title: Low-dose droperidol (≤1 mg or ≤15 μg kg-1) for the prevention of postoperative nausea and vomiting in adults: quantitative systematic review of randomised controlled trials.
abstract: BACKGROUND
  Droperidol is widely used for the prevention of postoperative nausea and vomiting (PONV) in European countries. It is unclear how efficacious low-dose droperidol is in the prevention of PONV.
  
  
  OBJECTIVE
  To test the efficacy of low-dose droperidol in the prevention of PONV in adults and to test for dose-responsiveness.
  
  
  METHODS
  Systematic review of randomised controlled trials with meta-analyses.
  
  
  METHODS
  Comprehensive search in electronic databases (Medline, Embase, Central) up to June 2011. Additional trials were obtained from bibliographies of retrieved reports. No language restriction was applied.
  
  
  METHODS
  Randomised trials testing prophylactic intravenous droperidol ≤1 mg or ≤15 μg kg compared with placebo (or no treatment) in adults undergoing general anaesthesia and reporting on PONV.
  
  
  RESULTS
  We analysed 25 trials (2957 patients). Doses varied from 0.25 to 1.0 mg. For prevention of early nausea (within 6 h postoperatively), relative risk (RR) was 0.45 (95% CI, 0.35 to 0.58); number needed to treat (NNT) was 7, 4, and 2 for low, medium and high baseline risk (i.e. control event rate 25, 50, 75%). For prevention of early vomiting, RR was 0.65 (95% CI, 0.57 to 0.74), NNT 11, 6, and 4. For prevention of late nausea (within 24 h), RR was 0.74 (95% CI, 0.62 to 0.87), NNT 15, 8, and 5. For prevention of late vomiting, RR was 0.61 (95% CI, 0.47 to 0.80), NNT 10, 5, and 3. Droperidol decreased the risk of headache but increased the risk of restlessness. For these outcomes there was no evidence of dose-responsiveness. There were no differences in the incidences of sedation or dizziness. Two patients receiving droperidol 0.625 mg had extrapyramidal symptoms. Cardiac toxicity data were not reported.
  
  
  CONCLUSIONS
  Prophylactic doses of droperidol of 1 mg or below are antiemetic. Because adverse drug reactions are likely to be dose-dependent, there is an argument to stop using doses of more than 1 mg.
authors.affiliation: Department of Anaesthesiology, Clinique Sainte Anne Saint Remi, 66 Boulevard Jules Graindor, Brussels, Belgium schaubisabelle@hotmail.com
authors.forename: Isabelle
authors.initials: I
authors.lastname: Schaub
authors.forename: Christopher
authors.initials: C
authors.lastname: Lysakowski
authors.forename: Nadia
authors.initials: N
authors.lastname: Elia
authors.forename: Martin R
authors.initials: MR
authors.lastname: Tramèr
mesh_terms: D000328:Adult; D000932:Antiemetics / Q000008:administration & dosage / Q000009:adverse effects / Q000627:therapeutic use*; D004305:Dose-Response Relationship, Drug; D004329:Droperidol / Q000008:administration & dosage / Q000009:adverse effects / Q000627:therapeutic use*; D006801:Humans; D020250:Postoperative Nausea and Vomiting / Q000517:prevention & control*; D016032:Randomized Controlled Trials as Topic; D013223:Statistics as Topic; D016896:Treatment Outcome
chemical_list: D000932:Antiemetics; D004329:Droperidol