Atrial Fibrillation Rate Control with Amiodarone and Digoxin

Introduction to Combination Therapy

The American College of Cardiology, American Heart Association, and European Society of Cardiology guidelines state that combination therapy with digoxin and amiodarone may be required to achieve adequate rate control in some patients with atrial fibrillation, though care must be taken to avoid bradycardia 1, 2, 3.
The American College of Cardiology, American Heart Association, and European Society of Cardiology recommend that amiodarone is positioned as a second-line or alternative agent for rate control when conventional measures fail, not as first-line therapy 1, 2, 3, 4.
The American Heart Association suggests that digoxin is no longer first-line therapy for rapid atrial fibrillation management except in patients with heart failure or left ventricular dysfunction 2, 4.

The European Society of Cardiology guidelines state that amiodarone can be useful for rate control as a last resort, particularly when heart rate cannot be controlled with combination therapy such as beta-blocker or calcium channel blocker combined with digoxin 5, 6.
The American College of Cardiology recommends that first-line agents, such as beta-blockers, diltiazem, or verapamil, should be optimized before considering amiodarone 1, 2, 4, 5.
The American Heart Association suggests that combination of digoxin with beta-blocker is preferred over digoxin with amiodarone 2, 4.

The American College of Cardiology, American Heart Association, and European Society of Cardiology guidelines state that the combination of amiodarone and digoxin carries increased risk and requires vigilant monitoring for bradycardia, heart block, and digoxin toxicity 1, 2, 3.
The European Society of Cardiology recommends that if rate control remains inadequate, AV node ablation with pacemaker may be more appropriate than escalating pharmacotherapy 5.
The American College of Cardiology notes that amiodarone has considerable potential toxicity, including pulmonary fibrosis, hepatic injury, and proarrhythmia, which must be weighed against benefits 1, 2, 3, 4.

The American College of Cardiology recommends that digoxin or amiodarone be used to control heart rate in patients with atrial fibrillation and heart failure (Class I) 7
The combination of digoxin and beta-blocker is reasonable (Class IIa) for controlling heart rate at rest and during exercise in patients with atrial fibrillation 7
The combination of beta-methyl digoxin and amiodarone should not be administered to patients with pre-excitation syndromes (Wolff-Parkinson-White), as both drugs are contraindicated (Class III: Harm) 7

The dose of digoxin should be reduced by approximately 50% when amiodarone is initiated 7
Serum digoxin levels should be monitored closely, especially because toxicity can occur with levels >2 ng/mL, and also with lower levels if hypokalemia, hypomagnesemia, or hypothyroidism coexist 7

The combination of amiodarone and digoxin is effective for controlling heart rate in patients with chronic atrial fibrillation, producing lower heart rates than placebo during all levels of exercise (p<0.0001) 7