From the Guidelines
Flecainide is a recommended treatment for atrial fibrillation, approximately doubling the likelihood of maintaining sinus rhythm, but its use should be cautious and monitored, especially in patients with structural heart disease or coronary artery disease. Flecainide works by blocking sodium channels in cardiac cells, which decreases the rate at which electrical signals move through the heart, making it effective for treating various supraventricular arrhythmias, particularly atrial fibrillation, atrial flutter, and supraventricular tachycardias 1.
The typical dosage ranges from 50-200 mg taken twice daily, with treatment usually starting at a lower dose and gradually increasing as needed. Patients should be aware that flecainide requires careful monitoring, especially when treatment begins, as it can occasionally worsen arrhythmias or cause new ones, particularly in people with structural heart disease or coronary artery disease 1.
Some key points to consider when using flecainide include:
- It can be safely administered in patients without significant structural heart disease, but should not be used in patients with coronary artery disease or in those with reduced LVEF 1.
- Precautions should be observed when using flecainide in the presence of intraventricular conduction delay, particularly left bundle branch block 1.
- Upon initiation of flecainide therapy, regular ECG monitoring is recommended to check for potential risk of proarrhythmia, and the drug should be stopped or the dose reduced if QRS duration increases by ≥25% compared to baseline 1.
- Concomitant atrioventricular node blockade is recommended because of the potential of flecainide to convert AF to atrial flutter, which then may be conducted rapidly to the ventricles 1.
Common side effects of flecainide include dizziness, visual disturbances, and nausea, and patients should immediately report any symptoms of heart failure, such as shortness of breath or swelling, as these could indicate serious adverse effects requiring prompt medical attention. Overall, flecainide is a useful treatment option for atrial fibrillation, but its use requires careful consideration of the potential risks and benefits, and close monitoring to minimize adverse effects 1.
From the FDA Drug Label
CLINICAL PHARMACOLOGY Flecainide acetate tablets, USP have local anesthetic activity and belong to the membrane stabilizing (Class 1) group of antiarrhythmic agents; they have electrophysiologic effects characteristic of the IC class of antiarrhythmics In man, flecainide acetate tablets, USP produce a dose-related decrease in intracardiac conduction in all parts of the heart with the greatest effect on the His-Purkinje system (H-V conduction). Flecainide acetate tablets, USP cause a dose-related and plasma-level related decrease in single and multiple PVCs and can suppress recurrence of ventricular tachycardia
Flecainide works by:
- Producing a dose-related decrease in intracardiac conduction in all parts of the heart
- Having the greatest effect on the His-Purkinje system (H-V conduction)
- Causing a dose-related and plasma-level related decrease in single and multiple PVCs
- Suppressing recurrence of ventricular tachycardia Key effects of flecainide include:
- Decrease in intracardiac conduction
- Suppression of PVCs and ventricular tachycardia 2
From the Research
Mechanism of Action
- Flecainide is a class Ic antiarrhythmic agent that inhibits Nav1.5 sodium channels in heart muscle cells and modulates cardiac conduction 3.
Indications
- Flecainide is used in the treatment of paroxysmal supraventricular tachycardias, including atrial fibrillation, atrioventricular nodal re-entrant tachycardia, atrioventricular re-entrant tachycardia, and ventricular arrhythmias in patients without structural heart disease 4, 5, 3.
- It can be used in some supraventricular tachycardia in children and for sustained fetal tachycardia 3.
Efficacy
- Flecainide has been shown to be effective in short-term and long-term studies for prevention of paroxysmal supraventricular tachycardia (SVT) and paroxysmal atrial fibrillation (AF) 6, 7.
- It has a good efficacy and safety profile for both cardioversion and sinus rhythm maintenance in patients with atrial fibrillation and no documented structural heart disease 4.
Safety
- Flecainide can increase mortality in patients with frequent ventricular ectopics and reduced left ventricular function who have survived an infarction, and is not recommended in patients with structural heart disease due to high proarrhythmic risk 4, 5.
- Common noncardiac adverse experiences include abnormal vision, dizziness, and headaches 6.