Tegaserod

Tegaserod is a serotonin (5-hydroxytryptamine; 5-HT) receptor partial agoni st which has been investigated for the treatment of irritable bowel syndrom e (IBS). Specifically, it binds with high affinity to human 5-HT4 receptors , thereby stimulating the release of neurotransmitters and the peristaltic reflex in vitro. Small bowel transit (increased colonic filling over 6 hours) was accelerate d in patients with constipation-predominant irritable bowel syndrome (IBS) receiving oral tegaserod 2 mg twice daily for 1 week compared with those re ceiving placebo. In addition, there was a mean 20% increase of proximal col onic emptying in these patients. Oral tegaserod 2 (p < 0.05) or 6 mg twice daily improved symptoms of abdomi nal discomfort, bloating and constipation (assessed using a Subjects' Globa l Assessment Scale) compared with placebo in patients with constipation-pre dominant IBS in a double-blind, dose-ranging study. The most frequent adverse events in patients with constipation-predominant IBS receiving oral tegaserod were transient diarrhoea and flatulence. No clinically relevant changes in blood pressure, pulse rate, QRS or QT(c) interval were reported with tegaserod doses of 25 to 100 mg.