Leflunomide: friend or foe for systemic lupus erythematosus?

Leflunomide is a new immunosuppressive medicine that has been effectively used in the therapy of rheumatoid arthritis and subsequently used with success in animal models and patients with systemic lupus erythematosus (SLE). However, its use has also been associated with significant and serious adverse reactions involving hematological, hepatic, immune, dermatological and respiratory systems. In the current review, we attempt to describe the two sides of this drug in the treatment of SLE.