Effect of tegaserod on gut transit in male and female subjects

Tegaserod is a novel selective serotonin receptor type-4 (5-HT(4)) partial agonist that stimulates gastrointestinal (GI) motility. Tegaserod has proven efficacy in irritable bowel syndrome with constipation in women and in men and women with chronic idiopathic constipation. The effects on gastric emptying, small bowel transit and colonic transit have not been studied in detail in male and female subjects. This study aimed therefore to assess the effect of gender on GI transit with and without tegaserod. A randomized, placebo-controlled, double-blind, crossover study was performed in 40 healthy subjects (23 males, 17 females). Each treatment period involved three and a half days of bid treatment with either 6 mg tegaserod or an identical placebo. Transit parameters were assessed by a scintigraphy. Tegaserod significantly accelerated gastric emptying, small bowel and colonic transit times (P<0.05-0.0001). The effect was more apparent in male subjects than in females (P=0.044 to P<0.0001). The most striking prokinetic effects were observed in the upper GI tract (stomach and small intestine). In both healthy male and female subjects, tegaserod markedly accelerated small intestinal transit, and induced a significant increase in gastric emptying time and colonic transit. The results imply that tegaserod is a potent prokinetic agent throughout the GI in both sexes.