Improvement in pain and bowel function in female irritable bowel patients with alosetron, a 5-HT3 receptor antagonist

Aliment Pharmacol Ther. 1999 Sep;13(9):1149-59. doi: 10.1046/j.1365-2036.1999.00610.x.


Background: No currently available treatment provides consistent relief of irritable bowel syndrome. Colonic sensory and motor function are modulated partly through 5HT3-receptors.

Aim: To evaluate effects of the 5HT3-receptor antagonist, alosetron, in irritable bowel syndrome.

Methods: Randomized, double-blind, placebo-controlled, dose-ranging (1, 2, 4, 8 mg b.d. alosetron), 12-week trial in 370 patients with diarrhoea-predominant or alternating constipation and diarrhoea irritable bowel syndrome. Weekly measurement of adequate relief was the key end-point; other irritable bowel syndrome symptoms were collected daily using an electronic phone system.

Results: Alosetron (1 mg or 2 mg b.d.) significantly (P < 0.05 vs. placebo) increased the proportion of females, but not males, reporting adequate relief. Stool consistency, frequency and percentage days with urgency improved over placebo (P < 0.05) within the first month with all doses of alosetron, and persisted throughout the trial with all doses in female patients. With 1 mg b.d. alosetron, females had improved stool consistency and urgency within the first week, and adequate relief and improved stool frequency within the first 2 weeks. There was no consistent improvement in bowel function among male patients.

Conclusion: In female irritable bowel syndrome patients with predominant diarrhoea or alternating constipation and diarrhoea, alosetron is effective in treatment of abdominal pain and discomfort and bowel-related symptoms.

Publication types

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

MeSH terms

  • Abdominal Pain / drug therapy
  • Adult
  • Canada
  • Carbolines / administration & dosage*
  • Colonic Diseases, Functional / drug therapy*
  • Diarrhea / drug therapy
  • Dose-Response Relationship, Drug
  • Double-Blind Method
  • Female
  • Germany
  • Humans
  • Male
  • Middle Aged
  • Netherlands
  • Serotonin Antagonists / administration & dosage*
  • Sex Factors
  • Treatment Outcome
  • United Kingdom
  • United States


  • Carbolines
  • Serotonin Antagonists
  • alosetron