Propafenone is an anti-arrhythmic medicine used to treat irregular heartbeats (arrhythmias). It is also known as Arythmol® and is available as tablets. Treatment is initiated by a heart specialist to correct abnormal heart rhythms, helping the heart beat normally by slowing nerve impulses in heart tissue.
About propafenone
Propafenone belongs to the group of medicines known as antiarrhythmics. It works directly on the heart tissue to slow nerve impulses, maintaining a normal heart rhythm. This is particularly useful for conditions like atrial fibrillation (AF), paroxysmal supraventricular tachycardia (PSVT), and certain ventricular arrhythmias in patients without structural heart disease.
| