Class Ic antiarrhythmic with beta-blocking activity
ATC code: C01BC03 (Propafenone)
Brand names
Rythmol, Rytmonorm
Blocks fast sodium channels at phase 0 of action potential (class Ic) – slows atrial, AV nodal and ventricular conduction. Active metabolite 5-hydroxypropafenone has weak beta-blocker activity. Metabolised by CYP2D6 with genetically determined variability (extensive vs poor metabolisers). Not recommended in structural heart disease (CAST 1989 – increased mortality).
Second line
Propafenone is second-line antiarrhythmic for sinus rhythm maintenance in paroxysmal atrial fibrillation in patients WITHOUT structural heart disease. 2024 supports the pill-in-the-pocket strategy (450-600 mg single dose during paroxysm). Contraindicated in coronary artery disease, LV dysfunction or heart failure.
3 pairs found. Sorted from critical to minor.
Mechanism
Additive AV node slowing and QT prolongation. Bradycardia, AV block.
Symptoms
Bradycardia below 50, AV block.
Management
Avoid combination. Choose one antiarrhythmic.
Mechanism
Propafenone inhibits renal P-glycoprotein. Digoxin rises 50-75%.
Symptoms
Nausea, yellow vision, bradycardia.
Management
Reduce digoxin by 50%, check level on day 5.
Mechanism
Propafenone inhibits CYP2C9 (S-warfarin metabolism). INR rises 25-50%.
Symptoms
Gum and nose bleeding, petechiae, haematuria within 5-10 days.
Management
Check INR 5-7 days after propafenone start. Warfarin usually reduced by 25%.
Opens the checker prefilled with this drug. Pick the second one from your regimen.
Limited data. Use when necessary.
Passes into milk. Breastfeeding not recommended.
Reference information, not a clinical decision. Discuss feeding pauses or changes with your physician or an IBCLC.
Propafenone is evaluated for the following indications with varying evidence strength: Atrial fibrillation (evidence tier B). See the full indication matrix with dosing and citations above on this page.
Common side effects of Propafenone (≥ 1 in 100): Metallic taste, Nausea, Dizziness, Bradycardia, QRS widening. See the Safety section for uncommon and serious reactions.
FDA category C. Limited data. Use when necessary.
Passes into milk. Breastfeeding not recommended.
Propafenone is contraindicated in: Structural heart disease (CAD, post-MI, LV dysfunction, HF); Second/third-degree AV block without pacemaker; Sick sinus syndrome; Severe hepatic impairment; Myasthenia gravis. Full list in the Safety section.