Tegaserod (HTF 919) stimulates gut motility in normal horses

REASONS FOR PERFORMING STUDY: It has been shown that the selective 5-HT4 receptor agonist tegaserod induces an increase in frequency and amplitude of contractions in isolated muscle preparations of equine ileum and pelvic flexure. OBJECTIVES: To investigate the effects of tegaserod on gut motility and transit of spheres in normal horses. METHODS: Six mature Freiberger horses were kept under standardised conditions. Effects of tegaserod (0.02 mg/kg bwt i.v. b.i.d. for 2 days) or vehicle on intestinal transit of barium-filled spheres, defaecation and gut sounds were studied in a cross-over design. Spheres were given via stomach tube prior to the first dosing of tegaserod or vehicle. Faeces were collected every 3 h and spheres eliminated were identified radiologically in the faeces. RESULTS: Tegaserod significantly accelerated the gastrointestinal (GI) transit time of spheres and increased the frequency of defaecation and scores of gut sounds compared to vehicle. The compound was well tolerated; no effects on behaviour, body temperature, heart rate, respiratory rate and clinical laboratory data were observed. CONCLUSIONS: Tegaserod efficaciously stimulated motility and accelerate GI transit in healthy horses. POTENTIAL RELEVANCE: Tegaserod may offer therapeutic potential in horses suffering from impaction or paralytic ileus.