Severe pancytopenia after leflunomide in rheumatoid arthritis

Leflunomide is a novel drug recently introduced for treatment of rheumatoid arthritis as a DMARD (disease-modifying antirheumatic drug). So far, leflunomide has not been associated with severe bone marrow toxicity and pancytopenia. We report of a 62-year-old woman with a 14-year history of rheumatoid arthritis with bone marrow toxicity and reversible pancytopenia developing after treatment with leflunomide.