CONTRAINDICATIONS / PRECAUTIONS
General Information
The use of memantine is contraindicated in any patient with a known memantine hypersensitivity or hypersensitivity to any inactive ingredients or excipients contained within the products.
Renal failure, renal impairment, renal tubular acidosis (RTA), urinary tract infection (UTI)
Memantine is predominantly eliminated by the kidneys in part by tubular secretion. Dosage adjustments of memantine are required in patients with severe renal impairment (CrCl less than 30 mL/minute). No data are available for use of memantine in patients with renal failure on dialysis. Use memantine with caution in patients with conditions that could affect urinary pH such as renal tubular acidosis (RTA), severe urinary tract infection (UTI), and renal failure. Conditions, drugs, and/or foods that raise urine pH may decrease urinary elimination of memantine and increase plasma concentrations, potentially increasing the risk of adverse effects, such as dizziness, headache or agitation. The concurrent use of drugs that use the same cationic renal tubular secretion system for elimination could potentially result in altered plasma concentrations of memantine or the co-prescribed drug. Carefully monitor patients for response and adverse effects related to each agent.
Hepatic disease
Memantine undergoes partial hepatic metabolism. Caution is advised when using memantine in those with severe hepatic disease as specific studies of the drug in these patients are not available and the elimination half-life may be prolonged. No dosage adjustments are required in patients with mild to moderate hepatic impairment.
Geriatric
The majority of people with Alzheimer's disease are 65 years and older; during clinical trials in patients with Alzheimer's dementia, there was no noted differences in adverse effects reported among geriatric patients and those younger than 65 years of age. Geriatric patients may be at greater risk for renal impairment due to age-related changes in renal function, concomitant medications or other risk factors that may influence dosage. The federal Omnibus Budget Reconciliation Act (OBRA) regulates medication use in residents of long-term care facilities (LTCFs). According to OBRA guidelines, the continued use of memantine for the treatment of a cognitive disorder in residents of a LTCF should be re-evaluated as the underlying disorder progresses into advanced stages. Adverse effects of memantine include restlessness, distress, dizziness, somnolence, hypertension, headache, hallucinations, and increased confusion.
Pregnancy
There are no adequate data on the potential developmental risks to the fetus during pregnancy; therefore, it is advisable to avoid memantine during pregnancy if possible. Results from animal studies during organogenesis showed that memantine was not teratogenic at doses above the maximum recommended human dose (MRHD); however, adverse developmental effects (e.g., decreased body weight and skeletal ossifications) were observed in the offspring. The effects of memantine during labor and delivery, if any, are unknown.
Breast-feeding
When considering the use of memantine during breast-feeding, assess the developmental and health benefits of breast-feeding, along with the potential risks of infant drug exposure, and the risk of an untreated or inadequately treated maternal condition. There are no data on the presence of memantine in human milk, the effects on the breastfed infant, or the effects of memantine on milk production.
Children, infants
Memantine is not indicated for use in infants, children, or adolescents less than 18 years of age. Memantine failed to demonstrate efficacy in two 12-week controlled trials (n = 578) of pediatric patients 6 to 12 years of age with autism spectrum disorders (ASD), including autism Asperger’s disorder and Pervasive Development Disorder Not Otherwise Specified (PDD-NOS). The dose of extended-release memantine was based upon weight as follows: weight less than 20 kg (3 mg/day), weight 20 to 39 kg (6 mg/day), weight 40 to 59 kg (9 mg/day), and weight 60 kg or more (15 mg/day). The overall safety profile of memantine in pediatric patients was generally comparable to the safety profile in adults.
DRUG INTERACTIONS
Abacavir; Dolutegravir; Lamivudine: (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.
Abacavir; Lamivudine, 3TC: (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.
Abacavir; Lamivudine, 3TC; Zidovudine, ZDV: (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.
Acetaminophen; Chlorpheniramine; Dextromethorphan: (Moderate) Dextromethorphan is a NMDA antagonist and may lead to additive adverse effects if combined with memantine, also an NMDA antagonist. It may be prudent to avoid coadministration of dextromethorphan with memantine. If coadministration cannot be avoided, monitor for increased adverse effects such as agitation, dizziness and other CNS events.
Acetaminophen; Chlorpheniramine; Dextromethorphan; Phenylephrine: (Moderate) Dextromethorphan is a NMDA antagonist and may lead to additive adverse effects if combined with memantine, also an NMDA antagonist. It may be prudent to avoid coadministration of dextromethorphan with memantine. If coadministration cannot be avoided, monitor for increased adverse effects such as agitation, dizziness and other CNS events.
