IBS drug approved for idiopathic constipation.(Clinical Rounds)

Tegaserod, approved in 2002 for constipation-predominant irritable bowel syndrome in women, was recently approved by the Food and Drug Administration for treating chronic idiopathic constipation in women and men younger than 65.

The approval of tegaserod, marketed as Zelnorm by Novartis, was based on the results of two 12-week studies of patients with chronic constipation (lasting at least 6 months).

More than 80% had fewer than two complete spontaneous bowel movements (CSBMs) per week at baseline. Among more than 2,000 patients under age 65, 45% of patients on 6 mg twice daily had an increase of at least one CSBM per week during 12 weeks of treatment, vs. 38% of those on 2 mg twice daily and 28% of patients on placebo.

The recommended dosage for chronic constipation is 6 mg orally twice daily before meals, the same dose recommended for IBS.

Tegaserod, a 5-H[T.sub.4] receptor partial agonist, activates 5-H[T.sub.4] receptors in the gut, increasing GI motility, according to Novartis.

At a meeting in July, the FDA's gastrointestinal drugs advisory panel voted 10-3 to recommend approval of tegaserod for this indication; most panel members agreed that approval should be limited to women, who made up 90% of the patients enrolled in clinical trials, although several panelists said men should also have access to the drug.

The three panel members voting against approval had concerns about the drug's risks, efficacy, or potential overuse for this indication.