oritavancin may result in decreased doravirine exposure, resulting in potential loss of virologic control. Doravirine is a CYP3A4 substrate; oritavancin is a weak CYP3A4 inducer.
    Orlistat: (Major) According to the manufacturer of orlistat, HIV RNA levels should be frequently monitored in patients receiving orlistat while being treated for HIV infection with tenofovir, PMPA. Loss of virological control has been reported in HIV-infected patients taking orlistat with tenofovir disoproxil fumarate and emtricitabine; efavirenz; tenofovir disoproxil fumarate. The exact mechanism for this interaction is not known, but may involve inhibition of systemic absorption of the anti-retroviral agent. If an increased HIV viral load is confirmed, orlistat should be discontinued. (Moderate) According to the manufacturer of orlistat, HIV RNA levels should be frequently monitored in patients receiving orlistat while being treated for HIV infection with anti-retroviral nucleoside reverse transcriptase inhibitors (NRTIs). Loss of virological control has been reported in HIV-infected patients taking orlistat with atazanavir, ritonavir, tenofovir disoproxil fumarate, emtricitabine, lopinavir; ritonavir, and emtricitabine; efavirenz; tenofovir disoproxil fumarate. The exact mechanism for this interaction is not known, but may involve inhibition of systemic absorption of the anti-retroviral agent. If an increased HIV viral load is confirmed, orlistat should be discontinued.
    Osimertinib: (Moderate) Monitor for an increase in tenofovir-related adverse reactions if coadministration with osimertinib is necessary. Concomitant use may result in increased tenofovir absorption. Tenofovir disoproxil is a BCRP and P-glycoprotein (P-gp) substrate. Osimertinib is a BCRP and P-gp inhibitor.
    Oxaliplatin: (Major) Avoid coadministration of oxaliplatin with tenofovir disoproxil fumarate due to the risk of increased oxaliplatin-related adverse reactions. Tenofovir disoproxil fumarate is known to be potentially nephrotoxic; because platinum-containing drugs like oxaliplatin are eliminated primarily through the kidney, oxaliplatin clearance may be decreased by coadministration with nephrotoxic agents.
    Oxaprozin: (Moderate) Avoid administering tenofovir, PMPA concurrently with or recently after a nephrotoxic agent, such as high-dose or multiple nonsteroidal antiinflammatory drugs (NSAIDs). Cases of acute renal failure, some requiring hospitalization and renal replacement therapy, have been reported after high-dose or multiple NSAIDs were initiated in patients who appeared stable on tenofovir. Consider alternatives to NSAIDs in patients at risk for renal dysfunction. If these drugs must be coadministered, carefully monitor the estimated creatinine creatinine, serum phosphorus, urine glucose, and urine protein prior to, and periodically during, treatment.
    Oxcarbazepine: (Contraindicated) Concurrent administration of doravirine and oxcarbazepine is contraindicated due to decreased doravirine exposure, resulting in potential loss of virologic control. At least a 4-week cessation period is recommended before initiating treatment with doravirine. Doravirine is a CYP3A4 substrate; oxcarbazepine is a CYP3A4 inducer.
    Pacritinib: (Moderate) Concomitant use of tenofovir disoproxil fumarate with pacritinib may result in increased plasma concentrations of tenofovir, leading to an increase in tenofovir-related adverse effects. Tenofovir disoproxil fumarate is a P-gp and BCRP substrate; pacritinib is a P-gp and BCRP inhibitor.
    Pamidronate: (Moderate) Tenofovir-containing products should be avoided with concurrent or recent use of a nephrotoxic agent, such as pamidronate. Tenofovir is primarily excreted via the kidneys by a combination of glomerular filtration and active tubular secretion. Coadministration of tenofovir with drugs that are eliminated by active tubular secretion may increase concentrations of tenofovir and/or the co-administered drug. Drugs that decrease renal function may also increase concentrations of tenofovir. Renal impairment, which may include hypophosphatemia, has been reported with the use of tenofovir with a majority of the cases occurring in patients who have underlying systemic or renal disease or who are concurrently taking nephrotoxic agents. Monitor patients receiving concomitant nephrotoxic agents for changes in serum creatinine and phosphorus.
    Paromomycin: (Moderate) Renal impairment, which may include hypophosphatemia, has been reported with the use of tenofovir with a majority of the cases occurring in patients who have underlying systemic or renal disease or who are concurrently taking nephrotoxic agents. Tenofovir should be avoided with concurrent or recent use of a nephrotoxic agent; patients receiving concomitant nephrotoxic agents should be carefully monitored for changes in serum creatinine and phosphorus.
    Pexidartinib: (Moderate) Concurrent administration of doravirine and pexidartinib may result in decreased doravirine exposure, resulting in potential loss of virologic control. Doravirine is a CYP3A4 substrate; pexidartinib is a moderate CYP3A4 inducer.
    Phenobarbital: (Contraindicated) Concurrent administration of doravirine and phenobarbital is contraindicated due to decreased doravirine exposure, resulting in potential loss of virologic control. At least a 4-week cessation period is recommended before initiating treatment with doravirine. Doravirine is a CYP3A4 substrate; phenobarbital is a strong CYP3A4 inducer.
    Phenobarbital; Hyoscyamine; Atropine; Scopolamine: (Contraindicated) Concurrent administration of doravirine and phenobarbital is contraindicated due to decreased doravirine exposure, resulting in potential loss of virologic control. At least a 4-week cessation period is recommended before initiating treatment with doravirine. Doravirine is a CYP3A4 substrate; phenobarbital is a strong CYP3A4 inducer.
    Phentermine; Topiramate: (Minor) Concurrent administration of doravirine and topiramate may result in decreased doravirine exposure, resulting in potential loss of virologic control. Doravirine is a CYP3A4 substrate; topiramate is a weak CYP3A4 inducer.
    Phenytoin: (Contraindicated) Concurrent administration of doravirine and phenytoin is contraindicated due to decreased doravirine exposure, resulting in potential loss of virologic control. At least a 4-week cessation period is recommended before initiating treatment with doravirine. Doravirine is a CYP3A4 substrate; phenytoin is a strong CYP3A4 inducer.
