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

Context: 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.

Objectives: To test the efficacy of low-dose droperidol in the prevention of PONV in adults and to test for dose-responsiveness.

Design: Systematic review of randomised controlled trials with meta-analyses.

Data sources: 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.

Eligibility criteria: 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.

Conclusion: 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.