Efficacy, dose-response, and adverse effects of droperidol for prevention of postoperative nausea and vomiting

Purpose: To estimate the efficacy and harm produced by droperidol in the pr evention of postoperative nausea and vomiting (PONV). Methods: Systematic search (MEDLINE, EMBASE, Cochrane library, hand-searchi ng, bibliographies, all languages, up to May 1999) for randomised compariso ns of droperidol with placebo in surgical patients. Relevant end points wer e prevention of early PONV (up to six hours postoperatively), and late PONV (24 hr), and adverse effects. Combined data were analysed using relative r isk and NNT. Results: In 76 trials, 5,351 patients received 24 different regimens of dro peridol. The average incidence of early and late PONV in controls was 34% a nd 51%, respectively. Droperidol was more efficacious than placebo in preve nting PONV In adults, the anti-nausea effect was short-lived, and there was no dose-responsiveness; with 0.25 to 0.30 mg the number-needed-to-treat (N NT) to prevent early nausea was 5, For both early and late anti-vomiting ef ficacy there was dose-responsiveness; best efficacy was with 1.5 mg to 2.5 mg (NNT; 7). In children, there was dose-responsiveness; best efficacy was with 75 mu g.kg(-1) (NNT to prevent early and late vomiting, 4). Two childr en had extrapyramidal symptoms with droperidol (NNT in children, 91, in any patient, 408). There was dose-responsiveness for sedation and drowsiness ( with 2.5 mg the NNT was 7.8). Droperidol prevented postoperative headache ( NNT, -25). Conclusions: Droperidol is anti-emetic in the surgical setting. The effect on nausea is short-lived but more pronounced than the effect on vomiting. S edation and drowsiness are dose-dependent, extrapyramidal symptoms are rare , and there is a protective effect against headache.