Dosing & Uses
Dosage Forms & Strengths
tablet
- 5mg
- 10mg
capsule, extended-release
- 7mg
- 14mg
- 21mg
- 28mg
oral solution
- 2mg/mL
Alzheimer-Type Dementia
Treatment of moderate-to-severe dementia
Tablet: 5 mg PO once daily initially; increased by increments of 5 mg/day each week; maintenance target dosage (>5 weeks): 20 mg/day PO divided q12hr
Extended-release capsule: 7 mg PO qDay initially; may be increased by increments of 7 mg/day each week; maintenance target dose is 28 mg PO qDay
Dosage Modifications
Renal impairment
- Mild or moderate: No dosage adjustment required
- Severe: (CrCl 5-29 mL/min): Not to exceed 14 mg/day (extended-release) or 5 mg BID (prompt-release)
Hepatic impairment
- Mild or moderate (Child Pugh A/B): No dosage adjustment required
- Severe (Child Pugh C): Caution
Administration
May take with or without food
Consume entire capsule contents, do not divide the dose
Swallow capsule whole or open and sprinkle on spoonful of applesauce; do not chew or crush
Do not mix oral solution with any other liquid
Missed dose: Do not double next dose, the next dose should be taken as scheduled; if missed for several days, dosing may need to be resumed at lower doses and retitrated as described above
Mild-to-Moderate Vascular Dementia (Off-label)
5 mg (immediate-release) PO qDay; titrate by 5 mg q7days to target dose 10 mg twice daily
Not indicated
Interactions
Interaction Checker
No Results
Contraindicated
Serious - Use Alternative
Significant - Monitor Closely
Minor
Contraindicated (0)
Serious - Use Alternative (4)
- dextromethorphan
memantine, dextromethorphan. Either increases toxicity of the other by pharmacodynamic synergism. Contraindicated.
- ketamine
memantine, ketamine. Either increases toxicity of the other by pharmacodynamic synergism. Contraindicated.
- tafenoquine
tafenoquine will increase the level or effect of memantine by Other (see comment). Avoid or Use Alternate Drug. Tafenoquine inhibits organic cation transporter-2 (OCT2) and multidrug and toxin extrusion (MATE) transporters in vitro. Avoid coadministration with OCT2 or MATE substrates. If coadministration cannot be avoided, monitor for substrate-related toxicities and consider dosage reduction if needed based on product labeling of the coadministered drug.
- trilaciclib
trilaciclib will decrease the level or effect of memantine by Other (see comment). Avoid or Use Alternate Drug. Avoid coadministration of trilaciclib (OCT2, MATE1, and MATE-2K inhibitor) with substrates where minimal increased concentration in kidney or blood may lead to serious or life-threatening toxicities.
Monitor Closely (16)
- acetazolamide
acetazolamide will increase the level or effect of memantine by passive renal tubular reabsorption - basic urine. Use Caution/Monitor.
- aluminum hydroxide
aluminum hydroxide will increase the level or effect of memantine by passive renal tubular reabsorption - basic urine. Use Caution/Monitor.
- amantadine
memantine, amantadine. Either increases toxicity of the other by pharmacodynamic synergism. Use Caution/Monitor. Combination may lead to additive adverse effects. If coadministration cannot be avoided, monitor for increased adverse effects such as agitation, dizziness and other CNS events.
- amiodarone
amiodarone will increase the level or effect of memantine by basic (cationic) drug competition for renal tubular clearance. Use Caution/Monitor.
- calcium carbonate
calcium carbonate will increase the level or effect of memantine by passive renal tubular reabsorption - basic urine. Use Caution/Monitor.
- cimetidine
cimetidine will increase the level or effect of memantine by basic (cationic) drug competition for renal tubular clearance. Use Caution/Monitor.
- digoxin
digoxin will increase the level or effect of memantine by basic (cationic) drug competition for renal tubular clearance. Use Caution/Monitor.
- dofetilide
dofetilide will increase the level or effect of memantine by basic (cationic) drug competition for renal tubular clearance. Use Caution/Monitor.