    Pioglitazone; Metformin: (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.
    Piroxicam: (Moderate) Avoid administering tenofovir, PMPA concurrently with or recently after a nephrotoxic agent, such as high-dose or multiple nonsteroidal antiinflammatory drugs (NSAIDs). Cases of acute renal failure, some requiring hospitalization and renal replacement therapy, have been reported after high-dose or multiple NSAIDs were initiated in patients who appeared stable on tenofovir. Consider alternatives to NSAIDs in patients at risk for renal dysfunction. If these drugs must be coadministered, carefully monitor the estimated creatinine creatinine, serum phosphorus, urine glucose, and urine protein prior to, and periodically during, treatment.
    Plazomicin: (Moderate) Renal impairment, which may include hypophosphatemia, has been reported with the use of tenofovir with a majority of the cases occurring in patients who have underlying systemic or renal disease or who are concurrently taking nephrotoxic agents. Tenofovir should be avoided with concurrent or recent use of a nephrotoxic agent; patients receiving concomitant nephrotoxic agents should be carefully monitored for changes in serum creatinine and phosphorus.
    Polymyxin B: (Moderate) Tenofovir-containing products should be avoided with concurrent or recent use of a nephrotoxic agent, such as polymyxin B. Tenofovir is primarily excreted via the kidneys by a combination of glomerular filtration and active tubular secretion. Coadministration of tenofovir with drugs that are eliminated by active tubular secretion may increase concentrations of tenofovir and/or the co-administered drug. Drugs that decrease renal function may also increase concentrations of tenofovir. Renal impairment, which may include hypophosphatemia, has been reported with the use of tenofovir with a majority of the cases occurring in patients who have underlying systemic or renal disease or who are concurrently taking nephrotoxic agents. Monitor patients receiving concomitant nephrotoxic agents for changes in serum creatinine and phosphorus.
    Posaconazole: (Moderate) Caution is advised when administering tenofovir, PMPA, a P-glycoprotein (P-gp) substrate, concurrently with inhibitors of P-gp, such as posaconazole. Coadministration may result in increased absorption of tenofovir. Monitor for tenofovir-associated adverse reactions. (Minor) Coadministration of doravirine and posaconazole may result in increased doravirine plasma concentrations. Doravirine is a CYP3A4 substrate; posaconazole is a strong inhibitor. In drug interaction studies, concurrent use of strong CYP3A4 inhibitors increased doravirine exposure by more than 3-fold; however, this increase was not considered clinically significant.
    Primidone: (Contraindicated) Concurrent administration of doravirine and primidone is contraindicated due to decreased doravirine exposure, resulting in potential loss of virologic control. At least a 4-week cessation period is recommended before initiating treatment with doravirine. Doravirine is a CYP3A4 substrate; primidone is a strong CYP3A4 inducer.
    Probenecid: (Moderate) Renal impairment, which may include hypophosphatemia, has been reported with the use of tenofovir with a majority of the cases occurring in patients who have underlying systemic or renal disease or who are concurrently taking nephrotoxic agents. Tenofovir should be avoided with concurrent or recent use of a nephrotoxic agent, such as probenecid; patients receiving concomitant nephrotoxic agents should be carefully monitored for changes in serum creatinine and phosphorus.
    Probenecid; Colchicine: (Moderate) Caution is advised when administering tenofovir, PMPA, a P-glycoprotein (P-gp) substrate, concurrently with inhibitors of P-gp, such as colchicine. Coadministration may result in increased absorption of tenofovir. Monitor for tenofovir-associated adverse reactions. (Moderate) Renal impairment, which may include hypophosphatemia, has been reported with the use of tenofovir with a majority of the cases occurring in patients who have underlying systemic or renal disease or who are concurrently taking nephrotoxic agents. Tenofovir should be avoided with concurrent or recent use of a nephrotoxic agent, such as probenecid; patients receiving concomitant nephrotoxic agents should be carefully monitored for changes in serum creatinine and phosphorus.
    Procainamide: (Moderate) Cationic drugs that are eliminated by renal tubular secretion such as procainamide may compete with lamivudine for common renal tubular transport systems, thus possibly decreasing the elimination of one of the drugs. Although theoretical, careful patient monitoring of the response to lamivudine and/or procainamide is recommended to individualize dosage. In selected individuals, procainamide serum concentration monitoring may be appropriate.
    Propafenone: (Moderate) Caution is advised when administering tenofovir, PMPA, a P-glycoprotein (P-gp) substrate, concurrently with inhibitors of P-gp, such as propafenone. Coadministration may result in increased absorption of tenofovir. Monitor for tenofovir-associated adverse reactions.
    Quinidine: (Moderate) Caution is advised when administering tenofovir, PMPA, a P-glycoprotein (P-gp) substrate, concurrently with inhibitors of P-gp, such as quinidine. Coadministration may result in increased absorption of tenofovir. Monitor for tenofovir-associated adverse reactions.
    Ranolazine: (Moderate) Caution is advised when administering tenofovir, PMPA, a P-glycoprotein (P-gp) substrate, concurrently with inhibitors of P-gp, such as ranolazine. Coadministration may result in increased absorption of tenofovir. Monitor for tenofovir-associated adverse reactions.
    Regorafenib: (Moderate) Use caution if coadministration of regorafenib with tenofovir, PMPA is necessary, and monitor for an increase in tenofovir-related adverse reactions. Tenofovir is a BCRP substrate and regorafenib is a BCRP inhibitor. Regorafenib-mediated BCRP inhibition may increase exposure to tenofovir.
