A.C.Mackey, A.Brinker, J.G.Beitz, S.Kress, CDER, FDA, Rockville, MD 20856
Alosetron is a 5-HT-3 receptor antagonist marketed in the U.S. between Feb 2000 and Nov 2000 for the treatment of women with diarrhea-predominant irritable bowel syndrome. The marketing of alosetron was suspended by its sponsor in Nov 2000. We review case counts, case definitions, and clinical attributes of three unique medical entities collected in review of domestic adverse event reports for alosetron as presented before an FDA Advisory Committee in April 2002. We report inclusion of 84 cases of ischemic colitis, 6 cases of small bowel ischemia, and 113 cases of serious complications of constipation. This series of 203 total cases includes 7 reports of death and 49 cases of surgery. These data do not reveal any potential risk factors; they do demonstrate the spectrum of events that have been reported to the FDA. We will continue to monitor these events closely now that alosetron has been reintroduced in the US market.