What is the maximum recommended dose of propafenone (anti-arrhythmic medication)?

Maximum Recommended Dose of Propafenone

The maximum recommended dose of propafenone is 900 mg per day, typically administered as 300 mg every 8 hours. 1

Dosage Guidelines

Propafenone dosing must be individually titrated based on patient response and tolerance. The recommended dosing schedule is:

• Initial dose: 150 mg every 8 hours (450 mg/day)
• Dose may be increased at minimum 3-4 day intervals to:
  • 225 mg every 8 hours (675 mg/day)
  • If necessary, up to 300 mg every 8 hours (900 mg/day)

The FDA label clearly states that "the usefulness and safety of dosages exceeding 900 mg per day have not been established." 1

Extended-Release Formulation

For the extended-release formulation, dosing differs slightly:

• 225-425 mg once every 12 hours 2
• Maximum daily dose remains 900 mg

Special Populations

Dose adjustments are recommended for:

• Elderly patients: Dose should be increased more gradually during initial treatment 1
• Patients with ventricular arrhythmias and marked myocardial damage: More gradual dose titration 1
• Hepatic impairment: 70-80% dose reduction in severe liver dysfunction 3

Monitoring During Therapy

When administering propafenone, especially at higher doses, monitor for:

• QRS complex widening (dose reduction recommended if significant widening occurs) 1
• Second or third degree AV block 1
• Hypotension 2
• Rapidly conducting atrial flutter (a potentially serious adverse effect) 2

Clinical Context

Propafenone is used for:

• Maintenance of sinus rhythm in patients with atrial fibrillation (450-900 mg daily) 2
• Suppression of ventricular arrhythmias (450-900 mg daily) 4

In clinical studies, propafenone has been used at doses up to 1200 mg/day in selected patients under inpatient monitoring settings 2, but this exceeds the FDA-approved maximum dose and should not be used in routine clinical practice.

Drug Interactions

• Reduce dose by 30-50% when administering with amiodarone 2
• Reduce dose by 50% when administering with dronedarone 2
• Monitor for increased effects when used with CYP2D6 inhibitors (quinidine, fluoxetine, tricyclic antidepressants) 2
• May increase digoxin and warfarin concentrations 2

Contraindications and Cautions

Propafenone should be avoided or used with extreme caution in patients with:

• Sinus or AV node dysfunction (without pacemaker) 2
• Heart failure 2
• Coronary artery disease 2
• Brugada syndrome 2
• Liver disease 2
• Asthma (due to weak beta-blocking properties) 2