[Methadone in the treatment of chronic non-malignant pain]

Abstract

Introduction: The use of methadone may be difficult and its use in the treatment of chronic non-malignant pain is only sparsely described in literature, whereas several works have shown the advantage of methadone in the treatment of cancer pain. The aim of this analysis is to assess the advantages and disadvantages of methadone in the treatment of chronic pain and to evaluate the method used in The Pain Centre of the Funen Region when initiating treatment.

Materials and method: The analysis is retrospective and includes 83 patients in an ambulatory setting with chronic pain who were treated with methadone either as the primary choice of opioid or by rotation with another opioid using a rotation ratio of 10:1 (morphine:methadone) initially and subsequently titrating to maximum effect with fewest adverse events.

Results: Among rotated patients 59% had good pain relief on methadone with a daily dose of 20.5 (1.5-82.5) mg: the frequency for dropping methadone because of adverse events was 24% and 17% because of lack of effect. Among opioid-naive 12% had good pain relief. The daily dose was 3.75 (3.5-4) mg. Here adverse events caused 76% of the cases to discontinue and a lack of effect caused 12% to discontinue.

Conclusion: Opioid treated chronic pain patients with insufficient pain relief may benefit from conversion to methadone, as 59% in our analysis achieved better pain relief, while the rotation was generally opioid-saving at the same time. The method used was safe and acceptable to the patients. The analyses did not result in any fundamental changes to the procedure.