Sulfasalazine in severe rheumatoid arthritis: a study to assess potential correlates of efficacy and toxicity.

Thirty-one patients with chronic active rheumatoid arthritis (RA) resistant to gold and/or penicillamine therapy, were treated with sulfasalazine, 2-3 g daily, in a 12-week open study. Nineteen patients completed the study, and of these, 13 showed clinical improvement. Twelve patients were withdrawn from the study because of nausea (8), mouth ulcers (1), disease flare (1) and noncompliance (2). There was no significant difference in serum sulfasalazine concentrations among responders, nonresponders and patients who were withdrawn. Our data suggest that sulfasalazine may be of benefit in the treatment of RA. Further studies are necessary to determine if toxicity and/or efficacy might be related to serum concentrations of sulfasalazine metabolites.