Erika Prouty, PharmD, is a professional community pharmacist who aids patients in medication management and pharmacy services in North Adams, Massachusetts.
Namenda (memantine ) is an oral prescription medication used to help treat the symptoms of dementia from Alzheimer’s disease.
Namenda is an N-methyl-D-aspartate (NMDA) receptor antagonist. It binds to the NMDA receptors in the brain, which are believed to play a role in Alzheimer’s disease, to decrease abnormal brain activity. Taking Namenda will not cure the disease, but it may help improve symptoms.
This medication is available in standard formulation tablets, extended-release (XR) capsules, and a solution (liquid).
Brand Name(s): Namenda, Namenda XR
Dosage Form(s): Tablet, solution, extended-release capsule
The Food and Drug Administration (FDA) approved Namenda for use in adults to treat moderate to severe Alzheimer’s dementia.
Alzheimer’s disease is a progressively worsening brain condition that causes memory and behavioral changes, usually starting after the age of 60. Namenda is not a cure for Alzheimer’s disease and will not prevent the eventual decline in cognitive abilities. However, it can help improve symptoms or may slow the loss of cognitive skills.
Usually, your healthcare provider will prescribe Namenda for you or your loved one at a low dose and increase it gradually. The dosing schedule will increase the dose no more than once every week.
Namenda can be taken with or without food. The tablets and solution are usually taken either once or twice a day, and the XR capsule is taken once a day. The capsules can be swallowed whole or opened and sprinkled on applesauce before consumption. Do not take only a partial dose or save the rest for later.
Keep this medication in its original container and away from the reach of children or pets.
Store the standard Namenda tablets and capsules between 68 degrees to 77 degrees Fahrenheit (F). It can be briefly kept in temperatures as low as 59 degrees and high as 86 degrees F.
This medication has been prescribed for several off-label uses or conditions that it is not specifically approved to treat.
The effects and dose for off-label uses have not been established.
The clinical effects of Namenda can take weeks or months to occur, and they are not always apparent to everyone. It may help improve the symptoms associated with Alzheimer's disease in the short term, but it will not stop the disease long-term.
This medication can cause side effects, and the side effects of the standard formulation and the XR formulation are similar, but there are some differences.
This is not a complete list of side effects and others may occur. A healthcare provider can advise you on side effects. If you experience other effects, contact your pharmacist or a healthcare provider. You may report side effects to the FDA at fda.gov/medwatch or 1-800-FDA-1088.
The most common side effects caused by the standard formulation of Namenda are:
The most common side effects of the XR formulation are:
Talk to a healthcare provider about treatment options for side effects if you notice any of these while you or a loved one are taking Namenda.
Namenda may cause other side effects. Call your healthcare provider if you have any unusual problems while taking this medication.
If you experience a serious side effect, you or your provider may send a report to the FDA's MedWatch Adverse Event Reporting Program or by phone (800-332-1088).
The dose of this medicine will be different for different patients. Follow your doctor's orders or the directions on the label. The following information includes only the average doses of this medicine. If your dose is different, do not change it unless your doctor tells you to do so.
The amount of medicine that you take depends on the strength of the medicine. Also, the number of doses you take each day, the time allowed between doses, and the length of time you take the medicine depend on the medical problem for which you are using the medicine.
It is recommended that people who have severe kidney failure take one-half of the regular dose of Namenda or Namenda XR.
There are no established differences in the effectiveness of Namenda and Namenda XR. If you are switching from Namenda 10 milligrams twice a day to the XR formulation, you will take 28 milligrams of the XR formulation once a day, starting the day after your last 10 milligrams dose of Namenda.
The instructions for missed doses depend on whether you take the standard formulation or the XR formulation:
If you miss your dose for a few days, your healthcare provider might recommend restarting the medication at a lower dose and gradually working up to your target dose.
Tell your healthcare provider if you take more Namenda than prescribed. Depending on how much you’ve taken, you may need medical observation so healthcare providers can detect the effects of an overdose if they occur.
An overdose can potentially cause the following symptoms:
You might not experience any symptoms from taking too much Namenda. If you do develop symptoms, you may need to seek medical attention for treatment.
If you think you or someone else may have overdosed on Namenda, call a healthcare provider or the Poison Control Center (800-222-1222).
If someone collapses, has a seizure, has trouble breathing, or can’t wake up after taking too much Namenda, call 911 immediately.
It is very important that your doctor check your progress at regular visits to make sure that this medicine is working properly and to check for unwanted effects.
Do not take other medicines unless they have been discussed with your doctor. This includes prescription or nonprescription (over-the-counter [OTC]) medicines and herbal or vitamin supplements.
You should not take this medication if you have ever had an allergic reaction to Namenda or any other components present in the formulation.
Medications that alter the urine pH can cause a high blood level of Namenda. These medications can include carbonic anhydrase inhibitors or sodium bicarbonate.
This medication should be used with caution if taken with other NMDA antagonists (e.g., amantadine, ketamine, and dextromethorphan).
Other medications used to treat the symptoms of Alzheimer’s disease include:
Typically, only one medication is prescribed to treat Alzheimer’s disease. There is no evidence suggesting that taking more than one at a time could be beneficial.
Namenda is often prescribed for treating Alzheimer’s dementia symptoms. It is sometimes prescribed off-label for treating other types of dementia.
Namenda is an N-methyl-D-aspartate (NMDA) receptor antagonist. Overactivity of these receptors is thought to be associated with Alzheimer’s disease.
This drug can reach excessive levels in the body if you take any medications that could change the urine pH. Additionally, taking this medication with other NMDA receptor antagonists may increase the risk of side effects.
The clinical effects of Namenda can take weeks or months to occur, and they are not always apparent for everyone. Generally, this medication slows the progression of Alzheimer’s dementia symptoms, but it does not reverse them.
This medication can cause headaches and dizziness. The standard formulation also can cause constipation and confusion, and the XR formulation can also cause diarrhea.
It is generally considered safe to stop taking Namenda. If you restart, your healthcare provider will need to resume your regimen at a low dose and gradually increase it until you reach a target dose.
If you are taking Namenda, it’s important that you also take steps to stay healthy. It can be scary and overwhelming to receive a diagnosis of Alzheimer's disease and cope with its symptoms. This can also be similar for those whose loved ones have been diagnosed and are dealing with this condition.
Stay healthy while taking Namenda includes:
Verywell Health's drug information is meant for educational purposes only and not intended as a replacement for medical advice, diagnosis, or treatment from a healthcare provider. Consult your healthcare provider before taking any new medication(s). IBM Watson Micromedex provides some of the drug content, as indicated on the page.
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Reddy V, Hernandez A, Grossman L, Angelo D, Frunzi J. Memantine usage for management of Korsakoff Syndrome in the setting of chronic alcohol use and unspecified eating disorder. Cureus. 2021;13(3):e13846. doi:10.7759/cureus.13846
Food and Drug Administration. Namenda label.
Food and Drug Administration. Namenda XR label.
Rossignol DA, Frye RE. The use of medications approved for Alzheimer's disease in autism spectrum disorder: a systematic review. Front Pediatr. 2014;2:87. doi:10.3389/fped.2014.00087
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