ABSTRACT
This chapter discusses the pulmonary adverse effects of antirheumatic drugs as well as other selected non-cytotoxic medications. It focuses on interstitial pneumonitis which is by far the most common complication. Methotrexate (MTX) is an antimetabolite used in the treatment of many benign and malignant disorders. The underlying mechanism of MTX-induced pneumonitis is thought to be acute hypersensitivity reaction. The diagnosis of MTX-induced pneumonitis can be challenging because there are no pathognomonic findings and the disease may be difficult to separate from an infection. Since the patients are immunosuppressed it is important to consider opportunistic infections such as Pneumocystis jiroveci or viral pneumonia. D-penicillamine should be withdrawn in patients suspected of having penicillamine-induced pneumonitis. In some cases of persistent symptoms, corticosteroids can be used. Leflunomide is an immunomodulatory disease-modifying antirheumatic drug used in the treatment of rheumatoid arthritis. Gold therapy can cause interstitial pneumonitis, bronchiolitis obliterans and bronchiolitis obliterans organizing pneumonia.
