Background: Cisapride improves symptoms in patients with idiopathic constipation. This trial compares the effect of cisapride with that of placebo in patients with irritable bowel syndrome (IBS) and constipation.
Methods: Seventy patients were randomized to 12 weeks' treatment with 5 mg cisapride three times daily or placebo in a double-blind trial. The dose could be doubled after 4 weeks in patients without satisfactory improvement. The patients scored their symptoms on a 100-mm visual analogue scale (VAS) (0 = best, 100 = worst), and the investigators evaluated the symptomatic effect.
Results: The dose was doubled in 17 and 23 patients in the cisapride and placebo groups, respectively, after 4 weeks. The patients' mean VAS score for global evaluation of IBS symptoms in the cisapride and placebo groups was 73 and 71 mm, respectively, at the start of treatment and 47 and 41 mm at the end. The difference between cisapride and placebo at the end was 6 mm in favour of placebo (95% confidence interval (CI), -6, 18) (NS). The investigators evaluated the effect as good or excellent in 39.2% and 58.8% in the cisapride and placebo groups, respectively. The difference in favour of placebo was 19.5% (95% CI, -5, 44) (NS). Nor were any statistically significant differences seen between cisapride and placebo in the other effect factors.
Conclusions: The trial seems to exclude a clinically significant effect of 15-30 mg cisapride daily in patients with IBS and constipation during a 12-week treatment period.