PurposeThe aim of this study was to examine the clinical effects of switching from transdermal (TTS)fentanyl to methadone, or vice versa, in patients with a poor response to the previous opioid.Patients and MethodsA prospective study was carried out on 31 patients who switched from TTS fentanyl to oralmethadone, or vice versa, because of poor opioid response. A fixed conversion ratio offentanyl to methadone of 1:20 was started and assisted by rescue doses of opioids, and thendoses were changed according to clinical response. Pain and symptom intensity, expressedas distress score, were recorded before switching doses of the two opioids and aftersubsequent doses. The number of changes of the daily doses, time to achieve stabilization,and hospital stay were also recorded.ResultsEighteen patients were switched from TTS fentanyl to methadone, and seven patients wereswitched from methadone to TTS fentanyl. A significant decrease in pain and symptomintensity, expressed as symptom distress score, was found within 24 hours after switchingtook place in both directions. Unsuccessful switching occurred in six patients, who weresubsequently treated with an alternative therapy.ConclusionA rapid switching using an initial fixed ratio of fentanyl to methadone of 1:20 is an effectivemethod to improve the balance between analgesia and adverse effects in cancer patientswith poor response to the previous opioid. No relationship between the final opioid dose andthe dose of the previous opioid has been found.
|Rivista||Journal of Clinical Oncology|
|Stato di pubblicazione||Published - 2005|
All Science Journal Classification (ASJC) codes