The therapeutic effect of methyl-salazosulphapyridine versus salazosulphapyridine in active ulcerative colitis. A double-blind controlled trial.

In an attempt to improve the ratio between therapeutic effect and side effects of salazosulphapyridine (SASP), methyl-salazosulphapyridine (methyl-SASP) was compared with SASP in a randomized controlled double-blind trial, without cross-over, in patients with active ulcerative colitis. The patient group comprised 53 patients. The daily doses were 1 g SASP x 3 and 125 mg methyl-SASP x 3. The methyl-SASP group comprised 26 patients, the SASP group 27 patients. The treatment period was 4 weeks. Applying clinical symptoms (bowel movements, registered by the patients on special charts), clinical condition (assessed by the patient), proctoscopic signs, and registration of side effects, it is concluded that methyl-SASP had an effect on ulcerative colitis indistinguishable from that of SASP. The rate of side effects was significantly less in the methyl-SASP group. The blood concentrations of SASP, methyl-SASP, sulphapyridine, and methyl-sulphapyridine were estimated at start during, and at the end of the trial. The methyl-SASP concentration was on an average twice as high as that of SASP, and the methyl-sulphapyridine on an average 1/13 of sulphapyridine, the differences being significant. It is concluded that methyl-SASP presents an improvement in the effect/side effect ratio when dealing with symptomatic ulcerative colitis. The discrepancy between the outcome of the present trial and the lack of effect in a controlled trial on the relapse-preventing effect of methyl-SASP is at present unexplained. A type II error in the present trial (or a type I error in the prophylactic one) is a possibility, or the patient-group selected for the present trial had a spontaneously benign course, cases demanding prednisone or colectomy having been excluded.