Background and Aims: Cancer pain significantly impacts patient well-being, with a high prevalence in India. While the World Health Organisation pain ladder is effective, a substantial proportion of patients experience opioid-refractory pain. Methadone, with its unique multi-modal analgesic mechanisms such as mu-receptor agonism, N-Methyl-D-Aspartate antagonism and serotonin/norepinephrine reuptake inhibition, offers a valuable option for such cases, despite its variable pharmacokinetics and potential for adverse effects, such as corrected QT (QTc) prolongation. Methods: This retrospective audit was conducted on a prospectively maintained database of 29 adult cancer patients with chronic pain who received methadone at a tertiary cancer care centre in India from March 2023 to June 2024. Demographics, pain severity (numeric rating scale, NRS), prior opioid use, methadone dosing regimens and reported adverse effects were collected. Institutional Review Board approval was obtained, with a waiver of individual consent. Results: At methadone initiation, 27 out of 29 patients reported severe pain (NRS 7-10). The majority had a neuropathic pain component. Twenty-seven patients were on strong opioids, of whom 22 were switched to methadone due to inadequate pain control. Methadone was most commonly started at 15–20 mg/day, at 6 to 8 hourly intervals. Two out of 28 patients who came for the first follow-up after initiation of methadone reported severe pain, resulting in a meaningful reduction in severe pain prevalence. By the second follow-up, attrition of 8 of 29 patients was noted, attributable to disease progression, inability to report to the pain clinic due to functional decline and death. One patient developed QTc prolongation (>463 ms) at 45 mg/day. Constipation was the most commonly reported adverse effect, resulting in a few discontinuations. Conclusion: Methadone is effective for refractory cancer pain. Its use requires cautious initiation and titration due to inter-individual variability and adverse effects like QTc prolongation. This audit highlights methadone’s utility in a real-world clinical setting.
Chowdhury et al. (Thu,) studied this question.