Comparative efficacy of ramosetron and ondansetron in preventing postoperative nausea and vomiting: An updated systematic review and meta-analysis with trial sequential analysis

BACKGROUND Postoperative nausea and vomiting is a distressing complication of surgery, and 5-HT3 receptor antagonists are often prescribed to prevent it. Ondansetron is the agent typically administered to prevent postoperative nausea and vomiting. Although ramosetron has a longer duration of action than ondansetron, it remains unclear whether ramosetron is the more effective medication. We performed an updated meta-analysis on the comparative efficacy of ramosetron and ondansetron in preventing postoperative nausea and vomiting. METHODS We searched six databases for all trials that randomly assigned patients to ramosetron or ondansetron groups. The primary outcome was postoperative nausea or vomiting in the early, late, and next-day periods. The secondary outcomes were side effects of the medications. We used the random-effects model to combine the results. Trial sequential analyses were performed to correct for repetitive testing in the updated meta-analysis. RESULTS Twenty-seven randomized controlled trials with 3,811 patients were included in the meta-analysis. The combined results of ramosetron vs. ondansetron efficacy in preventing postoperative nausea and vomiting were as follows: Risk ratio [95% confidence interval] = 0.82 [0.69-0.98] for early postoperative nausea, 0.76 [0.65-0.89] for late postoperative nausea, 0.69 [0.57-0.84] for next-day postoperative nausea, 0.78 [0.63-0.98] for early postoperative vomiting, 0.57 [0.45-0.72] for late postoperative vomiting, and 0.61 [0.43-0.86] for next-day postoperative vomiting. Dizziness was significantly lower in ramosetron groups than in ondansetron groups (risk ratio [95% confidence interval] = 0.81 [0.66-0.98]). Trial sequential analysis revealed that the results for late postoperative nausea, late postoperative vomiting, and next-day postoperative nausea were conclusive. CONCLUSIONS Ramosetron is more effective in preventing late postoperative nausea, late postoperative vomiting, and next-day postoperative nausea than ondansetron. The incidence of dizziness may be lower in patients receiving ramosetron than in patients receiving ondansetron. TRIAL REGISTRATION University hospital Medical Information Network Clinical Trials Registry: UMIN000022980.