Tegaserod,a 5-hydroxytryptamine type 4 receptor partial agonist,is devoid of electrocardiographic effects

OBJECTIVES: Certain GI prokinetic agents have been shown to affect cardiac repolarization, which may be associated with life-threatening arrhythmias. The selective 5-hydroxytryptamine type 4 receptor partial agonist tegaserod is a novel promotile agent developed for the treatment of functional motility disorders such as irritable bowel syndrome (IBS). The aim of the study was to investigate the cardiac safety profile of tegaserod through analysis of electrocardiographic data from clinical studies conducted in patients with IBS and a study conducted in healthy male subjects. METHODS: In three randomized, double blind, placebo-controlled, parallel group clinical studies, 2516 IBS patients with symptoms of abdominal pain and constipation received tegaserod 2 or 6 mg b.i.d. (n = 1679) or placebo (n = 837) for 12 wk. In an additional study, 36 healthy male subjects received iv. single doses of tegaserod (0.8 mg to 20 mg) or placebo. Standard 12-lead electrocardiograms were recorded at baseline and during treatment. Baseline values were compared with data collected during the treatment period. RESULTS: The proportion of patients with prolongation of the QTc interval was the same for placebo and tegaserod, as was the frequency of overall electrocardiographic abnormalities. No ventricular or supraventricular tachycardia was observed. Comparable electrocardiographic results were obtained during placebo and tegaserod treatment. In healthy volunteers, tegaserod at i.v. doses resulting in plasma concentrations up to 100 times those measured after therapeutic doses (6 mg b.i.d.) did not influence electrocardiographic parameters. CONCLUSIONS: Tegaserod is devoid of electrocardiographic effects and is not expected to adversely influence cardiac function. These data confirm preclinical findings.