Hawley Pippa, Chow Lawrance, Fyles Gillian, Shokoohi Aria, O'Leary Mary-Jane, Mittelstadt Matthew
1 Division of Palliative Care, University of British Columbia , Vancouver, British Columbia, Canada .
2 Pain and Symptom Management/Palliative Care, British Columbia Cancer Agency , Vancouver, British Columbia, Canada .
J Palliat Med. 2017 Nov;20(11):1244-1251. doi: 10.1089/jpm.2017.0090. Epub 2017 Jun 8.
Methadone has been shown to be effective for cancer pain. Most published switching methods are complete in less than three days, requiring very close supervision, usually in an inpatient setting. This need for hospitalization is a barrier to access. We present a large retrospective study of slow outpatient methadone starts and describe our starting method.
Charts were reviewed of patients referred to the Pain and Symptom Management/Palliative Care clinics at the six BC Cancer Agency's regional centers that underwent initiation of methadone for analgesia over a 14-year period. Patient characteristics, method of start, and outcomes of methadone treatment were recorded.
Of the 652 identified patients, we were able to determine outcomes of methadone initiation in 564 (86.5%). Among these, 422 (74.8%) were deemed successful initiations, as determined by whether or not the patient remained on methadone at follow-up with subjective improvement in pain control, on a stable dose of methadone. Of the unsuccessful trials, 97/142 were primarily due to adverse events, 16 of which were considered serious enough to require hospitalization, including two due to sudden cessation of opioid therapy leading to withdrawal. Some of the included adverse events were not necessarily causal from the initiation of methadone, for example, development of bowel obstruction or delirium. Only one death occurred from a deliberate overdose of multiple medications, including methadone.
Initiation of methadone for analgesia in ambulatory cancer patients can be done safely in an outpatient setting using a start-low go-slow method, and can be expected to be helpful in ∼75% of patients. Discontinuation is more likely to be for side effects than for inadequate analgesia. Access to methadone therapy can safely be widened by slow initiation, avoiding more dangerous rapid switching protocols and reducing the need for hospitalization.
美沙酮已被证明对癌症疼痛有效。大多数已发表的换药方法在不到三天内完成，需要非常密切的监测，通常是在住院环境中。这种住院需求是获得治疗的一个障碍。我们进行了一项关于门诊缓慢启动美沙酮治疗的大型回顾性研究，并描述我们的启动方法。
回顾了在14年期间转诊至不列颠哥伦比亚癌症机构六个区域中心的疼痛与症状管理/姑息治疗诊所并开始使用美沙酮镇痛的患者病历。记录患者特征、启动方法和美沙酮治疗结果。
在652名确定的患者中，我们能够确定564名（86.5%）患者美沙酮启动的结果。其中，422名（74.8%）被视为启动成功，这是根据患者在随访时是否继续使用美沙酮以及疼痛控制主观改善情况、美沙酮剂量是否稳定来确定的。在未成功的试验中，97/142主要是由于不良事件，其中16例被认为严重到需要住院治疗，包括2例因突然停止阿片类药物治疗导致戒断反应。一些纳入的不良事件不一定是美沙酮启动所致，例如肠梗阻或谵妄的发生。仅1例死亡是由于故意过量服用包括美沙酮在内的多种药物。
门诊癌症患者使用美沙酮镇痛可采用低剂量起步、缓慢增加剂量的方法在门诊安全启动，预计约75%的患者会从中受益。停药更可能是由于副作用而非镇痛不足。通过缓慢启动美沙酮治疗，可以安全地扩大其可及性，避免更危险的快速换药方案，并减少住院需求。
