Efficacy of Ramosetron in Male Patients With Irritable Bowel Syndrome With Diarrhea (Neurogastroenterol Motil 2011;23:1098-1104)

Abstract

Serotonin (5-Hydroxytryptamine [5-HT]) plays an important role in gastrointestinal (GI) motility and sensation, and abnormal levels have been shown in patients with irritable bowel syndrome (IBS).1,2 Drugs acting on 5-HT receptors have the potential to reduce the smooth muscle spasm, abdominal pain, and changes in bowel habit in IBS. Recently, Lee et al3 assessed the efficacy and safety of ramosetron, a 5-HT3 receptor antagonist, compared with mebeverine in male patients with diarrhea-predominant IBS (IBS-D). This study was performed in a multicenter, randomized, open-label, parallel-group, non-inferiority comparative design. A total of 343 male patients with IBS-D were randomized to either ramosetron 5 µg once daily or mebeverine 135 mg 3 times daily for 4 weeks. The weekly responder rates for global IBS symptoms, abdominal pain/discomfort and abnormal bowel habits in the ramosteron and mebeverine groups significantly increased during the treatment period (P < 0.001). The severity scores of abdominal pain/discomfort and urgency, the stool form scores and the stool frequency recorded daily were reduced significantly in both treatment arms, compared with the baselines (P < 0.001). There were no significant differences in the weekly responder rates (37% vs 38% at 4-week) and in the adverse event profiles between the ramosetron and mebeverine groups. Neither severe constipation nor ischemic colitis was reported. The authors concluded that the ramosetron 5 µg once daily was as effective as mebeverine 3 times daily in male patients with IBS-D.