Amisulpride Prevents Postoperative Nausea and Vomiting in Patients at High Risk: A Randomized, Double-blind, Placebo-controlled Trial

Background: Postoperative nausea and vomiting causes distress for patients and can prolong care requirements. Consensus guidelines recommend use of multiple antiemetics from different mechanistic classes as prophylaxis in patients at high risk of postoperative nausea and vomiting. The prophylactic efficacy of the dopamine D₂/D₃ antagonist amisulpride in combination with other antiemetics was investigated. Methods: This double-blind, randomized, placebo-controlled, international, multicenter trial was conducted in 1,147 adult surgical patients having three or four postoperative nausea and vomiting risk factors. Patients were randomized to receive either intravenous amisulpride (5 mg) or matching placebo at induction of general anesthesia, in addition to one standard, nondopaminergic antiemetic, most commonly ondansetron or dexamethasone. Vomiting/retching, nausea, and use of rescue medication were recorded for 24 h after wound closure. The primary endpoint was complete response, defined as no emesis or rescue medication use in the 24-h postoperative period. Results: Complete response occurred in 330 of 572 (57.7%) of the amisulpride group and 268 of 575 (46.6%) of the control group (difference 11.1 percentage points; 95% CI, 5.3 to 16.8; P < 0.001). The incidences of emesis (13.8% vs. 20.0%, P = 0.003), any nausea (50.0% vs. 58.3%, P = 0.002), significant nausea (37.1% vs. 47.7%, P < 0.001), and rescue medication use (40.9% vs. 49.4%, P = 0.002) were significantly lower in the amisulpride group. Adverse events and laboratory and electrocardiogram abnormalities occurred no more frequently with amisulpride than with placebo. Conclusions: Intravenous amisulpride was safe and effective as prophylaxis of postoperative nausea and vomiting when given in combination with an antiemetic from another class to adult patients at high risk for suffering postoperative nausea and vomiting undergoing elective surgery under inhalational general anesthesia.