Flecainide: study card

Generic name

Flecainide

Class

Class IC antiarrhythmic

Mechanism

Class IC membrane-stabilizing agent with local anesthetic activity; slows intracardiac conduction, most in the His-Purkinje system.

Used for

Prevention of paroxysmal supraventricular tachycardia with disabling symptoms in patients without structural heart disease; Prevention of paroxysmal atrial fibrillation or flutter with disabling symptoms in patients without structural heart disease; Prevention of documented, life-threatening ventricular arrhythmias such as sustained ventricular tachycardia; initiation for sustained VT requires hospital supervision

Common side effects

New or worsened arrhythmias; New or worsened heart failure; AV block; Sinus bradycardia or sinus arrest

Boxed warning

In CAST patients with non-life-threatening ventricular arrhythmias after myocardial infarction, flecainide increased death or nonfatal cardiac arrest compared with placebo; applicability to other populations is uncertain. Ventricular proarrhythmia can occur, and use in chronic atrial fibrillation is not recommended.

Warnings

New or worsened arrhythmias may occur; Excess death/nonfatal cardiac arrest occurred in CAST patients with non-life-threatening ventricular arrhythmias after myocardial infarction; Second/third-degree AV block is contraindicated unless a pacemaker can sustain the rhythm; cardiogenic shock is contraindicated

Brand questions use only name pairings verified against the linked product source. Unverified pairings are withheld from these questions; the other study content remains available.

Label date: 20260611 · For learning, not clinical decisions. US label and brand information; always consult the current source.

Source snapshot checked: 2026-10-21. The source document and selected fields were compared. The complete card has not had an independent clinical review.