What is the maximum daily dose of metoprolol (beta blocker) for a patient with atrial fibrillation?

Maximum Daily Dose of Metoprolol for Atrial Fibrillation

The maximum daily dose of metoprolol for atrial fibrillation is 400 mg once daily for metoprolol succinate (extended-release) or 100 mg twice daily (200 mg total daily) for metoprolol tartrate (immediate-release). 1

Formulation-Specific Maximum Dosing

Metoprolol Succinate (Extended-Release)

• Maximum dose: 400 mg once daily 1
• Initial dose: 50 mg once daily 1
• Administered once daily in the morning for consistent 24-hour rate control 2

Metoprolol Tartrate (Immediate-Release)

• Maximum dose: 100 mg twice daily (200 mg total daily) 1
• Initial dose: 25-100 mg twice daily 1
• Can be dosed as 25-200 mg twice daily based on clinical response 2

Titration Strategy

• Start with the lowest dose and gradually titrate upward at 2-week intervals based on heart rate response and patient tolerance 1
• Monitor blood pressure, heart rate, and symptoms during dose escalation 2
• The goal is to achieve adequate rate control without causing excessive bradycardia or hypotension 1

Rate Control Targets

• Lenient control: Resting heart rate <110 bpm (reasonable for asymptomatic patients with preserved left ventricular function) 1
• Strict control: Resting heart rate <80 bpm (for symptomatic management) 1
• Heart rate should be assessed both at rest and during physical activity to ensure adequate control throughout daily activities 1

Important Clinical Considerations

When Maximum Dose is Insufficient

• If rate control remains inadequate despite maximum tolerated metoprolol dose, consider adding a non-dihydropyridine calcium channel blocker (diltiazem or verapamil) 1
• Digoxin may be useful as adjunct therapy, particularly in patients with heart failure 1
• Amiodarone may be considered when other measures are unsuccessful or contraindicated 1

Contraindications and Cautions

• Avoid in decompensated heart failure 1
• Avoid in severe bradycardia or high-degree AV block without a pacemaker 1
• Contraindicated in asthma or severe COPD, atrial fibrillation with pre-excitation 2
• In hepatic impairment, initiate at low doses with cautious gradual titration as blood levels may increase substantially 3

Common Pitfalls

• If excessive bradycardia or hypotension occurs, reduce the dose rather than changing the timing of administration 2
• Monitor for hypotension, bradycardia, and worsening heart failure during titration 1
• For patients with coexisting heart failure, careful dose titration is essential to avoid symptom exacerbation 2