The U.S. Food and Drug Administration (FDA) recently approved Xifaxan® (rifaximin) for treating irritable bowel syndrome with diarrhea (IBS-D) in adult men and women.
The safety and effectiveness of Xifaxan® for treatment of IBS-D have been established in three double-blind, placebo-controlled clinical trials. In the first two trials, 1,258 patients were randomly assigned to receive treatment with either Xifaxan® or placebo for 14 days, and then followed for a 10-week treatment-free period. When the groups were directly compared, more Xifaxan®-treated patients reported improvements in abdominal pain and stool consistency than those treated with placebo.
A third clinical trial evaluated repeat courses of Xifaxan®, because some patients with IBS-D develop recurrent signs and symptoms after a single treatment course of Xifaxan® treatment. A total of 636 patients with recurrence of symptoms were treated with either Xifaxan® or placebo for two additional 14-day courses separated by 10 weeks and directly compared. Again, more patients treated with Xifaxan® than placebo had improvements in abdominal pain and stool consistency.
Xifaxan® treatment is generally well tolerated with few side effects. The most commonly reported side effects in patients treated with Xifaxan® for IBS-D are nausea and an increase in alanine aminotransferase (ALT), a liver enzyme measured in blood.