What medications are typically started for atrial fibrillation (AF)?

Medications to Start for Atrial Fibrillation

Beta-blockers (metoprolol, atenolol, or bisoprolol) or non-dihydropyridine calcium channel blockers (diltiazem or verapamil) are the first-line medications to start for rate control in atrial fibrillation, with beta-blockers preferred in patients with heart failure or reduced ejection fraction. 1

Initial Medication Selection Based on Clinical Context

For Hemodynamically Stable Patients with Normal Left Ventricular Function

Beta-blockers are the preferred first-line agents:

• Metoprolol tartrate: 25-100 mg twice daily orally for chronic management 1, 2
• Metoprolol succinate (extended-release): 50-400 mg once daily 1, 2
• Atenolol: 25-100 mg once daily 1
• Bisoprolol: 2.5-10 mg once daily 1

Beta-blockers achieved rate control targets in 70% of patients compared to 54% with calcium channel blockers in the AFFIRM study, making them the most effective drug class for rate control 1

Non-dihydropyridine calcium channel blockers are equally acceptable alternatives:

• Diltiazem extended-release: 120-360 mg once daily 1, 2
• Verapamil extended-release: 120-360 mg once daily 1

These agents are particularly useful in patients with bronchospasm or chronic obstructive pulmonary disease where beta-blockers are contraindicated 1

For Patients with Heart Failure or Reduced Ejection Fraction (LVEF ≤40%)

Beta-blockers and/or digoxin are the recommended agents 1:

• Metoprolol succinate, carvedilol (3.125-25 mg twice daily), or bisoprolol should be initiated cautiously 1
• Digoxin: 0.125-0.375 mg once daily can be added or used alone 1

Critical contraindication: Non-dihydropyridine calcium channel blockers (diltiazem, verapamil) should NOT be used in decompensated heart failure as they worsen systolic dysfunction 1, 2

For Acute/Emergency Rate Control in Hemodynamically Stable Patients

Intravenous beta-blockers or calcium channel blockers are recommended 1:

• Metoprolol: 2.5-5 mg IV bolus over 2 minutes, up to 3 doses 1, 2
• Diltiazem: 0.25 mg/kg IV over 2 minutes, then 5-15 mg/hour infusion (superior efficacy for rapid control) 1, 2
• Esmolol: 500 mcg/kg IV bolus over 1 minute, then 50-300 mcg/kg/min infusion (ultra-short acting, ideal for unstable situations) 1, 2

For Hemodynamically Unstable Patients

Immediate electrical cardioversion is indicated, NOT pharmacologic rate control 1, 2. Unstable features include decompensated heart failure, ongoing myocardial ischemia, or hypotension 2

Critical Contraindications to Avoid

Never use in pre-excitation syndromes (Wolff-Parkinson-White):

• Digoxin, diltiazem, verapamil, or amiodarone can paradoxically accelerate ventricular response and precipitate ventricular fibrillation 1, 2

Avoid beta-blockers in:

• Severe asthma or active bronchospasm 2
• Decompensated heart failure (until stabilized) 2
• Advanced heart block without pacemaker 1

Avoid calcium channel blockers in:

• Decompensated heart failure with reduced ejection fraction 1, 2
• Pre-excitation syndromes 1

Rate Control Targets

Lenient rate control (resting heart rate <110 bpm) is reasonable for asymptomatic patients with preserved left ventricular function 1, 2

Strict rate control (resting heart rate <80 bpm) is reasonable for symptomatic patients 1, 2

Heart rate control must be assessed during exertion, not just at rest, with pharmacological treatment adjusted accordingly 1

Alternative Agents When First-Line Therapy Fails

Digoxin monotherapy:

• 0.125-0.25 mg once daily 1
• Least effective for rate control, particularly ineffective during exercise and high sympathetic states 1
• Reasonable choice for physically inactive elderly patients (≥80 years) or as add-on therapy 3
• Preferred in heart failure patients when combined with beta-blockers 1, 3

Amiodarone:

• 100-200 mg once daily orally for chronic use 1
• Useful when other measures are unsuccessful or contraindicated 1, 2
• Should be reserved for refractory cases due to significant extracardiac toxicity (thyroid, pulmonary, hepatic, ocular) 1

Combination therapy with beta-blocker plus digoxin or calcium channel blocker plus digoxin is effective when monotherapy fails 1

Additional Considerations Beyond Rate Control

Anticoagulation must be initiated based on stroke risk (CHA₂DS₂-VASc score), independent of rate control strategy 1. This is a separate decision from rate control medication.

Rhythm control with antiarrhythmic drugs or catheter ablation should be considered early in newly diagnosed AF, as newer data suggest potential reduction in major adverse cardiovascular events compared to rate control alone 4