Effects of alosetron on gastrointestinal transit time and rectal sensation in patients with irritable bowel syndrome

Aliment Pharmacol Ther. 2000 Jul;14(7):869-78. doi: 10.1046/j.1365-2036.2000.00786.x.


Background: Alosetron, a 5-HT3-receptor antagonist, relieves abdominal pain and improves bowel function in non-constipated, female patients with irritable bowel syndrome. 5-HT3 antagonists delay colonic transit, increase colonic compliance, and increase small intestinal water absorption.

Aim: To evaluate the effects of alosetron on gastrointestinal and colonic transit, rectal compliance and rectal sensation in irritable bowel syndrome.

Methods: A double-blind, placebo-controlled, two-dose study of alosetron was performed in 25 non-constipated irritable bowel syndrome patients, with paired studies before and after 4 weeks of treatment with placebo (n=5), 1 mg alosetron (n=10) or 4 mg (n=10) alosetron b.d. Gastrointestinal and colonic transit were measured by scintigraphy. Rectal compliance and sensation were assessed by rectal balloon distention with a barostat.

Results: There was a trend (P=0.06) for 1 mg alosetron to increase rectal compliance (median pressure at half maximum volume 11 mmHg after alosetron vs. 15.6 mmHg before alosetron). The 1 mg b.d. alosetron dose non-significantly retarded proximal colonic transit. Alosetron and placebo reduced sensory scores relative to baseline values; none of the changes induced by alosetron was significant relative to placebo.

Conclusions: Alosetron had no significant effect on gastrointestinal transit or rectal sensory and motor mechanisms in non-constipated irritable bowel syndrome patients in this study. Alosetron's effects on colonic sensorimotor function and central sensory mechanisms deserve further evaluation.

Publication types

  • Clinical Trial
  • Randomized Controlled Trial
  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Adult
  • Aged
  • Carbolines / adverse effects
  • Carbolines / pharmacology
  • Carbolines / therapeutic use*
  • Colonic Diseases, Functional / drug therapy*
  • Colonic Diseases, Functional / physiopathology
  • Double-Blind Method
  • Female
  • Gastrointestinal Transit / drug effects*
  • Humans
  • Male
  • Middle Aged
  • Psychomotor Performance / drug effects
  • Rectum / drug effects
  • Rectum / physiology
  • Serotonin Antagonists / adverse effects
  • Serotonin Antagonists / pharmacology
  • Serotonin Antagonists / therapeutic use


  • Carbolines
  • Serotonin Antagonists
  • alosetron