Efficacy of palonosetron-dexamethasone combination compared to palonosetron alone for prophylaxis against postoperative nausea and vomiting

Objectives: Postoperative nausea and vomiting (PONV) is a common complication following surgery, and may be one of the most distressing parts of the surgical journey. With combination pharmacological therapy recommended for PONV prophylaxis, this systematic review and meta-analysis evaluates whether perioperative palonosetron and dexamethasone is more efficacious than palonosetron administered alone. Methods: We searched CENTRAL; EMBASE; CINAHL; Google Scholar; Web of Science citation index; the US clinical trials register; UK clinical trials register; Australia and New Zealand Clinical trials register; and conference abstracts for major anaesthesia conferences in the last three years. We included randomized controlled trials that compared adult patients undergoing surgery who received palonosetron and dexamethasone, against those who received palonosetron. Results: A total of 12 studies (1152 patients) were included. Medium-grade evidence showed that the palonosetron and dexamethasone combination significantly reduced 24-hour rescue anti-emetic requirement (RR: 0.59, 95% confidence interval (CI): 0.41–0.86). There was however no significant difference in the 6-hour (RR: 0.82, 95% CI: 0.61–1.09) and 24-hour PONV incidences (RR: 0.60, 95% CI: 0.33–1.10). Similarly, PONV incidences after 24 h did not differ between groups (RR:0.82, 95% CI: 0.59–1.14). Headache and dizziness were the most common side-effects reported. Conclusions: Combination prophylaxis with palonosetron and dexamethasone reduces post-operative anti-emetic requirement, although is not associated with a significant difference in PONV. There was considerable heterogeneity in the studies, and trial sequential analysis indicates that further studies are needed to strengthen the clinical evidence.