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What Is Memantine (Namenda)?

Medication may be used to treat cognitive symptoms of Alzheimer’s disease, although these drugs are not to be thought of as a cure or treatment, per se. One of these drugs is memantine, known as the brand name drug Namenda. This drug is an NMDA receptor antagonist and helps regulate glutamate activity in the brain, which is a chemical that helps with information processing.1 Memantine has been approved to treat moderate to severe Alzheimer’s disease. While this drug (and others) help address symptoms of Alzheimer’s, they do not treat the underlying disease or stop the progression of the disease.

What is/are the ingredient[s] in memantine?

Memantine hydrochloride is the active ingredient in memantine, which is an orally active NMDA receptor antagonist. Inactive ingredients include talc, magnesium stearate, microcrystalline cellulose, titanium dioxide, and others.2

How does memantine work?

Glutamate is an amino acid and neurotransmission, or transmission of this chemical in the brain, is necessary for activity of nerve cells. Excessive activity, though, can cause cell death and the neurodegeneration seen in Alzheimer’s disease.3 Memantine helps regulate glutamate activity and block extrasynaptic transmission of glutamate.3 This drug does not cure Alzheimer’s, but may help in addressing cognitive symptoms of the disease.

What are the possible side effects of memantine?

Any time a person takes a medication, side effects are a possibility. Many side effects resolve on their own, but for some people, they can be bothersome enough to stop the medication. The most common side effects of memantine can include dizziness, headache, confusion, and constipation.2 Other side effects can include fatigue, hypertension, vomiting, and sleepiness.2 If a patient experiences any side effects or any symptoms that are out of the ordinary when taking memantine, tell the doctor immediately.

Things to know about memantine

If a patient is taking any other medications, tell the doctor. Memantine has the potential to interact with other medications or cause adverse effects.

Dosing information

The recommended starting dose is 5mg once a day, and it can be taken with or without food.2 After at least one week of this dose, the dosage can be increased to 10mg daily (5mg twice a day).2 After at least one week on this dose, it can be increased to 15mg daily, with the doses being split into 5mg and 10mg.2 After at least one week on this dose, it can be increased to 20mg daily (10mg given twice a day).2 If a patient misses a dose, do not double up on the next dose; just take the next dose as regularly scheduled. If the patient misses several days of this medication, tell the doctor; they might need to reduce the dosage and start the dosing process over or return to a lower dosage temporarily and build back up.

For more information, read the full prescribing information for memantine.

Written by: Jaime Rochelle Herndon | Last reviewed: January 2020
  1. Alzheimer’s Association. Medications for Memory. 2019. Accessed February 26, 2019.
  2. Namenda prescribing information. 2018. Accessed February 27, 2019.
  3. Wang R, Reddy PH. Role of glutamate and NMDA receptors in Alzheimer’s disease. J Alzheimers Dis. 2017; 57(4): 1041-1048. Doi: 10.3233/JAD-160763. Accessed March 1, 2019.