Amiodarone IV Perfusion Protocol
The standard IV amiodarone protocol consists of a 150 mg bolus over 10 minutes, followed by 1 mg/min for 6 hours, then 0.5 mg/min for 18 hours, with a maximum total dose of 2.2 g over 24 hours. 1
Loading Dose Administration
Initial Bolus:
- 150 mg IV over 10 minutes for rapid loading 2, 3, 1
- Mix in 100 mL D5W to minimize hypotension 1
- Must use volumetric infusion pump, not drop counters (which can underdose by up to 30%) 1
Early Maintenance Phase:
- 1 mg/min for 6 hours (total 360 mg) 2, 3, 1
- This phase provides continued loading while minimizing hemodynamic effects 1
Late Maintenance Phase:
- 0.5 mg/min for 18 hours (total 540 mg) 2, 3, 1
- Combined with initial bolus and early maintenance, total 24-hour dose = 1050 mg 1
Supplemental Dosing for Breakthrough Arrhythmias
- 150 mg supplemental bolus over 10 minutes for breakthrough VF or hemodynamically unstable VT 1
- Mix in 100 mL D5W 1
- Can repeat as needed, but do not exceed 2.2 g total in 24 hours 3, 1
- Mean daily doses above 2100 mg associated with increased hypotension risk 1
Critical Administration Requirements
Infusion Setup:
- Use central venous catheter whenever possible 1
- For peripheral access: concentrations ≤2 mg/mL only (concentrations >3 mg/mL cause high phlebitis rates) 1
- Central line required for concentrations >2 mg/mL 1
- Must use glass or polyolefin bottles for infusions >2 hours 1
- Use in-line filter during administration 1
Concentration Limits:
- ≤2 mg/mL for peripheral IV (infusions >1 hour) 1
- Up to 6 mg/mL via central line 1
- Higher concentrations and faster rates than recommended have caused hepatocellular necrosis, acute renal failure, and death 1
Mandatory Monitoring During Infusion
Continuous monitoring required for: 2, 3
Watch for critical adverse effects:
- Hypotension (most common serious effect, occurred in 23% of patients in one study) 4
- Bradycardia (occurred in 11% in one study) 4
- AV block 2, 1
- Defibrillator must be immediately available 2
Special Clinical Contexts
Life-Threatening Ventricular Arrhythmias:
- Use standard protocol above for VF or hemodynamically unstable VT 2, 1
- Appropriate only after defibrillation and epinephrine in cardiac arrest 2
Atrial Fibrillation Cardioversion:
- Same dosing protocol as above 2, 3
- Conversion typically occurs after 6-8 hours, often requiring ≥1000 mg total dose 3
- Conversion rates: 34-69% with bolus-only, 55-95% with bolus plus continuous infusion 3
Patients with Structural Heart Disease:
- Amiodarone is particularly valuable when Class IC agents contraindicated 3
- Use with caution in moderate-severe LV dysfunction (may cause negative inotropic effects) 3
- However, can be used safely in heart failure patients when monitored appropriately 5, 6
Duration of IV Therapy
- Maintenance infusion (0.5 mg/min) can continue for 2-3 weeks regardless of age, renal function, or LV function 1
- Limited experience beyond 3 weeks of continuous IV therapy 1
- Transition to oral when arrhythmia controlled (see transition protocol below) 1
Transition to Oral Amiodarone
After <1 week IV (720 mg/day maintenance): 1
- 800-1600 mg PO daily 1
After 1-3 weeks IV: 1
- 600-800 mg PO daily 1
After >3 weeks IV: 1
- 400 mg PO daily 1
These recommendations based on 50% oral bioavailability 1
Critical Safety Warnings
Contraindications:
- Severe sinus node dysfunction 2
- Marked sinus bradycardia 2
- Second- or third-degree AV block without pacemaker 2
- Heart transplant recipients 2
Drug Interactions:
- Do not combine with procainamide or other QT-prolonging drugs without expert consultation 2, 3
- Numerous interactions due to effects on multiple ion channels 3
- Extremely long half-life (IV: 9-36 days) causes delayed adverse effects and drug interactions 3
Infusion Rate Warning: