Originally presented by Dr Jason Sritharan

Background

  • Methadone is a drug with unique pharmacokinetics and dynamics
  • It is increasingly being used for analgesia in the intraoperative setting
  • Many anaesthetists are unfamiliar with its dosing regimen so tend to use more familiar opioids

Unique advantages

  • Potent mu opioid receptor agonist
  • Longest half-life of clinically used opioids
  • NMDA receptor antagonist
  • Serotonin re-uptake inhibition
  • Noradrenaline re-uptake inhibition

Evidence

Summary of findings:

  • Intraoperative use of methadone reduced post operative opioid consumption when compared with the use of other opioids intraoperatively
  • Methadone dosing regimens varied between trials. Average dose 0.1-0.2mg/kg
  • There was no statistically significant difference in respiratory complications amongst the studies reviewed

Links

Clinical Effectiveness and Safety of Intraoperative Methadone, 2017.

Intra-operative methadone compared with morphine, 2021.