Amiodarone Loading Dose Guidelines

Initial Loading Dose Regimen

The American Heart Association recommends an oral loading dose of amiodarone of 400-600 mg daily in divided doses for 2-4 weeks, followed by a maintenance dose of 100-200 mg daily, for patients with arrhythmias 1
For ventricular arrhythmias, the American Academy of Family Physicians suggests starting with 800-1600 mg per day in divided doses until a total of 10 g has been administered, then transitioning to maintenance therapy of 200-400 mg per day 2
For atrial fibrillation, the American Academy of Family Physicians recommends using 600-800 mg per day in divided doses until a total of 10 g has been given, then reducing to a maintenance dose of 200 mg per day 2
Higher initial loading doses (up to 1200 mg daily) may be considered in an inpatient monitoring setting, though this increases the risk of adverse effects, according to the American College of Cardiology 1

Monitoring is essential during loading: watch for bradycardia, QT prolongation, hypotension, and heart block, as recommended by the American Academy of Family Physicians 2
Amiodarone has a very long half-life, and the full antiarrhythmic effect may take days to weeks to develop despite adequate serum levels, according to the American College of Cardiology 3
The American College of Cardiology recommends reducing the dose if side effects occur, and monitoring for pulmonary toxicity, thyroid dysfunction, and hepatic toxicity during long-term therapy 1

For patients receiving IV amiodarone for less than one week, the American Academy of Family Physicians suggests transitioning to 800-1600 mg oral amiodarone per day 2
For patients receiving IV amiodarone for 1-3 weeks, the American College of Cardiology recommends transitioning to 600-800 mg oral amiodarone per day 3
For patients receiving IV amiodarone for more than 3 weeks, the American College of Cardiology suggests transitioning to 400 mg oral amiodarone per day 3

The American College of Cardiology recommends avoiding coadministration with other QT-prolonging medications without expert consultation, and being aware of significant drug interactions, particularly with warfarin and digoxin 1
The American Academy of Pediatrics recommends avoiding coadministration with other QT-prolonging medications without expert consultation 4

The American Heart Association, American College of Cardiology, and Heart Rhythm Society recommend oral loading of 400-600 mg daily in divided doses for 2-4 weeks, followed by maintenance of 100-200 mg daily for rhythm control, although this applies to patients starting oral therapy de novo, not those transitioning from IV therapy who have already received significant drug loading 5
Patients who have been on IV amiodarone for 1-3 weeks have already accumulated significant tissue stores during this period, and lower oral doses are sufficient to maintain therapeutic levels 5

The American Heart Association, American College of Cardiology, and Heart Rhythm Society suggest reducing to maintenance dosing of 200-400 mg daily, or even lower (100-200 mg daily) if tolerated, after the initial transition period, as virtually all patients develop side effects at higher maintenance doses 5