Raleigh-based Salix Pharmaceuticals has started enrolling 1,200 patients in a Phase 3 clinical trial to test the safety and effectiveness of using rifaximin, its antibiotic for treating irritable bowel syndrome (IBS), three times a day.
The trial of Salix' 550-milligram dose is aimed at getting the U.S. Food and Drug Administration to approve the treatment regimen in people with IBS not currently experiencing constipation.
Two 600-subject trials are being conducted simultaneously in approximately 180 study centers throughout the United States and Canada. Volunteers are given rifaximin or placebo for 14 days and then followed for 10 weeks.
IBS is one of the most common chronic conditions, affecting some 15 percent of adults in the United States. Alterations in the normal bacteria that inhabit the healthy gut are often blamed for IBS, which causes changes in bowel habits, abdominal pain and discomfort.