Memantine

NHS medicines information about memantine, including what it's used for, who can take it, how to take it and side effects.

What memantine is for

Memantine is used to treat moderate to severe Alzheimer’s disease. It does not cure the condition but can help with the symptoms.

Alzheimer’s disease damages your brain and causes dementia, which affects thinking and memory.

If you have Alzheimer’s disease, you may have too much of a chemical called glutamate in your brain. Too much glutamate can affect your brain cells and stop them working properly.

Memantine reduces the effects of having too much glutamate in your brain. It protects the brain cells by blocking glutamate.

How to take memantine

Memantine usually comes as tablets or liquid (oral solution) that you swallow. Some tablets are put on your tongue to dissolve (orodispersible).

Your doctor may prescribe a low dose to start with and increase it each week for a few weeks. This reduces the chances of side effects.

You should see your doctor regularly so they can check how well memantine is working. They may suggest you keep taking it for as long as it’s helping to improve your symptoms.

When taking memantine:

• take it once a day at the same time each day
• take it with or without food
• swallow tablets whole with a drink of water, or if you have orodispersible tablets let them dissolve on your tongue before swallowing – you can swallow them with or without water
• take the liquid with some water

Always check the packet or leaflet that comes with your medicine. Ask a pharmacist or doctor for advice if you're not sure how to take it or have any problems taking it.

If you miss a dose of memantine

If you miss a dose of memantine, skip the missed dose and take your next dose at the usual time.

Do not take 2 doses to make up for a missed dose.

If you take too much memantine

Taking an extra dose of memantine is unlikely to cause problems, but it's important to get medical advice if you take too much because it can sometimes be dangerous.

Side effects of memantine

Like all medicines, memantine can cause side effects, although not everyone gets them.

Common side effects

Common side effects of memantine include:

• headaches
• dizziness
• balance problems
• shortness of breath
• feeling sleepy
• constipation
• high blood pressure

Your doctor will tell you if you’re able to drive or use machinery.

If you feel dizzy or sleepy after taking memantine, do not drive, ride a bike or use machinery until you no longer have these symptoms.

More about side effects

These are not all the side effects of memantine.

For a full list, see the leaflet that came with your medicine, or search for your medicine leaflet on the electronic medicines compendium website.

You can report any side effects you get on the Yellow Card Scheme website

Who can and cannot take memantine

Most adults can take memantine. It's not usually recommended for children and young people under the age of 18.

Memantine is not suitable for everyone. For example, it may not be suitable if:

• you've had an allergic reaction or serious side effect from memantine
• you have epilepsy, or you’ve had seizures (fits) in the past
• you’ve had a heart attack, or you have heart failure or uncontrolled high blood pressure (hypertension)
• you have severe kidney problems, or you’ve had severe urinary tract infections (UTIs)

Before taking memantine, tell your doctor if you have any other medical conditions.

Breastfeeding and memantine

Tell your doctor if you're breastfeeding.

Memantine is not usually recommended when breastfeeding.

Pregnancy and memantine

Tell your doctor if you're pregnant or you get pregnant while taking memantine.

Memantine is not usually used in pregnancy because not enough is known about its safety. But a doctor may recommend it if the benefits outweigh the risks.

Taking memantine with other medicines, food and drink

There are some medicines, remedies and supplements that may not mix well with memantine.

These include:

• some medicines used to treat Parkinson’s disease, such as amantadine and apomorphine
• some medicines used to treat restless legs syndrome, such as ropinirole, pramipexole and rotigotine
• cabergoline, which is a medicine that is sometimes used to reduce high levels of a hormone called prolactin

Before taking memantine, tell your doctor if you're taking any other medicines, herbal remedies, vitamins or supplements.

Food, drink and alcohol with memantine

You can eat and drink as normal while taking memantine.

But tell your doctor if you want to make changes to your diet, such as changing to a vegetarian diet. Your dose of memantine may need to be changed.

Find out more about your medicine

To find out more about your medicine, you can:

• check the leaflet that comes with it
• search for your medicine leaflet on the electronic medicines compendium website
• speak to a pharmacist or doctor for advice