Leflunomide는 항류마티스 약제로 최근 류마티스 관절염 치료에 효과적으로 사용되고 있다. 최근 본 약제로 인한 간질성 폐렴이 일본과 한국에서 서구에서보다 많이 보고되고 있으며 종종 사망하는 경우도 보고되고 있다. 저자들은 25세 여자에서 Methotrexate와 Leflunomide의 병합요법 중 발생한 간질성 폐렴을 진단하였고 Methylprednisolone과 Cholestyramine을 조기 투여하여 효과적으로 치료하였기에 문헌 고찰과 함께 보고하는 바이다.

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 She recovered quickly after leflunomide was withdrawn and steroids and cholestyramine were initiated quickly.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.