Alosetron controls bowel urgency and provides global symptom improvement in women with diarrhea-predominant irritable bowel syndrome

OBJECTIVES: Bowel urgency is one of the most bothersome symptoms for noncon stipated IBS patients. The efficacy of alosetron in control of bowel urgenc y and Global Improvement of IBS symptoms were evaluated in a multicenter do uble-blind, randomized, placebo-controlled study. METHODS: Female IBS patients with lack of satisfactory control of bowel urg ency were randomized 2:1 alosetron 1 mg twice daily or placebo treatment gr oups. The primary endpoint was the proportion of days wit satisfactory cont rol of bowel urgency during the 12-wk treatment period and 2-wk follow-up p eriod. Secondary endpoints included IBS Global Improvement (responder defin ed as patient-reported moderate or substantial improvement in IBS symptoms) and improvements in bowel function (stool frequency, consistency, and sens ation of incomplete evacuation). RESULTS: A total of 801 women were randomized to the alosetron (n = 532) or placebo groups (n = 269). Physicians classified 98% of patients with diarr hea-predominant IBS. Patients treated with alosetron had a significantly gr eater proportion of days with satisfactory control of urgency compared to p lacebo for the treatment period (73% vs 57%, p < 0.001). A significantly gr eater number of patients treated with alosetron were IBS Global Improvement responders compared to placebo at week 12 (76% vs 44%, p < 0.001). IBS Glo bal Improvement responders had more days with satisfactory control of urgen cy at week 12 (88% vs 48%) as well as firmer stools, fewer stools/day, and fewer days with incomplete evacuation compared with nonresponders. Alosetro n-treated patients showed improvements in bowel functions compared to place bo-treated patients. Constipation was the most commonly reported adverse ev ent. CONCLUSIONS: Alosetron is effective at managing bowel urgency in women with diarrhea-predominant IBS. The IBS Global Improvement assessment correlated with improvements in bowel function and may be a useful tool in future. IB S clinical trials. (Am J Gastroenterol 2001;96:2662-2670. (C) 2001 by Am. C oll. of Gastroenterology).