What is Leflunomide?

Leflunomide is a medication that is classed as a DMARD- a disease modifying anti-rheumatic drug. This means it acts on the disease itself to reduce the effects of the immune system.

The immune system causes inflammation that protects the body from infections and injury. In certain diseases however, the immune system is over active and this can target healthy tissues such as joints. This results in pain, swelling and tenderness and eventually permanent damage.

Leflunomide works to suppress the over activity of the immune system and prevent the inflammation from occurring, reducing the long-term risk of permanent joint damage.


What is Leflunomide used for?

Leflunomide like other DMARDs is used for a range of conditions in rheumatology. The most common conditions it is used in are rheumatoid arthritis and psoriatic arthritis.


How is it taken?

Leflunomide is a tablet that is taken daily. It is usually started at 10mg daily and then if needed it can be increased to 20mg daily. The tablets can be taken with or without food but should not be crushed.


Before you start leflunomide your bloods and chest x-ray will be checked in clinic to ensure that you do not have any underlying reason why you should not be taking it.


As leflunomide can affect the blood count, liver and kidneys, you will need blood monitoring whilst you are taking the medication. This will be carried out at 2 weeks, 4 weeks and 6 weeks after starting the tablets, then once a month for 3 months and then every 3 months for the time that you take the medication.


Leflunomide can take up to 12 weeks to have the full effects, therefore it is important to continue to take it.


An 8-week supply of medication will be provided from the hospital when you start on leflunomide. The initial monitoring of this will be carried out by the rheumatology nurse specialists and they will contact you via a phone call at 6-8 weeks to see how you are getting along. After 8 weeks, the prescribing and monitoring will be handed over to your GP.


Side effects

There are a few possible side effects that may occur when taking leflunomide, these are:



As the immune system is targeted by leflunomide, it is important to get your blood tests checked. Should you develop signs of infection, stop taking your leflunomide and speak to your GP as you may require antibiotics. Once you are feeling better and have completed any antibiotics you can restart taking your leflunomide.


In rare cases, leflunomide can cause a reaction in the lungs called pneumonitis. This can cause shortness of breath and a dry cough. If you get any symptoms, it is important to speak to your GP or rheumatology team as you may require a repeat chest X-ray or breathing tests.


Leflunomide can also affect the blood cell counts, liver and kidneys. If you notice any yellow discoloration to your skin or eyes, bruising and bleeding you should let your doctor know.


If toxicity of leflunomide is found, as it can remain in the body for a long time after stopping, you may need to take a course of medicine called cholestyramine to wash it out.


If you develop, or come into contact with anyone with shingles or chickenpox, you should speak to your doctor as you may need treatment and to stop taking your leflunomide temporarily.


Cautions of use 

Interactions with other medications

Contraindications with other conditions


During pregnancy and breastfeeding




Useful links

Versus Arthritis: http://www.versusarthritis.org