Background: This study was designed to compare the efficacy of prophylactic ramosetron with ondansetron in preventing PONV after elective supratentorial craniotomy in adult patients on preoperative steroids. Methods: A total of 145 American Society of Anesthesiologists (ASA) I–II patients aged 30–50 years on preoperative steroids scheduled to undergo elective supratentorial craniotomy under general anesthesia were enrolled in the study. A standard anesthesia regimen was followed in all patients. Patients were randomly allocated into two groups to receive ondansetron (4 mg/2 ml; Group O), or ramosetron (0.3 mg/2 ml; Group R) intravenously (IV) at the time of dural closure. The incidence of PONV, need for rescue antiemetics, rescue analgesics and any adverse events were recorded up to 48 hours postoperatively. Results: During 0–24 hours after surgery, complete response (no PONV) was observed in 30 patients of the ondansetron group and in 34 patients of the ramosetron group (p > 0.05). Complete response i.e., no PONV between 24–48 hours after surgery was observed in 31 patients of the ondansetron group and in 45 patients of the ramosetron group and was statistically significant (p < 0.05). During 0–24 hours, PONV requiring rescue antiemetics were comparable in both the groups, whereas between 24–48 hours PONV requiring rescue antiemetics was higher in ondansetron group (18 patients) as compared to ramosetron group (8 patients) and was statistically significant (p < 0.05). Conclusion: Ramosetron was more efficacious than ondansetron in preventing delayed PONV (24–48 hours) in patients on preoperative steroids following supratentorial craniotomy under general anesthesia. However, both the drugs were comparable in preventing early PONV (0–24 hours). The incidence of side effects was similar in ondansetron and ramosetron.

Keywords: Ondansetron; Postoperative nausea and vomiting (PONV); Ramosetron; Supratentorial craniotomy.