title: Torsade de pointes tachycardia in a patient on dronedarone therapy.
abstract: Dronedarone is a promising, relatively new antiarrhythmic agent characterized by structural similarities to amiodarone but without amiodarone's severe organ toxicity. The proarrhythmic potential of dronedarone, however, is of increasing concern. We describe a 76-year-old woman who had been receiving dronedarone 400 mg twice/day to prevent recurrent atrial tachycardia with rapid ventricular response. Several months later, she came to the emergency department with decompensated congestive heart failure and episodes of atrial tachycardia; digoxin 0.5 mg and furosemide 40 mg were administered intravenously. Thereafter nonsustained torsade de pointes (TdP) tachycardia occurred. She was transferred to the intensive care unit where a dose of amiodarone 150 mg was administered intravenously by mistake. Thereafter, the patient showed sustained TdP necessitating cardiac resuscitation. Dronedarone was discontinued, and digoxin and amiodarone were not administered again. Under dronedarone a relevant QT prolongation was documented that was additionally augmented after concomitant treatment with digoxin and amiodarone. Use of the Naranjo adverse drug reaction probability scale indicated a probable adverse drug reaction to dronedarone (score of 7). To our knowledge, this is the first case report of a patient who experienced TdP tachycardias while receiving dronedarone therapy in connection with a worsening of heart failure and possible drug interactions with digoxin and amiodarone. Clinicians should be aware of this potential adverse drug reaction and perform repeated heart rate-corrected QT (QTc) interval measurements as well as screening for congestive heart failure in patients receiving dronedarone therapy.
authors.affiliation: Department of Cardiology, Division for Rhythmology and Electrophysiology, Charité Universitätsmedizin Berlin, Berlin, Germany.
authors.forename: Martin
authors.initials: M
authors.lastname: Huemer
authors.affiliation: Clinical Pharmacology and Toxicology, Charité Universitätsmedizin Berlin, Berlin, Germany.
authors.forename: Giselle
authors.initials: G
authors.lastname: Sarganas
authors.affiliation: Clinical Pharmacology and Toxicology, Charité Universitätsmedizin Berlin, Berlin, Germany.
authors.forename: Elisabeth
authors.initials: E
authors.lastname: Bronder
authors.affiliation: Clinical Pharmacology and Toxicology, Charité Universitätsmedizin Berlin, Berlin, Germany.
authors.forename: Andreas
authors.initials: A
authors.lastname: Klimpel
authors.affiliation: Department of Clinical Epidemiology, Leibniz Institute for Prevention Research and Epidemiology, Bremen, Germany.|Faculty of Human and Health Sciences, University of Bremen, Bremen, Germany.
authors.forename: Edeltraut
authors.initials: E
authors.lastname: Garbe
authors.affiliation: Department of Cardiology, Division for Rhythmology and Electrophysiology, Charité Universitätsmedizin Berlin, Berlin, Germany.
authors.forename: Wilhelm
authors.initials: W
authors.lastname: Haverkamp
mesh_terms: D000368:Aged; D000638:Amiodarone / Q000009:adverse effects / Q000031:analogs & derivatives*; D000889:Anti-Arrhythmia Agents / Q000009:adverse effects*; D000077764:Dronedarone; D005260:Female; D006801:Humans; D016171:Torsades de Pointes / Q000139:chemically induced*
chemical_list: D000889:Anti-Arrhythmia Agents; D000077764:Dronedarone; D000638:Amiodarone
keywords: cardiac arrest; dronedarone; long QT syndrome; torsade de pointes; ventricular fibrillation; ventricular tachycardia