Torsades de Pointes on Chronic Methadone Use

Methadone is a drug associated with the development of prolonged Correcred QT (QTc) interval, as QT interval prolongation can occur in up to 15% of methadone-maintenance patients. In recent years, methadone found to be associated with an increased risk of sudden death in a community-based study (1, 2). ‘‘Torsades de Pointes’’ is a quick and dangerous rhythm that quickly becomes ventricular fibrillation. If this rhythm is rapid or prolonged, it can lead to ventricular fibrillation or sudden cardiac death. The usual clinical manifestations of TdP are palpitations, dizziness, and syncope. It is certain that no cardiac drugs are recognized to increase the propensity for TdP. The most common risk factors of methadone-associated QT prolongation and TdP include a high dose of methadone or chronic use, old age, accompaniment with enhancing drugs methadone levels, infections such as AIDS, old age, low potassium, kidney failure, heart disease, female gender, and cirrhosis of the liver (3). Despite the availability of methadone for over 60 years, only in the past 10 years has this medication received attention for its potential to cause QTc prolongation leading to Torsades de Pointes (4-6). We report 4 cases of methadone-induced Torsades de pointes. Through rapid taper of methadone, the patient’s ECG normalized.