Class Ic antiarrhythmic

Propafenone hydrochloride

Brand names: Arythmol

Propafenone is a class Ic antiarrhythmic with weak beta-blocking properties, used for paroxysmal atrial fibrillation and certain other supraventricular and ventricular arrhythmias.

Dosing — being independently re-sourced

ClinCalc Pro is rebuilding its dose data from primary open sources — the manufacturer SmPC (eMC), the WHO Model Formulary and other official references — under clinician review. This drug's structured dose is not yet published here. Confirm all doses against the product SmPC and your local formulary before prescribing.

Clinical monograph

How it works

It blocks fast cardiac sodium channels, slowing conduction and prolonging the refractory period, with additional mild beta-adrenoceptor blockade.

Prescribing in practice

Avoid in significant structural heart disease, including ischaemic heart disease and heart failure, because of the proarrhythmic risk seen with class Ic agents.
Use with caution in obstructive airways disease owing to its beta-blocking activity.
It can increase plasma concentrations of digoxin and warfarin, so monitor and adjust accordingly.

Monitoring

Monitor ECG (including QRS duration) and clinical response, particularly when initiating or up-titrating.

Counselling the patient

Report palpitations, fainting, breathlessness or worsening symptoms.
Do not stop or change the dose without medical advice.
Mention any new medicines, as some interact with this drug.

Evidence & guidelines

Class Ic antiarrhythmics are restricted to patients without significant structural heart disease, reflecting the proarrhythmic signal from the CAST trial.

Reference: NICE NG196; ESC; Drug verified in RxNorm (NLM); confirm dosing against the manufacturer SPC (eMC). Verify against your local formulary and current prescribing references before prescribing. Monograph status: clinician-reviewed (2026-07-04).

Curated clinical cross-links plus same-class fallbacks.

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