Preventive Acetaminophen Reduces Postoperative Opioid Consumption, Vomiting, and Pain Scores After Surgery: Systematic Review and Meta-Analysis.

Objective: Preventive analgesia has been proposed as a potential strategy to reduce postoperative pain. However, there is currently no review that focuses on acetaminophen for preventive analgesia.

Methods: We conducted a search of MEDLINE, EMBASE, Cinahl, AMED, and CENTRAL databases identifying randomized controlled trials that compared preventive acetaminophen with postincision acetaminophen.

Results: Seven studies with 544 participants were included. Overall, the studies showed a reduction in 24-hour opioid consumption (standardized mean difference [SMD] of -0.52; 95% confidence interval [95% CI], -0.98 to -0.06), lower pain scores at 1 hour (MD, -0.50; 95% CI, -0.98 to -0.02) and 2 hours (MD, -0.34; 95% CI, -0.67 to -0.01), and a lower incidence of postoperative vomiting (risk ratio, 0.50; 95% CI, 0.31-0.83) in the preventive acetaminophen group. Current studies are limited by a potential risk of bias.

Conclusions: To our knowledge, this is the first review to describe a potential preventive effect of acetaminophen. However, well-conducted randomized controlled trials are necessary to substantiate the conclusions of this review.