FLECAR

What it is

FLECAR contains flecainide acetate in 50 mg and 100 mg tablet strengths. Flecainide acetate belongs to the membrane stabilising (Class 1) group of antiarrhythmic agents. Its predominant action is to inhibit the fast, or sodium, channel which is largely responsible for the rapid upstroke of the myocardial action potential in cardiac conducting tissue.

Approved indications

— Supraventricular arrhythmias due to pre-excitation syndromes, such as Wolff-Parkinson-White and Lown-Ganong-Levine syndromes. — Supraventricular arrhythmias due to dual AV nodal pathways in patients with debilitating symptoms. — Paroxysmal atrial fibrillation or flutter associated with disabling symptoms. — Life threatening ventricular arrhythmias not controlled by other drugs, for continuous maintenance of normal rhythm following initial oral or intravenous therapy or conversion by other means.

Dosing overview

The dosage of flecainide acetate must be adjusted to individual patient needs based on therapeutic response and tolerance, with dosage modified according to age, weight or clinical status. Steady-state plasma levels may not be achieved until 3 to 5 days of therapy at a given dose; increases should be made no more frequently than once every four days. In patients with supraventricular arrhythmias, oral therapy may be started on an outpatient basis, however in patients with sustained ventricular arrhythmias oral therapy should be initiated in hospital.

Key safety warnings

Although flecainide acetate may be effective in supraventricular arrhythmias in patients with structural heart disease, its use has been associated with life-threatening and occasionally fatal ventricular arrhythmias. In these patients, particularly in the presence of impaired left ventricular function, flecainide acetate should be used with extreme caution, preferably after other antiarrhythmic drugs have been tried or considered inappropriate. In the Cardiac Arrhythmia Suppression Trial, a large randomised placebo-controlled study in patients with asymptomatic non-life threatening ventricular arrhythmias following myocardial infarction, oral flecainide was associated with a higher incidence of mortality or non-fatal cardiac arrest, with an even higher incidence observed in patients with more than one myocardial infarction. Because flecainide acetate has a mild negative inotropic effect, it may cause or worsen congestive heart failure, particularly in patients with cardiomyopathy, pre-existing severe heart failure (NYHA functional class III or IV) or ejection fractions ≤40%. Use of flecainide acetate in chronic atrial fibrillation has not been adequately studied and is not recommended.

Contraindications

Second or third degree A-V block, unless a pacemaker is present to sustain rhythm. Right bundle branch block when associated with a left hemi-block (bifascicular block) unless a pacemaker is present to sustain rhythm. Cardiogenic shock. Asymptomatic premature ventricular contractions and/or asymptomatic non-sustained ventricular tachycardia in patients with a history of myocardial infarction. Known hypersensitivity to the drug. Severe renal or hepatic impairment unless plasma level monitoring can be done.

Regulatory history

FLECAR flecainide acetate tablets were first listed on the Australian Register of Therapeutic Goods on 19 June 2018 as 50 mg and 100 mg formulations in blister packs.