Tegaserod (Zelnorm) for irritable bowel syndrome: reports of serious diarrhea and intestinal ischemia

Headnote

HEALTH AND DRUG ALERTS

Reason for posting: The serotonin 5-HT^sub 4^ receptor partial tegaserod (Zelnorm) is sometimes prescribed for patients who have irritable bowel syndrome with constipation.1 However, a recent letter to health care professionals from the drug's manufacturer warns of serious adverse events in some cases.2 Although 1 in 10 patients taking the drug will experience mild diarrhea, about 1 in 250 will have very serious diarrhea complicated by hypovolemia, hypotension and syncope that sometimes necessitates admission to hospital and intravenous therapy.2 As well, ischemic colitis and other forms of intestinal ischemia have occurred in some patients taking the drug; although the exact incidence of this adverse event is...