Flecainide

In patients without structural heart disease, flecainide acetate tablets, USP are 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 acetate tablets, USP are 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. …

• For patients with sustained VT, no matter what their cardiac status, flecainide acetate tablets, 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 tablets doses may be increased in increments of 50 mg bid every four days until efficacy is achieved
• For PAF patients, a substantial increase in efficacy without a substantial increase in discontinuations for adverse experiences may be achieved by increasing the flecainide acetate tablets dose from 50 to 100 mg bid
• The maximum recommended dose for patients with paroxysmal supraventricular arrhythmias is 300 mg/day
• For sustained VT the recommended starting dose is 100 mg every 12 hours
• This dose may be increased in increments of 50 mg bid every four days until efficacy is achieved
• Most patients with sustained VT do not require more than 150 mg every 12 hours (300 mg/day) and the maximum dose recommended is 400 mg/day. …

The safety and efficacy of flecainide acetate in the fetus, infant, or child have not been established in double-blind, randomized, placebo-controlled trials (see CLINICAL PHARMACOLOGY , WARNINGS , and DOSAGE AND ADMINISTRATION ).

• Flecainide acetate tablets are 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 acetate tablets are also contraindicated in the presence of cardiogenic shock or known hypersensitivity to the drug

Flecainide acetate has been administered to patients receiving digitalis preparations or beta-adrenergic blocking agents without adverse effects. During administration of multiple oral doses of flecainide acetate to healthy subjects stabilized on a maintenance dose of digoxin , a 13% to 19% increase in plasma digoxin levels occurred at six hours postdose. In a study involving healthy subjects receiving flecainide acetate and propranolol concurrently, plasma flecainide levels were increased about 20% and propranolol levels were increased about 30% compared to control values. …

PRECAUTIONS Drug Interactions Flecainide acetate has been administered to patients receiving digitalis preparations or beta-adrenergic blocking agents without adverse effects. During administration of multiple oral doses of flecainide acetate to healthy subjects stabilized on a maintenance dose of digoxin , a 13% to 19% increase in plasma digoxin levels occurred at six hours postdose. In a study involving healthy subjects receiving flecainide acetate and propranolol concurrently, plasma flecainide levels were increased about 20% and propranolol levels were increased about 30% compared to control values. …

In post-myocardial infarction patients with asymptomatic PVCs and non-sustained ventricular tachycardia, flecainide acetate 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. (See WARNINGS .) Adverse effects reported for flecainide acetate, 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. …

Pregnancy Pregnancy Category C . Flecainide has been shown to have teratogenic effects (club paws, sternebrae and vertebrae abnormalities, pale hearts with contracted ventricular septum) and an embryotoxic effect (increased resorptions) in one breed of rabbit (New Zealand White) when given doses of 30 and 35 mg/kg/day, but not in another breed of rabbit (Dutch Belted) when given doses up to 30 mg/kg/day. …

No specific antidote has been identified for the treatment of flecainide acetate overdosage. Overdoses ranging up to 8000 mg have been survived, with peak plasma flecainide concentrations as high as 5.3 mcg/mL. Untoward effects in these cases included nausea and vomiting, convulsions, hypotension, bradycardia, syncope, extreme widening of the QRS complex, widening of the QT interval, widening of the PR interval, ventricular tachycardia, AV nodal block, asystole, bundle branch block, cardiac failure, and cardiac arrest. …

Prenez-le dès que vous y pensez, sauf s'il est presque l'heure de la dose suivante. Dans ce cas, sautez la dose oubliée. Ne prenez jamais deux doses à la fois pour compenser. Vérifiez votre notice, certains médicaments font exception.