IV Amiodarone Dosing for Life-Threatening Ventricular Arrhythmias

Initial Loading Protocol

The American Academy of Family Physicians recommends administering IV amiodarone as a 150 mg bolus over 10 minutes, followed by 1 mg/min for 6 hours, then 0.5 mg/min for the remaining 18 hours, delivering approximately 1,050 mg total over 24 hours 1, 2
The standard three-phase infusion regimen consists of a rapid loading bolus of 150 mg IV diluted in 100 mL D5W over 10 minutes, a first maintenance phase of 1 mg/min for 6 hours, and a second maintenance phase of 0.5 mg/min for remaining 18 hours 1, 2

For pulseless ventricular tachycardia or ventricular fibrillation unresponsive to defibrillation and epinephrine, the American Heart Association recommends giving 300 mg IV/IO bolus over 10 minutes, with a second 150 mg bolus if the rhythm persists 1, 2

Hypotension occurs in 16-26% of patients receiving IV amiodarone, and the infusion rate should be slowed if hypotension develops 1, 2, 3
Bradycardia and AV block occur in 4.9% of IV patients, and the infusion should be slowed or discontinued if bradycardia develops 1, 3
QT prolongation is common but rarely causes torsades de pointes 1, 4

The American College of Cardiology recommends not administering IV amiodarone in patients with second- or third-degree AV block, marked sinus bradycardia, or sick sinus syndrome unless a functioning pacemaker is in place 2

When administering IV amiodarone with digoxin, the digoxin dose should be reduced by 50% immediately, as amiodarone doubles digoxin levels 3, 5
When administering IV amiodarone with warfarin, the warfarin dose should be reduced by 30-50% and INR should be checked within 3-5 days, as amiodarone significantly increases anticoagulation 3, 5

When converting from IV to oral amiodarone, the American Academy of Family Physicians recommends starting 800-1,600 mg oral daily after <1 week IV, 600-800 mg oral daily after 1-3 weeks IV, and continuing oral loading until 10 grams total accumulated dose 1, 5