Uses
What is memantine used for?
Memantine is commonly used to treat moderate to severe dementia related to Alzheimer’s disease.
Memantine may also be used for other conditions as determined by your healthcare provider.
How does memantine work (mechanism of action)?
Memantine may help manage symptoms of Alzheimer's disease by blocking the effects of glutamate. Glutamate is a natural brain chemical that is linked to Alzheimer’s disease symptoms. Memantine belongs to a class of medicines called N-methyl-D-aspartate (NMDA) antagonists.
How is memantine supplied (dosage forms)?
Memantine is available as Namenda, Namenda XR, and generic memantine in the following dosage forms that are taken by mouth.
- 5 mg oral tablets
- 10 mg oral tablets
- 2 mg/mL oral solution
- 7 mg extended-release oral capsules
- 14 mg extended-release oral capsules
- 21 mg extended-release oral capsules
- 28 mg extended-release oral capsules
How should I store memantine?
Memantine should be stored at room temperature, between 68 F to 77 F (20 C to 25 C). It can be exposed to temperatures between 59 F to 86 F (15 C to 30 C) for shorter periods of time, such as when transporting it. Store in a cool, dry place.
Side Effects
What are the most common side effects of memantine?
The most common side effects of memantine are listed below. Tell your healthcare provider if you have any of these side effects that bother you.
- Dizziness
- Headache
- Confusion (oral tablets and oral solution)
- Constipation (oral tablets and oral solution)
- Diarrhea (extended-release oral capsules)
There may be other side effects of memantine that are not listed here. Contact your healthcare provider if you think you are having a side effect of a medicine. In the U.S., you can report side effects to the FDA at www.fda.gov/medwatch or by calling 800-FDA-1088. In Canada, you can report side effects to Health Canada at www.health.gc.ca/medeffect or by calling 866-234-2345.
What are the serious side effects of memantine?
While less common, the most serious side effects of memantine are described below, along with what to do if they happen.
Severe Allergic Reactions. Memantine may cause allergic reactions, which can be serious. Stop using memantine and get help right away if you have any of the following symptoms of a serious allergic reaction.
- Breathing problems or wheezing
- Racing heart
- Fever or general ill feeling
- Swollen lymph nodes
- Swelling of the face, lips, mouth, tongue, or throat
- Trouble swallowing or throat tightness
- Itching, skin rash, or pale red bumps on the skin called hives
- Nausea or vomiting
- Dizziness, feeling lightheaded, or fainting
- Stomach cramps
- Joint pain
Warnings & Precautions
Who should not use memantine?
Allergies to Ingredients. People who are allergic to any of the following should not take memantine.
- Memantine
- Namenda or Namenda XR
- Any of the ingredients in the specific product dispensed
Your pharmacist can tell you all of the ingredients in the specific memantine products they stock.
What should I know about memantine before using it?
Do not take memantine unless it has been prescribed to you by a healthcare provider. Take it as prescribed.
Do not share memantine with other people, even if they have the same condition as you. It may harm them.
Keep memantine out of the reach of children.
Do not take memantine if the medicine is damaged or shows signs of tampering.
Memantine can affect your alertness or coordination. Do not drive or do other activities that require alertness or coordination until you know how memantine affects you.
Extended-Release Oral Capsules. Do not chew, cut, or crush memantine extended-release oral capsules. Swallow memantine extended-release oral capsules whole. If you cannot swallow the capsules whole, they may be opened and sprinkled on applesauce, making sure to swallow the entire contents of the capsule.
Oral Solution. Do not mix memantine oral solution with any other liquid. Use the syringe that comes with your medicine to draw up your dose, then slowly squirt the medicine into the corner of your mouth. A household spoon is not an accurate measuring device and may cause you to take the wrong dose. A patient instruction sheet is enclosed in your medicine container to show you how to use the oral syringe.
What should I tell my healthcare provider before using memantine?
Tell your healthcare provider about all of your health conditions and any prescription or over-the-counter (OTC) medicines, vitamins/minerals, herbal products, and other supplements you are using. This will help them determine if memantine is right for you.
In particular, make sure that you discuss any of the following.
Seizures. Memantine should be used with caution in people who have seizures. Tell your healthcare provider if you have seizures, or if you have had seizures in the past.
Bladder or Urine Problems. Memantine should be used with caution in people who have or have had bladder problems or problems passing urine. Tell your healthcare provider if you have had urinary tract infections. Tell your healthcare provider if you recently changed your diet, because it may affect your urine.
Kidney Problems. Memantine should be used with caution if your kidneys are not working as well as they should be. If there is a concern about the health of your kidneys, your healthcare provider may do tests to determine if you need a different dose of memantine.
Liver Problems. Memantine should be used with caution if your liver is not working as well as it should be. If there is a concern about the health of your liver, your healthcare provider may do tests to determine if it is working well enough to take this medicine.
Other Medicines and Supplements. Memantine may interact with other medicines and supplements. Before using memantine, tell your healthcare provider about any prescription or over-the-counter (OTC) medicines, vitamins/minerals, herbal products, and other supplements you are using. See the Interactions section for more details.
Pregnancy. It is not known if or how memantine could affect pregnancy or harm an unborn baby. Tell your healthcare provider if you are or plan to become pregnant.
Breastfeeding. It is not known if memantine passes into breast milk. Tell your healthcare provider if you are breastfeeding or plan to breastfeed. Your healthcare provider will advise you if you should take memantine while breastfeeding.
Interactions
Does memantine interact with foods or drinks?
There are no known interactions between memantine and foods or drinks.
It is unknown if drinking alcohol will affect memantine. The risk of dizziness or confusion may be increased if you drink alcohol while taking memantine.
Does memantine interact with other medicines (drug interactions)?
Always tell your healthcare provider about any prescription or over-the-counter (OTC) medicines, vitamins/minerals, herbal products, and other supplements you are using.
In particular, make sure that you discuss if you are using any of the following before taking memantine.
- Certain antacids that contain sodium bicarbonate
- A carbonic anhydrase inhibitor, such as zonisamide (Zonegran), acetazolamide (Diamox), or methazolamide
- Any other medicine known as an NMDA antagonist, such as amantadine (Symmetrel and others, which may be used for flu and Parkinson’s disease), ketamine (Ketalar or Spravato, which may be used for depression or anesthesia), and dextromethorphan (Delsym and others, which are commonly used for cough)
This may not be a complete list of medicines that can interact with memantine. Always check with your healthcare provider.
Overdose/Missed Dose
What should I do if I accidentally use too much memantine?
If you or someone else has used too much memantine, get medical help right away, call 911, or contact a Poison Control center at 800-222-1222.
What should I do if I miss a dose of memantine?
If you miss a dose, take it as soon as you remember. If it is almost time for your next dose, skip the missed dose and only take the next dose. Do not take double or extra doses. If you miss several days, tell your healthcare provider before restarting your medicine. Your healthcare provider may need to change your dose.
Are you currently using Memantine (Namenda)?
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