The incidence and predictors of overall adverse effects caused by low dose amiodarone in real-world clinical practice

• Published in: The Korean journal of internal medicine Vol. 29; no. 5; pp. 588 - 596
• Main Authors: Kim, Hack-Lyoung, Seo, Jae-Bin, Chung, Woo-Young, Kim, Sang-Hyun, Kim, Myung-A, Zo, Joo-Hee
• Format: Journal Article
• Language: English
• Published: Korea (South) The Korean Association of Internal Medicine 01.09.2014; 대한내과학회
• Subjects: Aged; Amiodarone - administration & dosage; Amiodarone - adverse effects; Anti-Arrhythmia Agents - administration & dosage; Anti-Arrhythmia Agents - adverse effects; Arrhythmias, Cardiac - drug therapy; Atrioventricular Block - chemically induced; Atrioventricular Block - epidemiology; Bradycardia - chemically induced; Bradycardia - epidemiology; Female; Humans; Incidence; Male; Middle Aged; Original; Republic of Korea; Retrospective Studies; Risk Factors; 내과학; Republic of Korea; Amiodarone; Adverse effects; Risk factors; Incidence
• ISSN: 1226-3303; 2005-6648; 2005-6648
• DOI: 10.3904/kjim.2014.29.5.588

Most current knowledge regarding amiodarone toxicity derives from clinical trials. This study was performed to investigate the incidence and risk factors of overall adverse effects of amiodarone in real-world practice using a large sample size. Between January 1, 2000 and March 10, 2012, a total of 930 consecutive patients who had been treated with amiodarone for arrhythmia were reviewed retrospectively. An amiodarone-associated adverse event was considered in cases of discontinuation or drug dose reduction due to an unexpected clinical response. The mean daily dose of amiodarone was 227 ± 126 mg, and the mean duration was 490 ± 812 days. During the mean follow-up duration of 982 ± 1,137 days, a total of 154 patients (16.6%) experienced adverse effects related to amiodarone, the most common being bradycardia or conduction disturbance (9.5%). Major organ toxicities in the thyroid (2.5%), liver (2.2%), eyes (0.6%), and lungs (0.3%) were rare. All patients recovered fully without complications after amiodarone discontinuation or dose reduction. The only independent predictor of adverse effects was the duration of amiodarone treatment (odds ratio, 1.21; 95% confidence interval, 1.03 to 1.41; p = 0.016, per year). Low-dose amiodarone is well tolerated in a real-world clinical population. Further studies with a prospective design are needed to confirm this finding.