From Dog

Methadone is a synthetic opioid used as a premedicant or analgesic agents in dogs.

It is commonly used as a premedicant in combination with acepromazine[1] or buprenorphine prior to induction of general anesthesia.

High doses can cause cardiorespiratory depression[2] but has the advantages of providing an isoflurane-sparing effect when administered epidurally[3].

Recommended dose rate is 0.2 - 0.2 mg/kg given orally[4], intramuscularly, intravenously[5] or epidurally[6].


  1. Van Vynckt D et al (2011) Evaluation of two sedation protocols for use before diagnostic intra-articular anaesthesia in lame dogs. J Small Anim Pract 52(12):638-644
  2. Garofalo NA et al (2012) Cardiorespiratory and neuroendocrine changes induced by methadone in conscious and in isoflurane anaesthetised dogs. Vet J 194(3):398-404
  3. Campagnol D et al (2012) Comparison of the effects of epidural or intravenous methadone on the minimum alveolar concentration of isoflurane in dogs. Vet J 192(3):311-315
  4. Kukanich B et al (2011) The effects of concurrent administration of cytochrome P-450 inhibitors on the pharmacokinetics of oral methadone in healthy dogs. Vet Anaesth Analg 38(3):224-230
  5. Rocchi A et al (2013) Effect of dexmedetomidine vs. acepromazine-methadone premedication on limb to lung circulation time in dogs. Vet J 195(3):357-360
  6. Bosmans T et al (2012) Comparison of analgesic efficacy of epidural methadone or ropivacaine/methadone with or without pre-operative oral tepoxalin in dogs undergoing tuberositas tibiae advancement surgery. Vet Anaesth Analg 39(6):618-627