Hypersensitivity pneumonitis associated with leflunomide therapy.

Abstract

Disease progression in rheumatoid arthritis is controlled with disease modifying drugs, many of which have toxic side effects. Pulmonary side effects are common and this has resulted in the development of newer medications with less pulmonary toxicity. We observed that even these newer drugs can be associated with potentially very serious pulmonary toxicity, with hypersensitivity pneumonitis developing after the initiation of leflunomide therapy. We urge caution in the use of leflunomide in patients with pulmonary side effects from other drugs or who have underlying pulmonary disease.