Effects of Methadone on Corrected Q-T Interval Prolongation in Critically Ill Children

Abstract

OBJECTIVESThis study aimed to determine the association between methadone use and corrected Q-T interval (QTc) prolongation in critically ill children METHODS A retrospective cohort study of critically ill children receiving methadone at a tertiary care pediatric hospital was conducted. Patients younger than 19 years who had been admitted to the intensive care unit between January 1, 2009, and June 21, 2013, who had received methadone while inpatients, and who had had electrocardiograms (ECGs) performed within 30 days before and after methadone initiation were included. The primary outcome was the net change in QTc interval between baseline and postmethadone ECGs. Secondary outcomes included percent change in QTc interval and the proportion of patients whose QTc intervals changed from normal to prolonged following methadone initiation. We also evaluated potential predictors of QTc interval prolongation, including age, sex, admission diagnosis category, exposure to other QTc-prolonging medications, presence of congenital heart disease or known arrhythmias, and methadone daily dose and route of administration.RESULTS Sixty-four patients met the inclusion criteria. The median (25th, 75th percentiles) change in QTc interval following methadone initiation was −8 msec (−34, 13.5 msec; p = 0.19). Five patients (8%) had a baseline normal QTc interval that became prolonged after methadone initiation. We identified no statistically significant predictors of QTc prolongation after methadone initiation.CONCLUSIONS In this dedicated pediatric safety study, methadone initiation did not result in prolongation of the QTc interval. Although these findings suggest methadone initiation may not have a substantial effect of QTc prolongation in critically ill children, a controlled, prospective evaluation in this population remains warranted.

How to Prescribe Drugs With an Identified Proarrhythmic Liability

“…In contrast to the medical specialties focusing on LQTS, drug‐induced QT prolongation is relevant to a much wider group of health care professionals involved in therapeutic decisions, for example, physicians in family practice and a wide variety of medical specialties, physician assistants, nurses, and pharmacists and hence this article's focus on this topic. A wide range of drugs and drug classes for many conditions as diverse as liver and kidney disease, chronic obstructive pulmonary disease, psychiatric conditions, and posttraumatic stress disorder have an identified proarrhythmic liability. If prescribed to patients with certain risk factors, they can occasionally precipitate bradyarrhythmias and tachyarrhythmias, including TdP.…”