Why is this medication prescribed?
Memantine is used to treat the symptoms of Alzheimer's disease (AD; a brain disease that slowly destroys the memory and the ability to think, learn, communicate and handle daily activities). Memantine is in a class of medications called NMDA receptor antagonists. It works by decreasing abnormal activity in the brain. Memantine may improve the ability to think and remember or may slow the loss of these abilities in people who have AD. However, memantine will not cure AD or prevent the loss of these abilities at some time in the future.
How should this medicine be used?
Memantine comes as a tablet, a solution (liquid), and an extended-release (long-acting) capsule to take by mouth. The solution and tablet are usually taken once or twice a day with or without food. The capsule is taken once a day with or without food. Follow the directions on your prescription label carefully, and ask your doctor or pharmacist to explain any part you do not understand. To help you remember to take memantine, take it at around the same time(s) every day. Take memantine exactly as directed. Do not take more or less of it or take it more often than prescribed by your doctor.
Swallow the extended-release capsules whole; do not chew, divide, or crush them. If you are unable to swallow the extended-release capsules, you can carefully open a capsule and sprinkle the contents on a spoonful of applesauce. Swallow this mixture immediately without chewing it. Do not save this mixture to use at a later time.
If you are taking the oral solution, follow the manufacturer's directions to measure your dose using the oral syringe that is supplied with the medication. Slowly squirt the medication from the syringe into a corner of your mouth and swallow it. Do not mix the medication with any other liquid. After you take your medication, follow the manufacturer's directions to re-seal the bottle and clean the oral syringe. Ask your pharmacist or doctor if you have any questions about how to use this medication.
Your doctor will probably start you on a low dose of memantine and gradually increase your dose, not more than once every week.
Memantine helps to control the symptoms of Alzheimer's disease but does not cure it. Continue to take memantine even if you feel well. Do not stop taking memantine without talking to your doctor.
Ask your doctor or pharmacist for a copy of the manufacturer's information for the patient.
Other uses for this medicine
This medication may be prescribed for other uses; ask your doctor or pharmacist for more information.
What special precautions should I follow?
Before taking memantine,
- tell your doctor and pharmacist if you are allergic to memantine, any other medications, or any of the ingredients in memantine tablets, capsules, and oral solution. Ask your pharmacist or check the manufacturer's patient information for a list of the ingredients.
- tell your doctor and pharmacist what prescription and nonprescription medications, vitamins, nutritional supplements, and herbal products you are taking. Be sure to mention any of the following: acetazolamide (Diamox); amantadine; dextromethorphan (Robitussin, others); methazolamide (Nepatazane); potassium citrate and citric acid (Cytra-K, Polycitra-K); sodium bicarbonate (Soda Mint, baking soda); and sodium citrate and citric acid (Bicitra, Oracit). Your doctor may need to change the doses of your medications or monitor you carefully for side effects.
- tell your doctor if you have or have a urinary tract infection now or if you develop one during your treatment with memantine and if you have or have ever had seizures, difficulty urinating, or kidney or liver disease.
- tell your doctor if you are pregnant, plan to become pregnant, or are breast-feeding. If you become pregnant while taking memantine, call your doctor.
- if you are having surgery, including dental surgery, tell the doctor or dentist that you are taking memantine.
What special dietary instructions should I follow?
Unless your doctor tells you otherwise, continue your normal diet.
What should I do if I forget a dose?
Take the missed dose as soon as you remember it. However, if it is almost time for the next dose, skip the missed dose and continue your regular dosing schedule. Do not take a double dose to make up for a missed one. If you forget to take memantine for several days, call your doctor before you start to take the medication again.
What side effects can this medication cause?
Memantine may cause side effects. Tell your doctor if any of these symptoms are severe or do not go away:
- weight gain
- pain anywhere in your body, especially your back
Some side effects can be serious. If you experience either of the following symptoms, call your doctor immediately or get emergency medical help:
- shortness of breath
- hallucination (seeing things or hearing voices that do not exist)
Memantine may cause other side effects. Call your doctor if you have any unusual problems while taking this medication.
If you experience a serious side effect, you or your doctor may send a report to the Food and Drug Administration's (FDA) MedWatch Adverse Event Reporting program online [at http://www.fda.gov/Safety/MedWatch] or by phone [1-800-332-1088].
What should I know about storage and disposal of this medication?
Keep this medication in the container it came in, tightly closed, and out of reach of children. Store it at room temperature and away from excess heat and moisture (not in the bathroom). Throw away any medication that is outdated or no longer needed. Talk to your pharmacist about the proper disposal of your medication.
In case of emergency/overdose
In case of overdose, call your local poison control center at 1-800-222-1222. If the victim has collapsed or is not breathing, call local emergency services at 911.
Symptoms of overdose may include:
- slowed movements
- slowed heartbeat
- double vision
- hallucination (seeing things or hearing voices that do not exist)
- loss of consciousness
- lack of energy
- sense that you or your surroundings are spinning
What other information should I know?
Keep all appointments with your doctor.
Do not let anyone else take your medication. Ask your pharmacist any questions you have about refilling your prescription.
It is important for you to keep a written list of all of the prescription and nonprescription (over-the-counter) medicines you are taking, as well as any products such as vitamins, minerals, or other dietary supplements. You should bring this list with you each time you visit a doctor or if you are admitted to a hospital. It is also important information to carry with you in case of emergencies.
- Namenda® Titration Pak¶
- Namenda XR®
- Namzaric®(as a combination product containing Donepezil, Memantine)
¶ This branded product is no longer on the market. Generic alternatives may be available.