Irritable Bowel Syndrome Remains a Difficult Condition to Manage

Nicholas J. Talley, MD, PhD

In This Article


Alosetron, a 5-HT3 antagonist, slows colonic transit and increases intestinal fluid absorption[48] and has been tested in patients with diarrhea-predominant IBS ( Table 5 ).[49,50,51,52,53,54,55,56] A meta-analysis of the efficacy of alosetron included 6 trials and concluded that this drug was superior to placebo (number needed to treat, 7).[53] A comparison with mebeverine, an antispasmodic agent available in Europe, also demonstrated the superior efficacy of this drug.[54] In addition, alosetron improved the quality of life of patients with IBS more than placebo, a claim not convincingly demonstrated by any other agent.[55,56] Alosetron is approved for use in women only; data for use in men are limited, although the drug may have some efficacy in men.

In 2000, alosetron was voluntarily withdrawn by its manufacturer following reports of serious constipation complications and ischemic colitis.[57] However, in part because of continued strong patient demand, the drug was reintroduced in June 2002, albeit with substantial restrictions on use. Currently, the recommended dosage is 1 mg daily, rather than 1 mg twice daily as was used in the clinical trials. The drug is indicated only for use in women with severe diarrhea-predominant IBS in whom conventional therapy has failed. Close monitoring of patients taking alosetron is mandatory. If constipation develops, the drug should be stopped. Use of this drug has been modest in clinical practice because of concerns about adverse effects.


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