Comparative study between Ondansetron and Dexamethasone in Post-operative Nausea Vomiting (PONV)

Background: Postoperative nausea and vomiting (PONV) is a frequent and distressing complication following anaesthesia and surgery that negatively affects patient comfort, delays recovery, and may prolong hospital stay. Ondansetron and dexamethasone are commonly used antiemetic agents; however, their comparative efficacy in PONV prevention remains clinically important. Objective: To compare the efficacy and safety of ondansetron and dexamethasone in preventing postoperative nausea and vomiting. Materials and Methods: This comparative observational study included 74 patients undergoing elective surgery under anaesthesia. Patients were equally allocated into two groups: Group A (n=37) received ondansetron and Group B (n=37) received dexamethasone for PONV prophylaxis. Demographic and intra-operative parameters were assessed. Postoperative outcomes including nausea, retching, vomiting, complete response, rescue antiemetic requirement, and adverse effects were evaluated at 0–3, 3–6, 6–9, 9–12, and 12–24 hours after surgery. Statistical analysis was performed with significance considered at p<0.05. Results: Baseline demographic and intra-operative characteristics were comparable between groups (p>0.05). Group B showed significantly lower incidences of nausea, retching, and vomiting during the early postoperative period (0–3 and 3–6 hours) compared with Group A (p<0.05). The complete response rate was significantly higher in Group B during early recovery and remained superior at 6–9 hours (83.78% vs. 59.46%, p=0.016). No significant differences were observed during 9–24 hours. Rescue antiemetic requirements and adverse effects, including headache, dizziness, and hypotension, were similar between groups. Conclusion: Dexamethasone provided better early postoperative control of PONV than ondansetron with a comparable safety profile, suggesting its effectiveness as a prophylactic antiemetic agent.