Droperidol and dimenhydrinate alone or in combination for the prevention of post-operative nausea and vomiting after nasal surgery in male patients

Droperidol and dimenhydrinate are inexpensive antiemetic drugs. Droperidol, especially, has been studied extensively, but there are no studies on the combination of both drugs for prevention of post-operative nausea and vomit ing. One hundred and forty male hospitalized patients undergoing nasal surg ery were randomized to receive one of four anti-emetic regimes: placebo, di menhydrinate (1 mg kg(-1)), droperidol (15 mu g kg(-1)), or the combination of both drugs (droperidol 15 mu g kg(-1) + dimenhydrinate 1 mg kg(-1)) adm inistered after induction of anaesthesia. Patients in the dimenhydrinate-gr oup and the combination-group received a second dose of dimenhydrinate 6h a fter the first administration to mitigate the short half-life of the drug. For general anaesthesia a standardized technique, including benzodiazepine premedication, propofol, desflurane in N2O/O-2, vecuronium, and a continuou s infusion of remifentanil, was used. Postoperative analgesia and anti-emet ic rescue medication were standardized. Episodes of vomiting, retching, nau sea, and the need for additional anti-emetics were recorded for 24 h. The m ain endpoint of this study was the number of patients who were completely f ree of post-operative nausea and vomiting (Fisher's Exact Test) Furthermore , the severity of post-operative nausea and vomiting was analysed using a s tandardized scoring algorithm. The incidence of patients completely free of post-operative nausea and vomiting was 62.9% in the placebo-group, 77.1% i n the dimenhydrinate-group (P=0.21), and 82.9% in the droperidol-group (P=0 .07). This increased to 94.3% in the combination-group (P=0.0015). In all t hree treatment groups the severity of post-operative nausea and vomiting wa s reduced significantly compared with placebo treatment (P=0.0003). The inc idence of side effects was similar in the four groups. Dimenhydrinate was i neffective in reducing the incidence of post-operative nausea and vomiting and droperidol only reduced the severity of post-operative nausea and vomit ing. However, the combination of both drugs significantly reduces the incid ence of post-operative nausea and vomiting when compared with placebo treat ment.