    Ribavirin: (Moderate) Use lamivudine with ribavirin and interferon with caution and closely monitor for hepatic decompensation and anemia. Dose reduction or discontinuation of interferon, ribavirin, or both should be considered if worsening clinical toxicities are observed, including hepatic decompensation (e.g., Child-Pugh greater than 6). Hepatic decompensation (some fatal) has occurred in HCV/HIV coinfected patients who received both ribavirin/interferon and anti-retroviral nucleoside reverse transcriptase inhibitors (NRTIs) therapies. In addition, ribavirin has been shown in cell culture to inhibit phosphorylation of lamivudine, which could lead to decreased antiretroviral activity; however, while ribavirin inhibits the phosphorylation reactions required to activate lamivudine, no evidence of a pharmacokinetic or pharmacodynamic interaction has been observed.
    Ribociclib: (Minor) Coadministration of doravirine and ribociclib may result in increased doravirine plasma concentrations. Doravirine is a CYP3A4 substrate; ribociclib is a strong inhibitor. In drug interaction studies, concurrent use of strong CYP3A4 inhibitors increased doravirine exposure by more than 3-fold; however, this increase was not considered clinically significant.
    Ribociclib; Letrozole: (Minor) Coadministration of doravirine and ribociclib may result in increased doravirine plasma concentrations. Doravirine is a CYP3A4 substrate; ribociclib is a strong inhibitor. In drug interaction studies, concurrent use of strong CYP3A4 inhibitors increased doravirine exposure by more than 3-fold; however, this increase was not considered clinically significant.
    Rifabutin: (Major) Increase the doravirine dose to 100 mg PO twice daily (approximately 12 hours apart) if coadministered with rifabutin. Concurrent use decreases doravirine exposure, resulting in potential loss of virologic control. Doravirine is a CYP3A4 substrate and rifabutin is a moderate CYP3A4 inducer.
    Rifampin: (Contraindicated) Concurrent administration of doravirine and rifampin is contraindicated due to decreased doravirine exposure, resulting in potential loss of virologic control. At least a 4-week cessation period is recommended before initiating treatment with doravirine. Doravirine is a CYP3A4 substrate; rifampin is a strong CYP3A4 inducer.
    Rifapentine: (Contraindicated) Concurrent administration of doravirine and rifapentine is contraindicated due to decreased doravirine exposure, resulting in potential loss of virologic control. At least a 4-week cessation period is recommended before initiating treatment with doravirine. Doravirine is a CYP3A4 substrate; rifapentine is a strong CYP3A4 inducer.
    Rifaximin: (Moderate) Concurrent administration of doravirine and rifaximin may result in decreased doravirine exposure, resulting in potential loss of virologic control. Doravirine is a CYP3A4 substrate. Rifaximin is a moderate CYP3A4 inducer in vitro; however, in patients with normal liver function, rifaximin at the recommended dosing regimen is not expected to induce CYP3A4. It is unknown whether rifaximin can have a significant effect on the pharmacokinetics of concomitant CYP3A4 substrates in patients with reduced liver function who have elevated rifaximin concentrations.
    Ritonavir: (Moderate) Caution is advised when administering tenofovir, PMPA, a P-glycoprotein (P-gp) and breast cancer resistance protein (BCRP) substrate, concurrently with inhibitors of P-gp and BCRP, such as ritonavir. Coadministration may result in increased absorption of tenofovir. Monitor for tenofovir-associated adverse reactions. (Minor) Coadministration of doravirine and ritonavir may result in increased doravirine plasma concentrations. Doravirine is a CYP3A4 substrate; ritonavir is a strong inhibitor. In a drug interaction study, concurrent use of ritonavir increased doravirine exposure by more than 3-fold; however, this increase was not considered clinically significant.
    Rofecoxib: (Moderate) Avoid administering tenofovir, PMPA concurrently with or recently after a nephrotoxic agent, such as high-dose or multiple nonsteroidal antiinflammatory drugs (NSAIDs). Cases of acute renal failure, some requiring hospitalization and renal replacement therapy, have been reported after high-dose or multiple NSAIDs were initiated in patients who appeared stable on tenofovir. Consider alternatives to NSAIDs in patients at risk for renal dysfunction. If these drugs must be coadministered, carefully monitor the estimated creatinine creatinine, serum phosphorus, urine glucose, and urine protein prior to, and periodically during, treatment.
    Rolapitant: (Moderate) Use caution if tenofovir, PMPA and rolapitant are used concurrently, and monitor for tenofovir-related adverse effects. Tenofovir is a substrate of the Breast Cancer Resistance Protein (BCRP) and P-glycoprotein (P-gp), where an increase in exposure may significantly increase adverse effects; rolapitant is a BCRP and P-gp inhibitor. The Cmax and AUC of another BCRP substrate, sulfasalazine, were increased by 140% and 130%, respectively, on day 1 with rolapitant, and by 17% and 32%, respectively, on day 8 after rolapitant administration. When rolapitant was administered with digoxin, a P-gp substrate, the day 1 Cmax and AUC were increased by 70% and 30%, respectively; the Cmax and AUC on day 8 were not studied.
    Salicylates: (Major) Renal impairment, which may include hypophosphatemia, has been reported with the use of tenofovir disoproxil fumarate with a majority of the cases occurring in patients who have underlying systemic or renal disease or who are concurrently taking nephrotoxic agents. Tenofovir should be avoided with concurrent or recent use of a nephrotoxic agent; patients receiving concomitant nephrotoxic agents, like salicylates should be carefully monitored for changes in serum creatinine and phosphorus.
    Salsalate: (Major) Renal impairment, which may include hypophosphatemia, has been reported with the use of tenofovir disoproxil fumarate with a majority of the cases occurring in patients who have underlying systemic or renal disease or who are concurrently taking nephrotoxic agents. Tenofovir should be avoided with concurrent or recent use of a nephrotoxic agent; patients receiving concomitant nephrotoxic agents, like salicylates should be carefully monitored for changes in serum creatinine and phosphorus.
    Saquinavir: (Moderate) Caution is advised when administering tenofovir, PMPA, a P-glycoprotein (P-gp) substrate, concurrently with inhibitors of P-gp, such as saquinavir. Coadministration may result in increased absorption of tenofovir. Monitor for tenofovir-associated adverse reactions. (Minor) Coadministration of doravirine and saquinavir may result in increased doravirine plasma concentrations. Doravirine is a CYP3A4 substrate; saquinavir is a strong inhibitor. In drug interaction studies, concurrent use of strong CYP3A4 inhibitors increased doravirine exposure by more than 3-fold; however, this increase was not considered clinically significant.Coadministration may increase doravirine exposure. Concurrent use of strong inhibitors like saquinavir increased doravirine exposure by more than 3-fold; however, this increase was not considered clinically significant.
