Prophylactic Antiemetic Effects of Midazolam, Ondansetron and their Combination after Middle Ear Surgery

Background: The purpose of the present study was to evaluate the efficacy of midazolam-ondansetron combination in prevention of postoperative nausea and vomiting (PONV) after middle ear surgery and its comparison with using midazolam or ondansetron alone. Methods: 140 patients were divided to four groups to received midazolam 0.75 mg/kg, ondansetron 4 mg, midazolam 0.75 mg/kg and ondansetron 4 mg or normal saline 0.9% (as control) intravenously just before the anesthesia. Assessment of nausea, vomiting, rescue antiemetic and side effects of study drugs such as headache and dizziness were carried out postoperatively for 24 hours. Findings: The incidence of postoperative nausea and vomiting was significantly lower in midazolam-ondansetron group compared to midazolam and ondansetron groups (P < 0.001) and there was no significant difference between the two last groups during the first 24 hours postoperatively. Need to the additional antiemetic was significantly more in the control group (71.4%) compared to other three groups; and in midazolam-ondansetron group (11.4%), it was lower than the midazolam (31.4%) and ondansetron (34.3%) groups (P < 0.001). Conclusion: Our study showed that prophylactic administration of midazolam 0.75 mg/kgcombined with ondansetron 4 mg was more effective than using midazolam or ondansetron alone in prevention of PONV after middle ear surgery.