title: Torsade de pointes associated with very-high-dose methadone.
abstract: BACKGROUND
  Methadone is an effective treatment for opioid dependency and chronic pain. A methadone derivative, levacetylmethadol, was withdrawn from the European market after being associated with torsade de pointes. To date, no association between methadone and this arrhythmia has been described.
  
  
  OBJECTIVE
  To evaluate a series of methadone-treated patients experiencing torsade de pointes.
  
  
  METHODS
  Retrospective case series.
  
  
  METHODS
  Methadone maintenance treatment programs in the United States and a pain management center in Canada.
  
  
  METHODS
  17 methadone-treated patients who developed torsade de pointes.
  
  
  METHODS
  Chart review for concomitant arrhythmia risk factors and quantification of corrected QT interval (QTc).
  
  
  RESULTS
  The mean daily methadone dose was 397 +/- 283 mg, and the mean QTc interval was 615 +/- 77 msec. Fourteen patients had a predisposing risk factor for arrhythmia. A cardiac defibrillator or pacemaker was placed in 14 patients; all 17 patients survived.
  
  
  CONCLUSIONS
  This series raises concern that very-high-dose methadone may be associated with torsade de pointes. Given the likely expansion of methadone treatment into primary care, further investigation of these findings is warranted.
authors.affiliation: Denver Health Medical Center, and The University of Colorado Health Sciences Center, Bannock Street, Mailcode 0960, Denver, CO 80204-4507, USA.
authors.forename: Mori J
authors.initials: MJ
authors.lastname: Krantz
authors.forename: Laurent
authors.initials: L
authors.lastname: Lewkowiez
authors.forename: Helen
authors.initials: H
authors.lastname: Hays
authors.forename: Mary Ann
authors.initials: MA
authors.lastname: Woodroffe
authors.forename: Alastair D
authors.initials: AD
authors.lastname: Robertson
authors.forename: Philip S
authors.initials: PS
authors.lastname: Mehler
mesh_terms: D000328:Adult; D000701:Analgesics, Opioid / Q000008:administration & dosage / Q000009:adverse effects*; D002170:Canada; D002908:Chronic Disease; D004562:Electrocardiography; D005260:Female; D006556:Heroin Dependence / Q000534:rehabilitation; D006801:Humans; D008297:Male; D008691:Methadone / Q000008:administration & dosage / Q000009:adverse effects*; D008875:Middle Aged; D010146:Pain / Q000188:drug therapy; D012189:Retrospective Studies; D012307:Risk Factors; D016171:Torsades de Pointes / Q000139:chemically induced* / Q000175:diagnosis; D014481:United States
chemical_list: D000701:Analgesics, Opioid; D008691:Methadone