Amiodarone IV Maintenance Dose
The standard IV maintenance dose of amiodarone is 0.5 mg/min (or 0.4-0.5 mg/kg/hr) for 18 hours after the initial loading phase, then the dosage should be reduced or converted to oral therapy. 1
Dosing Algorithm
The complete IV amiodarone regimen follows this three-phase approach for life-threatening arrhythmias:
Phase 1: Loading Bolus
- 150 mg IV over 10 minutes
- May repeat bolus in 10-30 minutes if necessary
Phase 2: Fast Maintenance Infusion
- 1 mg/min for 6 hours (360 mg total)
Phase 3: Slow Maintenance Infusion
- 0.5 mg/min for 18 hours (540 mg total)
- This is the maintenance dose you're asking about
Phase 4: Transition
Important Dosing Considerations
Concentration limits matter for safety: Do not exceed 2 mg/mL concentration for infusions longer than 1 hour unless using a central venous catheter, as higher concentrations cause peripheral vein phlebitis 2. The FDA label specifically warns that concentrations >3 mg/mL are associated with high incidence of phlebitis.
Pediatric dosing differs significantly: In infants and children, the maintenance dose is 5-25 mcg/kg/min (not the adult 0.5 mg/min), with stepwise increases until arrhythmia control 3, 4.
Transition to Oral Therapy
When converting from IV to oral amiodarone, the oral dose depends on duration of IV therapy 1:
- <1 week IV: Start 800-1,600 mg/day oral
- 1-3 weeks IV: Start 600-800 mg/day oral
- >3 weeks IV: Start 400 mg/day oral
This accounts for amiodarone's 50% oral bioavailability and long half-life 2.
Critical Safety Warnings
Monitor for hypotension and bradycardia during the maintenance infusion, as these are the most common dose-related adverse effects requiring dose reduction 1. The FDA label emphasizes that loading infusions at rates faster than recommended have resulted in hepatocellular necrosis, acute renal failure, and death 2.
Use glass or polyolefin bottles (not PVC) for infusions exceeding 2 hours, as amiodarone adsorbs to PVC tubing and leaches plasticizers 2.