Prospective, randomized, double-blind comparison of benzalazine and sulfasalazine in the treatment of active ulcerative colitis

Abstract

Benzalazine (salicylazobenzoic acid, SAB), a 5-azo derivative of 5-aminosalicylic acid, has been designed as a new therapeutic agent for the treatment of inflammatory bowel disease which might lack the frequent side effects caused by the sulfapyridine moiety of the sulfasalazine molecule (SASP). Here, we report on a prospective, randomized, double-blind comparison of SAB and SASP in patients with an acute relapse of ulcerative colitis. 43 patients with an acute relapse of ulcerative colitis proven by the pertinent endoscopic-macroscopic and histologic criteria were randomized to receive a 6-week course of either 1 g SASP (n = 21) or the equivalent dose of 0.72 g SAB (n = 22) three times a day. Both groups were comparable with respect to demographic data, previous duration and extension of the disease as well as clinical, endoscopic and histologic severity of the relapse. 1 patient on SASP had to be removed from the study due to side effects, while 3 patients on SAB were removed due to rapid worsening of the disease requiring either surgery (1 patient with toxic megacolon) or additional steroid treatment (2 patients). 2 SAB patients were lost to follow-up after substantial improvement had been observed within the first 3 weeks of treatment. In the remaining patients (20 SASP, 17 SAB), stool frequency, stool consistency and macroscopic appearance as well as histology of the diseased mucosa were improved within 6 weeks, with no significant difference between the two groups with respect to any of the parameters recorded. Side effects were recorded in 5 patients on SASP (3 with nausea, 1 with pruritus and 1 with a generalized exanthema) and in 3 patients on SAB (all nausea and vomiting; difference not statistically significant). We conclude that SAB and SASP in equivalent doses are of similar efficacy in the treatment of active ulcerative colitis.