Leflunomide-associated weight loss in rheumatoid arthritis

Objective. To determine the frequency of weight loss in patients treated with leflunomide for rheumatoid arthritis at an arthritis referral center. Methods. We queried 35 rheumatologists at the Robert Breck Brigham Arthritis Center to determine if weight loss had occurred as an adverse event in patients treated with leflunomide between November 1998 and January 2000. Five such patients were identified and their clinical course was reviewed. Results. Five of 70 patients who had begun leflunomide therapy had significant weight loss that could not be linked to other identifiable etiologies. The amount of weight loss was substantial in this group of patients, ranging from 19 pounds to 53 pounds. All patients had normal levels of thyroid-stimulating hormone and no other gastrointestinal complaints; evaluation revealed no other cause for the weight loss. Despite the significant weight loss, 4 of the 5 patients continued to take the drug due to its efficacy. Conclusion. Significant weight loss is a potential adverse event in patients with rheumatoid arthritis treated with leflunomide. Awareness of this may obviate the need for extensive medical evaluations.