Comparative efficacy of ondansetron versus granisetron to prevent perioperative nausea and vomiting in patients undergoing gynaecological surgery under spinal anaesthesia

Background: Posotoprative nausea and vomiting remains a persistent and distressing problem inspite of many advances on perioperative care and anti-emetic drugs. A newer antiemetic drug Granisetron has not been studied in patients undergoing gynaecological surgery under spinal anaesthesia. Objective: A randomized double blind study was conducted to compare Ondansetron and Granisetron for prevention of postoperative nausea and vomiting in patients undergoing gynaecological surgery under spinal anaesthesia. Material and methods: 60 consecutive patients, age between 20-65 years, ASA grade I and II undergoing gynaeacologicla surgery under spinal anaesthesia were randomized into two goups of 30 each. One group received intravenous Ondansetron 4.0 mg and the second received intravenous Granisetron 2.0 mg 5 minutes before induction of anaesthesia. For the first 24 hours postoperatively all episodes of nausea and vomiting were recorded. A complete response to the drug was considered if there was no nausea or vomiting and no need for rescue anti-emetic. The observations were tabulated and analysed. Results: During early postoperative period (0-3 hrs) there was statistically no significant difference in the study groups. Statistically significant difference was found in the study groups in the late postoperative period (3-24 hrs). Conclusion: In the early postoperative period both Ondansetron and Granisetron are equally effective in preventing postoperative nausea and vomiting in patients undergoing gynaecological surgery under spinal anaesthesia. Granisetron is better than Ondansetron in the late postoperative period of upto 24 hrs.