Sulphasalazine in ankylosing spondylitis: a prospective, randomized, double-blind, placebo-controlled study and meta-analysis of other controlled studies

Objective To assess the efficacy and tolerability of sulfasalazine in ankylosing spondylitis including a meta-analysis of comparable trials. Methods In a prospective, randomized, double-blind, placebo-controlled trial 70 patients with established diagnosis of ankylosing spondylitis and a mean disease duration of 16.7 years were investigated in two centers for 26 weeks comparing 3 g/d sulfasalazine to placebo. Results The main outcome parameters, pain score, fingers-to-floor test, and CRP, did not improve significantly in the sulfasalazine group compared to the placebo group. Altogether sulfasalazine was significantly superior to placebo only concerning the IgA levels. The dropout rate was 47% for the sulfasalazine group and 19% for the placebo group. Due to side effects, 38% and 11%, respectively, stopped treatment. Ten other prospective, double-blind, controlled studies were analyzed. Altogether 959 patients with a mean disease duration of 13.9 years were evaluated. Most parameters did not improve significantly in the sulfasalazine groups compared to the placebo groups. Spinal motility remained nearly unchanged (0.3-3.5% improvement). Pain, morning stiffness, functional index, and global assessment were slightly influenced (1.9-11.7%). Reduction of ESR, CRP, IgA, IgG, and IgM was more distinct (12.6-20.3%). In 4 studies SSZ had greater efficacy in patients with peripheral joint involvement. Conclusion Sulfasalazine has no clinically relevant benefit in patients with ankylosing spondylitis. The dropout-rate due to adverse effects is high with a daily dose of 3 g. Sulfasalazine may be beneficial in peripheral joint involvement. Only few data exist about patients with a disease duration of less than 10 years.