Acetaminophen; Chlorpheniramine; Dextromethorphan; Pseudoephedrine: (Moderate) Dextromethorphan is a NMDA antagonist and may lead to additive adverse effects if combined with memantine, also an NMDA antagonist. It may be prudent to avoid coadministration of dextromethorphan with memantine. If coadministration cannot be avoided, monitor for increased adverse effects such as agitation, dizziness and other CNS events.
Acetaminophen; Dextromethorphan: (Moderate) Dextromethorphan is a NMDA antagonist and may lead to additive adverse effects if combined with memantine, also an NMDA antagonist. It may be prudent to avoid coadministration of dextromethorphan with memantine. If coadministration cannot be avoided, monitor for increased adverse effects such as agitation, dizziness and other CNS events.
Acetaminophen; Dextromethorphan; Doxylamine: (Moderate) Dextromethorphan is a NMDA antagonist and may lead to additive adverse effects if combined with memantine, also an NMDA antagonist. It may be prudent to avoid coadministration of dextromethorphan with memantine. If coadministration cannot be avoided, monitor for increased adverse effects such as agitation, dizziness and other CNS events.
Acetaminophen; Dextromethorphan; Guaifenesin; Phenylephrine: (Moderate) Dextromethorphan is a NMDA antagonist and may lead to additive adverse effects if combined with memantine, also an NMDA antagonist. It may be prudent to avoid coadministration of dextromethorphan with memantine. If coadministration cannot be avoided, monitor for increased adverse effects such as agitation, dizziness and other CNS events.
Acetaminophen; Dextromethorphan; Guaifenesin; Pseudoephedrine: (Moderate) Dextromethorphan is a NMDA antagonist and may lead to additive adverse effects if combined with memantine, also an NMDA antagonist. It may be prudent to avoid coadministration of dextromethorphan with memantine. If coadministration cannot be avoided, monitor for increased adverse effects such as agitation, dizziness and other CNS events.
Acetaminophen; Dextromethorphan; Phenylephrine: (Moderate) Dextromethorphan is a NMDA antagonist and may lead to additive adverse effects if combined with memantine, also an NMDA antagonist. It may be prudent to avoid coadministration of dextromethorphan with memantine. If coadministration cannot be avoided, monitor for increased adverse effects such as agitation, dizziness and other CNS events.
Acetaminophen; Dextromethorphan; Pseudoephedrine: (Moderate) Dextromethorphan is a NMDA antagonist and may lead to additive adverse effects if combined with memantine, also an NMDA antagonist. It may be prudent to avoid coadministration of dextromethorphan with memantine. If coadministration cannot be avoided, monitor for increased adverse effects such as agitation, dizziness and other CNS events.
Acetazolamide: (Moderate) Systemic carbonic anhydrous inhibitors have the potential to increase urine pH, and potentially reduce the renal clearance of memantine. The clearance of memantine is reduced by about 80% under alkaline urine conditions at pH 8. Increases in urinary pH may decrease elimination of memantine, resulting in drug accumulation and potential toxicity.
Adefovir: (Moderate) Adefovir is eliminated renally by a combination of glomerular filtration and active tubular secretion; coadministration of adefovir dipivoxil with drugs that reduce renal function or compete for active tubular secretion, such as memantine, may decrease adefovir elimination by competing for common renal tubular transport systems; therefore increasing serum concentrations of either adefovir and/or memantine may occur.
Aliskiren; Hydrochlorothiazide, HCTZ: (Minor) Memantine reduced the bioavailability of hydrochlorothiazide by roughly 20% in a drug interaction study. The clinical significance of this pharmacokinetic interaction, if any, is unknown.
Alkalinizing Agents: (Moderate) Urinary alkalinizing agents may decrease the elimination of memantine, resulting in drug accumulation and potential toxicity. The clearance of memantine is reduced by about 80% under alkaline urine conditions at pH 8. Memantine should be used with caution with drugs known to increase urinary pH.
Alogliptin; Metformin: (Moderate) Certain medications used concomitantly with metformin may increase the risk of lactic acidosis. Drugs that are eliminated by renal tubular secretion (e.g., memantine) may decrease metformin elimination by competing for common renal tubular transport systems. It should be noted that in a pharmacokinetic study in which memantine and glyburide; metformin (Glucovance) were coadministered, the pharmacokinetics of memantine, metformin, or glyburide were not altered. Regardless, careful patient monitoring is recommended.
Amantadine: (Moderate) Amantadine is a NMDA antagonist and may lead to additive adverse effects if combined with memantine, also an NMDA antagonist. It may be prudent to avoid coadministration of amantadine with memantine. If coadministration cannot be avoided, monitor for increased adverse effects such as agitation, dizziness and other CNS events.
Amiloride: (Minor) Cationic drugs that are eliminated by renal tubular secretion, such as amiloride, may decrease memantine elimination by competing for common renal tubular transport systems. Careful patient monitoring and dose adjustment of memantine and/or amiloride is recommended.
