Highlights for memantine

  1. Memantine oral tablet is available as a brand-name drug and a generic drug. Brand name: Namenda.
  2. Memantine comes in three forms: immediate-release tablet, oral solution, and extended-release capsule.
  3. Memantine oral tablet is used to treat moderate to severe dementia caused by Alzheimer’s disease.

Important warnings

  • Seizures warning: This drug may increase your risk of seizures. Tell your doctor if you’re taking any medications to treat seizures.
  • Kidney and liver problems warning: If you have or develop serious kidney or liver problems, your dose may need to be adjusted.

What is memantine?

Memantine is a prescription drug. It comes in three forms: immediate-release tablet, oral solution, and extended-release capsule.

Memantine oral tablet is available as the brand-name drug Namenda. It’s also available as a generic drug. Generic drugs usually cost less than the brand-name version. In some cases, they may not be available in every strength or form as the brand-name drug.

Memantine may be used as part of a combination therapy. That means you need to take it with other drugs to treat dementia associated with Alzheimer’s disease.

Why it's used

Memantine oral tablet is used to treat moderate to severe dementia in adults with Alzheimer’s disease.

How it works

Memantine belongs to a class of drugs called NMDA receptor antagonists. A class of drugs is a group of medications that work in a similar way. These drugs are often used to treat similar conditions.

The cause of Alzheimer’s disease isn’t fully understood. People with the disease may be overexposed to the chemical glutamate. This is thought to cause damage to the brain cells in people with Alzheimer’s disease.

Memantine works by blocking the receptors in the brain that glutamate would normally bind to. This decreases the harmful effect of glutamate in the brain and may help improve your symptoms of dementia.

Memantine side effects

Memantine oral tablet may cause drowsiness. It can also cause other side effects.

More common side effects

The more common side effects that can occur with memantine include:

  • dizziness
  • headache
  • confusion
  • diarrhea
  • vomiting
  • abdominal pain
  • constipation

If these effects are mild, they may go away within a few days or a couple of weeks. If they’re more severe or don’t go away, talk to your doctor or pharmacist.

Serious side effects

Call your doctor right away if you have serious side effects. Call 911 if your symptoms feel life-threatening or if you think you’re having a medical emergency. Serious side effects and their symptoms can include the following:

  • Allergic reaction. Symptoms can include:
    • swelling of your tongue, lips, or face
    • shortness of breath
    • skin rash
    • hives
  • Seizures or convulsions
  • Hepatitis (inflammation of the liver). Symptoms can include:
    • yellowing of your skin or the whites of your eyes
  • Pancreatitis (inflammation of the pancreas). Symptoms can include:
    • severe nausea
    • severe abdominal pain
  • Change in mental health. Symptoms can include:
    • hallucinations
    • thoughts of suicide
  • Congestive heart failure. Symptoms can include:
    • shortness of breath
    • swelling in your feet and ankles

Disclaimer: Our goal is to provide you with the most relevant and current information. However, because drugs affect each person differently, we cannot guarantee that this information includes all possible side effects. This information is not a substitute for medical advice. Always discuss possible side effects with a healthcare provider who knows your medical history.

Memantine may interact with other medications

Memantine oral tablet can interact with other medications, vitamins, or herbs you may be taking. An interaction is when a substance changes the way a drug works. This can be harmful or prevent the drug from working well.

To help avoid interactions, your doctor should manage all of your medications carefully. Be sure to tell your doctor about all medications, vitamins, or herbs you’re taking. To find out how this drug might interact with something else you’re taking, talk to your doctor or pharmacist.

Examples of drugs that can cause interactions with memantine are listed below.

Drugs used to treat glaucoma

Taking these drugs with memantine can increase the amount of memantine in your body. This can lead to more side effects. Examples of these drugs include:

  • acetazolamide
  • methazolamide

Sodium bicarbonate

This drug, which can be used to treat heartburn, can increase the amount of memantine in your body. This can lead to more side effects.

Parkinson’s disease medication

Amantadine works in a similar way to memantine. Taking them together may lead to increased side effects.

Anesthesia medication

Ketamine works in a similar way to memantine. Taking them together may lead to increased side effects.

Cough medication

Dextromethorphan works in a similar way to memantine. Taking them together may lead to increased side effects.

Disclaimer: Our goal is to provide you with the most relevant and current information. However, because drugs interact differently in each person, we cannot guarantee that this information includes all possible interactions. This information is not a substitute for medical advice. Always speak with your healthcare provider about possible interactions with all prescription drugs, vitamins, herbs and supplements, and over-the-counter drugs that you are taking.

Memantine warnings

This drug comes with several warnings.

Allergy warning

This drug can cause a severe allergic reaction. Symptoms may include:

  • itching
  • hives
  • rash
  • peeling or blistering skin
  • swelling of your tongue, lips, or face
  • trouble breathing

If you develop these symptoms, call 911 or go to the nearest emergency room.

Don’t take this drug again if you’ve ever had an allergic reaction to it. Taking it again could be fatal (cause death).

Warnings for people with certain health conditions

For people with kidney problems: If your kidneys aren’t working well, more of this drug may stay in your body longer. This puts you at greater risk of side effects. If you have severe kidney problems, your doctor may reduce your dosage of this drug.

