Amiodarone Maintenance Infusion at 1 mg/min for One Hour
Administering amiodarone at 1 mg/min for one hour delivers 60 mg total and represents the standard maintenance infusion rate used after initial loading doses for life-threatening ventricular arrhythmias. 1, 2
Standard Dosing Protocol
The American Heart Association guidelines establish that after initial loading (150 mg over 10 minutes), amiodarone should be infused at 1 mg/min for 6 hours as part of the first 24-hour regimen, followed by 0.5 mg/min thereafter. 1 Therefore, a 1 mg/min rate for one hour is:
- Part of the standard 6-hour maintenance phase following the loading dose 2
- Delivers 60 mg over that hour (1 mg × 60 minutes)
- Contributes to the recommended ~1000 mg total dose over the first 24 hours 2
Clinical Context and Indications
This infusion rate is appropriate for:
- Hemodynamically stable monomorphic ventricular tachycardia 1
- Polymorphic VT with normal QT interval 1
- Stable irregular narrow complex tachycardia (atrial fibrillation) 1
- Control of rapid ventricular rate in pre-excited atrial arrhythmias 1
Critical Safety Considerations
Administration Requirements
Amiodarone MUST be delivered by volumetric infusion pump—never use drop counter sets, as they can underdose by up to 30%. 2 Additional requirements include:
- Use central venous catheter whenever possible for concentrations >2 mg/mL 2
- Administer through dedicated IV line with in-line filter 2
- Use glass or polyolefin bottles (not evacuated glass containers) for infusions >2 hours 2
- Prepare in D5W only—amiodarone forms precipitates with multiple other solutions 2
Concentration Limits
For peripheral venous access during this 1 mg/min infusion:
- Do not exceed 2 mg/mL concentration to minimize phlebitis risk 2
- Concentrations >3 mg/mL cause high incidence of peripheral vein phlebitis 2
- Central line required for concentrations >2 mg/mL 2
Monitoring for Adverse Effects
The primary risks during this maintenance infusion include:
- Hypotension (most common reason for discontinuation)—slow infusion rate and add vasopressors/volume as needed 1, 2
- Bradycardia—slow or discontinue infusion 1, 2
- Phlebitis at peripheral sites 1
Maximum Duration
Maintenance infusion up to 0.5 mg/min can be continued for 2-3 weeks regardless of age, renal function, or left ventricular function, though experience beyond 3 weeks is limited. 2 The rate may be increased from 0.5 mg/min to achieve arrhythmia suppression, but total 24-hour dose should not exceed 2.2 g (mean daily doses >2100 mg increase hypotension risk). 1, 2
Breakthrough Arrhythmias
If VF or hemodynamically unstable VT recurs during the 1 mg/min maintenance infusion, administer supplemental 150 mg bolus (in 100 mL D5W over 10 minutes). 1, 2
Transition to Oral Therapy
When switching from IV to oral amiodarone after this infusion phase, the oral dose depends on duration of IV therapy. 2 For example, after <1 week of IV therapy at 0.5-1 mg/min, initiate oral amiodarone at 800-1600 mg daily. 2