The FDA has approved tegaserod maleate (Zelnorm; Novartis, East Hanover, NJ) for short-term treatment of women with irritable bowel syndrome (IBS) whose primary bowel symptom is constipation. Zelnorm is a selective serotonin type-4 receptor partial agonist that increases motility of the gastrointestinal tract. The drug, the first of its kind, does not treat diarrhea-predominant IBS, and its effectiveness in men has not been established.
The approval was based on the results of three 12-week, randomized, double-blind, placebo-controlled clinical studies, including a total of 2470 women with at least a 3-month history of IBS symptoms of abdominal pain, bloating, and constipation. Patients received 6 mg of Zelnorm twice daily or placebo. Participants in both arms were asked each week to rate their overall well-being, symptoms of abdominal discomfort and pain, and altered bowel habits.
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