Merck received approval from the FDA for Emend for the prevention of postoperative nausea and vomiting (PONV), one of the most common side effects associated with surgical procedures. The recommended dose of Emend for PONV is a single, oral 40 mg dose administered within three hours prior to the induction of anesthesia.

Emend is believed to work through a novel mechanism that primarily blocks nausea and vomiting signals to the brain. This mechanism is distinct from how current anti-vomiting therapies work, including 5-HT3 receptor antagonists (Zofran). Emend represents the first new class of therapy for the management of PONV in more than 10 years.

The approval for Emend is based on two multi-center, randomized, double-blind, active comparator-controlled, parallel-group studies of 1,658 patients undergoing open abdominal surgery. Emend 40 mg was superior to Zofran 4 mg IV for the prevention of vomiting (emesis) from 0 to 24 hours following surgery. Prevention of vomiting was defined as no emetic episodes and was one of two primary endpoints in the study. Of patients taking Emend 40 mg, 84% of patients did not experience vomiting through 24 hours compared to 71% of patients taking Zofran 4 mg IV.