Leflunomide
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Taken as a tablet once a day, with or without food, at the same time each day. It stays in the body a long time, so if you have a serious side effect or plan a pregnancy, a special washout medicine is used to clear it quickly.
- Rheumatoid arthritis and psoriatic arthritis: Usually 20 mg once a day. A higher loading dose for the first 3 days is optional and often skipped.
Tests while you take it
You will have regular blood tests for your liver and blood counts, at least monthly for the first 6 months, then periodically. Effective contraception is essential.
What to know
Common side effects
The most common effects are loose stools or diarrhoea, feeling sick, some hair thinning, and a rise in blood pressure. It can also affect the liver, which is why blood tests are done.
Tests and monitoring
You will have blood tests to check your liver, blood counts, and kidney function, before you start and then during treatment. They are more frequent in the first few months (about every 2 to 4 weeks) and usually about every 3 months once your dose is steady. Your blood pressure is also checked. If you have risk factors, your team may test for hepatitis B and C before you start.
Important cautions
Leflunomide stays in the body for a long time. It is stopped, and a special washout may be needed, before pregnancy, for both women and men planning a baby, so reliable contraception is important. Keeping alcohol low is advised because both affect the liver. Reproductive-health guidance is covered separately.
What to watch for
- Signs of infection with a fever.
- Yellowing of the skin or eyes, or severe or ongoing diarrhoea.
- A new cough or breathlessness, which is uncommon but should be checked.