All about Namenda (Memantine HCL) for Treating Alzheimer's

Memantine Molecule

What It Is:

One of the drugs used to treat the symptoms of Alzheimer's disease. Namenda was FDA-approved in 2003 to treat moderate and severe stages of the disease.

How It Works:

In technical terms, Namenda is an N-methyl-D-aspartate (NMDA) antagonist that regulates the activity of glutamate in the brain. Glutamate plays a key role in memory and learning, but excess glutamate can lead to the disruption of nerve cell communication or nerve cell death.


Some studies involving Namenda have shown that the drug can slow the rate of decline in thinking and the ability to perform daily activities in individuals who have moderate to severe Alzheimer's disease, while other studies do not show a significant change. For many, the improvement is minimal, yet worthwhile.


Namenda is available in tablet and liquid form and is commonly started at 5 mg a day. If it's well tolerated, the dosage may be gradually increased -- at a minimum of one-week intervals -- to 5 mg twice a day, 15 mg/day (5 mg and 10 mg separately), and 10 mg twice a day. Your health care professional will determine the best dosage for you or your loved one.

Side Effects:

Although generally well-tolerated, the most common side effects are dizziness, headache, constipation, and confusion. Unlike cholinesterase inhibitors such as Aricept, Exelon, and Razadyne, those taking Namenda have a low risk of gastrointestinal side effects.

A study published in 2013 concluded that people taking Namenda were at higher risk of somnolence (sleepiness), confusion, weight gain, high blood pressure, nervous system disorders and falling.

Potential Interactions:

Namenda has a low potential for drug interactions. However, other NMDA antagonist medications, which include some cold and flu medications (like dextromethorphan), should be used with caution while taking Namenda.

Sometimes, doctors prescribe Namenda along with a cholinesterase inhibitor to treat moderate Alzheimer's disease, as some studies have shown additional benefit from combining these medications.


Be sure to tell your doctor if you have severe renal impairment so that your dosage can be reduced accordingly.


Namenda is manufactured by Forest Pharmaceuticals, Inc.

Generic Available:

Namenda is available in generic form (memantine HCL).


About Namenda. Forest Pharmaceuticals, Inc. 2008.

Alzheimer's disease medications fact sheet. Alzheimer's Disease Education and Referral Center, National Institute on Aging. January 15, 2008.

FDA-approved treatments for Alzheimer's. Alzheimer's Association. July 2007.

Journal of Alzheimer's Disease. 2013;36(3):445-58. Effectiveness and safety of memantine treatment for Alzheimer's disease.

-Edited by Esther Heerema, MSW

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