comparison of parenteral promethazine versus midazolam effect as a preoperative medication on postoperative nausea and vomiting after appendectomy

background: postoperative nausea and vomiting is a high unpleasant symptom in surgical procedures. this study compares the effectiveness of midazolam with promethazine as multipurpose drug in postoperative nausea and vomiting as a preoperative and anesthetic medication after appendectomy. methods: this randomized, double – blind clinical trial study was performed in patients who underwent appendectomy. these patients randomly received either placebo or midazolam or promethazine 5 minutes before appendectomy. all episodes of vomiting and nausea within 24 hours after surgery were recorded. the study population (n=75) comprised 3 comparable subgroups (n=25 in each group). a standard general anesthetic technique and postoperative analgesia were used. the data were collected and analyzed. results: vomiting and nausea occurred in 19.20%, 0% and 81.80% of the patients in the midazolam, promethazine and placebo groups, respectively. the frequency of postoperative nausea and vomiting was as follows: the first 6 hours after surgery 0%, 0% and 50%, during the second 6 hours after surgery 19%, 0% and 19%, during the third 6 hours after surgery 0%, 0% and 7%, during the fourth 6 hours after surgery 0%, 0% and 4% in the midazolam, promethazine and placebo groups, respectively. there were no significant differences between promethazine with midazolam in reduction of postoperative nausea and vomiting. conclusion: our study suggests that midazolam can be used as multipurpose drugs in postoperative nausea and vomiting as a preoperative medication after appendectomy and treatment using midazolam for anti-emetic, prophylaxis provide a similar effect compared to promethazine in the present study.