Noncardiogenic pulmonary edema in low-dose oral methotrexate therapy

In the past two decades, low-dose methotrexate (MTX) has been widely used in the treatment of rheumatoid arthritis (RA). As adverse effects, various types of pulmonary toxicity have been reported with this therapy. We report a case of MTX-induced noncardiogenic pulmonary edema in a 35-year-old woman. MTX used in high dose for anti-cancer therapy is known to cause noncardiogenic pulmonary edema. However, there are no previous reports of noncardiogenic pulmonary edema caused by low-dose MTX therapy. This report suggests that patients receiving oral weekly, low-dose MTX may be at risk for the development of noncardiogenic pulmonary edema.