Dexmedetomidine for opioid-sparing postoperative analgesia: a systematic review and meta-analysis

Postoperative opioid use is associated with adverse effects and increased risk of long-term dependence. Dexmedetomidine (Dex), a selective alpha-2 adrenergic agonist, has analgesic and sedative properties and may reduce opioid requirements when used perioperatively. This systematic review assessed its efficacy in reducing postoperative opioid consumption and improving recovery outcomes in adult surgical patients. A systematic search of PubMed, Embase, and the Cochrane Library (to 1 May 2025) identified randomised controlled trials comparing intravenous Dex with placebo or standard opioid-based analgesia in adults undergoing surgery. The primary outcome was cumulative opioid consumption in the first 24 h postoperatively. Secondary outcomes included pain intensity, postoperative nausea and vomiting, sedation, haemodynamic events, and indicators of recovery. Data were synthesised using a random-effects model. Risk of bias and certainty of evidence were assessed using the Cochrane Risk of Bias 2 tool and GRADE approach, respectively. This review was prospectively registered in PROSPERO (CRD420251126259). Twenty studies involving 1,793 patients met inclusion criteria. Dex was administered intraoperatively (bolus 0.5–1 µg per kilogram; infusion 0.2–0.7 µg per kilogram per hour) or via patient-controlled analgesia (PCA). Compared with control, Dex significantly reduced 24-hour opioid consumption (mean difference − 7.7 milligrams morphine equivalents; 95% confidence interval − 9.5 to − 6.0; P < 0.001; I² = 46%). Pain scores were lower, and incidence of postoperative nausea and vomiting was reduced. Bradycardia and hypotension were more frequent but typically transient and manageable. Dex is an opioid sparing adjunct that modestly reduces postoperative opioid requirements and is associated with lower pain scores and less postoperative nausea and vomiting. Haemodynamic monitoring is advised during administration, and Dex should be integrated into wider multimodal analgesia pathways rather than used as a stand alone solution to opioid reduction. CRD420251126259.