- erdafitinib
memantine increases levels of erdafitinib by decreasing renal clearance. Modify Therapy/Monitor Closely. Consider alternatives that are not OCT2 substrates or consider reducing the dose of OCT2 substrates based on tolerability.
- procainamide
memantine will increase the level or effect of procainamide by basic (cationic) drug competition for renal tubular clearance. Use Caution/Monitor.
- quinidine
quinidine will increase the level or effect of memantine by basic (cationic) drug competition for renal tubular clearance. Use Caution/Monitor.
- sodium bicarbonate
sodium bicarbonate will increase the level or effect of memantine by passive renal tubular reabsorption - basic urine. Use Caution/Monitor.
- sodium citrate/citric acid
sodium citrate/citric acid will increase the level or effect of memantine by passive renal tubular reabsorption - basic urine. Use Caution/Monitor.
- sodium lactate
sodium lactate will increase the level or effect of memantine by passive renal tubular reabsorption - basic urine. Use Caution/Monitor.
- tenofovir DF
tenofovir DF increases levels of memantine by decreasing renal clearance. Use Caution/Monitor. Potential for increased toxicity. .
- vandetanib
vandetanib increases levels of memantine by Other (see comment). Modify Therapy/Monitor Closely. Comment: Vandetanib inhibits the uptake of substrates of organic cation transporter type 2 (OCT2).
Minor (12)
- hydrochlorothiazide
hydrochlorothiazide will increase the level or effect of memantine by basic (cationic) drug competition for renal tubular clearance. Minor/Significance Unknown.
- isavuconazonium sulfate
isavuconazonium sulfate will increase the level or effect of memantine by Other (see comment). Minor/Significance Unknown. Isavuconazonium sulfate, an OCT2 inhibitor, may increase the effects or levels of OCT2 substrates.
- metformin
memantine will increase the level or effect of metformin by basic (cationic) drug competition for renal tubular clearance. Minor/Significance Unknown.
- methyclothiazide
methyclothiazide will increase the level or effect of memantine by basic (cationic) drug competition for renal tubular clearance. Minor/Significance Unknown.
- midodrine
memantine will increase the level or effect of midodrine by basic (cationic) drug competition for renal tubular clearance. Minor/Significance Unknown.
- ofloxacin
memantine will increase the level or effect of ofloxacin by basic (cationic) drug competition for renal tubular clearance. Minor/Significance Unknown.
- pramipexole
memantine will increase the level or effect of pramipexole by basic (cationic) drug competition for renal tubular clearance. Minor/Significance Unknown.
- quinine
memantine will increase the level or effect of quinine by basic (cationic) drug competition for renal tubular clearance. Minor/Significance Unknown.
- sulfamethoxazole
sulfamethoxazole will increase the level or effect of memantine by basic (cationic) drug competition for renal tubular clearance. Minor/Significance Unknown.
- triamterene
memantine will increase the level or effect of triamterene by basic (cationic) drug competition for renal tubular clearance. Minor/Significance Unknown.
- trimethoprim
memantine will increase the level or effect of trimethoprim by basic (cationic) drug competition for renal tubular clearance. Minor/Significance Unknown.
- verapamil
memantine will increase the level or effect of verapamil by basic (cationic) drug competition for renal tubular clearance. Minor/Significance Unknown.
