Perioperative Management Considerations for Patients on Methadone and Buprenorphine

Abstract

Introduction: Patients with chronic pain or opioid use disorders (OUD) are often managed with prescriptions or medication-assisted treatments (MAT) involving methadone and buprenorphine.

The pharmacology and mu opioid receptor (μOR) binding affinity of methadone and buprenorphine presents a multitude of challenges perioperatively, increasing the risk of ineffective pain management, marginalization, opioid withdrawal, and relapse.

Literature review: Thorough preoperative assessment and preparation of patients on methadone and buprenorphine is advised to establish a tailored perioperative plan and postoperative analgesic expectations. Several perioperative pain management guidelines and protocols have been suggested, but there remains a lack of high quality evidence-based research and consensus to guide anesthesia and pain management providers. Appropriate strategies for patients on methadone and buprenorphine requires a multidisciplinary approach that considers the patient’s history with pain management, substance abuse, opioid use or abuse, and history of effective analgesic therapies. Existing case studies, expert opinions, and clinical practice advisories recommend continuation of methadone and buprenorphine perioperatively to avoid regimen disruptions and drug level fluctuations. Most recommendations are also in agreement for providers to implement multimodal analgesia and incorporate regional/neuraxial anesthesia when appropriate.

Description of the case: The patient was a 52-year-old female undergoing spinal cord stimulator removal. Patient’s chart indicated a history of chronic pain and methadone therapy. Preoperative assessment was performed methodically to evaluate patient’s compliance with methadone. Although patient reported to have discontinued methadone therapy approximately six months prior, optimal perioperative pain management was addressed with a short-acting opioid, multimodal analgesia, and local anesthesia infiltration. Patient did not experience postoperative complications or inadequate pain control and was discharged within the same day.

Discussion and conclusions: Methadone is a full μOR agonist with significant analgesic properties and should be continued on the day of surgery. Abrupt discontinuation of methadone can result in opioid withdrawal or place the patient at risk for relapse. Optimal perioperative pain management for patients on methadone includes utilization of short-acting opioid agonists, multimodal analgesia, regional/neuraxial anesthesia, and other non-opioid interventions. Consider incorporating agents such as volatile anesthetics, ketamine, benzodiazepines, acetaminophen, non-steroidal anti-inflammatory drugs (NSAIDs), gabapentinoids, alpha-2 adrenergic receptor agonists, local anesthetics, and regional/neuraxial anesthesia. Buprenorphine is a partial μOR agonist with high receptor binding affinity and slow dissociation properties. Perioperative buprenorphine management varies widely, but many guidelines and protocols recommend continuing buprenorphine preoperatively. Appropriate pain management may be achieved with administration of multimodal analgesia, regional/neuraxial anesthesia, and opioid agonists with similar μOR binding affinity to buprenorphine. Hydromorphone and sufentanil are examples of full μOR agonists with high Ki values that may be used to overcome the receptor.