FDA Approves Treatments for Irritable Bowel Syndrome with Diarrhea

The FDA today approved eluxadoline (Viberzi) and rifaximin (Xifaxan) to treat irritable bowel syndrome with diarrhea (IBS-D).

Viberzi can be taken twice daily with food, while Xifaxan can be taken orally 3 times a day for 2 weeks to treat abdominal pain and diarrhea. In addition, if patients experience a recurrence of symptoms, they can retake Xifaxan over a 2-week period up to 2 times.

Trials involving 2425 patients taking Viberzi or placebo demonstrated that the treatment was more effective than placebo in reducing abdominal pain and improving stool consistency over a 26-week treatment period.

Xifaxan’s efficacy was shown in 3 trials. The first 2 trials involved 1258 patients who were randomly assigned to take Xifaxan or placebo for 2 weeks, followed by a 10-week period with no treatment. The researchers found that patients taking Xifaxan saw improvements in abdominal pain and stool consistency compared with those on placebo. The third trial with 636 subjects demonstrated that patients saw improvements on Xifaxan, even through repeat rounds of the treatment with some periods off treatment.

“For some people, IBS can be quite disabling, and no 1 medication works for all patients suffering from this gastrointestinal disorder,” Julie Beitz, MD, director of the Office of Drug Evaluation III in FDA’s Center for Drug Evaluation and Research, said in a press release. “The approval of 2 new therapies underscores the FDA’s commitment to providing additional treatment options for IBS patients and their doctors.”

Patients may experience adverse side effects while taking Viberzi including constipation, nausea, and abdominal pain. Xifaxan may cause nausea and an increase in alanine aminotransferase.

Viberzi is manufactured by Patheon Pharmaceuticals Inc, and Xifaxan is marketed by Salix Pharmaceuticals Inc.