Evaluation of the effective drugs for the prevention of nausea and vomiting induced by morphine used for postoperative pain: a quantitative systematic review.

Postoperative nausea and vomiting (PONV) with morphine therapy develops in more than 60% of patients after surgery, markedly reducing patient QOL. The prophylactic effect of several antiemetics has already been studied, but evaluations, and even those using the same drug, are not uniform. The present research involved a meta-analysis of randomized controlled trials on prophylactic drug therapy for PONV in patients receiving morphine for the treatment of postoperative pain. The efficacy of the prophylactic administration of the drugs was examined. As a result, meta-analysis of five drugs was possible and the evidence of efficacy was shown for three drugs ranked in order of an increasing odds ratio (OR) and confidence interval (CI): dexamethasone (OR: 0.23, 95% CI: 0.15-0.35, p < 0.00001), droperidol (OR: 0.27, 95% CI: 0.21-0.34, p < 0.00001), and metoclopramide (OR: 0.48, 95% CI: 0.30-0.75, p < 0.001). These results suggest that the three drugs are effective in prophylactic treatment for PONV. Of them, dexamethasone used as a prophylactic drug for PONV provided the best results. Dexamethasone was shown to reduce the incidence of PONV from 66-80% to 16-50% with a dose of 1.25 to 10 mg and to be suitable as a first drug of choice.