Amiloride; Hydrochlorothiazide, HCTZ: (Minor) Cationic drugs that are eliminated by renal tubular secretion, such as amiloride, may decrease memantine elimination by competing for common renal tubular transport systems. Careful patient monitoring and dose adjustment of memantine and/or amiloride is recommended. (Minor) Memantine reduced the bioavailability of hydrochlorothiazide by roughly 20% in a drug interaction study. The clinical significance of this pharmacokinetic interaction, if any, is unknown.
Amlodipine; Valsartan; Hydrochlorothiazide, HCTZ: (Minor) Memantine reduced the bioavailability of hydrochlorothiazide by roughly 20% in a drug interaction study. The clinical significance of this pharmacokinetic interaction, if any, is unknown.
Anticholinergics: (Moderate) The adverse effects of anticholinergics, such as dry mouth, urinary hesitancy or blurred vision may be enhanced with use of memantine; dosage adjustments of the anticholinergic drug may be required when memantine is coadministered. In addition, preliminary evidence indicates that chronic anticholinergic use in patients with Alzheimer's Disease may possibly have an adverse effect on cognitive function. Therefore, the effectiveness of drugs used in the treatment of Alzheimer's such as memantine, may be adversely affected by chronic antimuscarinic therapy.
Benazepril; Hydrochlorothiazide, HCTZ: (Minor) Memantine reduced the bioavailability of hydrochlorothiazide by roughly 20% in a drug interaction study. The clinical significance of this pharmacokinetic interaction, if any, is unknown.
Bisoprolol; Hydrochlorothiazide, HCTZ: (Minor) Memantine reduced the bioavailability of hydrochlorothiazide by roughly 20% in a drug interaction study. The clinical significance of this pharmacokinetic interaction, if any, is unknown.
Bromocriptine: (Moderate) The pharmacologic effects of dopaminergic agents, including the ergot derivative bromocriptine, may be enhanced with use of memantine; dosage adjustments of dopaminergic agents may be required when memantine is coadministered.
Brompheniramine; Dextromethorphan; Guaifenesin: (Moderate) Dextromethorphan is a NMDA antagonist and may lead to additive adverse effects if combined with memantine, also an NMDA antagonist. It may be prudent to avoid coadministration of dextromethorphan with memantine. If coadministration cannot be avoided, monitor for increased adverse effects such as agitation, dizziness and other CNS events.
Brompheniramine; Dextromethorphan; Phenylephrine: (Moderate) Dextromethorphan is a NMDA antagonist and may lead to additive adverse effects if combined with memantine, also an NMDA antagonist. It may be prudent to avoid coadministration of dextromethorphan with memantine. If coadministration cannot be avoided, monitor for increased adverse effects such as agitation, dizziness and other CNS events.
Brompheniramine; Pseudoephedrine; Dextromethorphan: (Moderate) Dextromethorphan is a NMDA antagonist and may lead to additive adverse effects if combined with memantine, also an NMDA antagonist. It may be prudent to avoid coadministration of dextromethorphan with memantine. If coadministration cannot be avoided, monitor for increased adverse effects such as agitation, dizziness and other CNS events.
Canagliflozin; Metformin: (Moderate) Certain medications used concomitantly with metformin may increase the risk of lactic acidosis. Drugs that are eliminated by renal tubular secretion (e.g., memantine) may decrease metformin elimination by competing for common renal tubular transport systems. It should be noted that in a pharmacokinetic study in which memantine and glyburide; metformin (Glucovance) were coadministered, the pharmacokinetics of memantine, metformin, or glyburide were not altered. Regardless, careful patient monitoring is recommended.
Candesartan; Hydrochlorothiazide, HCTZ: (Minor) Memantine reduced the bioavailability of hydrochlorothiazide by roughly 20% in a drug interaction study. The clinical significance of this pharmacokinetic interaction, if any, is unknown.
Captopril; Hydrochlorothiazide, HCTZ: (Minor) Memantine reduced the bioavailability of hydrochlorothiazide by roughly 20% in a drug interaction study. The clinical significance of this pharmacokinetic interaction, if any, is unknown.
Carbinoxamine; Dextromethorphan; Pseudoephedrine: (Moderate) Dextromethorphan is a NMDA antagonist and may lead to additive adverse effects if combined with memantine, also an NMDA antagonist. It may be prudent to avoid coadministration of dextromethorphan with memantine. If coadministration cannot be avoided, monitor for increased adverse effects such as agitation, dizziness and other CNS events.
Carbonic anhydrase inhibitors: (Moderate) Systemic carbonic anhydrous inhibitors have the potential to increase urine pH, and potentially reduce the renal clearance of memantine. The clearance of memantine is reduced by about 80% under alkaline urine conditions at pH 8. Increases in urinary pH may decrease elimination of memantine, resulting in drug accumulation and potential toxicity.
