When is propafenone indicated?

Indications for Propafenone

Propafenone is primarily indicated for the treatment of paroxysmal atrial fibrillation/flutter and paroxysmal supraventricular tachycardia in patients without structural heart disease, and for documented life-threatening ventricular arrhythmias. 1

Supraventricular Arrhythmias

Atrial Fibrillation/Flutter

• Propafenone is indicated for:
  • Prolonging time to recurrence of paroxysmal atrial fibrillation/flutter associated with disabling symptoms 1
  • Long-term management of supraventricular tachycardia (SVT) as a third-line option when other agents fail 2
  • Maintenance of sinus rhythm in patients with atrial fibrillation 2

Paroxysmal Supraventricular Tachycardia (PSVT)

• Indicated for PSVT associated with disabling symptoms 1
• May be considered for long-term management of SVT if digoxin, beta-blockers, and other agents like sotalol or flecainide fail 2

Wolff-Parkinson-White Syndrome

• Effective in patients with WPW syndrome, particularly those with rapid anterograde conduction 3
• Useful for management of non-ventricular arrhythmias associated with WPW syndrome 4

Ventricular Arrhythmias

Life-Threatening Ventricular Arrhythmias

• Indicated for documented ventricular arrhythmias such as sustained ventricular tachycardia that are deemed life-threatening 1
• Should be considered for long-term management of idiopathic sustained ventricular tachycardia if other drugs fail 2

Contraindications and Precautions

Absolute Contraindications

• Ischemic heart disease 2
• Reduced left ventricular ejection fraction or heart failure 2
• Severe sinus bradycardia and sinus node dysfunction (unless pacemaker present) 2
• Severe AV conduction disturbances (unless pacemaker present) 2
• Severe intraventricular conduction disturbances 2
• Brugada syndrome 2
• Inherited long QT syndrome (except LQTS3) 2

Special Precautions

• Initiation of treatment for life-threatening ventricular arrhythmias should be carried out in the hospital 1
• Should not be used to control ventricular rate during atrial fibrillation 1
• Caution with concomitant treatments that prolong QT interval 2
• Careful monitoring required due to risk of proarrhythmic effects 2
• Some patients with atrial flutter treated with propafenone have developed 1:1 conduction, requiring concomitant treatment with drugs that increase AV refractory period 1

Dosing Considerations

• Typical daily dosage ranges from 450-900 mg 2
• Dosage must be individualized due to:
  • Dose-dependent pharmacokinetics
  • Wide range of effective plasma concentrations
  • Presence of active metabolites
  • Genetic variations in metabolism 5

Algorithmic Approach to Propafenone Use

1. For Supraventricular Arrhythmias:

   • First-line: Vagal maneuvers, adenosine, beta-blockers, or digoxin
   • Second-line: Sotalol or flecainide
   • Third-line: Consider propafenone when first and second-line agents fail 2

2. For Ventricular Tachycardia:

   • First-line: Beta-blockers (metoprolol, propranolol) or verapamil for idiopathic VT
   • Second-line: Sotalol, flecainide
   • Third-line: Consider propafenone when other agents fail 2

Key Monitoring Parameters

• ECG monitoring for QRS prolongation
• Watch for signs of proarrhythmia
• Monitor for AV block and sinus bradycardia
• Assess for development of heart failure or ischemia 2

Propafenone should be used with caution and close follow-up is necessary to avoid adverse effects due to the development of ischemia or heart failure 2. The risk-benefit ratio should always be carefully assessed, particularly for ventricular arrhythmias, where its use should be reserved for patients in whom the potential benefits outweigh the risks 1.