Flecainide

In patients without structural heart disease, flecainide is indicated for the prevention of - paroxysmal supraventricular tachycardias (PSVT), including atrioventricular nodal reentrant tachycardia, atrioventricular reentrant tachycardia and other supraventricular tachycardias of unspecified mechanism associated with disabling symptoms - paroxysmal atrial fibrillation/flutter (PAF) associated with disabling symptoms. Flecainide is also indicated for the prevention of - documented ventricular arrhythmias, such as sustained ventricular tachycardia ( sustained VT), that in the judgment of the physician, are life-threatening. Use of flecainide for the treatment of sustained VT, like other antiarrhythmics, should be initiated in the hospital. The use of flecainide is not recommended in patients with less severe ventricular arrhythmias even if the patients are symptomatic.

For patients with sustained VT, no matter what their cardiac status, flecainide, like other antiarrhythmics, should be initiated in hospital with rhythm monitoring. Flecainide has a long half-life (12 to 27 hours in patients). Steady-state plasma levels, in patients with normal renal and hepatic function, may not be achieved until the patient has received 3 to 5 days of therapy at a given dose. Therefore, increases in dosage should be made no more frequently than once every four days, since during the first 2 to 3 days of therapy the optimal effect of a given dose may not be achieved. For patients with PSVT and patients with PAF the recommended starting dose is 50 mg every 12 hours. Flecainide acetate doses may be increased in increments of 50 mg bid every four days until efficacy is achieved.

Flecainide is contraindicated in patients with preexisting second- or third degree AV block, or with right bundle branch block when associated with a left hemiblock (bifascicular block), unless a pacemaker is present to sustain the cardiac rhythm should complete heart block occur. Flecainide is also contraindicated in the presence of cardiogenic shock or known hypersensitivity to the drug.

Mortality Flecainide was included in the National Heart Lung and Blood Institute’s Cardiac Arrhythmia Suppression Trial (CAST), a long-term, multi center, randomized, double-blind study in patients with asymptomatic non-life-threatening ventricular arrhythmias who had a myocardial infarction more than six days, but less than two years previously. An excessive mortality or non-fatal cardiac arrest rate was seen in patients treated with flecainide compared with that seen in a carefully matched placebo-treated group. This rate was 16/315 (5.1%) for flecainide and 7/309 (2.3%) for the matched placebo. The average duration of treatment with flecainide in this study was 10 months.

In post-myocardial infarction patients with asymptomatic PVCs and nonsustained ventricular tachycardia, flecainide therapy was found to be associated with a 5.1% rate of death and non-fatal cardiac arrest, compared with a 2.3% rate in a matched placebo group. Adverse effects reported for flecainide, described in detail in the WARNINGS section, were new or worsened arrhythmias which occurred in 1% of 108 patients with PSVT and in 7% of 117 patients with PAF, and new or exacerbated ventricular arrhythmias which occurred in 7% of 1330 patients with PVCs, non-sustained or sustained VT.

Store at 20° to 25°C (68° to 77°F). Store in a tight, light-resistant container.