Get your analgesic tools ready: The advent of methadone in Canada

Presented by Paulo Steagall, DVM, PhD, Dipl. ACVAA, Associate professor of anesthesia and pain management

Continuing education questionnaire

CE credit: 1

Name

Questions

1. Methadone is a full agonist of opioid receptors similar to morphine and hydromorphone. For this reason, it produces dose-dependent analgesia. *
2. Butorphanol was given to a fearful cat as part of a premedication protocol. Shortly after anesthesia induction, methadone was given intraoperatively for more analgesia. The analgesic effects of methadone should not be affected by the butorphanol. *
3. Common adverse effects of methadone include respiratory depression and bradycardia. Vomiting and nausea are not expected after methadone administration as seen with hydromorphone, for example. *
4. NMDA receptors are involved in central sensitization. Methadone (a NMDA receptor antagonist) can be considered in surgical patients with chronic pain, and for the prevention and treatment of central sensitization and persistent postsurgical pain. *
5. Methadone should not be combined in the same syringe with sedative agents such as acepromazine or dexmedetomidine. *
6. Unless contraindications exist, all surgical patients should be administered a multimodal analgesic protocol, including local anesthetic techniques, non-steroidal anti-inflammatory drugs, and opioids such as methadone. *
7. Methadone should not be administered intravenously due to the increased risk of respiratory depression. *
8. When compared with butorphanol or buprenorphine alone, methadone has superior analgesic effects. *
9. Naloxone is an opioid receptor antagonist usually administered to reverse opioid-induced adverse effects. Nevertheless, the analgesic effects of opioids are maintained after the administration of naloxone. *
10. Analgesic response can vary among animals despite the same surgical procedure and analgesic protocols. Even when multimodal analgesic techniques are used, assessment should be performed during the postoperative period to ensure adequate pain control. *