Voici une étude plus récente beaucoup plus positive en soins palliatifs

" 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.

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. "

Conclusions

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.

Mercadante S. A 10-Year Experience of 345 Patients in an Acute Palliative   Care Unit. Pain Medicine 2012 Feb.