    Secobarbital: (Moderate) Concurrent administration of doravirine and secobarbital may result in decreased doravirine exposure, resulting in potential loss of virologic control. Doravirine is a CYP3A4 substrate; secobarbital is a moderate CYP3A4 inducer.
    Simeprevir: (Moderate) Closely monitor for tenofovir-associated adverse reactions if simeprevir is administered with tenofovir, PMPA. Tenofovir is a substrate of the drug transporters P-glycoprotein (P-gp) and breast cancer resistance protein (BCRP); simeprevir is an inhibitor of both P-gp and BCRP.
    Sofosbuvir; Velpatasvir: (Moderate) Monitor patients for tenofovir-associated adverse reactions, such as renal toxicity, in patients receiving regimens containing tenofovir disoproxil fumarate and velpatasvir due to potential increases in tenofovir serum concentrations. When administered concurrently with velpatasvir, the peak concentration (Cmax), systemic exposure (AUC), and the trough concentration (Cmin) of tenofovir increased by 44%, 40%, and 84%, respectively. Tenofovir is a substrate of the breast cancer resistance protein (BCRP) and P-glycoprotein (P-gp) transporters, while velpatasvir inhibits both BCRP and P-gp. Consider use of tenofovir alafenamide in place of tenofovir disoproxil fumarate.
    Sofosbuvir; Velpatasvir; Voxilaprevir: (Major) Avoid concurrent administration of voxilaprevir with tenofovir disoproxil fumarate. Taking these medications together may increase tenofovir plasma concentrations, potentially increasing the risk for adverse events. Tenofovir disoproxil fumarate is a substrate for the drug transporter Breast Cancer Resistance Protein (BCRP). Voxilaprevir is a BCRP inhibitor. (Moderate) Monitor patients for tenofovir-associated adverse reactions, such as renal toxicity, in patients receiving regimens containing tenofovir disoproxil fumarate and velpatasvir due to potential increases in tenofovir serum concentrations. When administered concurrently with velpatasvir, the peak concentration (Cmax), systemic exposure (AUC), and the trough concentration (Cmin) of tenofovir increased by 44%, 40%, and 84%, respectively. Tenofovir is a substrate of the breast cancer resistance protein (BCRP) and P-glycoprotein (P-gp) transporters, while velpatasvir inhibits both BCRP and P-gp. Consider use of tenofovir alafenamide in place of tenofovir disoproxil fumarate.
    Sorafenib: (Moderate) Monitor for an increase in tenofovir-related adverse reactions if coadministration with sorafenib is necessary. Tenofovir is a P-glycoprotein (P-gp) substrate and sorafenib inhibits P-gp in vitro. Sorafenib may increase the concentrations of concomitantly administered drugs that are P-gp substrates.
    Sorbitol: (Major) Avoid coadministration of lamivudine oral solution and sorbitol if possible due to sorbitol dose-dependent reduction in lamivudine exposure. An all-tablet regimen should be used when possible to avoid a potential interaction with sorbitol. Consider more frequent monitoring of viral load when treating with lamivudine oral solution. In a drug interaction study in 16 healthy adult patients, coadministration of a single 300 mg dose of lamivudine oral solution with sorbitol 3.2 g, 10.2 g, or 13.4 g resulted in dose-dependent decreases of 20%, 39%, and 44% in the AUC24 and 28%, 52%, and 55% in the Cmax of lamivudine.
    Sotorasib: (Moderate) Coadministration of tenofovir disoproxil fumarate with sotorasib may result in increased plasma concentrations of tenofovir, leading to an increase in tenofovir-related adverse effects. Tenofovir disoproxil fumarate is a P-gp substrate and sotorasib is a P-gp inhibitor. (Moderate) Concurrent administration of doravirine and sotorasib may result in decreased doravirine exposure, resulting in potential loss of virologic control. Doravirine is a CYP3A4 substrate; sotorasib is a moderate CYP3A4 inducer.
    St. John's Wort, Hypericum perforatum: (Contraindicated) Concurrent administration of doravirine and St. John's Wort is contraindicated due to decreased doravirine exposure, resulting in potential loss of virologic control. At least a 4-week cessation period is recommended before initiating treatment with doravirine. Doravirine is a CYP3A4 substrate; St. John's Wort is a strong CYP3A4 inducer.
    Streptomycin: (Moderate) Renal impairment, which may include hypophosphatemia, has been reported with the use of tenofovir with a majority of the cases occurring in patients who have underlying systemic or renal disease or who are concurrently taking nephrotoxic agents. Tenofovir should be avoided with concurrent or recent use of a nephrotoxic agent; patients receiving concomitant nephrotoxic agents should be carefully monitored for changes in serum creatinine and phosphorus.
    Sulindac: (Moderate) Avoid administering tenofovir, PMPA concurrently with or recently after a nephrotoxic agent, such as high-dose or multiple nonsteroidal antiinflammatory drugs (NSAIDs). Cases of acute renal failure, some requiring hospitalization and renal replacement therapy, have been reported after high-dose or multiple NSAIDs were initiated in patients who appeared stable on tenofovir. Consider alternatives to NSAIDs in patients at risk for renal dysfunction. If these drugs must be coadministered, carefully monitor the estimated creatinine creatinine, serum phosphorus, urine glucose, and urine protein prior to, and periodically during, treatment.
    Sumatriptan; Naproxen: (Moderate) Avoid administering tenofovir, PMPA concurrently with or recently after a nephrotoxic agent, such as high-dose or multiple nonsteroidal antiinflammatory drugs (NSAIDs). Cases of acute renal failure, some requiring hospitalization and renal replacement therapy, have been reported after high-dose or multiple NSAIDs were initiated in patients who appeared stable on tenofovir. Consider alternatives to NSAIDs in patients at risk for renal dysfunction. If these drugs must be coadministered, carefully monitor the estimated creatinine creatinine, serum phosphorus, urine glucose, and urine protein prior to, and periodically during, treatment.