Chlorpheniramine; Dextromethorphan: (Moderate) Dextromethorphan is a NMDA antagonist and may lead to additive adverse effects if combined with memantine, also an NMDA antagonist. It may be prudent to avoid coadministration of dextromethorphan with memantine. If coadministration cannot be avoided, monitor for increased adverse effects such as agitation, dizziness and other CNS events.
Chlorpheniramine; Dextromethorphan; Phenylephrine: (Moderate) Dextromethorphan is a NMDA antagonist and may lead to additive adverse effects if combined with memantine, also an NMDA antagonist. It may be prudent to avoid coadministration of dextromethorphan with memantine. If coadministration cannot be avoided, monitor for increased adverse effects such as agitation, dizziness and other CNS events.
Chlorpheniramine; Dextromethorphan; Pseudoephedrine: (Moderate) Dextromethorphan is a NMDA antagonist and may lead to additive adverse effects if combined with memantine, also an NMDA antagonist. It may be prudent to avoid coadministration of dextromethorphan with memantine. If coadministration cannot be avoided, monitor for increased adverse effects such as agitation, dizziness and other CNS events.
Cimetidine: (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 cimetidine, could result in elevated serum concentrations of one or both drugs.
Citric Acid; Potassium Citrate; Sodium Citrate: (Moderate) Increases in urinary pH may decrease elimination of memantine, resulting in drug accumulation and potential toxicity.
Clofarabine: (Moderate) Concomitant use of clofarabine and memantine may result in altered clofarabine levels because both agents are a substrate of OCT2. Therefore, monitor for signs of clofarabine toxicity such as gastrointestinal toxicity (e.g., nausea, vomiting, diarrhea, mucosal inflammation), hematologic toxicity, and skin toxicity (e.g. hand and foot syndrome, rash, pruritus) in patients also receiving OCT2 substrates.
Dapagliflozin; Metformin: (Moderate) Certain medications used concomitantly with metformin may increase the risk of lactic acidosis. Drugs that are eliminated by renal tubular secretion (e.g., memantine) may decrease metformin elimination by competing for common renal tubular transport systems. It should be noted that in a pharmacokinetic study in which memantine and glyburide; metformin (Glucovance) were coadministered, the pharmacokinetics of memantine, metformin, or glyburide were not altered. Regardless, careful patient monitoring is recommended.
Dexchlorpheniramine; Dextromethorphan; Pseudoephedrine: (Moderate) Dextromethorphan is a NMDA antagonist and may lead to additive adverse effects if combined with memantine, also an NMDA antagonist. It may be prudent to avoid coadministration of dextromethorphan with memantine. If coadministration cannot be avoided, monitor for increased adverse effects such as agitation, dizziness and other CNS events.
Dextromethorphan: (Moderate) Dextromethorphan is a NMDA antagonist and may lead to additive adverse effects if combined with memantine, also an NMDA antagonist. It may be prudent to avoid coadministration of dextromethorphan with memantine. If coadministration cannot be avoided, monitor for increased adverse effects such as agitation, dizziness and other CNS events.
Dextromethorphan; Bupropion: (Moderate) Dextromethorphan is a NMDA antagonist and may lead to additive adverse effects if combined with memantine, also an NMDA antagonist. It may be prudent to avoid coadministration of dextromethorphan with memantine. If coadministration cannot be avoided, monitor for increased adverse effects such as agitation, dizziness and other CNS events.
Dextromethorphan; Diphenhydramine; Phenylephrine: (Moderate) Dextromethorphan is a NMDA antagonist and may lead to additive adverse effects if combined with memantine, also an NMDA antagonist. It may be prudent to avoid coadministration of dextromethorphan with memantine. If coadministration cannot be avoided, monitor for increased adverse effects such as agitation, dizziness and other CNS events.
Dextromethorphan; Guaifenesin: (Moderate) Dextromethorphan is a NMDA antagonist and may lead to additive adverse effects if combined with memantine, also an NMDA antagonist. It may be prudent to avoid coadministration of dextromethorphan with memantine. If coadministration cannot be avoided, monitor for increased adverse effects such as agitation, dizziness and other CNS events.
Dextromethorphan; Guaifenesin; Phenylephrine: (Moderate) Dextromethorphan is a NMDA antagonist and may lead to additive adverse effects if combined with memantine, also an NMDA antagonist. It may be prudent to avoid coadministration of dextromethorphan with memantine. If coadministration cannot be avoided, monitor for increased adverse effects such as agitation, dizziness and other CNS events.
