Amiodarone Dosing for Atrial Flutter
For acute rate control in atrial flutter with systolic heart failure (when beta blockers are contraindicated or ineffective), use IV amiodarone: 150 mg over 10 minutes, followed by 1 mg/min infusion for 6 hours, then 0.5 mg/min for the remaining 18 hours, with a maximum of 2.2 g over 24 hours. 1
Acute Management Dosing
Intravenous Amiodarone for Rate Control
- Loading dose: 150 mg IV over 10 minutes 1
- Initial infusion: 1 mg/min (360 mg) over the next 6 hours 1
- Maintenance infusion: 0.5 mg/min (540 mg) over the remaining 18 hours 1
- Maximum total dose: Do not exceed 2.2 g over 24 hours 1
- The 150 mg bolus can be repeated if necessary 1
Important Clinical Context
Amiodarone is specifically a Class IIa recommendation (can be useful) for acute rate control in atrial flutter patients with systolic heart failure when beta blockers are contraindicated or ineffective 1. This is a more limited indication than for other agents—beta blockers, diltiazem, or verapamil are Class I recommendations (should be used) for acute rate control in hemodynamically stable atrial flutter patients without heart failure 1.
Chronic Maintenance Dosing
Oral Amiodarone for Rhythm Control
For maintaining sinus rhythm in patients with symptomatic, recurrent atrial flutter (Class IIa recommendation), amiodarone can be useful with drug choice depending on underlying heart disease and comorbidities 1:
- Loading regimen: Up to 1200 mg daily may be considered in an inpatient monitoring setting (to minimize long-term adverse effects, use up to 200 mg daily for maintenance) 1
- Standard loading: 600 mg daily for 7 days 2
- Maintenance dose: 200-400 mg daily 1, 2
- Mean maintenance dose in clinical studies: 268 ± 100 mg/day 3
High-Dose Oral Loading (Inpatient Only)
For more urgent situations requiring faster loading 4:
This high-dose protocol achieves electrophysiologic effects by day 1 but requires close monitoring 4.
Critical Precautions and Contraindications
Absolute Contraindications
- Sinus or AV conduction disease without a pacemaker 1
- Cardiogenic shock 1
- Acute inflammatory lung disease 1
Use With Extreme Caution
- Hepatic dysfunction: Amiodarone undergoes hepatic metabolism 1
- Hypothyroidism or hyperthyroidism: Monitor thyroid function 1
- Peripheral neuropathy or optic neuritis: Baseline and periodic neurologic assessment 1
- WPW with atrial flutter: Contraindicated due to risk of accelerated conduction 1
Common Adverse Effects
- Acute IV administration: Hypotension, bradycardia, phlebitis, QT prolongation (though torsades de pointes is rare) 1
- Chronic oral therapy: Skin discoloration (4.5%), pulmonary fibrosis (3.6%), thyroid toxicity (2.7%), corneal deposits, photosensitivity 1, 3
Drug Interactions Requiring Dose Adjustments
Mandatory Dose Reductions
Significant Interactions
Amiodarone is a substrate of and inhibits P-glycoprotein, CYP2C9 (moderate), CYP2D6 (moderate), and CYP3A4 (weak) 1. Exercise caution with: dabigatran, edoxaban, rivaroxaban, flecainide, propafenone, simvastatin, lovastatin, and numerous other medications 1.
Key Clinical Pitfalls
Amiodarone is NOT first-line for atrial flutter rate control—it is reserved for patients with systolic heart failure when beta blockers cannot be used 1. For rhythm control (maintaining sinus rhythm), catheter ablation of the cavotricuspid isthmus (CTI) is the preferred strategy (Class I recommendation) over chronic antiarrhythmic therapy 1.
The conversion rate with IV amiodarone for recent-onset atrial fibrillation/flutter is 55-95% with bolus followed by infusion regimens, but most conversions occur after 6-8 hours, making it slower than alternatives like ibutilide 5, 6. However, amiodarone's relative safety in structural heart disease makes it valuable when other agents are contraindicated 5.