Ripamonti C, De Conno F, Groff L, Belzile M, Pereira J, Hanson J, Bruera E
Pain Therapy and Palliative Care Division, National Cancer Institute, Milan, Italy.
Ann Oncol. 1998 Jan;9(1):79-83. doi: 10.1023/a:1008263910494.
Oral methadone is considered to be a valid opioid analgesic alternative to morphine and hydromorphone in treating cancer pain. However, the use of methadone could be complicated by the limited knowledge of the equianalgesic dose/ratio with the other analgesic opioids when switching in tolerant patients.
In two Palliative Care Units, data collected regarding 88 advanced cancer patients with pain switched from different opioids to oral methadone were reviewed and compared with the aim of determining the equianalgesic dose ratio in relation to the dose of opioid previously administered.
The results of this retrospective study suggest that: (1) methadone is much more potent than previously described in literature, (2) the dose ratio between hydromorphone and methadone is higher than as suggested by equianalgesic tables, and (3) the ratio correlates with total opioid dose administered before switching.
The fact that methadone ratio is different according to the opioid dose used previously should be taken into careful consideration by the clinician in order to avoid severe toxicity or death during switchover. Prospective studies should be carried out in order to better define our findings.
口服美沙酮被认为是治疗癌症疼痛时吗啡和氢吗啡酮的一种有效的阿片类镇痛替代药物。然而，在耐受性患者换药时，由于对与其他镇痛阿片类药物的等效镇痛剂量/比率了解有限，美沙酮的使用可能会变得复杂。
在两个姑息治疗单元，回顾并比较了收集的88例晚期癌症疼痛患者从不同阿片类药物换用口服美沙酮的数据，目的是确定与先前使用的阿片类药物剂量相关的等效镇痛剂量比率。
这项回顾性研究的结果表明：（1）美沙酮的效力比文献中先前描述的要强得多；（2）氢吗啡酮与美沙酮之间的剂量比率高于等效镇痛表所建议的比率；（3）该比率与换药前给予的阿片类药物总剂量相关。
临床医生应仔细考虑美沙酮比率因先前使用的阿片类药物剂量而异这一事实，以避免换药期间出现严重毒性或死亡。应开展前瞻性研究以更好地明确我们的研究结果。
