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

Author(s): Camilleri M, Mayer EA, Drossman DA, Heath A, Dukes GE, McSorley D, Kong S, Mangel AW, Northcutt AR

Affiliation(s): Gastroenterology Research Unit, Mayo Foundation, Rochester, Minnesota 55905, USA. camilleri.michael@mayol.edu

Publication date & source: 1999-09, Aliment Pharmacol Ther., 13(9):1149-59.

Publication type: Clinical Trial; Multicenter Study; Randomized Controlled Trial

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.