Prophylactic Effectiveness of Ramosetron versus Ondansetron for Preventing Postoperative Nausea and Vomiting in Adults: A Randomized Comparative Study

BACKGROUND: Postoperative nausea and vomiting remain a significant perioperative challenge affecting patient recovery and satisfaction. While 5-hydroxytryptamine type 3 receptor antagonists provide effective prophylaxis, comparative data between different agents within this class require further evaluation. This investigation examined the relative prophylactic performance of ramosetron and ondansetron in preventing postoperative emetic episodes. MATERIALS AND METHODS: A prospective randomized trial was conducted involving 72 adult patients (American Society of Anesthesiologists I-II, ages 20-60 years) scheduled for elective surgery under general anesthesia. Participants were randomly allocated to receive either ramosetron 0.3 mg intravenously (Group R, n = 36) or ondansetron 4 mg intravenously (Group O, n = 36) administered 30 min before anticipated extubation. Primary outcomes included emetic episodes, requirement for rescue antiemetics, and adverse reactions during three observation periods: 0-2 h, 2-12 h, and 12-24 h postoperatively. Complete prophylactic success was defined as the absence of nausea, retching, vomiting, and rescue medication throughout the 24-h surveillance period. RESULTS: Demographics were comparable between the groups. Ramosetron demonstrated superior prophylactic efficacy with 92% of patients achieving a complete response compared to 58% in the ondansetron group (P = 0.001). Early postoperative vomiting (0-2 h) occurred in 19.4% of ondansetron recipients versus 0% receiving ramosetron (P = 0.005). Rescue antiemetic requirements were significantly higher in the ondansetron cohort during the initial 2-h period (16.7% vs. 0%, P < 0.05). Both the medications exhibited comparable safety profiles with minimal adverse effects. CONCLUSIONS: Ramosetron provides superior prophylactic effectiveness against postoperative nausea and vomiting compared to ondansetron, particularly during the early recovery phase, while maintaining equivalent tolerability.