Adverse Effects
1-10%
Dizziness (7%)
Confusion (6%)
Headache (6%)
Constipation (5%)
Cough (4%)
Hypertension (4%)
Backache (3%)
Pain (3%)
Somnolence (3%)
Syncope (3%)
Vomiting (3%)
Dyspnea (2%)
Fatigue (2%)
<1%
Acute renal failure
Cerebral infarction
Cerebrovascular accident
Deep venous thrombosis
Hepatitis, liver failure
Intracranial hemorrhage
Neuroleptic malignant syndrome
Seizure (including grand mal)
Stevens-Johnson syndrome
Transient ischemic attack
Postmarketing Reports
Blood and lymphatic system disorders: Agranulocytosis, leukopenia (including neutropenia), pancytopenia, thrombocytopenia, thrombotic thrombocytopenic purpura
Cardiac disorders: Cardiac failure congestive
Gastrointestinal disorders: Pancreatitis
Hepatobiliary disorders: Hepatitis
Psychiatric disorders: Suicidal ideation
Renal and urinary disorders: Acute renal failure (including increased creatinine and renal insufficiency)
Skin disorders: Stevens Johnson syndrome
Warnings
Contraindications
Hypersensitivity to memantine or components of the formulation
Cautions
Not evaluated in patients with seizure disorder; seizures occurred in 0.2% of patients
Conditions that raise urine pH may decrease urinary elimination and increase plasma levels of memantine
Use caution in cardiovascular disease, seizure disorder, ophthalmic disease, hepatic and/or renal impairment
Pregnancy & Lactation
Pregnancy
There are no adequate data on developmental risk associated with use; adverse developmental effects (decreased body weight, and skeletal ossification) observed in offspring of rats during pregnancy at doses associated with minimal maternal toxicity; doses are higher than used in humans at maximum recommended daily dose
Animal data
- Oral administration to rats during period of organogenesis resulted in decreased skeletal ossification in fetuses at highest dose tested; the higher no-effect dose (6 mg/kg/day) was approximately 3 times MRHD on a mg/m² basis
- Oral administration of memantine to rabbits during period of organogenesis resulted in no adverse developmental effects; highest dose tested was approximately 30 times the MRHD on a mg/m² basis
- Oral administration to rats from late gestation throughout lactation to weaning, resulted in decreased pup weights at highest dose tested; the higher no-effect dose (6 mg/kg/day) is approximately 3 times the MRHD on a mg/ m² basis
Lactation
There are no data on presence of drug in human milk, effects on breastfed infant, or on milk production
Developmental and health benefits of breastfeeding should be considered along with mother’s clinical need for therapy and any potential adverse effects on breastfed infant from drug or from underlying maternal condition
Pregnancy Categories
A: Generally acceptable. Controlled studies in pregnant women show no evidence of fetal risk.
B: May be acceptable. Either animal studies show no risk but human studies not available or animal studies showed minor risks and human studies done and showed no risk. C: Use with caution if benefits outweigh risks. Animal studies show risk and human studies not available or neither animal nor human studies done. D: Use in LIFE-THREATENING emergencies when no safer drug available. Positive evidence of human fetal risk. X: Do not use in pregnancy. Risks involved outweigh potential benefits. Safer alternatives exist. NA: Information not available.Pharmacology
Mechanism of Action
Low- to moderate-affinity uncompetitive N-methyl-D-aspartate (NMDA) receptor (NMDAR) antagonist that binds preferentially to NMDAR-operated cation channels, blocking receptor only under conditions of excessive stimulation, with no effect on normal neurotransmission
Absorption
Peak plasma time: 3-7 hr (immediate release); 9-12 hr (extended release)
Distribution
Protein bound: 45%
Vd: 9-11 L/kg
Metabolism
Metabolites: 3 polar metabolites (minimally active)
Elimination
Half-life: 60-80 hr
Excretion: Urine (74%)
Images
| BRAND | FORM. | UNIT PRICE | PILL IMAGE |
|---|---|---|---|
| memantine oral - | 10 mg tablet |  | |
| memantine oral - | 10 mg tablet |  | |
| memantine oral - | 10 mg tablet |  | |
| memantine oral - | 10 mg tablet |  | |
| memantine oral - | 5 mg tablet |  | |
| memantine oral - | 5 mg tablet |  | |
| memantine oral - | 10 mg tablet |  | |
| memantine oral - | 5 mg tablet |  | |
| memantine oral - | 28 mg capsule |  | |
| memantine oral - | 28 mg capsule |  | |
| memantine oral - | 14 mg capsule |  | |
