doi:10.1016/j.jemermed.2007.03.053 Clinical Communications: Adults CHRONIC METHADONE THERAPY COMPLICATED BY TORSADES DE POINTES: A CASE REPORT Laura Pimentel, MD*† and Douglas Mayo, MD* *University of Maryland School of Medicine, Baltimore, Maryland and †Department of Emergency Medicine, Mercy Medical Center, Baltimore, Maryland Reprint Address: Laura Pimentel, MD, Department of Emergency Medicine, Mercy Medical Center, 301 St. Paul Pl., Baltimore, MD 21202 e Abstract—Methadone is commonly used by patients pre- senting to the Emergency Department (ED). The common, acute side effects of central nervous system depression and respiratory depression are easily recognizable by treating phy- sicians as attributable to methadone; however, the cardiac toxicity of chronic methadone use recently has only been recognized. Both chronic use of large doses and a recent increase in the daily dose of methadone have been associated with QT prolongation and subsequent development of tor- sades de pointes. We describe the case of a 40-year-old woman whose methadone dose recently had been increased to 135 mg per day. She then presented to the ED with symptomatic torsades de pointes. She was stabilized in the ED by cardio- version and infusions of magnesium sulfate and lidocaine. The markedly prolonged corrected QT interval significantly short- ened after discontinuing methadone. Inpatient cardiology evaluation found no other cause for the dysrhythmia. She was definitively treated with reduction of the daily methadone dose and an implanted cardioverter-defibrillator. © 2008 Elsevier Inc. e Keywords—torsades de pointes; methadone; cardiac tox- icity; implantable cardioverter-defibrillator; drug toxicity INTRODUCTION Patients on chronic methadone therapy are frequently seen in the Emergency Department (ED). Co-morbidities and concurrent use of other drugs, licit and illicit, are common. Expected side effects and toxicities are respi- ratory depression, central nervous system depression, and hypotension. Cardiac toxicity is unusual and only recently recognized. We report the case of a patient on daily oral methadone who presented to our ED symp- tomatic from torsades de pointes (Tdp) after an increase in her daily dose of methadone the previous week. CASE REPORT A 40-year-old woman presented to the ED by ambu- lance. She had been on a bus en route to the methadone clinic when she developed vomiting and tremulousness. The triage nurse placed the patient on a monitor and noted bigeminy. The rhythm quickly deteriorated to ven- tricular tachycardia, and the patient developed seizure- like activity for 5–10 s. The patient was moved to the main resuscitation area, and was immediately evaluated by an emergency physician. She denied chest pain or shortness of breath; the patient admitted to ingestion of wine coolers the previous night, but denied a history of alcoholism or alcohol withdrawal. The past medical his- tory was positive for hypertension, for which she took 100 mg of metoprolol daily. She had no history of other cardiovascular diseases or seizures. The only other re- ported medication was 135 mg of methadone adminis- tered daily at a local methadone clinic for the manage- RECEIVED: 20 September 2006; FINAL SUBMISSION RECEIVED: 6 March 2007; ACCEPTED: 7 March 2007 The Journal of Emergency Medicine, Vol. 34, No. 3, pp. 287–290, 2008 Copyright © 2008 Elsevier Inc. Printed in the USA. All rights reserved 0736-4679/08 $–see front matter 287