Post-operative nausea and vomiting (PONV) observed in a clinical study designed to assess the analgesic effects of intravenous and subcutaneous methadone in dogs.

Opioids are a key component of multimodal analgesia. Methadone is licensed in Europe for IV, IM and SC use in dogs despite there being no published studies assessing the analgesic efficacy of SC administration. Our intention was to compare the analgesic effect of IV or SC methadone. Fifteen dogs presenting for stifle surgery were administered 0.4mg/kg methadone IV followed by a randomised 0.4mg/kg methadone IV or SC dose 3h later. All dogs received ultrasound-guided sciatic and saphenous nerve blocks with bupivacaine prior to surgery. This protocol resulted in opioid adverse effects (hypersalivation, vomiting and/or regurgitation) in 5/15 dogs (33%). Thus, in consultation with the ethical review committee, an otherwise identical protocol using a revised 0.2mg/kg methadone dose was implemented. In the next three dogs studied, similar opioid adverse effects were found in all three dogs and the study was terminated. This paper highlights the potential for post operative nausea and vomiting (PONV), which may have been induced by methadone when used in combination with efficacious locoregional anaesthesia.

[1]  C. Sandersen,et al.  Opioid requirements after locoregional anaesthesia in dogs undergoing tibial plateau levelling osteotomy: a pilot study. , 2021, Veterinary anaesthesia and analgesia.

[2]  J. Murrell,et al.  A comparison between methadone and buprenorphine for perioperative analgesia in dogs undergoing ovariohysterectomy , 2018, The Journal of small animal practice.

[3]  F. Corletto,et al.  A retrospective comparison of two analgesic strategies after uncomplicated tibial plateau levelling osteotomy in dogs. , 2018, Veterinary anaesthesia and analgesia.

[4]  A. Zorrilla-Vaca,et al.  The role of sciatic nerve block to complement femoral nerve block in total knee arthroplasty: a meta-analysis of randomized controlled trials , 2018, Journal of Anesthesia.

[5]  T. Schiller,et al.  Blood concentration of bupivacaine and duration of sensory and motor block following ultrasound-guided femoral and sciatic nerve blocks in dogs , 2018, PloS one.

[6]  D. Campagnol,et al.  Effects of three methadone doses combined with acepromazine on sedation and some cardiopulmonary variables in dogs. , 2017, Veterinary anaesthesia and analgesia.

[7]  G. Homanics,et al.  Pathophysiological and neurochemical mechanisms of postoperative nausea and vomiting. , 2014, European journal of pharmacology.

[8]  M. Gurney,et al.  Peripheral nerve blocks of the pelvic limb in dogs: A retrospective clinical study , 2012, Veterinary and Comparative Orthopaedics and Traumatology.

[9]  U. Bondesson,et al.  Clinical pharmacology of methadone in dogs. , 2010, Veterinary anaesthesia and analgesia.

[10]  D. Campagnol,et al.  Comparative study on the sedative effects of morphine, methadone, butorphanol or tramadol, in combination with acepromazine, in dogs. , 2009, Veterinary anaesthesia and analgesia.

[11]  D. Campagnol,et al.  Effects of methadone, alone or in combination with acepromazine or xylazine, on sedation and physiologic values in dogs. , 2008, Veterinary anaesthesia and analgesia.

[12]  J. Willems,et al.  Emetic and antiemetic effects of opioids in the dog. , 1986, European journal of pharmacology.