Octylonium bromide plus diazepam versus diazepam or octylonium bromide alone in the treatment of irritable bowel syndrome. An open controlled clinical trial

The authors report the results obtained in 121 patients with irritable bowel syndrome (IBS) associated with habitual anxiety. Patients were divided into three groups treated with octylonium bromide 40 mg plus diazepam 2 mg (OB + D, three tablets/day), octylonium bromide 40 mg (OB, three tablets/day), or diazepam 2 mg (D, three tablets/day), respectively. In each group, treatment was continued for 3 months and was preceded by a 15-day washout with placebo. Efficacy of treatment in controlling abdominal pain symptoms and gas distension was evaluated by means of a visual analogue scale (VAS) and a visual rating scale (VRS). The OB + D combination proved effective in most treated patients, and a statistically significant difference was found (P < 0.001) between this treatment and treatment with D alone in reducing abdominal pain intensity (87.2% mean reduction of VAS and VRS scores) and in reducing gas distension (60.3% mean reduction of VAS and VRS scores). Comparison between the combination and OB alone showed a significant difference only in reduction of abdominal pain (P < 0.001). The anxiety symptoms associated with IBS were assessed using Zung's self-rating anxiety scale and were found to be reduced in all three patient groups after 90 days' treatment, although the reductions were more marked in patients treated with the OB + D combination and with D alone.