Hospital Pharmacy - April 2012 - (Page 285)

Hosp Pharm 2012;47(4):285–288 2012 Ó Thomas Land Publishers, Inc. www.thomasland.com doi: 10.1310/hpj4704-285 Case Report Symptomatic Bradycardia, Syncope, and Prolonged QTc Interval Associated With Dronedarone Therapy Heather Draper Eppert, PharmD, BCPS,p and Kara B. Goddard, PharmD† Abstract Objective: To report a case of symptomatic bradycardia, prolonged QT interval, and syncope associated with dronedarone in a patient with atrial ﬁbrillation who was maintained in sinus rhythm. Case Summary: A 58-year-old man presented to the emergency department with a chief complaint of chest pain and ‘‘passing out.’’ Three months prior, dronedarone had been initiated for maintenance of sinus rhythm. An initial electrocardiogram (ECG) revealed normal sinus rhythm with a prolonged corrected QT (QTc) interval of 645 ms. Upon hospital admission, dronedarone was discontinued. Approximately 17 hours after hospitalization and 35 hours after the last ingested dronedarone dose, a repeat ECG revealed a QTc interval of 457 ms, and the patient reported symptomatic improvement. The patient was discharged home after a 3-day hospital stay without further event. The Naranjo Adverse Drug Reaction Probability Scale indicated a probable relationship between the patient’s symptoms and dronedarone. Discussion: Dronedarone is an antiarrhythmic drug that exhibits multiple mechanisms of action, including potassium, sodium, and calcium channel blockade, in addition to antiadrenegic activity. In clinical evaluations of dronedarone therapy, dronedarone was associated with a mean decrease in resting heart rate and potential to prolong the QT interval by 10 ms. These effects may result in clinically signiﬁcant outcomes, as was observed in this patient. Conclusions: This case of symptomatic bradycardia and prolonged QTc interval emphasizes the importance of monitoring the heart rate and ECG in patients prescribed dronedarone, particularly in those on concomitant drug therapy that may precipitate these events. Key Words—adverse drug reaction, bradycardia, dronedarone, drug-induced arrhythmia, prolonged QT interval, syncope Hosp Pharm—2012;47(4):285–288 A ntiarrhythmic drugs are indicated for the treatment and prevention of cardiac arrhythmias, both atrial and ventricular in nature. However, their use in clinical practice has been limited by their adverse reaction proﬁles.1 Among the potential adverse reactions, cardiovascular effects have been of primary concern. These include bradycardia, hypotension, and development of drug-induced arrhythmias, or proarrhythmias. The risk for these reactions is considered greatest upon initiation of therapy, during dosage titrations, and when multiple causative agents are used in combination.1,2 In addition to medication-related causes, there are several clinical conditions that may contribute to these adverse reactions, including electrolyte abnormalities and cardiovascular disease.1,3 Dronedarone is a derivative of amiodarone that is indicated for the prevention of cardiovascular hospitalization in patients with paroxysmal or persistent atrial ﬁbrillation or ﬂutter.4 The appeal of dronedarone as an antiarrhythmic drug is the reportedly improved safety proﬁle as compared to amiodarone.5,6 *Clinical Specialist, Emergency Medicine, Associate Professor, Department of Clinical Pharmacy, University of Tennessee College of Pharmacy, Knoxville, Tennessee; †Emergency Medicine Pharmacy Resident, Grady Health System, Atlanta, Georgia. Corresponding author: Heather Draper Eppert, PharmD, BCPS, Department of Clinical Pharmacy, University of Tennessee College of Pharmacy, 1924 Alcoa Highway, Box 117, Knoxville, Tennessee 37920; phone: 865-974-2100; fax: 865-974-2022; e-mail: heppert@uthsc.edu Hospital Pharmacy 285 http://www.thomasland.com

Table of Contents for the Digital Edition of Hospital Pharmacy - April 2012

Hospital Pharmacy - April 2012
Editorial
ISMP Medication Error Report Analysis
ISMP Adverse Drug Reactions
Cancer Chemotherapy Update
Off-Label Drug Uses
Original Article
Symptomatic Bradycardia, Syncope, and Prolonged Qtc Interval Associated With Dronedarone Therapy
Extended Stability of Magnesium Sulfate Infusions Prepared in Polyolefin Bags
Formulary Drug Reviews
Continuing Education Case Study Quiz (0.15 CEU)
Current FDA-Related Drug Information
Pharmacy Automation and Technology
Director’s Forum
Hospital Pharmacy Pulse
Index to Advertisers

Hospital Pharmacy - April 2012