Methadone is increasingly being used for its analgesic properties. Despite the increasing popularity, many healthcare providers are not familiar with methadone’s complex pharmacology and best practices surrounding its use. The purpose of this narrative review article is to discuss the pharmacology of methadone, the evidence surrounding methadone’s use in acute pain management and both chronic cancer and non-cancer pain settings, as well as highlight pertinent safety, monitoring, and opioid rotation considerations. Methadone has a unique mechanism of action when compared with all other opioids and for this reason methadone has come to hold a niche role in the management of opioid-induced hyperalgesia and central sensitization. Understanding of the mechanisms of variability in methadone disposition and drug interactions has evolved over the years, with the latest evidence revealing that CYP 2B6 is the major determinant of methadone elimination and plays a key role in methadone-related drug interactions. From an acute pain perspective, most studies evaluating the use of intraoperative intravenous methadone have reported lower pain scores and post-operative opioid requirements. Oral methadone is predominantly used as a second-line opioid treatment for select chronic pain conditions. As a result, several oral morphine to oral methadone conversion ratios have been proposed, as have methods in which to rotate to methadone. From an efficacy standpoint, limited literature exists regarding the effectiveness of methadone in the chronic pain setting with most of the available efficacy data pertaining to methadone’s use in the treatment of cancer pain. Many of the prospective studies that exist feature low participant numbers. Few clinical trials investigating the role of methadone as an analgesic treatment are currently underway. The complicated pharmacokinetic properties of methadone and risks of harm associated with this drug highlight how critically important it is that healthcare providers understand these features before prescribing/dispensing methadone. Particular caution is required when converting patients from other opioids to methadone and for this reason only experienced healthcare providers should undertake such a task. Further randomized trials with larger sample sizes are needed to better define the effective and safe use of methadone for pain management.

美沙酮因其镇痛特性而越来越多地被使用。尽管越来越受欢迎，但许多医疗保健提供者并不熟悉美沙酮的复杂药理学及其使用的最佳实践。这篇叙述性评论文章的目的是讨论美沙酮的药理学、围绕美沙酮在急性疼痛管理以及慢性癌症和非癌症疼痛环境中使用的证据，并强调相关的安全性、监测和阿片类药物轮换注意事项。与所有其他阿片类药物相比，美沙酮具有独特的作用机制，因此美沙酮在管理阿片类药物引起的痛觉过敏和中枢敏化方面发挥了特殊作用。多年来，人们对美沙酮处置和药物相互作用的可变性机制的理解不断发展，最新证据表明，CYP 2B6 是美沙酮消除的主要决定因素，并在与美沙酮相关的药物相互作用中起关键作用。从急性疼痛的角度来看，大多数评估术中静脉注射美沙酮使用的研究都报告了较低的疼痛评分和术后阿片类药物的需求。口服美沙酮主要用作特定慢性疼痛病症的二线阿片类药物治疗。因此，已经提出了几种口服吗啡到口服美沙酮的转化率，以及轮换为美沙酮的方法。从功效的角度来看，关于美沙酮在慢性疼痛环境中的有效性的文献有限，大多数可用的功效数据都与美沙酮在治疗癌症疼痛中的使用有关。现有的许多前瞻性研究的参与者人数都很少。目前很少有临床试验研究美沙酮作为镇痛治疗的作用。美沙酮复杂的药代动力学特性以及与该药物相关的危害风险凸显了医疗保健提供者在开具/配药美沙酮之前了解这些特征的重要性。将患者从其他阿片类药物转换为美沙酮时需要特别小心，因此只有经验丰富的医疗保健提供者才能承担此类任务。需要更大样本量的进一步随机试验来更好地定义美沙酮在疼痛管理中的有效和安全使用。目前很少有临床试验研究美沙酮作为镇痛治疗的作用。美沙酮复杂的药代动力学特性以及与该药物相关的危害风险凸显了医疗保健提供者在开具/配药美沙酮之前了解这些特征的重要性。将患者从其他阿片类药物转换为美沙酮时需要特别小心，因此只有经验丰富的医疗保健提供者才能承担此类任务。需要更大样本量的进一步随机试验来更好地定义美沙酮在疼痛管理中的有效和安全使用。目前很少有临床试验研究美沙酮作为镇痛治疗的作用。美沙酮复杂的药代动力学特性以及与该药物相关的危害风险凸显了医疗保健提供者在开具/配药美沙酮之前了解这些特征的重要性。将患者从其他阿片类药物转换为美沙酮时需要特别小心，因此只有经验丰富的医疗保健提供者才能承担此类任务。需要更大样本量的进一步随机试验来更好地定义美沙酮在疼痛管理中的有效和安全使用。美沙酮复杂的药代动力学特性以及与该药物相关的危害风险凸显了医疗保健提供者在开具/配药美沙酮之前了解这些特征的重要性。将患者从其他阿片类药物转换为美沙酮时需要特别小心，因此只有经验丰富的医疗保健提供者才能承担此类任务。需要更大样本量的进一步随机试验来更好地定义美沙酮在疼痛管理中的有效和安全使用。美沙酮复杂的药代动力学特性以及与该药物相关的危害风险凸显了医疗保健提供者在开具/配药美沙酮之前了解这些特征的重要性。将患者从其他阿片类药物转换为美沙酮时需要特别小心，因此只有经验丰富的医疗保健提供者才能承担此类任务。需要更大样本量的进一步随机试验来更好地定义美沙酮在疼痛管理中的有效和安全使用。