What are the contraindications for propafenone?

Contraindications for Propafenone

Propafenone is contraindicated in patients with uncontrolled congestive heart failure, cardiogenic shock, conduction disorders without a pacemaker, bronchospastic disorders, and structural heart disease, particularly ischemic heart disease. 1

Absolute Contraindications

• Cardiac Contraindications:

  • Uncontrolled congestive heart failure 1
  • Cardiogenic shock 1
  • Sinoatrial, atrioventricular, and intraventricular disorders of impulse generation/conduction without an artificial pacemaker 1
  • Bradycardia 1
  • Marked hypotension 1
  • Structural heart disease, particularly ischemic heart disease 2, 3
  • Wolff-Parkinson-White syndrome with pre-excited atrial fibrillation 3

• Pulmonary Contraindications:

  • Bronchospastic disorders 1
  • Obstructive lung disease 3

• Other Contraindications:

  • Manifest electrolyte imbalance 1
  • Known hypersensitivity to propafenone 1

Relative Contraindications and Cautions

• Reduced Left Ventricular Function:

  • Should be used cautiously or avoided in patients with reduced ejection fraction 3, 4
  • Higher risk of proarrhythmic effects in patients with ventricular dysfunction 4

• Conduction System Disease:

  • Use with caution in patients with conduction system disease 3

• Renal Impairment:

  • Caution in patients with renal impairment 3

Mechanism of Risk

Propafenone is a class IC antiarrhythmic agent that blocks sodium channels and has weak beta-blocking properties 5. These properties create specific risks:

1. Proarrhythmic Effects: Can cause ventricular tachycardia, particularly in patients with structural heart disease 3
2. Conduction Abnormalities: May enhance AV nodal conduction, potentially converting atrial fibrillation to atrial flutter with rapid ventricular response 3
3. Negative Inotropic Effects: Can worsen heart failure in susceptible patients 3

Special Populations at Risk

• Elderly Patients: Higher incidence of adverse effects in patients >65 years 6
• Patients with Coronary Artery Disease: Increased risk of proarrhythmic effects 4
• Poor Metabolizers: About 10% of Caucasians have reduced capacity to metabolize propafenone, leading to drug accumulation and increased risk of adverse effects 5

Monitoring Recommendations

When propafenone must be used in patients without absolute contraindications:

• Monitor QRS duration (should not exceed 150% of pretreatment QRS) 3
• Consider exercise testing to detect use-dependent conduction slowing 3
• Monitor for signs of heart failure exacerbation 6
• Check periodic electrolyte levels and renal function 3

Alternative Therapies When Propafenone is Contraindicated

For patients with structural heart disease or contraindications to propafenone:

• Beta-blockers (first-line for patients with ischemic heart disease) 2
• Non-dihydropyridine calcium channel blockers (diltiazem, verapamil) 2
• Sotalol or dofetilide for rhythm control in patients with structural heart disease 2
• Amiodarone when other agents are ineffective or contraindicated 2

Propafenone should be used with particular caution in patients with structural heart disease, as the risk-benefit ratio becomes less favorable in these populations 4. For patients with supraventricular arrhythmias and no structural heart disease, propafenone has a more favorable safety profile 6.