FDA approves Viberzi and Xifaxan for IBS

The Food and Drug Administration has approved Viberzi (eluxadoline) and Xifaxan (rifaximin) to treat irritable bowel syndrome with diarrhea (IBS-D) in adults, the agency announced May 27.

Viberzi is a locally active mixed mu-opioid–receptor agonist and delta-opioid–receptor antagonist that targets nervous system receptors to lessen bowel contractions. The medication is taken twice daily with food, the FDA said in a statement.

Phase III clinical trial results presented at the 2014 Digestive Disease Week showed that 31% of IBS-D patients who took Viberzi had improved abdominal pain and stool consistency at 26 weeks, compared with 19.5% of placebo patients. Xifaxan is an antibiotic originally approved as a therapy for travelers’ diarrhea caused by Escherichia coli, and for recurring overt hepatic encephalopathy. It is taken orally three times per day for 14 days, and can be re-administered up to two times in patients who experience symptom recurrence. Its efficacy was established in three clinical trials, including a phase III trial of 636 patients with recurrence which showed greater improvement of symptoms in patients taking Xifaxan than in those who received placebo, the FDA statement said.

Viberzi should not be taken by patients with a history of bile duct obstruction, pancreatitis, severe liver impairment, or severe constipation, or patients who drink more than three alcoholic beverages per day. Common side effects in patients treated with Viberzi were constipation, nausea, and abdominal pain.

In patients treated with Xifaxan for IBS-D, common side effects included nausea and an increase in the liver enzyme alanine aminotransferase (ALT).

Viberzi is manufactured by Patheon Pharmaceuticals. Xifaxan is marketed by Salix Pharmaceuticals, based in Raleigh, N.C.

For more safety information, please visit the FDA website.