This module dives into how a single intraoperative dose of methadone can transform postoperative pain management for surgical patients. You’ll review methadone’s unique pharmacology as a potent μ-agonist with NMDA antagonism and monoamine reuptake inhibition, and see how its long, stable half-life can smooth out the peaks and troughs of traditional short-acting opioids—improving comfort while reducing total opioid requirements. Practical perioperative dosing strategies are covered in detail, including adjustments for outpatient, inpatient, pediatric, and higher-risk populations, along with safety considerations around respiratory depression, QT prolongation, and drug interactions. By the end, you’ll be equipped to thoughtfully incorporate methadone into multimodal and ERAS pathways as a cost-effective, long-acting analgesic that supports better recovery room and ward outcomes.