Comparison of sulfasalazine and placebo in the treatment of psoriatic arthritis

Objective. To determine whether sulfasalazine (SSZ) at a dosage of 2,000 mg/day is effective for the treatment of active psoriatic arthritis (PsA) resistant to nonsteroidal antiinflammatory drug therapy. Methods. Two hundred twenty-one patients with PsA were recruited from 15 clinics, randomized (double-blind) to SSZ or placebo treatment, and followed up for 36 weeks. Treatment response was based on joint pain/ tenderness and swelling scores and physician and patient global assessments. Results. Longitudinal analysis revealed a trend favoring SSZ treatment (P = 0.13). At the end of treatment, response rates were 57.8% for SSZ compared with 44.6% for placebo (P = 0.05). The Westergren erythrocyte sedimentation rate declined more in the PsA patients taking SSZ than in those taking placebo (P < 0.0001). Adverse reactions were fewer than expected and were mainly due to nonspecific gastrointestinal complaints, including dyspepsia, nausea, vomiting, and diarrhea. Conclusion. SSZ at a dosage of 2,000 mg/day is well tolerated and may be more effective than placebo in the treatment of patients with PsA.