    Tacrolimus: (Major) Renal impairment, which may include hypophosphatemia, has been reported with the use of tenofovir disoproxil fumarate with a majority of the cases occurring in patients who have underlying systemic or renal disease or who are concurrently taking nephrotoxic agents. Tenofovir should be avoided with concurrent or recent use of a nephrotoxic agent, including tacrolimus.
    Tafamidis: (Moderate) Caution is advised with the coadministration of tafamidis and tenofovir disoproxil fumarate due to the potential for increased plasma concentrations of tenofovir disoproxil fumarate increasing the risk of adverse effects. Tenofovir disoproxil fumarate dose adjustment may be needed with coadministration. Tenofovir disoproxil fumarate is a substrate of breast cancer resistance protein (BCRP) and tafamidis is a BCRP inhibitor.
    Tazemetostat: (Minor) Concurrent administration of doravirine and tazemetostat may result in decreased doravirine exposure, resulting in potential loss of virologic control. Doravirine is a CYP3A4 substrate; tazemetostat is a weak CYP3A4 inducer.
    Tedizolid: (Moderate) If possible, stop use of tenofovir disoproxil fumarate temporarily during treatment with oral tedizolid. If coadministration cannot be avoided, closely monitor for tenofovir-associated adverse events. Tenofovir plasma concentrations may be increased when tenofovir disoproxil fumarate is administered concurrently with oral tedizolid.Tenofovir disoproxil fumarateis a substrate of the Breast Cancer Resistance Protein (BCRP); oral tedizolid inhibits BCRP in the intestine.
    Telaprevir: (Moderate) Close clinical monitoring is advised when coadministering tenofovir, PMPA with telaprevir due to an increased potential for tenofovir-related adverse events. When used in combination, the plasma concentrations of tenofovir were increased, resulting in an increased potential for tenofovir-associated adverse reactions. If tenofovir dose adjustments are made, re-adjust the dose upon completion of telaprevir treatment.
    Telithromycin: (Moderate) Caution is advised when administering tenofovir, PMPA, a P-glycoprotein (P-gp) substrate, concurrently with inhibitors of P-gp, such as telithromycin. Coadministration may result in increased absorption of tenofovir. Monitor for tenofovir-associated adverse reactions. (Minor) Coadministration of doravirine and telithromycin may result in increased doravirine plasma concentrations. Doravirine is a CYP3A4 substrate; telithromycin is a strong inhibitor. In drug interaction studies, concurrent use of strong CYP3A4 inhibitors increased doravirine exposure by more than 3-fold; however, this increase was not considered clinically significant.
    Telotristat Ethyl: (Minor) Concurrent administration of doravirine and telotristat may result in decreased doravirine exposure, resulting in potential loss of virologic control. Doravirine is a CYP3A4 substrate; telotristat is a weak CYP3A4 inducer.
    Temsirolimus: (Moderate) Monitor for an increase in tenofovir disoproxil fumarate-related adverse reactions if coadministration with temsirolimus is necessary. Tenofovir disoproxil fumarate is a P-glycoprotein (P-gp) substrate and temsirolimus is a P-gp inhibitor. Concomitant use may lead to increased concentrations of tenofovir disoproxil fumarate.
    Tepotinib: (Moderate) Coadministration of tenofovir disoproxil fumarate with tepotinib may result in increased plasma concentrations of tenofovir, leading to an increase in tenofovir-related adverse effects. Tenofovir disoproxil fumarate is a P-gp substrate and tepotinib is a P-gp inhibitor.
    Tezacaftor; Ivacaftor: (Moderate) Caution is advised when administering tenofovir, PMPA, a P-glycoprotein (P-gp) substrate, concurrently with inhibitors of P-gp, such as ivacaftor. Coadministration may result in increased absorption of tenofovir. Monitor for tenofovir-associated adverse reactions.
    Ticagrelor: (Moderate) Caution is advised when administering tenofovir, PMPA, a P-glycoprotein (P-gp) substrate, concurrently with inhibitors of P-gp, such as ticagrelor. Coadministration may result in increased absorption of tenofovir. Monitor for tenofovir-associated adverse reactions.
    Tipranavir: (Moderate) Concurrent administration of tipranavir and ritonavir with tenofovir, results in decreased tipranavir concentrations. The clinical significance of this interaction has not been established, and no recommendations for tenofovir dosage adjustments are available. (Minor) Coadministration of doravirine and tipranavir may result in increased doravirine plasma concentrations. Doravirine is a CYP3A4 substrate; tipranavir is a strong inhibitor. In drug interaction studies, concurrent use of strong CYP3A4 inhibitors increased doravirine exposure by more than 3-fold; however, this increase was not considered clinically significant
    Tobramycin: (Moderate) Renal impairment, which may include hypophosphatemia, has been reported with the use of tenofovir with a majority of the cases occurring in patients who have underlying systemic or renal disease or who are concurrently taking nephrotoxic agents. Tenofovir should be avoided with concurrent or recent use of a nephrotoxic agent; patients receiving concomitant nephrotoxic agents should be carefully monitored for changes in serum creatinine and phosphorus.
    Tolmetin: (Moderate) Avoid administering tenofovir, PMPA concurrently with or recently after a nephrotoxic agent, such as high-dose or multiple nonsteroidal antiinflammatory drugs (NSAIDs). Cases of acute renal failure, some requiring hospitalization and renal replacement therapy, have been reported after high-dose or multiple NSAIDs were initiated in patients who appeared stable on tenofovir. Consider alternatives to NSAIDs in patients at risk for renal dysfunction. If these drugs must be coadministered, carefully monitor the estimated creatinine creatinine, serum phosphorus, urine glucose, and urine protein prior to, and periodically during, treatment.
    Topiramate: (Minor) Concurrent administration of doravirine and topiramate may result in decreased doravirine exposure, resulting in potential loss of virologic control. Doravirine is a CYP3A4 substrate; topiramate is a weak CYP3A4 inducer.
    Trandolapril; Verapamil: (Moderate) Caution is advised when administering tenofovir, PMPA, a P-glycoprotein (P-gp) substrate, concurrently with inhibitors of P-gp, such as verapamil. Coadministration may result in increased absorption of tenofovir. Monitor for tenofovir-associated adverse reactions.
