Wojciech Leppert

Chair and Department of Palliative Medicine, Poznan University of Medical Sciences, Osiedle Rusa 25 A, 61-245 Poznan, Poland.

Abstract  

Morphine or other strong opioids (fentanyl, oxycodone, hydromorphone, buprenorphine) are usually administered in patients with severe cancer and chronic non-malignant pain. However, when these analgesics are ineffective in terms of analgesia or induce intractable adverse effects, a switch to methadone might prove beneficial. Consequently methadone is used in opioid rotation (switch) when other opioids have failed. Methadone may be considered as the first strong opioid, especially in patients with neuropathic pain and renal failure. Still, methadone dosing is more difficult than dosing of other strong opioids due to unpredictable pharmacokinetics, numerous drug interactions and a possibility of QTc interval prolongation. Preferably, methadone should be prescribed by physicians experienced in cancer and chronic pain management. The knowledge on methadone cardiotoxicity among health care professionals is limited. The aim of this article is to outline methadone drug interactions and adverse effects with focus on the QTc interval prolongation. Several recommendations grounded in the literature review are provided to clinicians who use methadone in pain management.