Pain Relief and Palliative Care Unit, La Maddalena Cancer Center, Palermo, Italy.
Pain Med. 2012 Mar;13(3):399-404. doi: 10.1111/j.1526-4637.2012.01334.x. Epub 2012 Feb 23.
The aim of this study was to retrospectively review the chart of cancer patients switched to methadone for unfavorable response to the previous opioid.
Retrospective reviewed consecutive medical records of patients undergoing opioid switching to methadone were evaluated. Patients who were switched from different opioids to methadone, because of poor pain relief in the presence of adverse effects limiting further dose increases despite symptomatic treatment, were selected. After the initial oral dose, the subsequent doses were flexible and were changed timely to fit the patients' needs in an attempt to find the best balance between pain and opioid-related symptoms.
Three hundred forty-five patients underwent switching to methadone. Twenty-seven patients were not considered feasible for analysis. Only one patient required the use of naloxone for the occurrence of bradypnea. A total of 77.4% substitutions for methadone were considered successful. The median time to achieve daily dose stabilization in patients successfully switched was 3 days. Fifty-one substitutions failed. For all previous opioids, no significant differences between initial conversion ratios and ratios achieved after stabilization were found (P = 0.42). No significant correlation between the previous opioid dose and the final conversion ratio was found (P = 0.19).
Switching to methadone from different opioids, using an initial fixed ratio followed by a flexible dosing, according to the clinical need, is highly effective and safe when performed in an acute pain relief and palliative care unit. Further studies should assess this approach in other settings.
本研究旨在回顾癌症患者因对先前阿片类药物反应不佳而改用美沙酮的病历。
回顾性评估了接受阿片类药物转换为美沙酮的连续病历。选择了因不良反应限制进一步增加剂量，尽管进行了对症治疗，但仍导致疼痛缓解不佳而从不同阿片类药物转换为美沙酮的患者。初始口服剂量后，后续剂量灵活，并及时调整以适应患者的需求，试图在疼痛和阿片类相关症状之间找到最佳平衡。
共有 345 名患者接受了美沙酮转换。有 27 名患者未被认为可进行分析。只有 1 名患者因呼吸过缓需要使用纳洛酮。总共 77.4%的美沙酮替代被认为是成功的。成功转换的患者达到每日剂量稳定的中位时间为 3 天。有 51 次替代失败。对于所有先前的阿片类药物，初始转换比率与稳定后达到的比率之间没有显著差异（P = 0.42）。先前阿片类药物剂量与最终转换比率之间也没有显著相关性（P = 0.19）。
在急性疼痛缓解和姑息治疗单位，使用初始固定比率，然后根据临床需要灵活调整剂量，将不同阿片类药物转换为美沙酮是高效且安全的。应在其他环境中进一步评估这种方法。
