When methadone fails in cancer pain management. A retrospective analysis.

Background: Methadone is increasingly used. It is expected that some patients will lose the analgesic response or develop adverse effects. Opioid switching (OS) from methadone to other opioids has not been well described METHODS: The charts of patients with cancer pain receiving methadone, both intravenously and orally were reviewed for a period of 2 years (2023-2024). Patients who were switched from methadone, prescribed prior to or during admission to APCU were collected and analyzed. Epidemiological data were recorded. Opioid drugs, doses and route of administration prior to admission, at admission and at discharge were recorded.

Results: In the period taken into consideration ten patients were switched from methadone to other opioids. The final treatment included morphine and transdermal buprenorphine, in four and four patients, respectively, intravenous fentanyl in one patient, and spinal analgesia in one patient. Significant improvements were reported at time of discharge for most symptoms, with a decrease of total burden (P=0.005).

Conclusion: OS from methadone was effective in most cases, but the treatment was challenging as higher doses of opioids are expected, due to the loss of the extra-opioid analgesic effects of methadone.