Coated oral 5-aminosalicylic acid (Claversal) is equivalent to sulfasalazine for remission maintenance in ulcerative colitis. A double-blind study.

In a double-blind, single-center, 1-year prospective trial, we compared a pH-dependent Eudragit L-coated formulation of oral 5-aminosalicylic acid (5-ASA) (Claversal), 0.5 g b.i.d., and sulfasalazine (SASP), 1 g b.i.d., in the prophylactic treatment of quiescent ulcerative colitis. Forty-four patients received 5-ASA and 44 received SASP. Clinical, sigmoidoscopic, and histologic findings were assessed at 6 and 12 months. The two groups were comparable in all pretrial characteristics. No significant difference was observed in the relapse rate in the two groups either after 6 months [5-ASA 20.5%, SASP 27.5%, p = 0.32, 95% confidence interval (CI) 0.28 +/- 0.13] or after 12 months (5-ASA 38.4%, SASP 51%, p = 0.18, 95% CI 0.38 +/- 0.1). We conclude that (a) 5-ASA was as effective as SASP in maintaining remission of ulcerative colitis; (b) the relapse rate was, however, higher than expected in both groups; (c) the incidence of side effects was similar with both treatments.