Background: Postoperative nausea and vomiting (PONV) occurs commonly in surgical patients despite widespread prophylactic antiemetic use. Rescue options are currently limited. 5HT3 antagonists are most frequently used for prophylaxis, but if they fail, additional doses are not effective as rescue medication. Intravenous (IV) amisulpride, a well-studied D2/D3 antagonist, has been shown in trials to prevent PONV. This study was designed to determine if amisulpride could be used to treat established PONV in patients at low-to-moderate risk of PONV who had not received any prior prophylaxis.
Methods: Men and women aged over 18 years were permitted to enroll if they were to undergo general inhalational anesthesia, expected to last at least 1 hour, for an outpatient or inpatient surgical procedure. Patients who then suffered PONV were randomized equally to 1 of 3 single-dose IV regimens: placebo or 5 or 10 mg amisulpride. The primary end point was complete response, defined as no emesis in the period 30 minutes to 24 hours after study drug treatment and no use of rescue medication in the entire 24-hour period.
Results: One thousand nine hundred eighty-eight patients were enrolled preoperatively, of whom 560 were randomized to a treatment arm. Complete response occurred in 39 of 181 patients (21.5%) in the placebo group compared to 60 of 191 patients (31.4%; P = .016) and 59 of 188 patients (31.4%; P = .016) in the amisulpride 5 and 10 mg groups, respectively. The adverse event profile of amisulpride at either dose was similar to placebo.
Conclusions: IV amisulpride at 5 and 10 mg was safe and efficacious in the treatment of established PONV in surgical patients undergoing general anesthesia with no prior PONV prophylaxis.
Trial registration: ClinicalTrials.gov NCT02449291.