Eur J Clin Pharmacol(1988) 33:571-575 European Journal of Clinical Pharmacology © Springer-Verlag 1988 Reduction by Cimetropium Bromide of the Colonic Motor Response to Eating in Patients with the Irritable Bowel Syndrome G. A. Lanfranchi ~, G. Bazzocchi 1, M. CampierP, C. Brignola 1, F. Fois 1, and B. E Imbimbo 2 1 lstituto di Clinica Medica e Gastroenterologia,Universit& di Bologna,Bolognaand 2Medical Department, Istituto De AngeliS.p.A., Milano, Italy Summary. Cimetropium bromide is an antimuscar- inic compound with antispasmodic properties. Its effect on meal-stimulated sigmoid motor activity in 30 patients with the irritable bowel syndrome, main- ly with pain and constipation, has been evaluated. The mechanical activity of the sigmoid colon was recorded with a probe with three open-tipped tubes ending 45, 30, and 15 cm from the anal mar- gin. After a recording period of 60 min, 5 mg cime- tropium bromide or saline was given i.v., according to a randomized, double-blind design 5 rain before a 1000 calorie meal, and motility was then recorded for 2 h. The meal caused a significant increase in motor activity for 90 rain in the saline-treated group. Cimetropium bromide abolished the peak of motor activity 10-20 rain after the meal and significantly inhibited postprandial colonic motility for at least 2 h (p< 0.01). This effect provides a rationale for the use of cimetropium bromide in treatment of the irritable bowel syndrome. Key words: cimetropium bromide; colonic motility, anticholinergics The irritable bowel syndrome (IBS) is a clinical dis- order characterized by abdominal pain and alter- ation in bowel habits, not due to organic, infectious or parasitic disease. The symptoms of patients with IBS are believed to be caused by colonic motor dys- function [1-5]. Eating is the most important physio- logical stimulus of colonic motility [1, 6, 7] and IBS symptoms are often related temporally to meals [1, 4, 5]. In IBS patients eating produces an abnormal gastrocolic response, which is either larger or more prolonged than in healthy subjects [1, 3, 8, 9]. There is evidence that the food-stimulated hypermotility and distension of the colon are associated with the onset of the typical symptoms [1, 2, 10]. For these reasons anticholinergic agents are widely used in the treatment of IBS. Cimetropium bromide (scopolamine N-cyclo- propylmethyl bromide) is a quaternary ammonium compound, chemically related to hyoscine butylbro- mide. Its antispasmodic activity is due to competi- tion with acetylcholine for the muscarinic receptors of the smooth muscle of the gastrointestinal tract [11]. The drug has been used in several disorders in which there is spasm of the musculature of the gas- trointestinal, biliary and genito-urinary tracts [12-151. The aim of the present study was to investigate whether cimetropium bromide could inhibit stimu- lated motor activity in the sigmoid colon in patients with symptomatic IBS. The stimulus chosen was a standard meal, which has a reliable and reproduc- ible effect on colonic motor activity. Only a sub- group of patients with IBS was involved in the study, namely those with "spastic constipation". In those constipated patients it has previously been shown that the gastrointestinal transit time is not prolonged [16] and, in comparison with that in sub- jects with slow transit constipation, basal and food- induced sigmoid motor activity are more marked [17]. Material and Methods Colonic motility was examined in 30 patients with IBS who complained of constipation and abdomi- nal pain. The diagnosis was made on the basis of