A DOUBLE-BLIND PLACEBO-CONTROLLED TRIAL WITH LOPERAMIDE IN IRRITABLE-BOWEL-SYNDROME

Background: Loperamide has a relaxing effect on localized and segmenta l large-bowel spasms. On the basis of previously observed effects on p ain and stool habits in patients with diarrhoea, the present trial int ended to examine the regulating effect in an unselected cohort of pati ents with the irritable bowel syndrome (IBS). The symptoms in IBS are dependent on variations in motility initiated by different mechanisms. Therefore, when examining the effect of treatment, characterization o f the patient material is important. Methods: Ninety patients were inc luded in this prospective double-blind trial comparing loperamide with placebo over 5 weeks. The two groups were characterized and compared with healthy controls (n = 33), matched by age and sex. Demographic, c linical, and biochemical data were recorded. Results: Clinical variabl es and social and personal relationships were similar for the loperami de group (n = 35), the placebo group (n = 34), the dropouts (n = 21), and the controls. Somatic diseases and mental disturbances were increa sed in the patients compared with the controls. Throughout the 5 weeks of treatment an improved stool consistency (32%) reduced defecation f requency (36%), and reduced intensity of pain (30%) were found in the loperamide group. An increase in nightly pain was observed in the lope ramide group. Conclusions: This trial lends support to a multifactoria l aetiology in IBS. Treatment must be individualized with regard to bo th the effect and the risk of constipation and abdominal pain. The tri al shows a benefit of loperamide in an unselected cohort of IBS patien ts with regard to stool frequency, stool consistency, and the overall pain intensity, but with increased abdominal pain during the night. It should be recommended that the patients take the medication in divide d daily doses.