CHF and arrhythmias:
Indications for: Propafenone HCl Tablets
Documented life-threatening sustained ventricular arrhythmias. To prolong the time to recurrence of disabling paroxysmal atrial fibrillation/flutter or paroxysmal supraventricular tachycardia in patients without structural heart disease.
Propafenone reduced the rate of both paroxysmal atrial fibrillation/flutter (PAF) and paroxysmal supraventricular tachycardia (PSVT) in 2 randomized, crossover, placebo-controlled, double-blind trials of 60 to 90 days duration. The patient population was 50% male with a mean age of 57.3 years.
- Propafenone (n=30) vs placebo (n=30)
- Percent attack free: 53% vs 13%
- Median time to first recurrence: >98 days vs 8 days
- Propafenone (n=45) vs placebo (n=45)
- Percent attack free: 47% vs 16%
- Median time to first recurrence: >98 days vs 12 days
- Propafenone (n=9) vs placebo (n=9)
- Percent attack free: 67% vs 22%
- Median time to first recurrence: 62 days vs 5 days
- Propafenone (n=15) vs placebo (n=15)
- Percent attack free: 38% vs 7%
- Median time to first recurrence: 31 days vs 8 days
Long-term Safety Analysis
- 474 patients with supraventricular arrhythmias were treated with propafenone for up to 5 years (mean, 14.4 months).
- 14 patients died; no age-adjusted difference in mortality was noted when compared with the rate in a similar patient population.
- Comparison was not a randomized trial and the 95% CI around the comparison was large.
Individualize. Initially 150mg every 8hrs. May increase at intervals of at least 3–4 days (longer for elderly or marked myocardial damage) to 225mg every 8hrs; max 300mg every 8hrs. QRS widening, 2nd or 3rd degree AV block, or hepatic impairment: reduce dose.
Propafenone HCl Tablets Contraindications:
Heart failure. Cardiogenic shock. SA, AV and intraventricular disorders of impulse generation or conduction (eg, sick sinus syndrome, AV block), unless paced. Known Brugada Syndrome. Bradycardia. Marked hypotension. Bronchospastic disorders. Severe obstructive pulmonary disease. Marked electrolyte imbalance.
Propafenone HCl Tablets Warnings/Precautions:
Significant proarrhythmic risk in structural heart disease. Avoid in patients with non-life-threatening ventricular arrhythmias. Monitor ECG, pacemakers before and during therapy. May provoke overt heart failure. Discontinue if ECG changes are suggestive of Brugada Syndrome. Monitor for agranulocytosis. Hepatic or renal dysfunction: monitor. Elderly. Labor & delivery, fetal/neonatal: monitor. Pregnancy. Nursing mothers.
Propafenone HCl Tablets Classification:
Class IC antiarrhythmic.
Propafenone HCl Tablets Interactions:
Avoid drugs that may prolong the QT interval (eg, antiarrhythmics, some phenothiazines, tricyclic antidepressants, oral macrolides). Avoid concomitant Class IA and III antiarrhythmics (including quinidine, amiodarone). Potentiates β-blockers, warfarin, digoxin (consider reducing their doses when starting propafenone). Potentiated by CYP2D6 inhibitors (eg, desipramine, paroxetine, ritonavir, sertraline) and CYP3A4 inhibitors (eg, ketoconazole, saquinavir, erythromycin, grapefruit juice); avoid simultaneous use with both. Antagonized by rifampin. May be antagonized by orlistat. Local anesthetics may increase CNS effects.
Unusual taste, nausea, vomiting, dizziness, constipation, headache, fatigue, 1st degree AV block, intraventricular conduction delay, palpitations, chest pain, dyspnea, anxiety, upper respiratory tract infection, edema, influenza, angina pectoris, atrial flutter, heart failure, bradycardia, blurred vision; new or worsened arrhythmias, conduction disturbances, elevated ANA titers, exacerbation of myasthenia gravis.
Extensive metabolizers: Elimination half-life from 2 to 10 hours.
Slow metabolizers: Elimination half-life from 10 to 32 hours.
Generic Drug Availability:
Tabs—Contact supplier; SR caps—60