Methadone-induced Torsade de pointes tachycardias

Swiss Med Wkly. 2005 May 14;135(19-20):282-5. doi: 10.4414/smw.2005.10939.

Abstract

Methadone is a synthetic opioid frequently used in drug maintenance programs for heroin addicts. It prolongs the QT-interval and is mainly metabolized by the isoenzyme CYP3A4 of the hepatic cytochrome-P450-system, which is used by numerous other QT-prolonging agents. Its most severe side effect is the development of life-threatening Torsade de pointes ventricular tachycardia in the setting of a prolonged QT-interval. Since drug addicts are prone to concomitant medical conditions requiring additional medication as well as to continued abuse of cocaine, they are at higher risk for developing this major complication of methadone therapy. Before subjecting patients on methadone to other drugs, the QT-interval should be determined and it should be ascertained whether the new agent has the property to prolong the QT-interval or is metabolised by the cytochrome-P450 system.

Publication types

  • Review

MeSH terms

  • Adult
  • Analgesics, Opioid / adverse effects*
  • Analgesics, Opioid / therapeutic use
  • Cocaine-Related Disorders / rehabilitation
  • Electrocardiography
  • Female
  • Humans
  • Long QT Syndrome / chemically induced*
  • Long QT Syndrome / physiopathology
  • Male
  • Methadone / adverse effects*
  • Methadone / therapeutic use
  • Torsades de Pointes / chemically induced*

Substances

  • Analgesics, Opioid
  • Methadone