Dextromethorphan; Guaifenesin; Potassium Guaiacolsulfonate: (Moderate) Dextromethorphan is a NMDA antagonist and may lead to additive adverse effects if combined with memantine, also an NMDA antagonist. It may be prudent to avoid coadministration of dextromethorphan with memantine. If coadministration cannot be avoided, monitor for increased adverse effects such as agitation, dizziness and other CNS events.
Dextromethorphan; Guaifenesin; Pseudoephedrine: (Moderate) Dextromethorphan is a NMDA antagonist and may lead to additive adverse effects if combined with memantine, also an NMDA antagonist. It may be prudent to avoid coadministration of dextromethorphan with memantine. If coadministration cannot be avoided, monitor for increased adverse effects such as agitation, dizziness and other CNS events.
Dextromethorphan; Quinidine: (Major) Cationic drugs that are eliminated by renal tubular secretion, such as quinidine, may compete with memantine for common renal tubular transport systems, thus possibly decreasing the elimination of one of the drugs. Although theoretical, careful patient monitoring of response to memantine and/or quinidine is recommended to assess for needed dosage adjustments. In selected individuals, quinidine serum concentration monitoring may be appropriate. (Moderate) Dextromethorphan is a NMDA antagonist and may lead to additive adverse effects if combined with memantine, also an NMDA antagonist. It may be prudent to avoid coadministration of dextromethorphan with memantine. If coadministration cannot be avoided, monitor for increased adverse effects such as agitation, dizziness and other CNS events.
Digoxin: (Moderate) Digoxin is eliminated by renal tubular secretion and may compete with memantine for common renal tubular transport systems, thus possibly decreasing the elimination of one of the drugs. Although theoretical, careful patient monitoring of response to memantine and/or digoxin is recommended to assess for needed dosage adjustments. In selected individuals, digoxin serum concentration monitoring may be appropriate
Dofetilide: (Major) Drugs that are actively secreted via cationic secretion (e.g., memantine) should be co-administered with dofetilide with caution since they could increase dofetilide plasma concentrations via potential competition for renal tubular secretion. Competition for renal elimination may increase plasma concentrations of dofetilide and increase the risk of pro-arrhythmias.
Dolutegravir; Lamivudine: (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.
Doravirine; Lamivudine; Tenofovir disoproxil fumarate: (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.
Efavirenz; Lamivudine; Tenofovir Disoproxil Fumarate: (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.
Empagliflozin; Linagliptin; Metformin: (Moderate) Certain medications used concomitantly with metformin may increase the risk of lactic acidosis. Drugs that are eliminated by renal tubular secretion (e.g., memantine) may decrease metformin elimination by competing for common renal tubular transport systems. It should be noted that in a pharmacokinetic study in which memantine and glyburide; metformin (Glucovance) were coadministered, the pharmacokinetics of memantine, metformin, or glyburide were not altered. Regardless, careful patient monitoring is recommended.
Empagliflozin; Metformin: (Moderate) Certain medications used concomitantly with metformin may increase the risk of lactic acidosis. Drugs that are eliminated by renal tubular secretion (e.g., memantine) may decrease metformin elimination by competing for common renal tubular transport systems. It should be noted that in a pharmacokinetic study in which memantine and glyburide; metformin (Glucovance) were coadministered, the pharmacokinetics of memantine, metformin, or glyburide were not altered. Regardless, careful patient monitoring is recommended.
Enalapril; Hydrochlorothiazide, HCTZ: (Minor) Memantine reduced the bioavailability of hydrochlorothiazide by roughly 20% in a drug interaction study. The clinical significance of this pharmacokinetic interaction, if any, is unknown.
Entecavir: (Moderate) Entecavir is eliminated by active tubular secretion. In theory, coadministration of entecavir with other drugs that are eliminated by active tubular secretion, such as memantine, may increase the serum concentrations of entecavir or memantine due to competition for the drug elimination pathway.
Eprosartan; Hydrochlorothiazide, HCTZ: (Minor) Memantine reduced the bioavailability of hydrochlorothiazide by roughly 20% in a drug interaction study. The clinical significance of this pharmacokinetic interaction, if any, is unknown.
Ertugliflozin; Metformin: (Moderate) Certain medications used concomitantly with metformin may increase the risk of lactic acidosis. Drugs that are eliminated by renal tubular secretion (e.g., memantine) may decrease metformin elimination by competing for common renal tubular transport systems. It should be noted that in a pharmacokinetic study in which memantine and glyburide; metformin (Glucovance) were coadministered, the pharmacokinetics of memantine, metformin, or glyburide were not altered. Regardless, careful patient monitoring is recommended.
Fosinopril; Hydrochlorothiazide, HCTZ: (Minor) Memantine reduced the bioavailability of hydrochlorothiazide by roughly 20% in a drug interaction study. The clinical significance of this pharmacokinetic interaction, if any, is unknown.
