Maximum Amiodarone Boluses After Two Doses
You can give one additional 150 mg bolus of amiodarone for a total of three boluses (450 mg total), then continue the maintenance infusion at 0.5 mg/min. 1
Standard IV Amiodarone Dosing Protocol
The guideline-recommended regimen for IV amiodarone is structured as follows:
- Initial bolus: 150 mg over 10 minutes 1
- Second bolus: May repeat 150 mg if needed 1
- Maintenance infusion: 1 mg/min for 6 hours, then 0.5 mg/min for 18 hours 1
- Maximum loading dose: 300 mg total in bolus form (two 150 mg boluses), though some protocols allow up to 450 mg in refractory cases 1
Your Current Situation
Since you've already administered two boluses (300 mg total) and are running a maintenance infusion at 0.5 mg/min, you are at the standard maximum for routine bolus dosing. 1
For refractory arrhythmias, a third 150 mg bolus can be considered, particularly in cardiac arrest scenarios with persistent ventricular fibrillation or pulseless ventricular tachycardia. 1 However, this should be done with extreme caution and continuous monitoring.
Critical Monitoring Requirements
After additional boluses, watch closely for:
- Hypotension (occurs in 16% of IV amiodarone patients) 2
- Bradycardia and heart block (occurs in 4.9% with IV therapy) 2
- QT prolongation (common but rarely causes torsades de pointes with amiodarone) 1, 2
Alternative Considerations
If the arrhythmia persists despite maximum amiodarone dosing:
- Synchronized cardioversion is recommended for atrial fibrillation/flutter with rapid ventricular response not responding to pharmacological therapy 1
- Consider other antiarrhythmics such as ibutilide (1 mg IV over 10 minutes) for atrial fibrillation, though this requires QT monitoring 1
- Magnesium (8 mmol bolus) may be effective, particularly if the arrhythmia is associated with acute myocardial infarction 1
Common Pitfall
Do not exceed 2.2 grams total amiodarone in 24 hours (including boluses and infusion), as this increases risk of severe hypotension and bradycardia. 1 With two 150 mg boluses already given and a 0.5 mg/min infusion running, you're accumulating approximately 720 mg per 24 hours from the infusion alone, plus the 300 mg already bolused.