QT Prolongation and Arrhythmia Risk in Methadone Maintenance Treatment

Methadone maintenance therapy (MMT) is the most widely prescribed and most effective treatment for opioid dependence. Methadone is a long-acting synthetic opioid that is a potent blocker of the delayed rectifier potassium ion channel, which may result in QT interval prolongation (QTP) and increased risk of torsades de pointes (TdP) in susceptible individuals. MMT-associated TdP is rare; however, its gravity has prompted a re-examination of the risks and benefits of MMT. This article reviews the current understanding of the benefits and the arrhythmia risk of MMT and presents a perspective on current primary and secondary prevention strategies, including advances that may alter future management.