Tolerance of High-Dose Oral Amiodarone for Cardioversion of Atrial Flutter

In atrial arrhythmias, amiodarone is usually given either intravenously for acute management, requiring in-hospital monitoring, or orally for chronic control, as doses given 60 times per half-life, requiring weeks to reach full effect. A high-risk, 245-kg male with heart failure exacerbated by atrial flutter was successfully cardioverted using an atypically large, 8000-mg oral amiodarone dose. The only adverse effect was transient sinus arrest, which did not require intervention, only 24 hours of inpatient monitoring. Amiodarone's unique pharmacokinetics, including its long elimination half-life and its extensive distribution into a large volume of adipose tissue, make high-dose oral amiodarone boluses a reasonable strategy for cardioversion of atrial arrhythmias.