Perioperative Methadone for Spine Surgery: A Scoping Review.

Complex spine surgery is associated with significant acute postoperative pain. Methadone possesses pharmacological properties that make it an attractive analgesic modality for major surgeries. This scoping review aimed to summarize the evidence for the perioperative use of methadone in adults undergoing complex spine surgery. The review was conducted according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses extension for Scoping Reviews (PRISMA-ScR). A search was performed using MEDLINE, CINAHL, Cochrane Library, Scopus, Embase, and Joanna Briggs between January 1946 and April 2023. The initial search identified 317 citations, of which 12 met the criteria for inclusion in the review. There was significant heterogeneity in the doses, routes of administration, and timing of perioperative methadone administration in the included studies. On the basis of the available literature, methadone has been associated with reduced postoperative pain scores and reduced postoperative opioid consumption. Though safety concerns have been raised by observational studies, these have not been confirmed by prospective randomized studies. Further research is required to explore optimal methadone dosing regimens, the potential synergistic relationships between methadone and other pharmacological adjuncts, as well as the potential long-term antinociceptive benefits of perioperative methadone administration.