| memantine oral - | 14 mg capsule |  | |
| memantine oral - | 28 mg capsule |  | |
| memantine oral - | 10 mg tablet |  | |
| memantine oral - | 5 mg tablet |  | |
| memantine oral - | 10 mg tablet |  | |
| memantine oral - | 10 mg tablet |  | |
| memantine oral - | 14 mg capsule |  | |
| memantine oral - | 2 mg/mL solution |  | |
| memantine oral - | 28 mg capsule |  | |
| memantine oral - | 21 mg capsule |  | |
| memantine oral - | 7 mg capsule |  | |
| memantine oral - | 7 mg capsule |  | |
| memantine oral - | 7 mg capsule |  | |
| memantine oral - | 2 mg/mL solution |  | |
| memantine oral - | 10 mg tablet |  | |
| memantine oral - | 21 mg capsule |  | |
| memantine oral - | 14 mg capsule |  | |
| memantine oral - | 28 mg capsule |  | |
| memantine oral - | 2 mg/mL solution |  | |
| memantine oral - | 5 mg tablet |  | |
| memantine oral - | 21 mg capsule |  | |
| memantine oral - | 7 mg capsule |  | |
| memantine oral - | 10 mg tablet |  | |
| memantine oral - | 5 mg tablet |  | |
| memantine oral - | 14 mg capsule |  | |
| memantine oral - | 10 mg tablet |  | |
| memantine oral - | 5 mg tablet |  | |
| memantine oral - | 5 mg tablet |  | |
| memantine oral - | 5 mg tablet |  | |
| memantine oral - | 10 mg tablet |  | |
| memantine oral - | 5 mg tablet |  | |
| memantine oral - | 28 mg capsule |  | |
| memantine oral - | 28 mg capsule |  | |
| memantine oral - | 21 mg capsule |  | |
| memantine oral - | 14 mg capsule |  | |
| memantine oral - | 5 mg tablet |  | |
| memantine oral - | 10 mg tablet |  | |
| memantine oral - | 5 mg tablet |  | |
| memantine oral - | 5 mg tablet |  | |
| memantine oral - | 7 mg capsule |  | |
| memantine oral - | 10 mg tablet |  | |
| memantine oral - | 5 mg tablet |  | |
| memantine oral - | 10 mg tablet |  | |
| memantine oral - | 10 mg tablet |  | |
| memantine oral - | 28 mg capsule |  | |
| memantine oral - | 5 mg tablet |  | |
| memantine oral - | 21 mg capsule |  | |
| memantine oral - | 14 mg capsule |  | |
| memantine oral - | 7 mg capsule |  | |
| memantine oral - | 5-10 mg tablet |  | |
| memantine oral - | 5 mg tablet |  | |
| memantine oral - | 10 mg tablet |  | |
| memantine oral - | 5 mg tablet |  | |
| memantine oral - | 7 mg capsule |  | |
| memantine oral - | 2 mg/mL solution |  | |
| Namenda oral - | 10 mg tablet | | |
| Namenda oral - | 5 mg tablet | | |
| Namenda Titration Pak oral - | 5-10 mg tablet |  | |
| Namenda XR oral - | 21 mg capsule | | |
| Namenda XR oral - | 14 mg capsule | | |
| Namenda XR oral - | 28 mg capsule | | |
| Namenda XR oral - | 7 mg capsule | | |
| Namenda XR oral - | 7-14-21-28 mg capsule |  |
Copyright © 2010 First DataBank, Inc.
Patient Handout
memantine oral
MEMANTINE - ORAL
(MEM-an-teen)
COMMON BRAND NAME(S): Namenda
USES: Memantine is used to treat moderate to severe confusion (dementia) related to Alzheimer's disease. It does not cure Alzheimer's disease, but it may improve memory, awareness, and the ability to perform daily functions. This medication works by blocking the action of a certain natural substance in the brain (glutamate) that is believed to be linked to symptoms of Alzheimer's disease.
HOW TO USE: Read the Patient Information Leaflet if available from your pharmacist before you start taking memantine and each time you get a refill. If you have any questions, ask your doctor or pharmacist.Take this medication by mouth with or without food as directed by your doctor, usually twice daily. The dosage is based on your medical condition and response to treatment. When you first start taking this medication, you will usually take it once daily. To reduce your risk of side effects, your doctor may direct you to start this medication at a low dose and gradually increase your dose. Follow your doctor's instructions carefully.If you are taking memantine oral liquid, read the manufacturer's instruction sheet that comes with the bottle. Follow the directions exactly. Use the oral syringe that comes with the product to measure out your dose. Do not use a household spoon because you may not get the correct dose. Swallow the medication directly from the syringe. Do not mix it with water or other liquids. Rinse the syringe with water after each use. Consult your doctor or pharmacist if you have any questions.Use this medication regularly to get the most benefit from it. To help you remember, take it at the same time(s) each day.Tell your doctor if your condition worsens.