For people with liver problems: Tell your doctor if you have a history of severe liver problems. If your liver isn’t working well, more of this drug may stay in your body longer. This puts you at greater risk for side effects.

For people with seizure disorders: This drug may increase your risk of having a seizure.

Warnings for other groups

For pregnant women: This drug is a pregnancy category B drug. That means two things:

  1. Studies of the drug in pregnant animals haven’t shown risk to the fetus.
  2. There aren’t enough studies done in pregnant women to show the drug poses a risk to the fetus.

Tell your doctor if you’re pregnant or plan to become pregnant. This drug should be used during pregnancy only if the potential benefit justifies the potential risk.

For women who are breastfeeding: It isn’t known if this drug passes through breast milk. If it does, it may cause serious effects in a breastfeeding child. Talk to your doctor if you’re currently taking this drug and you’re thinking about breastfeeding.

For seniors: Older adults may process this drug more slowly. A typical adult dosage may cause levels of the drug to be higher than normal in your body. You may need a lower dosage or a different dosing schedule.

For children: This drug hasn’t been studied in children. It shouldn’t be used in children younger than 18 years old.

How to take memantine

All possible dosages and forms may not be included here. Your dose, form, and how often you take it will depend on:

  • your age
  • the condition being treated
  • how severe your condition is
  • other medical conditions you have
  • how you react to the first dose

Drug forms and strengths

Generic: Memantine

  • Form: oral immediate-release tablet
  • Strengths: 5 mg, 10 mg

Brand: Namenda

  • Form: oral immediate-release tablet
  • Strengths: 5 mg, 10 mg

Dosage for Alzheimer’s disease

Adult dosage (ages 18 years and older)

  • Typical starting dosage: 5 mg taken once per day.
  • Dosage increases: Your doctor will likely increase your dosage to 5 mg twice per day or higher.
  • Maximum dosage: 20 mg per day.

Child dosage (ages 0–17 years)

This drug hasn’t been studied in children. It shouldn’t be used in children younger than 18 years old.

Special dosage considerations

For people with kidney problems: If you have severe kidney issues, your doctor may give you a lower dosage of memantine.

Disclaimer: Our goal is to provide you with the most relevant and current information. However, because drugs affect each person differently, we cannot guarantee that this list includes all possible dosages. This information is not a substitute for medical advice. Always speak with your doctor or pharmacist about dosages that are right for you.

Take as directed

Memantine oral tablet is used for long-term treatment. It comes with serious risks if you don't take it as prescribed.

If you take too much: If you take too much of this drug, you may be at higher risk of having side effects. These can include:

  • agitation
  • confusion
  • hallucinations
  • slowed heart rate
  • increased blood pressure
  • dizziness
  • unsteadiness
  • fainting
  • fatigue
  • weakness

If you think you’ve taken too much of this drug, call your doctor or local poison control center. If your symptoms are severe, call 911 or go to the nearest emergency room right away.

What to do if you miss a dose: If you miss your dose of this drug, skip that dose and take your next dose as scheduled. Never try to catch up by taking two doses at once. This could cause dangerous side effects.

How to tell if the drug is working: Your mental function should get better. Your ability to perform your simple, everyday tasks should improve.

This drug is not a cure

  • All people with Alzheimer’s disease get worse over time, even if they take medications to help treat it.

Important considerations for taking memantine

Keep these considerations in mind if your doctor prescribes memantine for you.

General

You can crush or cut the immediate-release tablet.

Storage

  • Keep this drug at a temperature between 59°F and 77°F (15°C and 25°C).
  • Don’t freeze this drug.
  • Keep this drug away from light and high temperature.
  • Don’t store this medication in moist or damp areas, such as bathrooms.

Refills

A prescription for this medication is refillable. You should not need a new prescription for this medication to be refilled. Your doctor will write the number of refills authorized on your prescription.

Travel

When traveling with your medication:

  • Always carry your medication with you. When flying, never put it into a checked bag. Keep it in your carry-on bag.
  • Don’t worry about airport X-ray machines. They can’t harm your medication.
  • You may need to show airport staff the pharmacy label for your medication. Always carry the original prescription-labeled container with you.
  • Don’t put this medication in your car’s glove compartment or leave it in the car. Be sure to avoid doing this when the weather is very hot or very cold.

Clinical monitoring

During your treatment with this drug, your doctor will monitor your cognitive function (how well your memory and thought processes function). They will also check your kidney and liver function.

Availability

Not every pharmacy stocks this drug. When filling your prescription, be sure to call ahead to make sure your pharmacy carries it.

Prior authorization

Many insurance companies require a prior authorization for this drug. This means your doctor will need to get approval from your insurance company before your insurance company will pay for the prescription.

Are there any alternatives?

There are other drugs available to treat your condition. Some may be better suited for you than others. Talk to your doctor about other drug options that may work for you.

Disclaimer: Healthline has made every effort to make certain that all information is factually correct, comprehensive, and up-to-date. However, this article should not be used as a substitute for the knowledge and expertise of a licensed healthcare professional. You should always consult your doctor or other healthcare professional before taking any medication. The drug information contained herein is subject to change and is not intended to cover all possible uses, directions, precautions, warnings, drug interactions, allergic reactions, or adverse effects. The absence of warnings or other information for a given drug does not indicate that the drug or drug combination is safe, effective, or appropriate for all patients or all specific uses.