Corrected QT Interval Prolongation in Pediatric and Young Adult Patients on Methadone for Cancer-Related Pain

J Pain Symptom Manage. 2019 Oct;58(4):678-684. doi: 10.1016/j.jpainsymman.2019.05.021. Epub 2019 Jun 11.


Context: Methadone has been reported to prolong the corrected QT (QTc) interval and increase the risk of torsades de pointes.

Objectives: Our study examined the frequency of QTc prolongation among pediatric and young adult patients starting methadone for cancer pain.

Methods: All patients followed a standardized protocol. Electrocardiograms (ECGs) were obtained at baseline (methadone starting day to 14 days prior), 1-2 weeks, and 4-6 weeks later. QTc values were manually calculated using the Bazett formula. QTc prolongation was defined as ≥460 milliseconds (ms) for prepubertal children, ≥470 ms for pubertal males, and ≥480 ms for pubertal females.

Results: Baseline ECGs were completed in 42 patients. Follow-up ECGs were completed in 38 of 42 (91%) and 31 of 42 (74%) patients at 1-2 weeks and 4-6 weeks, respectively. No patients had prolongation of the QTc at baseline, and 1 of 38 (3%) patients had a prolonged QTc at weeks 1-2. This patient had a history of prolonged QTc that the family did not initially report. No patients had prolongation of the QTc at weeks 4-6. No patients had torsades de pointes or ventricular fibrillation, and none died suddenly. Median (interquartile range [IQR]) baseline QTc was 391 (377-400) ms; median (IQR) 1-2 week follow-up QTc was 399 (374-411) ms (P = .05), and median (IQR) 4-6 week follow-up QTc was 393 (379-423) ms (P = .01).

Conclusion: Clinically significant prolongation of the QTc interval occurred only in one patient who had a history of prolonged QTc. Prolonged QTc is rare in this population.

Keywords: Palliative Care; cardiotoxicity; pain management; pediatric; pediatric oncology.

MeSH terms

  • Adolescent
  • Adult
  • Age Factors
  • Analgesics, Opioid / therapeutic use*
  • Cancer Pain / drug therapy*
  • Cancer Pain / pathology
  • Child
  • Child, Preschool
  • Electrocardiography
  • Female
  • Humans
  • Infant
  • Long QT Syndrome / chemically induced*
  • Long QT Syndrome / diagnosis
  • Long QT Syndrome / epidemiology*
  • Male
  • Methadone / therapeutic use*
  • Retrospective Studies
  • Risk Factors
  • Young Adult


  • Analgesics, Opioid
  • Methadone