Efficacy of intravenous amisulpride and ondansetron in preventing post-operative nausea and vomiting in patients undergoing craniotomy for supratentorial tumour surgery: A randomised non-inferiority trial

Background and Aims: Patients undergoing neurosurgical procedures are at a high risk of post-operative nausea and vomiting (PONV). Amisulpride, a dopamine (D2, D3) receptor antagonist, has been recently approved for intravenous use in antiemesis and has demonstrated safety and efficacy in managing PONV in non-neurosurgical settings. We hypothesised that amisulpride would be non-inferior to ondansetron in preventing PONV. Methods: Adult patients scheduled for elective supratentorial craniotomy for tumour surgery under general anaesthesia were randomised to receive either intravenous amisulpride (5 mg) or intravenous ondansetron (4 mg) intra-operatively, administered 30 minutes before skin closure. Patients were then assessed for PONV in the post-operative intensive care unit. The primary objective was to evaluate the incidence of nausea and vomiting in the first 24 hours post-operatively. Secondary outcomes included nausea severity, the need for rescue antiemetic medications, and treatment-related adverse events. Incidence of PONV was compared using the Chi-square test. Secondary outcomes like severity of nausea, rescue medications, and adverse events were tested using Chi-square/Fisher’s exact test. Non-inferiority of amisulpride to ondansetron was assessed using the pre-specified absolute non-inferiority margin of 20%. Results: A total of 100 patients were included in the final analysis. The incidence of nausea and vomiting was significantly lower in the amisulpride group (22% and 8%) compared to the ondansetron group (36% and 8%) ( P = 0.032 and P = 0.045, respectively). Nausea severity was also significantly lower in the amisulpride group during the first four post-operative hours ( P < 0.05). Additionally, patients receiving amisulpride required fewer rescue antiemetics. No treatment-related adverse events were observed in the amisulpride group. Conclusion: A single intra-operative intravenous dose of amisulpride (5 mg) at the end of the surgery was found to be non-inferior to 4 mg intravenous ondansetron in reducing the incidence and severity of PONV in patients undergoing supratentorial craniotomy.