Review article: Prophylactic metoclopramide for patients receiving intravenous morphine in the emergency setting: a systematic review and meta-analysis of randomized controlled trials.

The objective of the present study was to conduct a systematic review and meta-analysis of randomized controlled trials, comparing metoclopramide with placebo, for preventing vomiting in patients who have received i.v. morphine for acute pain in the emergency setting, and to determine the level of evidence supporting the use of prophylactic metoclopramide in this population. Comprehensive systematic electronic searches were conducted of MEDLINE, EMBASE and the Cochrane Library for randomized controlled trials addressing the clinical question. Reference lists of identified articles were hand-searched. Methodologically appropriate clinical trials identified in the search process were included in a meta-analysis to provide a pooled estimate of effect. Three randomized controlled trials fulfilled the search criteria. All three studies were included in the final meta-analysis that demonstrated an overall result of no difference between metoclopramide and placebo for the primary outcome of vomiting (odds ratios 0.72; 95% confidence intervals 0.11-4.58). There was little evidence that routine prophylactic administration of metoclopramide following the administration of i.v. morphine for acute pain management in the emergency setting is clinically beneficial. Routine metoclopramide administration might expose patients to a risk of harm which is not justifiable given a lack of evidence of benefit.