Leflunomide was initially developed for use in the treatment of cancer and has been used successfully in rheumatoid arthritis for which it has been approved. Leflunomide was only recently studied in psoriatic arthritis, and prove to be efficacious. In fact, it works very well for about 40% of the patients who are prescribed it. Although it is still not indicated for psoriatic arthritis in North America, it has recently been approved in Europe.

Mechanism of action

Leflunomide is an anti-T cell medication and as such is thought to control inflammation by interfering with T cell production of cytokines.

Mode of administration

Leflunomide is given as one table (20mg per day). It usually takes 8-12 weeks for the effect of leflunomide to be observed. One requires to continue administration to maintain disease control.

Side effects

The most common side effect of leflunomide is diarrhea. If it is severe the medication must be stopped. It may cause liver toxicity, and it may affect the bone marrow. It also may cause hair loss. Hypertension is also a possible side effect of leflunomide. If there are serious side effects from leflunomide cholestyramine is given to facilitate its removal from the body. Blood tests, including liver and kidney function tests should be performed routinely in people taking leflunomide.

Use in pregnancy

Leflunomide is contraindicated in pregnancy. It is recommended that both men and women be off leflunomide for several months before conception.