What it is used for

Parkinson's disease, alongside levodopa, when the effect of each dose wears off too early

Read our guides:

Parkinson's disease

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.

Entacapone is not commonly used off-label.

How it works

Entacapone blocks an enzyme called COMT that breaks down levodopa in the body. More levodopa reaches the brain and it lasts longer, which reduces the "wearing off" between doses.

Side effects

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

Common side effects

harmless reddish brown pee
feeling sick
diarrhoea
uncontrolled movements (dyskinesia)
dizziness
trouble sleeping

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:

severe or long-lasting diarrhoea
seeing or hearing things that are not there, or confusion
high temperature, stiff muscles and confusion
urges you cannot control, such as gambling, shopping or eating

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 always taken at the same time as each levodopa dose.
It can make you suddenly fall asleep. Do not drive if this happens.

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.