The Food and Drug Administration (FDA) has approved Viberzi (eluxadoline; Actavis) and Xifaxan 550mg (rifaximin; Salix) for the treatment of irritable bowel syndrome with diarrhea (IBS-D) in adults.

Viberzi, a first-in-class mu receptor agonist, delta opioid receptor antagonist, and a kappa opioid receptor agonist, acts locally in the gastrointestinal tract to treat the symptoms of IBS-D while reducing the incidence of constipation that can occur with unopposed mu opioid receptor agonists. The safety and efficacy of Viberzi was established in two Phase 3 clinical trials of 2,425 patients with IBS-D, which demonstrated significant superiority on the composite endpoint of simultaneous improvement in both abdominal pain and diarrhea compared to placebo for at least 50% of the days from weeks 1 to 12 and weeks 1 to 26.

Viberzi is taken orally twice daily with food and will be available as 75mg and 100mg strength tablets in 60-count bottles. A recommendation from the FDA that Viberzi be classified as a controlled substance has been submitted to the U.S. Drug Enforcement Administration (DEA). After Viberzi receives final scheduling designation, the updated label will be available. It is expected to launch in early 2016 pending final scheduling designation.