What it is used for

Moderate to severe dementia caused by Alzheimer's disease, on its own or with donepezil, galantamine or rivastigmine

Read our guides:

Dementia

Off-label uses

Doctors sometimes prescribe a medicine for a condition it is not officially licensed for. This is called off-label use. It is legal and common when there is good evidence it helps, and your doctor should explain why they are suggesting it.

Dementia with Lewy bodies, and agitation in dementia, under a specialist

How it works

In Alzheimer's disease, too much of a chemical messenger called glutamate can damage nerve cells. Memantine blocks NMDA receptors, which protects the cells from too much glutamate.

Side effects

Like all medicines, Memantine can cause side effects, although not everyone gets them. Many are mild and ease after the first few weeks.

Common side effects

headache
feeling dizzy or sleepy
constipation
high blood pressure
shortness of breath

Tell your doctor or pharmacist if these bother you or do not go away.

Serious side effects

These are rare. Call 111 or contact your doctor straight away if you get:

fits
seeing or hearing things that are not there, or sudden confusion
severe stomach pain

Call 999 if you have signs of a serious allergic reaction, such as swelling of your lips, mouth, throat or tongue, or trouble breathing.

You can report any side effect to the Yellow Card scheme, run by the medicines regulator.

Stopping and withdrawal

Important safety information

People with kidney problems may need a lower dose.

Questions about your medicine?

A pharmacist can answer questions about your medicines for free, without an appointment. You can also ask your GP for a medication review. Check if you can get free prescriptions.