What it is used for

Rheumatoid arthritis
Psoriatic arthritis

Read our guides:

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.

Leflunomide is not commonly used off-label.

How it works

Leflunomide blocks an enzyme that immune cells need to multiply. This reduces the immune attack on the joints, easing pain, swelling and joint damage.

Side effects

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

Common side effects

diarrhoea
feeling sick
raised blood pressure
hair thinning
rash
headache

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:

yellowing of the skin or eyes, or dark pee
signs of infection, such as a high temperature or sore throat
unusual bruising or bleeding
a new cough or breathlessness

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

You need regular blood tests and blood pressure checks.
Avoid pregnancy during treatment and until it has been washed out of the body. This applies to men planning to father a child too.
Limit alcohol.

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.