[Durgical](https://durgical.com/en/) › [DurgiPedia](https://durgical.com/en/durgipedia/) › [Pharmacology](https://durgical.com/en/pharmacology/) › [Antiarrhythmics](https://durgical.com/en/pharmacology/classes/antiarrhythmics/) › Propafenone

# Propafenone

## Antiarrhythmics?

Antiarrhythmics

A class IC antiarrhythmic with mild beta-blocking action, used to keep sinus rhythm in atrial fibrillation in hearts without structural disease.

Updated Nov 1, 2026

## Quick facts

**Group**
[Antiarrhythmics](https://durgical.com/en/pharmacology/classes/antiarrhythmics/)

**Target**
Cardiac sodium channel Nav1.5 (and β-adrenergic receptors)

**Used for**
Prolonging the time to recurrence

**Key effects**
Unusual or metallic taste · Nausea · Dizziness

**Monitor**
ECG before and during treatment

**ATC**
C01BC03

No doses: the clinician sets them by the current guideline.

On this page

- The basics Mechanism of action
- Indications
- Adverse effects
- Pharmacokinetics
- Memory aid

- Safety Contraindications
- Key interactions
- What is monitored
- Administration and safety
- Pregnancy and breastfeeding
- Nursing care

- Study Test yourself

- Connections Connections

## Mechanism of action

⇅**Cardiac sodium channel Nav1.5 (and β-adrenergic receptors)**Propafenone

ⓘ The figure shows propafenone bound to the rat cardiac sodium channel Nav1.5, very similar to the human channel.

**Target in 3D:** Cardiac sodium channel Nav1.5 (and β-adrenergic receptors). PDB structure 7FBS (RCSB PDB, public domain). [View the structure at RCSB PDB](https://www.rcsb.org/structure/7FBS) · Drag to rotate · pinch to zoom

Propafenone blocks the fast inward sodium current, mainly in Purkinje fibres, slowing the action potential upstroke and conduction (longer PR and QRS). It also has weak beta-blocking activity, which can slow the heart and narrow the airways, and a local anaesthetic effect.

- Propafenone blocks the Nav1.5 sodium channel
- Conduction slows: longer PR and wider QRS
- Weak beta blockade adds slowing of the heart

## Indications

- Prolonging the time to recurrence of symptomatic paroxysmal or persistent atrial fibrillation, without structural heart disease [Atrial fibrillation →](https://durgical.com/en/conditions/atrial-fibrillation/)
- Prolonging the time to recurrence of disabling PSVT, without structural heart disease [Supraventricular tachycardia (AVNRT, AVRT) →](https://durgical.com/en/conditions/supraventricular-tachycardia/)
- Documented life-threatening ventricular arrhythmias [Ventricular tachycardia →](https://durgical.com/en/conditions/ventricular-tachycardia/)

## Adverse effects

### Common

- Unusual or metallic taste
- Nausea, vomiting and constipation
- Dizziness, headache and fatigue
- First-degree AV block and QRS widening

### Serious (rare, important)

- New or worse arrhythmias (proarrhythmia)
- Unmasking of Brugada syndrome
- Heart failure
- Agranulocytosis
- Worsening of myasthenia gravis

## Contraindications

- Heart failure or cardiogenic shock
- Sinoatrial, AV or intraventricular conduction disorders without a pacemaker
- Known Brugada syndrome
- Bradycardia or marked hypotension
- Bronchospastic disorders and severe obstructive lung disease
- Marked electrolyte imbalance

## Key interactions

**CYP2D6 inhibitors combined with CYP3A4 inhibitors**
Large rise in propafenone levels and proarrhythmia; the combination is avoided

**Digoxin**
Higher digoxin levels

**Warfarin**
Higher warfarin levels; INR is checked

**Lidocaine**
More central nervous system effects

## What is monitored

- ECG before and during treatment: PR and QRS
- Blood count if infection signs appear
- Pacemaker function in patients with devices

## Administration and safety

- Used only in hearts without structural disease; ECG is taken before starting.
- In atrial fibrillation or flutter it is given with a drug that slows the AV node.
- Immediate-release and extended-release products are not interchangeable one for one: the product is checked.

## Pregnancy and breastfeeding

Human data are limited; it is used in pregnancy only if the benefit justifies the risk to the fetus.

## Nursing care

- Check pulse and ECG; report QRS widening, fainting or palpitations.
- Ask about wheeze or breathlessness in patients with lung disease.
- Teach the patient to report fever, sore throat or chills (agranulocytosis).

## Pharmacokinetics

**Metabolism**
Liver, mainly CYP2D6 (also CYP3A4 and CYP1A2); poor CYP2D6 metabolisers reach higher levels

**Elimination**
Mostly as metabolites; dose is lowered in liver impairment

## Memory aid

PROPAfenone has a PROPranolol touch: class IC plus a little beta block (and a metallic taste).

## Test yourself

Think of the answer, then tap the question to see it.

## What property distinguishes propafenone from flecainide?

Weak beta-blocking activity, so it can cause bradycardia and bronchospasm.

## Which inherited ECG syndrome can propafenone unmask?

Brugada syndrome.

## Why do some patients reach much higher propafenone levels?

They are poor CYP2D6 metabolisers or take CYP2D6 and CYP3A4 inhibitors together.

[Add to my cards (3)](https://durgical.app/estudiar/?add=/en/pharmacology/propafenone/)

[More Pharmacology questions →](https://durgical.com/en/practice/?f=pharmacology)

## Connections

## Related drugs 4

- [Flecainide](https://durgical.com/en/pharmacology/flecainide/)
- [Propranolol](https://durgical.com/en/pharmacology/propranolol/)
- [Digoxin](https://durgical.com/en/pharmacology/digoxin/)
- [Warfarin](https://durgical.com/en/pharmacology/warfarin/)

## Related conditions 3

- [Atrial fibrillation](https://durgical.com/en/conditions/atrial-fibrillation/)
- [Supraventricular tachycardia (AVNRT, AVRT)](https://durgical.com/en/conditions/supraventricular-tachycardia/)
- [Ventricular tachycardia](https://durgical.com/en/conditions/ventricular-tachycardia/)

[← Back to the class: Antiarrhythmics](https://durgical.com/en/pharmacology/classes/antiarrhythmics/)

Educational content on how drugs work; not a prescribing guide and no substitute for a health professional's advice. No doses are given.

Sources: [DailyMed - PROPAFENONE HYDROCHLORIDE tablet, film coated](https://dailymed.nlm.nih.gov/dailymed/drugInfo.cfm?setid=c65253ab-937f-4982-b841-69c2b9f9ccdb) (DailyMed (U.S. National Library of Medicine), 2026); [Propafenone: MedlinePlus Drug Information](https://medlineplus.gov/druginfo/meds/a698002.html) (MedlinePlus (U.S. National Library of Medicine), 2026); [ATCDDD - ATC/DDD Index](https://atcddd.fhi.no/atc_ddd_index/?code=C01BC03) (WHO Collaborating Centre for Drug Statistics Methodology, 2026); [7FBS: structure of a channel](https://www.rcsb.org/structure/7FBS) (RCSB Protein Data Bank, 2021).

## **Spotted a mistake?** We are always improving for the community. Tell us what is wrong and our team will review it. Report a mistake

Representative model, for educational purposes only.

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Source: https://durgical.com/en/pharmacology/propafenone/
License: CC BY 4.0 (https://creativecommons.org/licenses/by/4.0/). Cite as: DurgiPedia (durgical.com), https://durgical.com/en/pharmacology/propafenone/