Glipizide; Metformin: (Moderate) Certain medications used concomitantly with metformin may increase the risk of lactic acidosis. Drugs that are eliminated by renal tubular secretion (e.g., memantine) may decrease metformin elimination by competing for common renal tubular transport systems. It should be noted that in a pharmacokinetic study in which memantine and glyburide; metformin (Glucovance) were coadministered, the pharmacokinetics of memantine, metformin, or glyburide were not altered. Regardless, careful patient monitoring is recommended.
Glyburide; Metformin: (Moderate) Certain medications used concomitantly with metformin may increase the risk of lactic acidosis. Drugs that are eliminated by renal tubular secretion (e.g., memantine) may decrease metformin elimination by competing for common renal tubular transport systems. It should be noted that in a pharmacokinetic study in which memantine and glyburide; metformin (Glucovance) were coadministered, the pharmacokinetics of memantine, metformin, or glyburide were not altered. Regardless, careful patient monitoring is recommended.
Hydralazine; Hydrochlorothiazide, HCTZ: (Minor) Memantine reduced the bioavailability of hydrochlorothiazide by roughly 20% in a drug interaction study. The clinical significance of this pharmacokinetic interaction, if any, is unknown.
Hydrochlorothiazide, HCTZ: (Minor) Memantine reduced the bioavailability of hydrochlorothiazide by roughly 20% in a drug interaction study. The clinical significance of this pharmacokinetic interaction, if any, is unknown.
Hydrochlorothiazide, HCTZ; Methyldopa: (Minor) Memantine reduced the bioavailability of hydrochlorothiazide by roughly 20% in a drug interaction study. The clinical significance of this pharmacokinetic interaction, if any, is unknown.
Hydrochlorothiazide, HCTZ; Moexipril: (Minor) Memantine reduced the bioavailability of hydrochlorothiazide by roughly 20% in a drug interaction study. The clinical significance of this pharmacokinetic interaction, if any, is unknown.
Irbesartan; Hydrochlorothiazide, HCTZ: (Minor) Memantine reduced the bioavailability of hydrochlorothiazide by roughly 20% in a drug interaction study. The clinical significance of this pharmacokinetic interaction, if any, is unknown.
Ketamine: (Moderate) Ketamine is a NMDA antagonist and may lead to additive adverse effects if combined with memantine, also an NMDA antagonist. It may be prudent to avoid coadministration of ketamine with memantine. If coadministration cannot be avoided, monitor for increased adverse effects such as agitation, dizziness and other CNS events.
Lamivudine, 3TC: (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.
Lamivudine, 3TC; Zidovudine, ZDV: (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.
Lamivudine; Tenofovir Disoproxil Fumarate: (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.
Linagliptin; Metformin: (Moderate) Certain medications used concomitantly with metformin may increase the risk of lactic acidosis. Drugs that are eliminated by renal tubular secretion (e.g., memantine) may decrease metformin elimination by competing for common renal tubular transport systems. It should be noted that in a pharmacokinetic study in which memantine and glyburide; metformin (Glucovance) were coadministered, the pharmacokinetics of memantine, metformin, or glyburide were not altered. Regardless, careful patient monitoring is recommended.
Lisinopril; Hydrochlorothiazide, HCTZ: (Minor) Memantine reduced the bioavailability of hydrochlorothiazide by roughly 20% in a drug interaction study. The clinical significance of this pharmacokinetic interaction, if any, is unknown.
Losartan; Hydrochlorothiazide, HCTZ: (Minor) Memantine reduced the bioavailability of hydrochlorothiazide by roughly 20% in a drug interaction study. The clinical significance of this pharmacokinetic interaction, if any, is unknown.
Metformin: (Moderate) Certain medications used concomitantly with metformin may increase the risk of lactic acidosis. Drugs that are eliminated by renal tubular secretion (e.g., memantine) may decrease metformin elimination by competing for common renal tubular transport systems. It should be noted that in a pharmacokinetic study in which memantine and glyburide; metformin (Glucovance) were coadministered, the pharmacokinetics of memantine, metformin, or glyburide were not altered. Regardless, careful patient monitoring is recommended.
Metformin; Repaglinide: (Moderate) Certain medications used concomitantly with metformin may increase the risk of lactic acidosis. Drugs that are eliminated by renal tubular secretion (e.g., memantine) may decrease metformin elimination by competing for common renal tubular transport systems. It should be noted that in a pharmacokinetic study in which memantine and glyburide; metformin (Glucovance) were coadministered, the pharmacokinetics of memantine, metformin, or glyburide were not altered. Regardless, careful patient monitoring is recommended.
