QT Interval Prolongation and Torsades de Pointes Due to a Coadministration of Metronidazole and Amiodarone


Address for reprints: Stavros P. Kounas, M.D., 14 Trapezoudos Str, Drossia 145 72, Athens, Greece. Fax: 0030-210-8137026; e-mail: skounas@hol.gr


This report documents the occurrence of torsades de pointes (TdP) caused by marked QT interval prolongation in the case of a 71-year-old woman receiving both metronidazole and amiodarone for the treatment of pseudomembranous colitis and paroxysmal atrial fibrillation. The case highlights a previously unknown drug interaction. The role of inhibition of cytochrome P-450 CYP3A4 is discussed.