Identification of Patients with Non-D, Non-C Irritable Bowel Syndrome and Treatment with Renzapride: An Exploratory, Multicenter, Randomized, Double-Blind, Placebo-Controlled Clinical Trial

This was an exploratory study of renzapride in 168 male and female patients with non-D, non-C irritable bowel syndrome (IBS). Patients were randomized to placebo or renzapride (1, 2, or 4 mg/day) for 8 weeks. The primary efficacy variable was patient-reported satisfactory relief of IBS symptoms. Secondary variables included relief of abdominal pain/discomfort. The proportion of patients reporting satisfactory relief of their IBS symptoms for at least 50% of the time did not differ significantly from those on placebo. However, post hoc analysis in women showed differences in responder rate on renzapride versus placebo of 18.2% (95% CI -5% to 42%; P = 0.066) during weeks 1-4 and 6% (95% CI -21% to 33%; P = 0.339) during weeks 5-8. Renzapride was well tolerated and most adverse events were mild to moderate in intensity. Further studies are warranted to determine whether renzapride is beneficial in this patient population.