A Double-blind, Placebo-controlled, Randomized Study to Evaluate the Efficacy, Safety and Tolerability of Tegaserod in Patients with Irritable Bowel Syndrome

Background: Tegaserod has been shown to be an effective therapy for the multiple symptoms of irritable bowel syndrome (IBS) in Western and Asia-Pacific populations. This study evaluated the efficacy, safety and tolerability of tegaserod versus placebo in patients with IBS.

Methods: Patients with IBS (excluding those whose primary bowel symptom was diarrhoea) were randomized to receive either tegaserod 6 mg b.i.d. (n = 327) or placebo (n = 320) for a 12-week double-blind treatment period. The primary efficacy variable (over weeks 1 to 4) was the response to the question: 'Over the past week do you consider that you have had satisfactory relief from your IBS symptoms?' Secondary efficacy variables assessed overall satisfactory relief over 12 weeks and the individual IBS symptoms.

Results: Overall satisfactory relief was greater in the tegaserod group than in the placebo group. Over weeks I to 4, the odds ratio was 1.54, that is, the odds of satisfactory relief were 54% higher in the tegaserod group than in the placebo group (95% confidence interval for odds ratio (CI) (1.14, 2.08), P = 0.0049). Over weeks 1 to 12, the odds ratio was 1.78, that is, the odds of satisfactory relief were 78% higher in the tegaserod group than in the placebo group (95% CI (1.35, 2.34), P < 0.0001). A statistically significant therapeutic gain over placebo was observed for the majority of weeks from week 1 to week 12 (except weeks I and 4), with a mean therapeutic gain of 7.3 and 10.6 percentage points over weeks 1-4 and weeks 1-12, respectively. Headache was the most commonly reported adverse event (8.0% tegaserod versus 4.7% placebo). Diarrhoea was reported by 9.2% of patients on tegaserod (1.3% on placebo) and led to discontinuation in 2.8% of tegaserod patients.

Conclusion: Tegaserod 6 mg b.i.d. is an effective, safe and well-tolerated treatment in patients suffering from IBS without diarrhoea as primary bowel symptom.