Longterm treatment of irritable bowel syndrome with cimetropium bromide: a double blind placebo controlled clinical trial.

The aim of this study was to evaluate the efficacy of cimetropium bromide, a new antimuscarinic compound, in relieving symptoms of patients with irritable bowel syndrome over a three month period. Seventy consecutive outpatients were given cimetropium (50 mg tid) or placebo according to a double blind, randomised, parallel groups design. Symptoms were evaluated initially and at monthly intervals up to the end of the study period. One patient receiving placebo withdrew because of treatment failure. Pain score decreased by 40, 66, 85% in the cimetropium group, at the end of the first, second and third months respectively, compared with 26, 32 and 52% reductions among controls (p = 0.0005). At the end of treatment there was a 86% reduction in the number of abdominal pain episodes per day in the cimetropium group compared with 50% in the placebo group (p = 0.001). Constipation and diarrhoea scores decreased by 59 and 49% in the cimetropium treated patients, compared with 37 and 39% in controls, the differences between being not significant. At the end of the study 89% of the patients treated with cimetropium considered themselves as globally improved as opposed to 69% in the placebo group (p = 0.039). The corresponding 95% confidence intervals for the differences between the proportion of improved patients in the two groups were from 11% to 29%. Six patients taking cimetropium complained of slight dry mouth. The results of this study showed that cimetropium bromide is effective in relieving pain in patients with irritable bowel syndrome.