The efficacy and safety profile of methadone for intractable cancer pain in advanced lung cancer patients: a single-center retrospective analysis of 37 Japanese patients.

[BACKGROUND] For patients suffering from intractable cancer pain, which cannot be sufficiently relieved even with strong opioid analgesics, methadone is recommended in Japan. However, the real-world data on the efficacy and safety of methadone for intractable pain in patients with lung cancer remain scarce in clinical setting. The aim of this clinical study was to investigate the efficacy and safety of methadone for intractable pain in advanced lung cancer patients.

[METHODS] All the cases of advanced lung cancer patients who were administered methadone for intractable pain at the Shizuoka Cancer Center between September 2014 and December 2022 were extracted, and their medical information in the electronic medical records were examined. We investigated pain intensity in Numeric Rating Score (NRS) on the day before and 5 days after the initiation of methadone administration, when methadone blood levels were expected to reach a plateau. In addition, the adverse events possibly caused by methadone were also investigated.

[RESULTS AND CONCLUSIONS] Methadone was prescribed for intractable pain in 37 patients with advanced lung cancer during the study period. The leading cause of intractable pain was bone metastasis (including invasion). Both the pain intensity in NRS and the number of rescue doses were significantly reduced by the introduction of methadone (P < .001). In only two patients, methadone was discontinued due to the side effects thought to be caused by this drug. The results of this study indicated the favorable efficacy and safety profile of methadone for intractable pain in patients with advanced lung cancer.