Metformin; Rosiglitazone: (Moderate) Certain medications used concomitantly with metformin may increase the risk of lactic acidosis. Drugs that are eliminated by renal tubular secretion (e.g., memantine) may decrease metformin elimination by competing for common renal tubular transport systems. It should be noted that in a pharmacokinetic study in which memantine and glyburide; metformin (Glucovance) were coadministered, the pharmacokinetics of memantine, metformin, or glyburide were not altered. Regardless, careful patient monitoring is recommended.
Metformin; Saxagliptin: (Moderate) Certain medications used concomitantly with metformin may increase the risk of lactic acidosis. Drugs that are eliminated by renal tubular secretion (e.g., memantine) may decrease metformin elimination by competing for common renal tubular transport systems. It should be noted that in a pharmacokinetic study in which memantine and glyburide; metformin (Glucovance) were coadministered, the pharmacokinetics of memantine, metformin, or glyburide were not altered. Regardless, careful patient monitoring is recommended.
Metformin; Sitagliptin: (Moderate) Certain medications used concomitantly with metformin may increase the risk of lactic acidosis. Drugs that are eliminated by renal tubular secretion (e.g., memantine) may decrease metformin elimination by competing for common renal tubular transport systems. It should be noted that in a pharmacokinetic study in which memantine and glyburide; metformin (Glucovance) were coadministered, the pharmacokinetics of memantine, metformin, or glyburide were not altered. Regardless, careful patient monitoring is recommended.
Methazolamide: (Moderate) Systemic carbonic anhydrous inhibitors have the potential to increase urine pH, and potentially reduce the renal clearance of memantine. The clearance of memantine is reduced by about 80% under alkaline urine conditions at pH 8. Increases in urinary pH may decrease elimination of memantine, resulting in drug accumulation and potential toxicity.
Metoprolol; Hydrochlorothiazide, HCTZ: (Minor) Memantine reduced the bioavailability of hydrochlorothiazide by roughly 20% in a drug interaction study. The clinical significance of this pharmacokinetic interaction, if any, is unknown.
Midodrine: (Moderate) Cationic drugs that are eliminated by renal tubular secretion, such as midodrine, may decrease memantine elimination by competing for common renal tubular transport systems. Although this interaction is theoretical, careful patient monitoring and dose adjustment of memantine and/or midodrine is recommended.
Morphine: (Moderate) Cationic drugs that are eliminated by renal tubular secretion, such as morphine, may compete with memantine for common renal tubular transport systems, thus possibly decreasing the elimination of one of the drugs. Although theoretical, careful patient monitoring of response to memantine and/or morphine is recommended to assess for needed dosage adjustments.
Morphine; Naltrexone: (Moderate) Cationic drugs that are eliminated by renal tubular secretion, such as morphine, may compete with memantine for common renal tubular transport systems, thus possibly decreasing the elimination of one of the drugs. Although theoretical, careful patient monitoring of response to memantine and/or morphine is recommended to assess for needed dosage adjustments.
Nicotine: (Minor) Memantine is excreted in part by renal tubular secretion. Competition of memantine for excretion with other drugs that are also eliminated by tubular secretion, like nicotine, could result in elevated serum concentrations of one or both drugs.
Olmesartan; Amlodipine; Hydrochlorothiazide, HCTZ: (Minor) Memantine reduced the bioavailability of hydrochlorothiazide by roughly 20% in a drug interaction study. The clinical significance of this pharmacokinetic interaction, if any, is unknown.
Olmesartan; Hydrochlorothiazide, HCTZ: (Minor) Memantine reduced the bioavailability of hydrochlorothiazide by roughly 20% in a drug interaction study. The clinical significance of this pharmacokinetic interaction, if any, is unknown.
Pioglitazone; Metformin: (Moderate) Certain medications used concomitantly with metformin may increase the risk of lactic acidosis. Drugs that are eliminated by renal tubular secretion (e.g., memantine) may decrease metformin elimination by competing for common renal tubular transport systems. It should be noted that in a pharmacokinetic study in which memantine and glyburide; metformin (Glucovance) were coadministered, the pharmacokinetics of memantine, metformin, or glyburide were not altered. Regardless, careful patient monitoring is recommended.
Potassium Bicarbonate: (Moderate) Increases in urinary pH may decrease elimination of memantine, resulting in drug accumulation and potential toxicity.
Potassium Chloride: (Moderate) Increases in urinary pH may decrease elimination of memantine, resulting in drug accumulation and potential toxicity.
Potassium Citrate: (Moderate) Increases in urinary pH may decrease elimination of memantine, resulting in drug accumulation and potential toxicity.
Potassium Citrate; Citric Acid: (Moderate) Increases in urinary pH may decrease elimination of memantine, resulting in drug accumulation and potential toxicity.
