1. ¹Division of Gastroenterology Products, Food and Drug Administration, Center for Drug Evaluation and Research, Office of New Drugs, Office of Drug Evaluation III, Maryland
2. ²Division of Drug Risk Evaluation, Food and Drug Administration, Center for Drug Evaluation and Research, Office of Drug Safety Silver Spring, Maryland

Correspondence: Hugo Gallo-Torres, MD, PhD, PNS, Division of Gastroenterology Products, Food and Drug Administration, Center for Drug Evaluation and Research, 10903 New Hampshire Avenue, Building 22, Room 5106, Silver Spring, MD 20993-0002.

Received 26 January 2006; Accepted 29 January 2006.

Abstract

Drugs such as alosetron that modulate serotonin effects by stimulating or blocking its receptors may play an important role in the treatment of some patients with irritable bowel system. In the case of alosetron, a 5HT-3 antagonist, an analysis of data from randomized clinical trials and postmarketing experiences have demonstrated a causal relationship between this drug and ischemic colitis and serious complications of constipation. Because the mechanism(s) of drug-induced ischemic colitis and possibly other forms of intestinal ischemia associated with alosetron have not been elucidated, there is need to further assess risk with regard to patient susceptibility and other factors.