We are using cookies to give you the best experience on our site. Cookies are files stored in your browser and are used by most websites to help personalise your web experience.

By continuing to use our website without changing the settings, you are agreeing to our use of cookies.

Find out more
For more information, go to


Print page Open all Reset all

What is leflunomide and why is it prescribed?

Leflunomide is a type of disease-modifying anti-rheumatic drug (DMARD). It's also known by its trade name, Arava.

It's used to treat rheumatoid arthritis, psoriatic arthritis and other types of auto-immune disease.

It can reduce the inflammation that causes pain, swelling and stiffness.

Read more >

How do I take leflunomide and how long does it take to work?

Leflunomide is usually given as a 10 or 20 mg tablet once a day. It may be six weeks or more before you notice any benefit.

Read more >

What are the possible risks and side-effects of leflunomide?

The most common side-effects of leflunomide include nausea, diarrhoea and mouth ulcers.

You should stop leflunomide and see your doctor straight away if you have severe side-effects, if you haven’t had chickenpox and you come into contact with someone who has chickenpox or shingles or if you develop chickenpox or shingles.

Leflunomide can also affect your liver and make you more likely to develop infections. Tell your doctor or rheumatology nurse specialist straight away if you develop any symptoms of infection.

Read more >

Can leflunomide affect other medicines and treatments?

You may be prescribed leflunomide alongside other drugs. Discuss any new medications with your doctor because some drugs interact with leflunomide.

Always tell any other doctor treating you that you’re on leflunomide.

If you're on leflunomide it's generally recommended that you don't have live vaccines. Pneumovax and yearly flu vaccines are safe and recommended.

You may be advised to stop taking leflunomide if you're going to have an operation.

Read more >

Can I drink alcohol while I'm on leflunomide?

Leflunomide and alcohol may interact and damage your liver. If you drink alcohol you should drink no more than 4–8 units per week.

Read more >

Does leflunomide affect fertility, pregnancy or breastfeeding?

We don’t yet know the risks of leflunomide to an unborn baby. To be on the safe side, both men and women taking leflunomide are advised to use contraception.

If you’re planning to have a baby, you may be advised to have wash-out treatment to help remove the leflunomide from your body before trying for a baby.

Breastfeeding isn’t recommended if you’re on leflunomide because it may pass into your breast milk.

Read more >

What is a wash-out treatment and why might I need it?

Because leflunomide can remain in your body for a long time, in some situations you may be advised to have a wash-out treatment to remove it more quickly – for example, if you have side-effects, need to start another treatment or become pregnant.

Read more >
For more information, go to or call 0300 790 0400 to order the complete printed booklet.
Arthritis Research UK fund research into the cause, treatment and cure of arthritis. You can support Arthritis Research UK by volunteering, donating or visiting our shops.