Procainamide: (Major) Cationic drugs that are eliminated by renal tubular secretion such as procainamide, may compete with memantine for common renal tubular transport systems, thus possibly decreasing the elimination of one of the drugs. Although theoretical, careful patient monitoring of response to memantine and/or procainamide is recommended to assess for needed dosage adjustments. In selected individuals, procainamide serum concentration monitoring may be appropriate.
Promethazine; Dextromethorphan: (Moderate) Dextromethorphan is a NMDA antagonist and may lead to additive adverse effects if combined with memantine, also an NMDA antagonist. It may be prudent to avoid coadministration of dextromethorphan with memantine. If coadministration cannot be avoided, monitor for increased adverse effects such as agitation, dizziness and other CNS events.
Propranolol; Hydrochlorothiazide, HCTZ: (Minor) Memantine reduced the bioavailability of hydrochlorothiazide by roughly 20% in a drug interaction study. The clinical significance of this pharmacokinetic interaction, if any, is unknown.
Quinapril; Hydrochlorothiazide, HCTZ: (Minor) Memantine reduced the bioavailability of hydrochlorothiazide by roughly 20% in a drug interaction study. The clinical significance of this pharmacokinetic interaction, if any, is unknown.
Quinidine: (Major) Cationic drugs that are eliminated by renal tubular secretion, such as quinidine, may compete with memantine for common renal tubular transport systems, thus possibly decreasing the elimination of one of the drugs. Although theoretical, careful patient monitoring of response to memantine and/or quinidine is recommended to assess for needed dosage adjustments. In selected individuals, quinidine serum concentration monitoring may be appropriate.
Quinine: (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 quinine, could result in elevated serum concentrations of one or both drugs.
Ranitidine: (Minor) 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 ranitidine, could result in elevated serum concentrations of one or both drugs.
Ropinirole: (Moderate) The pharmacologic effects of dopaminergic agents, including dopamine agonists and certain ergot derivatives may be enhanced with use of memantine; dosage adjustments of dopaminergic agents may be required when memantine is coadministered.
Rotigotine: (Moderate) The pharmacologic effects of dopaminergic agents, including dopamine agonists such as rotigotine, may be enhanced with use of memantine; dosage adjustments of dopaminergic agents may be required when memantine is coadministered.
Solifenacin: (Moderate) The adverse effects of solifenacin may be enhanced with use of memantine; dosage adjustments of the solifenacin may be required when memantine is coadministered.
Spironolactone; Hydrochlorothiazide, HCTZ: (Minor) Memantine reduced the bioavailability of hydrochlorothiazide by roughly 20% in a drug interaction study. The clinical significance of this pharmacokinetic interaction, if any, is unknown.
Sulfamethoxazole; Trimethoprim, SMX-TMP, Cotrimoxazole: (Moderate) Cationic drugs that are eliminated by renal tubular secretion, such as trimethoprim, may decrease memantine elimination by competing for common renal tubular transport systems. Although this interaction is theoretical, careful patient monitoring and dose adjustment of memantine and/or trimethoprim is recommended.
Telmisartan; Hydrochlorothiazide, HCTZ: (Minor) Memantine reduced the bioavailability of hydrochlorothiazide by roughly 20% in a drug interaction study. The clinical significance of this pharmacokinetic interaction, if any, is unknown.
Triamterene: (Minor) 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 triamterene, could result in elevated serum concentrations of one or both drugs.
Triamterene; Hydrochlorothiazide, HCTZ: (Minor) 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 triamterene, could result in elevated serum concentrations of one or both drugs. (Minor) Memantine reduced the bioavailability of hydrochlorothiazide by roughly 20% in a drug interaction study. The clinical significance of this pharmacokinetic interaction, if any, is unknown.
Trimethoprim: (Moderate) Cationic drugs that are eliminated by renal tubular secretion, such as trimethoprim, may decrease memantine elimination by competing for common renal tubular transport systems. Although this interaction is theoretical, careful patient monitoring and dose adjustment of memantine and/or trimethoprim is recommended.
Trospium: (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 trospium, could result in elevated serum concentrations of one or both drugs.
Valsartan; Hydrochlorothiazide, HCTZ: (Minor) Memantine reduced the bioavailability of hydrochlorothiazide by roughly 20% in a drug interaction study. The clinical significance of this pharmacokinetic interaction, if any, is unknown.
Vancomycin: (Moderate) Cationic drugs that are eliminated by renal tubular secretion, such as vancomycin, may compete with memantine for common renal tubular transport systems, thus possibly decreasing the elimination of one of the drugs. Although theoretical, careful patient monitoring of response to memantine and/or vancomycin is recommended to assess for needed dosage adjustments. In selected individuals, vancomycin serum concentration monitoring may be appropriate.