SAFETY OF FLECAINIDE VERSUS PROPAFENONE FOR THE LONG-TERM MANAGEMENT OF SYMPTOMATIC PAROXYSMAL SUPRAVENTRICULAR TACHYARRHYTHMIAS - REPORT FROM THE FLECAINIDE AND PROPAFENONE ITALIAN STUDY (FAPIS) GROUP

In order to compare the long-term safety of flecainide and propafenone , an open label, randomized, parallel group study was performed in 335 patients with paroxysmal atrial fibrillation (n = 200) or paroxysmal supraventricular tachycardia (n = 135), and no history of heart diseas e. Patients were treated with an initial daily dose of flecainide 100 mg (n = 72) or propafenone 450 mg (n = 63) for paroxysmal supraventric ular tachycardia and flecainide 200 mg (n = 97) or propafenone 450 mg (n = 103) for paroxysmal atrial fibrillation. Dose escalations were pe rmitted after greater than or equal to 2 attacks, up to maximum of fle cainide 300 mg or propafenone 900 mg.day(-1). Follow-up duration was 1 2 months, or when patients stopped the treatment as a result of inadeq uate efficacy or adverse experiences. Twelve patients on flecainide re ported 16 cardiac adverse experiences, of whom six discontinued the tr eatment. Seven propafenone patients had eight cardiac adverse experien ces, of whom five discontinued the treatment. Serious proarrhythmic ev ents were infrequent: one case of ventricular tachycardia on propafeno ne; two cases of atrial fibrillation with rapid ventricular response o n flecainide, associated in one patient with pulmonary oedema. An inte ntion-to-treat analysis showed that the probability of 12 months' safe and effective treatment of paroxysmal supraventricular tachycardia wa s 93% for flecainide and 86% for propafenone (P = 0.24), whereas in pa roxysmal atrial fibrillation it was 77% for flecainide and 75% for pro pafenone (P = 0.72). In conclusion, flecainide and propafenone were sa fe in the long-term treatment of patients with paroxysmal supraventric ular tachyarrhythmias and without evidence of clinically significant h eart disease.