Donepezil

What it is used for

• Mild to moderate dementia caused by Alzheimer's disease
• Severe Alzheimer's disease

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 dementia in Parkinson's disease

How it works

Donepezil stops an enzyme breaking down acetylcholine, a chemical messenger in the brain that is important for memory and learning. Higher levels can help nerve cells communicate better.

Side effects

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

Common side effects

• feeling sick
• diarrhoea
• trouble sleeping or vivid dreams
• muscle cramps
• headache
• feeling tired
• loss of appetite

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:

• a slow heartbeat, fainting or dizziness
• black or bloody poo, or vomiting blood
• fits

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

• It is usually taken at night. If it causes vivid dreams, taking it in the morning may help.
• Tell the doctor if the person has heart rhythm problems, asthma or stomach ulcers.

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.