Cibenzoline versus flecainide in the prevention of paroxysmal atrial arrhythmias: a double-blind randomized study.

In a randomized, double-blind, parallel clinical trial, the authors tested and compared flecainide and cibenzoline, a new antiarrhythmic drug, on atrial arrhythmias. Sixty-eight patients (36 men, 32 women, mean age 62.5 +/- 1.6 years) with documented symptomatic paroxysmal atrial arrhythmias (fibrillation in 56, flutter in 12) were recruited and received either cibenzoline 260 mg/day (n = 33) or flecainide 200 mg/day (n = 35). Patients were assessed with physical examination, resting ECG, 24-hour ambulatory ECG recording, two-dimensional echocardiography, and standard biologic titrations before the inclusion day, and 3 months and 6 months after the randomization day. Sixteen patients were withdrawn (7 were lost to follow-up, 7 had side effects, 2 had another medical event). Seventeen patients had documented recurrence of atrial arrhythmia (9 in the cibenzoline group, 8 in the flecainide group) during the study. The efficacy of cibenzoline and flecainide for preventing recurrence of atrial arrhythmias was not significantly different (62.5% versus 71.4%). Eleven patients complained of one or more side effects (cibenzoline, n = 6; flecainide, n = 5), justifying leaving the trial in 6 cases (cibenzoline, n = 3; flecainide, n = 3). Two ventricular proarrhythmic effects were observed. No atrial proarrhythmic effects were reported. The efficacy of cibenzoline and flecainide for preventing atrial arrhythmia is good and similar during a follow-up period of 6 months. In view of these results, cibenzoline may be administered first to prevent atrial arrhythmia.