SHORT-TERM AND LONG-TERM EFFICACY AND SAFETY OF FLECAINIDE ACETATE FOR SUPRAVENTRICULAR ARRHYTHMIAS

This report summarizes efficacy and safety data on the use of flecainide acetate for supraventricular arrhythmias. For this purpose, 60 original articles were identified by a literature search representing data from 1,835 treatment courses. In 18 trials, flecainide was administered intravenously; in 19, orally; and in 23, bath forms of therapy were applied. There were 5 placebo-controlled and 12 comparative studies, whereas data ftom uncontrolled studies were represented in 43 articles. Short-term flecainide administration terminated atrial fibrillation in 65% of attempts and terminated atrial flutter in 28%. The drug was effective during long-term therapy for atrial fibrillation in 49% of patients, with similar efficacy rates in 11 comparative trials and in 16 uncontrolled studies. In randomized, placebo-controlled studies in patients with paroxysmal atrial fibrillation, flecainkle was shown to reduce significantly the number of attacks, to prolong the time between attacks, and to improve quality of life. In patients wkh atrioventricular (AV) reciprocating tachycardias, acute drug administration was successful in 720/o; S30/o af patients with AV nodal reentrant tachycardias and 74% exhibiting arrhythmias associated with the Wolff-Parkinson-Whke syndrome responded acutely. During long-term therapy, efficacy rates were 70%, 78%, and 69%, respectively. Ectopic atrial tachycardia responded in 86% and 95% of patients treated with flecainide acutely or chronically. Data concerning drug-related side effects were avallable for 1,794 of 1,835 treatment courses (98%). Overall, 352 of 1,794 patients (20%) reported at least one noncardiac or cardiac adverse experience. Noncardiac side effects occurred in 12% af patients, most frequently in the gastrointestinal tract or central nervous system. Unwanted cardiac reactions were observed in 8% of patients. Proarrhythmic events consisting of the occurrence of new or exacerbation of preexisting atrial tachyarrhythmias were nated in 29 patients (1.6%). Ventricular proarrhythmia occurred in 34 cases (1.9%) All together, worsening af arrhythmia was documented in 63 patients (3.5%). Flecainide is a thoroughly evaluated and effective new antiarrhythmic compound for use in patients with supravefftricular tachyarrhythmias.