    Trospium: (Moderate) Trospium is eliminated by active tubular secretion and has the potential for pharmacokinetic interactions with other drugs that are eliminated by active tubular secretion including lamivudine. In theory, coadministration of trospium with lamivudine may increase the serum concentrations of trospium or lamivudine due to competition for the drug elimination pathway. (Minor) Both trospium and tenofovir are eliminated by active renal tubular secretion; coadministration has the potential to increase serum concentrations of trospium or tenofovir due to competition for the drug elimination pathway. Careful patient monitoring and dosage adjustment of trospium and/or tenofovir, PMPA is recommended.
    Tucatinib: (Moderate) Coadministration of tenofovir disoproxil fumarate with tucatinib may result in increased plasma concentrations of tenofovir, leading to an increase in tenofovir-related adverse effects. Tenofovir disoproxil fumarate is a P-glycoprotein (P-gp) substrate and tucatinib is a P-gp inhibitor. (Minor) Coadministration of doravirine and tucatinib may result in increased doravirine plasma concentrations. Doravirine is a CYP3A4 substrate; tucatinib is a strong inhibitor. In drug interaction studies, concurrent use of strong CYP3A4 inhibitors increased doravirine exposure by more than 3-fold; however, this increase was not considered clinically significant.
    Valacyclovir: (Moderate) Monitor for changes in serum creatinine and phosphorus if tenofovir disoproxil fumarate is administered in combination with nephrotoxic agents, such as valacyclovir. Tenofovir is primarily excreted via the kidneys by a combination of glomerular filtration and active tubular secretion. Concurrent administration with drugs that decrease renal function may increase concentrations of tenofovir. In addition, use with drugs that are also eliminated by active tubular secretion may increase concentrations of the co-administered drug. Renal impairment, which may include hypophosphatemia, has been reported with the use of tenofovir disoproxil fumarate; a majority of the cases occurred in patients who had underlying systemic or renal disease or who are concurrently taking nephrotoxic agents. Tenofovir containing products should be avoided with concurrent or recent use of a nephrotoxic agent; patients receiving concomitant nephrotoxic agents should be carefully monitored for changes in serum creatinine and phosphorus, and urine glucose and protein.
    Valdecoxib: (Moderate) Avoid administering tenofovir, PMPA concurrently with or recently after a nephrotoxic agent, such as high-dose or multiple nonsteroidal antiinflammatory drugs (NSAIDs). Cases of acute renal failure, some requiring hospitalization and renal replacement therapy, have been reported after high-dose or multiple NSAIDs were initiated in patients who appeared stable on tenofovir. Consider alternatives to NSAIDs in patients at risk for renal dysfunction. If these drugs must be coadministered, carefully monitor the estimated creatinine creatinine, serum phosphorus, urine glucose, and urine protein prior to, and periodically during, treatment.
    Valganciclovir: (Minor) Since tenofovir is primarily eliminated by the kidneys, concurrent administration of tenofovir disoproxil with valganciclovir may increase serum concentrations of tenofovir via competition for renal tubular secretion.
    Vancomycin: (Moderate) Tenofovir should be avoided with concurrent or recent use of a nephrotoxic agent, such as vancomycin. Patients receiving these drugs together should be carefully monitored for changes in serum creatinine and phosphorus. Renal impairment, which may include hypophosphatemia, has been reported with the use of tenofovir; a majority of cases occurring in patients who have underlying systemic or renal disease or who are concurrently taking nephrotoxic agents.
    Vemurafenib: (Moderate) Caution is advised when administering tenofovir, PMPA, a P-glycoprotein (P-gp) substrate, concurrently with inhibitors of P-gp, such as vemurafenib. Coadministration may result in increased absorption of tenofovir. Monitor for tenofovir-associated adverse reactions.
    Verapamil: (Moderate) Caution is advised when administering tenofovir, PMPA, a P-glycoprotein (P-gp) substrate, concurrently with inhibitors of P-gp, such as verapamil. Coadministration may result in increased absorption of tenofovir. Monitor for tenofovir-associated adverse reactions.
    Voclosporin: (Moderate) Coadministration of tenofovir disoproxil fumarate and voclosporin may result in increased plasma concentrations of tenofovir, leading to an increase in tenofovir-related adverse effects. Concomitant use may also may result in additive nephrotoxicity. Monitor for renal toxicity if concomitant use is required. Tenofovir disoproxil fumarate is a P-gp substrate and voclosporin is a P-gp inhibitor.
    Voriconazole: (Minor) Coadministration of doravirine and voriconazole may result in increased doravirine plasma concentrations. Doravirine is a CYP3A4 substrate; voriconazole is a strong inhibitor. In drug interaction studies, concurrent use of strong CYP3A4 inhibitors increased doravirine exposure by more than 3-fold; however, this increase was not considered clinically significant.
    Zoledronic Acid: (Moderate) Tenofovir-containing products should be avoided with concurrent or recent use of a nephrotoxic agent, such as zoledronic acid. Tenofovir is primarily excreted via the kidneys by a combination of glomerular filtration and active tubular secretion. Coadministration of tenofovir with drugs that are eliminated by active tubular secretion may increase concentrations of tenofovir and/or the co-administered drug. Drugs that decrease renal function may also increase concentrations of tenofovir. Renal impairment, which may include hypophosphatemia, has been reported with the use of tenofovir with a majority of the cases occurring in patients who have underlying systemic or renal disease or who are concurrently taking nephrotoxic agents. Monitor patients receiving concomitant nephrotoxic agents for changes in serum creatinine and phosphorus.
    Zonisamide: (Minor) Caution is advised when administering tenofovir disoproxil fumarate concurrently with zonisamide, as coadministration may result in elevated tenofovir plasma concentrations. Inhibitors of the drug transporter P-glycoprotein (P-gp), such as zonisamide, may increase absorption of tenofovir, a P-gp substrate. If these medications are administered together, monitor for tenofovir-associated adverse reactions.

