Pronunciation: mee-man-teen
Generic name: memantine
Brand name: Namenda
Dosage form: oral tablets, extended-release capsules
Drug class: Miscellaneous central nervous system agents

Medically reviewed by Carmen Pope, BPharm. Last updated on Jul 5, 2024.

What is memantine?

Memantine (brand name Namenda) is an oral NMDA blocker that may be used to treat moderate to severe dementia in people with Alzheimer’s disease.

Memantine is an NMDA (N-methyl-D-aspartate) blocker that works by binding to NMDA-receptor-operated cation channels and blocking their effect. Persistent activation of NDMA receptors by glutamate is thought to contribute to Alzheimer’s disease symptoms, and blocking this persistent activation is believed to be memantine’s mechanism of action. However, there is no evidence that memantine prevents or slows nerve degeneration in Alzheimer’s disease.

Memantine was FDA-approved on October 16, 2003, under the brand name Namenda. Generic memantine became available in 2010.

Memantine side effects

The most common side effects of memantine include:

• dizziness
• headache
• confusion
• constipation.

Serious side effects and warnings

Memantine can cause serious allergic reactions, including anaphylaxis. Get emergency medical help if you have signs of an allergic reaction to memantine with symptoms such as hives, difficulty breathing, and swelling of your face, lips, tongue, or throat.

Conditions that increase the pH of the urine (such as kidney disease, prolonged vomiting, and some medications) may decrease how much memantine is excreted which may increase blood levels of memantine. Tell your healthcare provider about all your medical conditions.

Call your doctor at once if you have:

• severe headache, blurred vision, pounding in your neck or ears;
• seizure (convulsions); or
• unusual changes in mood or behavior.

These are not all the possible side effects of memantine. For more information, ask your doctor or pharmacist. Call your doctor for medical advice about side effects. You may report side effects to the FDA at 1-800-FDA-1088.

Before taking

Before taking memantine, tell your doctor if you are allergic to any memantine, Namenda, or any inactive ingredients in the tablets or capsules.

Tell your healthcare provider about all your medical conditions including if you:

• Have a seizure disorder
• Have cataracts
• Have liver or kidney disease
• Have a bladder or kidney infection
• Have problems passing urine
• Are pregnant or intending to become pregnant
• Are breastfeeding.

It is not known if memantine is safe and effective in children.

Pregnancy

It is not known if memantine will harm an unborn baby.

Breastfeeding

It is not known if memantine passes into your breast milk. Talk to your doctor about the best way to feed your baby during treatment.

How should I take memantine?

Your doctor will tell you how much memantine to take and when to take it.

Memantine tablets or extended-release capsules may be taken with food or without food.

• Do not use any tablets or capsules of memantine that are damaged or show signs of tampering.
• Memantine hydrochloride extended-release capsules should be swallowed whole or may be opened and the contents sprinkled on applesauce and then swallowed. The entire contents of each memantine hydrochloride extended-release capsule should be consumed; the dose should not be divided.

Memantine dosage

Immediate-release tablets

The usual starting dose of memantine is 5 mg once daily.

• This can be increased in 5 mg increments to a maximum dose of 10 mg twice daily.
• Your healthcare provider should allow at least one week before dosage increases before increasing the dose again.
• The maximum dose of memantine for people with severe kidney disease is 5mg twice daily.

Extended-release capsules

The usual starting dose of memantine extended-release capsules is 7 mg once daily.

• The dose should be increased in 7 mg increments to the recommended maintenance dose of 28 mg once daily.
• The minimum recommended interval between dose increases is one week.
• The dose should only be increased if the previous dose has been well tolerated.
• The maximum recommended dose is 28 mg once daily.

Switching from memantine tablets to memantine extended-release capsules

People on a regimen of 10 mg twice daily of memantine tablets can be switched to memantine extended-release 28 mg once daily capsules the day following the last dose of 10 mg memantine hydrochloride.

People with severe renal impairment taking 5 mg twice daily of memantine should be switched to memantine extended-release 14 mg once daily capsules the day following the last dose of 5 mg memantine tablets.

Related/similar drugs

Namenda, donepezil, memantine, Aricept, rivastigmine, Exelon

What happens if I forget a dose?

If you forget to take one dose of memantine, do not double up on the next dose. You should take only the next dose as scheduled.

If you have forgotten to take memantine for several days, you should not take the next dose until you talk to your doctor.

What happens if I overdose?

If you take too much memantine, call your doctor or poison control center at 1-800- 222-1222 right away, or go to the nearest hospital emergency room.

What should I avoid?

Memantine can cause side effects that may impair your thinking or reactions. Be careful if you drive or do anything that requires you to be awake and alert.

What other drugs will affect memantine?

Tell your doctor about all the medicines you take, including prescription and nonprescription medicines, vitamins, and herbal supplements. Taking memantine with certain other medicines may affect each other or cause serious side effects. Especially tell your doctor if you take:

• other NMDA antagonists such as amantadine, ketamine, and dextromethorphan
• medicines that make your urine alkaline such as carbonic anhydrase inhibitors and sodium bicarbonate.

Ask your doctor or pharmacist for a list of these medicines, if you are not sure. Know the medicines you take. Keep a list of them to show your doctor and pharmacist when you get a new medicine.

Storage

Store memantine at room temperature between 59°F to 77°F (15°C to 30°C).

Ingredients

Namenda ingredients

Active ingredient: memantine hydrochloride

Inactive ingredients: microcrystalline cellulose/colloidal silicon dioxide, talc, croscarmellose sodium, and magnesium stearate

Inactive ingredients of tablet film coating: hypromellose, titanium dioxide, polyethylene glycol 400, FD&C yellow #6 and FD&C blue #2 (5 mg tablets), and hypromellose, titanium dioxide, macrogol/polyethylene glycol 400 and iron oxide black (10 mg tablets).

Available as Namenda 5 mg and 10 mg tablets and Namenda XR (extended-release capsule) 7 mg, 14 mg, 21 mg, 28 mg.

Generic memantine ingredients

Active ingredient: memantine hydrochloride

Inactive ingredients: These vary depending on the manufacturer.

Available as memantine 5 mg and 10 mg tablets and memantine XR (extended-release capsule) 7 mg, 14 mg, 21 mg, 28 mg.

Who makes memantine?

Namenda is made by Allergan.

Various manufacturers make generic memantine including Amneal Pharmaceuticals LLC, Aurobindo Pharma Limited, and Sun Pharmaceutical Industries, Inc.

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Further information

Always consult your healthcare provider to ensure the information displayed on this page applies to your personal circumstances.

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