Analgesic efficacy of intravenous naloxone for the treatment of postoperative pruritus: A meta-analysis

Objectives: Pruritus may be a significant problem for patients in the postoperative period. There are many options for the treatment of pruritus including intravenous (IV) naloxone. However, it is not clear whether the use of IV naloxone may also affect analgesia or other opioid-related side effects. The authors have performed a systematic review to further examine this issue. Methods: Systematic literature searches of the National Library of Medicine's PubMed and EMBASE databases were conducted using terms related to postoperative use of IV naloxone. Only randomized controlled trials comparing IV naloxone used either as a continuous infusion or part of an IV patient-controlled analgesia (PCA) regimen after surgical procedures were considered. The data on pertinent study characteristics and relevant outcomes were extracted from accepted articles. There was no restriction on language for inclusion. Meta-analysis was performed using the Review Manager 4.2.10 (The Cochrane Collaboration, 2004). A random effects model was used. Results: The literature searches yielded eight articles that met all inclusion criteria. There were a total of 424 subjects in the naloxone group and 376 in the saline group. The authors found that the use of naloxone was associated with a decreased risk for pruritus (odds ratio [OR] = 0.40, 95% confidence interval [CI] = 0.21-0.79, p = 0.006] and nausea [OR = 0.62, 95% CI = 0.43-0.89, p = 0.0091. However, the use of IV naloxone (vs no naloxone) did not significantly influence the risk of postoperative emesis [OR = 0.97, 95% CI = 0.70-1.33, P = 0.83], opioid consumption [OR = 0.29, 95% CI = -3.54-4.13, p = 0.88], or sedation [OR = 0.82, 95% CI = 0.38-1.74, p = 0.60]. Finally, the use of IV naloxone did not appear to be associated with any significant change in visual analog score pain scores at 24 hours postoperatively (weighted mean difference = -0.14, 95% CI= -0.50-0.23, p = 0.46). Conclusions: Our pooled analysis examining the analgesic efficacy of IV naloxone (either as a continuous infusion or IV PCA) revealed that naloxone was associated with a decrease in pruritus and nausea without any increase in pain scores. When compared with controls, the use of IV naloxone was not associated with any significant changes in opioid consumption or with the risk of sedation or emesis.