title: Methadone maintenance dose/weight ratio, long QTc, and EKG screening.
abstract: Electrocardiogram (EKG) monitoring during methadone maintenance treatment (MMT) has been recommended to prevent potentially fatal prolonged computed QT intervals (QTc). However, risk indicators for obtaining EKGs do not exist. This study assessed 23 variables that might help identify prolonged QTc during MMT.
  
  
  
  EKGs concurrent with methadone serum levels were obtained from 69 veterans during a 5-year study, encompassing 302.8 person-years. Two cardiologists hand-measured QT intervals, selecting each patient's longest QTc. QTc categories included: normal duration <440 ms; borderline duration of 440-469 ms; and abnormal duration ≥470 ms. QTc's were compared with seven methadone parameters and 16 bio-psycho-social variables using two QTc cut-offs (440 and 470 ms).
  
  
  
  Among the 69 patients, 19 had normal QTc's, 28 had borderline QTc's, and 22 had abnormal QTc's. Methadone dose/weight was moderately correlated with QTc, and independently associated with longer QTc at both 440 and 470 cut-offs.
  
  
  
  Dose/weight ≥.49 is useful for screening EKGs for QTc's ≥440 cut-off. Dose/weight ≥.65 produces high-yield abnormal QTc's ≥470 cut-off.
  
  
  
  Methadone dose/weight provides moderately reliable thresholds for making routine screening decisions and urgent clinical decisions to obtain an EKG for prolonged QTc. (Am J Addict 2016;25:499-507).
authors.affiliation: Mental Health Service, Minneapolis VA Medical Center, Minneapolis, Minnesota.
authors.forename: Joseph
authors.initials: J
authors.lastname: Westermeyer
authors.affiliation: Cardiology Service, Minneapolis VA Medical Center, Minneapolis, Minnesota.|Department of Medicine, Health Sciences Center, University of Minnesota, Minnesota.
authors.forename: Selcuk
authors.initials: S
authors.lastname: Adabag
authors.affiliation: Cardiology Service, Minneapolis VA Medical Center, Minneapolis, Minnesota.|Department of Medicine, Health Sciences Center, University of Minnesota, Minnesota.
authors.forename: Vidhu
authors.initials: V
authors.lastname: Anand
authors.affiliation: Mental Health Service, Minneapolis VA Medical Center, Minneapolis, Minnesota.
authors.forename: Paul
authors.initials: P
authors.lastname: Thuras
authors.affiliation: Mental Health Service, West Haven VA Medical Center, West Haven, Connecticut.|Department of Psychiatry, Yale University, Connecticut.
authors.forename: Gihyun
authors.initials: G
authors.lastname: Yoon
authors.affiliation: Mental Health Service, Minneapolis VA Medical Center, Minneapolis, Minnesota.
authors.forename: Tegan
authors.initials: T
authors.lastname: Batres-Y-Carr
mesh_terms: D000328:Adult; D001835:Body Weight; D053840:Brugada Syndrome; D000075224:Cardiac Conduction System Disease; D004305:Dose-Response Relationship, Drug; D004562:Electrocardiography / Q000379:methods*; D005260:Female; D006801:Humans; D008133:Long QT Syndrome / Q000139:chemically induced / Q000175:diagnosis / Q000517:prevention & control; D008297:Male; D008403:Mass Screening / Q000379:methods*; D008691:Methadone / Q000008:administration & dosage / Q000009:adverse effects; D008875:Middle Aged; D009294:Narcotics / Q000008:administration & dosage / Q000009:adverse effects; D058850:Opiate Substitution Treatment / Q000009:adverse effects / Q000379:methods; D009293:Opioid-Related Disorders / Q000628:therapy*; D012307:Risk Factors; D013223:Statistics as Topic; D058014:Veterans Health
chemical_list: D009294:Narcotics; D008691:Methadone