Fluctuating QTc interval in an asymptomatic patient treated with methadone for chronic pain

Authors

  • Katherine Ower, MD, FRCPC
  • Patricia Morley-Forster, MD, FRCPC
  • Dwight Moulin, MD, FRCPC

DOI:

https://doi.org/10.5055/jom.2005.0019

Keywords:

methadone, prolonged QT interval, chronic pain syndrome, electrocardiogram

Abstract

Prolongation of the QT interval associated with ventricular arrhythmias has been the most common cause of the restriction or withdrawal of drugs from the market in the past 10 years. Methadone, a synthetic opioid that is increasingly used for the management of chronic pain, has recently been implicated in the development of the prolonged QT syndrome. We present a case report of a patient who developed a prolonged QT while being treated with oral methadone for a chronic pain syndrome. Of particular interest in this patient is the fluctuation of the QT interval at a stable dose of methadone, suggesting that a single normal electrocardiogram (ECG) does not guarantee that the patient is not at risk of ventricular arrhythmias. After reviewing the current literature, we suggest that there is no dose of methadone that may be considered to be completely safe. Other risk factors for prolonged QT interval such as underlying cardiac abnormalities, electrolyte disturbances, and concurrent medications should be sought, and all patients should be monitored with serial ECGs even when methadone doses remain stable.

Author Biographies

Katherine Ower, MD, FRCPC

Fellow, Department of Anesthesiology and Perioperative Medicine, University of Western Ontario, St. Joseph’s Health Care Center, London, Ontario, Canada.

Patricia Morley-Forster, MD, FRCPC

Associate Professor, Dept of Anesthesiology and Perioperative Medicine, University of Western Ontario, St. Joseph’s Health Care Center, London, Ontario, Canada.

Dwight Moulin, MD, FRCPC

Professor, Departments of Oncology and Clinical Neurological Sciences, University of Western Ontario, London Health Sciences Centre, London, Ontario, Canada.

References

Roden DM: Drug-induced prolongation of the QT interval. N Engl J Med. 2004; 350: 1013-1022.

Hays H, Woodroffe MA: Use of methadone in treating chronic noncancer pain. Pain Res Manage. 1999; 4: 23-27.

Krantz MJ, Lewkowiez L, Hays H, et al.: Torsade de pointes associated with very high-dose methadone. Ann Intern Med. 2002; 137: 501-504.

Krantz MJ, Kutinsky IB, Robertson AD, et al.: Dose-related effects of methadone on QT prolongation in a series of patients with torsade de pointes. Pharmacotherapy. 2003; 23(6): 802-805.

Gil M, Sala M, Anguera I, et al.: QT prolongation and torsades de pointes in patients with human immunodeficiency virus and treated with methadone. Am J Cardiol. 2003; 92: 995-997.

Kornick CA, Kilborn MJ, Santiago-Palmer J, et al.: QTc prolongation associated with intravenous methadone. Pain. 2003; 105: 499-506.

Cruciani RA, Sekine R, Homel P, et al.: Measurement of QTc in patients receiving chronic methadone therapy. J Pain Symptom Manage, in press.

Martell BA, Arnsten JH, Ray B, et al.: The impact of methadone induction on cardiac conduction in opiate users. Ann Intern Med. 2003; 139: 154-155.

Inturrisi CE, Colburn WA, Kaiko RF, et al.: Pharmacokinetics and pharmakodynamics of methadone in patients with chronic pain. Clin Pharmacol Ther. 1987; 41: 392-401.

Fishman SM, Wilsey B, Mahajan G, et al.: Methadone reincarnated: Novel clinical applications with related concerns. Pain Medicine. 2002; 3: 339-348.

Hayes H, Woodroffe MA: High-dose methadone and a possible relationship to serious cardiac arrythmias. Pain Res Manage. 2001; 6: 64.

College of Physicians and Surgeons of Ontario: Methadone for Pain Guidelines. November 2004.

Downloads

Published

05/01/2005

How to Cite

Ower, MD, FRCPC, K., P. Morley-Forster, MD, FRCPC, and D. Moulin, MD, FRCPC. “Fluctuating QTc Interval in an Asymptomatic Patient Treated With Methadone for Chronic Pain”. Journal of Opioid Management, vol. 1, no. 2, May 2005, pp. 73-76, doi:10.5055/jom.2005.0019.

Issue

Section

Articles