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

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. 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. 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). 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.