    PREGNANCY AND LACTATION

    Pregnancy

    Antiretroviral therapy should be provided to all women during pregnancy, regardless of HIV RNA concentrations or CD4 cell count. Using highly active antiretroviral combination therapy (HAART) to maximally suppress viral replication is the most effective strategy to prevent the development of resistance and to minimize the risk of perinatal transmission. In treatment-naive women, begin HAART as soon as pregnancy is recognized or HIV is diagnosed, without waiting for the results of resistance testing; subsequent modifications to the treatment regimen should be made once the test results are available. Women who are currently receiving antiretroviral treatment when pregnancy is recognized should continue their treatment regimen if it is currently effective in suppressing viral replication; consider resistance testing if HIV RNA concentrations are more than 500 copies/mL. For women not currently receiving HAART, but who have previously received treatment, obtain a complete and accurate history of all prior antiretroviral regimens used and results of prior resistance testing, and perform resistance testing if HIV RNA concentrations are more than 500 copies/mL; treatment should be initiated prior to receiving resistance test results. There are insufficient data to recommend the use of doravirine; lamivudine; tenofovir disoproxil fumarate (DF) in pregnant patients or patients who are trying to become pregnant. However, for virologically suppressed patients who become pregnant while receiving doravirine; lamivudine; tenofovir DF, consider whether to change to an alternative treatment option or continue the same regimen. If the decision is made with the patient to continue, viral loads should be monitored more frequently (i.e., every 1 to 2 months). The Antiretroviral Pregnancy Registry (APR) has monitored 4 patients treated with doravirine during the first trimester and 1 patient treated during the second and third trimesters. One infant with first trimester exposure was noted to have a birth defect. This information is insufficient to make conclusions regarding the safety of doravirine during pregnancy. Other data from the APR, which includes more than 5,430 first trimester exposures to lamivudine and more than 4,480 first trimester exposures to tenofovir DF, have shown no difference in the risk of overall major birth defects when compared to the 2.7% background rate among pregnant women in the US. When exposure occurred in the first trimester, prevalence of defects was 3.1% (95% CI: 2.7 to 3.6) for lamivudine and 2.4% (95% CI: 2 to 2.9) for tenofovir DF. Nucleoside reverse transcriptase inhibitors (NRTIs) are known to induce mitochondrial dysfunction. An association of mitochondrial dysfunction in infants and in-utero antiretroviral exposure has been suggested, but not established. While the development of severe or fatal mitochondrial disease in exposed infants appears to be extremely rare, more intensive monitoring of hematologic and electrolyte parameters during the first few weeks of life is advised. Nucleoside analogs have been associated with the development of lactic acidosis, especially during pregnancy. It is unclear if pregnancy augments the incidence of lactic acidosis/hepatic steatosis in patients receiving nucleoside analogs. However, because pregnancy itself can mimic some of the early symptoms of the lactic acid/hepatic steatosis syndrome or be associated with other significant disorders of liver metabolism, clinicians need to be alert for early diagnosis of this syndrome. Pregnant women receiving nucleoside analogs should have LFTs and serum electrolytes assessed more frequently during the last trimester of pregnancy, and any new symptoms should be evaluated thoroughly. Regular laboratory monitoring is recommended to determine antiretroviral efficacy. Monitor CD4 counts at the initial visit. Women who have been on HAART for at least 2 years and have consistent viral suppression and CD4 counts consistently greater than 300 cells/mm3 do not need CD4 counts monitored after the initial visit during the pregnancy. However, CD4 counts should be monitored every 3 months during pregnancy for women on HAART less than 2 years, women with CD4 count less than 300 cells/mm3, or women with inconsistent adherence or detectable viral loads. Monitor plasma HIV RNA at the initial visit, 2 to 4 weeks after initiating or changing therapy, monthly until undetectable, then at least every 3 months during pregnancy, and at 34 to 36 weeks gestation. Perform antiretroviral resistance assay (genotypic testing, and if indicated, phenotypic testing) at baseline in all women with HIV RNA concentrations greater than 500 copies/mL, unless they have already been tested for resistance. First trimester ultrasound is recommended to confirm gestational age and provide an accurate estimation of gestational age at delivery. A second trimester ultrasound can be used for both anatomical survey and determination of gestational age in those patients not seen until later in gestation. Perform standard glucose screening in women receiving antiretroviral therapy at 24 to 28 weeks gestation, although it should be noted that some experts would perform earlier screening with ongoing chronic protease inhibitor-based therapy initiated prior to pregnancy, similar to recommendations for women with high-risk factors for glucose intolerance. Liver function testing is recommended within 2 to 4 weeks after initiating or changing antiretroviral therapy, and approximately every 3 months thereafter during pregnancy (or as needed). All pregnant women should be counseled about the importance of adherence to their antiretroviral regimen to reduce the potential for the development of resistance and perinatal transmission. It is strongly recommended that antiretroviral therapy, once initiated, not be discontinued. If a woman decides to discontinue therapy, a consultation with an HIV specialist is recommended. There is a pregnancy exposure registry that monitors outcomes in pregnant patients exposed to doravirine; lamivudine; tenofovir disoproxil fumarate; information about the registry can be obtained at www.apregistry.com or by calling 1-800-258-4263.[27468] [23512] [46638] [63485]

    To reduce the risk of postnatal transmission, mothers with HIV within the United States are advised by the Centers for Disease Control and Prevention to avoid breast-feeding. This recommendation applies to both untreated women and women who are receiving antiretroviral therapy, including doravirine; lamivudine; tenofovir disoproxil fumarate. If a mother with HIV opts to breast-feed, the infant should undergo immediate diagnostic and virologic HIV testing. Testing should continue throughout breast-feeding and up to 6 months after cessation of breast-feeding. For expert consultation, health care workers may contact the Perinatal HIV Hotline (888-448-8765).[42452] It is unknown if doravirine is present in human milk; however, both lamivudine and tenofovir have been shown to pass into human breast milk. Lamivudine was found to be secreted in human breast milk during a study involving 20 breast-feeding women with HIV who were administered either 300 mg of lamivudine twice daily as a single agent (n = 10) or lamivudine 150 mg twice daily in combination with zidovudine (n = 10). The mean breast milk concentrations of lamivudine in the respective groups were similar at 1.22 mg/L (range less than 0.5 to 6.09 mg/L) and 0.9 mg/L (range less than 0.5 to 8.2 mg/L). In another study, tenofovir exposure in exclusively breast-fed infants was found to be equivalent to approximately 4.2 micrograms per day. Other antiretroviral medications whose passage into human breast milk have been evaluated include efavirenz, nevirapine, zidovudine, lamivudine, and nelfinavir.[46774] [46675] [46688] [46679] [46680] [46682] [23512] [63485]

    MECHANISM OF ACTION

    Doravirine is a non-nucleoside reverse transcriptase inhibitor (NNRTI), lamivudine is a nucleoside reverse transcriptase inhibitor (NRTI), and tenofovir disoproxil fumarate is a nucleotide reverse transcriptase inhibitor (although sometimes classified with the NRTIs). Combination therapy targets different points in the life cycle of HIV, reducing viral capacity to mutate to drug-resistant strains
     