SIDE EFFECTS: Body aches, dizziness, constipation, and headache may occur. If any of these effects last or get worse, tell your doctor or pharmacist promptly.Remember that this medication has been prescribed because your doctor has judged that the benefit to you is greater than the risk of side effects. Many people using this medication do not have serious side effects.A very serious allergic reaction to this drug is rare. However, get medical help right away if you notice any symptoms of a serious allergic reaction, including: rash, itching/swelling (especially of the face/tongue/throat), severe dizziness, trouble breathing.This is not a complete list of possible side effects. If you notice other effects not listed above, contact your doctor or pharmacist.In the US -Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088 or at www.fda.gov/medwatch.In Canada - Call your doctor for medical advice about side effects. You may report side effects to Health Canada at 1-866-234-2345.
PRECAUTIONS: Before taking memantine, tell your doctor or pharmacist if you are allergic to it; or if you have any other allergies. This product may contain inactive ingredients which can cause allergic reactions or other problems. Talk to your pharmacist for more details.Before using this medication, tell your doctor or pharmacist your medical history, especially of: kidney problems, severe urinary tract infections, recent dietary change (from a high-protein diet to a vegetarian diet).This drug may make you dizzy. Alcohol or marijuana (cannabis) can make you more dizzy. Do not drive, use machinery, or do anything that needs alertness until you can do it safely. Limit alcoholic beverages. Talk to your doctor if you are using marijuana (cannabis).Before having surgery, tell your doctor or dentist about all the products you use (including prescription drugs, nonprescription drugs, and herbal products).During pregnancy, this medication should be used only when clearly needed. Discuss the risks and benefits with your doctor.It is unknown if this drug passes into breast milk. Consult your doctor before breast-feeding.
DRUG INTERACTIONS: Drug interactions may change how your medications work or increase your risk for serious side effects. This document does not contain all possible drug interactions. Keep a list of all the products you use (including prescription/nonprescription drugs and herbal products) and share it with your doctor and pharmacist. Do not start, stop, or change the dosage of any medicines without your doctor's approval.Some products that may interact with this drug include: carbonic anhydrase inhibitors (such as acetazolamide, methazolamide), sodium bicarbonate.
OVERDOSE: If someone has overdosed and has serious symptoms such as passing out or trouble breathing, call 911. Otherwise, call a poison control center right away. US residents can call their local poison control center at 1-800-222-1222. Canada residents can call a provincial poison control center. Symptoms of overdose may include: restlessness, personality change, hallucinations, drowsiness, loss of consciousness.
NOTES: Do not share this medication with others.
MISSED DOSE: If you miss a dose, take it as soon as you remember. If it is near the time of the next dose, skip the missed dose. Take your next dose at the regular time. Do not double the dose to catch up.If you forget to take memantine for several days, talk to your doctor before your next dose. You may need to start at a lower dose again and slowly increase it.
STORAGE: Store at room temperature away from light and moisture. Do not store in the bathroom. Keep all medications away from children and pets.Do not flush medications down the toilet or pour them into a drain unless instructed to do so. Properly discard this product when it is expired or no longer needed. Consult your pharmacist or local waste disposal company.
Information last revised May 2023. Copyright(c) 2023 First Databank, Inc.
IMPORTANT: HOW TO USE THIS INFORMATION: This is a summary and does NOT have all possible information about this product. This information does not assure that this product is safe, effective, or appropriate for you. This information is not individual medical advice and does not substitute for the advice of your health care professional. Always ask your health care professional for complete information about this product and your specific health needs.
Formulary
Adding plans allows you to compare formulary status to other drugs in the same class.
To view formulary information first create a list of plans. Your list will be saved and can be edited at any time.
Adding plans allows you to:
- View the formulary and any restrictions for each plan.
- Manage and view all your plans together – even plans in different states.
- Compare formulary status to other drugs in the same class.
- Access your plan list on any device – mobile or desktop.
