A Case of Interstitial Pneumonitis in a Patient with Rheumatoid Arthritis Treated with Leflunomide

Abstract

Leflunomide, a disease-modifying antirheumatic drug (DMARD) for the treatment of rheumatoid arthritis has been available in Korea since 2003. Leflunomide-associated interstitial pneumonitis has been appearing recently. A 25-year-old woman with a 12-month history of seronegative rheumatoid arthritis (RA) presented with acute respiratory insufficiency. She developed fever, dyspnea, and non-productive cough. Her medication history included methotrexate (15 mg/week. commencing 1 year prior) and leflunomide (20 mg/day, no loading dose, commencing 4 months prior). She was diagnosed with leflunomide-associated interstitial pneumonitis based on history, physical examination, laboratory and radiologic findings. She recovered quickly after leflunomide was withdrawn and steroids and cholestyramine were initiated quickly. We report a case of leflunomide-associated interstitial pneumonitis treated successfully with intravenous high-dose steroid and cholestyramine.Key Words: Leflunomide, Interstitial lung diseases, Rheumatoid arthritis