Torsades de pointes is a polymorphic ventricular tachycardia characterized by marked QT prolongation on the electrocardiogram. It can be induced by both antiarrhythmic and nonantiarrhythmic drugs, such as quinidine and erythromycin. ⋯ He developed torsades de pointes and subsequently cardiac arrest. Since erythromycin and quinidine are known to cause arrhythmias individually, caution and close monitoring are necessary when the drugs are administered concomitantly.
College of Pharmacy, University of Illinois, Chicago, USA.
Pharmacotherapy. 1997 May 1; 17 (3): 626-30.
AbstractTorsades de pointes is a polymorphic ventricular tachycardia characterized by marked QT prolongation on the electrocardiogram. It can be induced by both antiarrhythmic and nonantiarrhythmic drugs, such as quinidine and erythromycin. No extensive literature documents an interaction between quinidine and erythromycin when the agents are administered orally. A 95-year-old man received oral quinidine and erythromycin for the treatment of atrial fibrillation and community-acquired pneumonia. He developed torsades de pointes and subsequently cardiac arrest. Since erythromycin and quinidine are known to cause arrhythmias individually, caution and close monitoring are necessary when the drugs are administered concomitantly.