    Doravirine: Doravirine inhibits HIV-1 reverse transcriptase. Unlike NRTIs, it does not compete for binding nor does it require phosphorylation to be active. Doravirine binds directly to a site on reverse transcriptase that is distinct from where NRTIs bind. This binding causes disruption of the enzyme's active site thereby blocking RNA-dependent and DNA-dependent DNA polymerase activities. The 50% maximal inhibitory concentrations (EC50) for wild-type laboratory-adapted strains of HIV-1 is approximately 12 nM. Human cellular DNA polymerase alpha, beta, and mitochondrial gamma are not inhibited by doravirine.
    Doravirine-resistant strains have been selected in cell cultures, with observed emergent RT amino acid substitutions being V106A, V106I, V106M, V108I, H221Y, F227C, F227I, F227L, F227V, M230I, L234I, P236L, and Y318F. In clinical trials, 10 of the 24 subjects (42%) in the resistance analysis subset showed doravirine-associated resistance substitutions in RT; which included 1 or more of the following: V90V/G, A98G, V106A, V106I, V106M/T, V108I, E138G, Y188L, H221Y, P225H, P225L, P225P/S, F227C, F227C/R, Y318Y/F, and Y318Y/S. Cross-resistance to efavirenz, etravirine, rilpivirine, and nevirapine is likely after the development of treatment-emergent doravirine resistance.[63485]
    Avoid the use of doravirine in patients with HIV-2, as HIV-2 is intrinsically resistant to NNRTIs. To identify the HIV strain, The Centers for Disease Control and Prevention guidelines for HIV diagnostic testing recommend initial HIV testing using an HIV-1/HIV-2 antigen/antibody combination immunoassay and subsequent testing using an HIV-1/HIV-2 antibody differentiation immunoassay.[46638]
     
    Lamivudine: Lamivudine inhibits viral reverse transcriptase in both HIV-1 and hepatitis B virus (HBV). When used in combination with doravirine and tenofovir, it is used specifically for its activity against HIV. Lamivudine is a synthetic nucleoside analog of cytosine and is phosphorylated by cellular enzymes to its active 5'-triphosphate metabolite, lamivudine triphosphate. Lamivudine triphosphate inhibits the activity of HIV-1 reverse transcriptase by competing with the deoxycytidine 5'-triphosphate and by being incorporated into nascent viral DNA, resulting in chain termination.
    HIV-1 resistance to lamivudine is predominately due to a methionine to valine or isoleucine (M184V/I) substitution in reverse transcriptase. Cross-resistance is expected with abacavir, didanosine, and emtricitabine.[63485]
     
    Tenofovir disoproxil fumarate: Tenofovir inhibits viral reverse transcriptase in both HIV-1 and HBV. Tenofovir disoproxil fumarate (tenofovir DF) is an acyclic nucleoside phosphonate (nucleotide) diester analog of adenosine monophosphate. Tenofovir DF requires initial diester hydrolysis for conversion to tenofovir. Tenofovir is then taken up by cells and undergoes phosphorylation to form tenofovir diphosphate (PMPApp). Tenofovir diphosphate competes with the natural substrate deoxyadenosine 5'-triphosphate (dATP) for incorporation into the DNA. Once incorporated, tenofovir diphosphate, which lacks a 3' hydroxyl group, causes premature DNA chain termination.
    HIV-1 isolates that express a K65R amino acid substitutions in reverse transcriptase show a 2- to 4-fold reduction in the susceptibility to tenofovir. In addition, a K70E substitution in HIV-1 reverse transcriptase has been selected by tenofovir and results in reduced susceptibility. The K70E substitution selected clinically by tenofovir results in reduced susceptibility to abacavir, emtricitabine, and lamivudine. HIV-1 isolates with the K65R substitution also show reduced susceptibility to lamivudine and emtricitabine.[63485]

    PHARMACOKINETICS

    Doravirine; lamivudine; tenofovir is administered orally.
     
    Doravirine: Doravirine is administered orally. Following systemic absorption, doravirine has a volume of distribution of 60.5 liters and is 76% bound to plasma proteins. The drug undergoes extensive metabolism in the liver by CYP3A enzymes. Metabolites account for the majority of the elimination, with only 6% of the dose being excreted in the urine as unchanged drug. Biliary/fecal excretion is a minor elimination pathway. The elimination half-life is 15 hours.[63485] Lamivudine: Lamivudine exhibits low plasma protein binding (less than 36%) and has a 1.3 L/kg volume of distribution. The drug is only minimally metabolized, with the majority of the dose (71%) being eliminated unchanged in the urine by glomerular filtration and active organic cationic secretion. The observed mean elimination half-life ranges from 5 to 7 hours.[63485] Tenofovir disoproxil fumarate: Protein binding of tenofovir is negligible (less than 0.7%) and binding is independent of concentration over the range of 0.01 to 25 mcg/mL. Intracellularly, tenofovir undergoes phosphorylation to its active metabolite, tenofovir diphosphate (PMPApp). Tenofovir and tenofovir diphosphate have a prolonged intracellular half-life (15 to 50 hours). In vitro studies indicate that neither tenofovir disoproxil fumarate nor tenofovir are substrates of cytochrome P450 enzymes. Approximately 70% to 80% of the dose is recovered as unchanged drug in the urine. Tenofovir is eliminated by a combination of glomerular filtration and active renal tubular secretion; there may be competition for elimination with other compounds that are also renally eliminated. The terminal elimination half-life is approximately 17 hours.[63485]
     
    Affected cytochrome P450 isoenzymes and transporters: CYP3A, P-gp, BRCP
    Doravirine is primarily metabolized CYP3A4. The drug is neither an inducer nor an inhibitor of CYP450 isoenzymes or drug transporters. Tenofovir disoproxil fumarate is a substrate of P-glycoprotein (P-gp) and breast cancer resistance protein (BCRP) transporters. Administration with inhibitors of these transporters may result in increased absorption of tenofovir.[28193] [63485]

    Oral Route

    Doravirine: The absolute oral bioavailability of doravirine is 64%, and the time to reach maximum plasma concentrations (Tmax) is 2 hours. Although doravirine may be administered with or without food, administration with a high-fat meal (i.e., 1,000 kcal, 50% fat) increases the exposure ratio by 1.10 (1.01, 1.20) and the 24-hour drug concentration by 1.26 (1.13, 1.41).[63485]
    Lamivudine: Following oral administration, the absolute bioavailability of lamivudine is approximately 86%. Drug exposure (AUC) and the maximum plasma concentration (Cmax) increase in proportion to the dose over a range from 0.25 to 10 mg/kg.[29240] [63485]
    Tenofovir disoproxil fumarate: The bioavailability in a fasting state is 25%; when given with either a high fat or light meal, tenofovir AUC and Cmax increase by 35% and 15%, respectively.[28193] [63485]