Propafenone

RYTHMOL

Open Propafenone in the interactive console ↗

What it isClass IC sodium channel blocker with weak beta blockade; atrial fibrillation in structurally normal hearts.

Why this oneIt works as a pill-in-the-pocket strategy and its beta blockade gives some rate control that flecainide lacks.

What limits itContraindicated in structural or ischemic heart disease after CAST. Pair with an AV nodal blocker; a metallic taste is characteristic.

FDA-approved for

arrhythmias (1989)

FDA label

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BOXED WARNING Increased mortality (death/reversed cardiac arrest) seen with Class IC antiarrhythmics in post-MI patients; avoid antiarrhythmics in non-life-threatening ventricular arrhythmias and structural heart disease.

FDA dosing	Population	Start	Target	Max
Atrial fibrillation (prolong time to recurrence)	Adults	225 mg BID	325 mg BID	425 mg BID

Titration Increase at minimum 5-day intervals

Renal Undefined

Hepatic Consider dose reduction; increased bioavailability, monitor for excessive effects

Instructions

Take with or without food
Do not crush or divide capsule contents
Avoid simultaneous use with both a CYP2D6 inhibitor and a CYP3A4 inhibitor
Consider dose reduction with hepatic impairment, marked QRS widening, or 2nd/3rd-degree AV block

Contraindications

Heart failure
Cardiogenic shock
Sinoatrial, AV, and intraventricular conduction disorders without a pacemaker (e.g., sick sinus syndrome, AV block)
Known Brugada Syndrome
Bradycardia
Marked hypotension
Bronchospastic disorders or severe obstructive pulmonary disease
Marked electrolyte imbalance

Cautions

Proarrhythmic effects (may cause new/worsened arrhythmias) — ECG before and during therapy
May unmask Brugada Syndrome — ECG after initiation
Avoid QT-prolonging drugs and Class IA/III antiarrhythmics
May provoke overt heart failure
Dose-related AV block/conduction disturbances — not for conduction defects without pacemaker
May alter pacemaker/defibrillator thresholds — monitor devices
Agranulocytosis — report signs of infection
Caution in hepatic and renal impairment
May exacerbate myasthenia gravis

Adverse reactions

Dizziness
Palpitations
Chest pain
Dyspnea
Taste disturbance
Nausea
Fatigue
Anxiety
Constipation
Upper respiratory tract infection
Edema
Influenza

Pregnancy No drug-associated risks identified from case reports/postmarketing; crosses placenta — monitor fetus/neonate for arrhythmia during and after treatment.

Lactation Present in human milk, levels likely low; weigh benefits against clinical need.

⚠ BOXED WARNING