Cilansetron (also known as Calmactin; Solvay Pharmaceuticals, Marietta, Ga), a selective serotonin (5-hydroxytryptamine; 5-HT) type 3 (5-HT3) receptor antagonist, has shown promising efficacy in patients with irritable bowel syndrome with diarrhea (IBS-D). Results, however, from summary phase 3 data presented as an abstract and an oral presentation at the 105th Annual Meeting of the American Gastroenterological Association and Digestive Disease Week (held from May 15 to 20, 2004, in New Orleans, La), raise questions regarding its safety, particularly in women. In a 6-month, double-blind, placebo-controlled study of 792 patients (358 men and 434 women) presented by Marc Bradette, MD, and colleagues, 12% of patients in the cilansetron group (n = 395) experienced constipation, compared with 3% in the placebo group (n = 397). In addition, 3 cases (of 395) of suspected ischemic colitis were reported in the cilansetron group.
A comprehensive appropriate-use program accompanied the recent cilansetron NDA submission to the FDA.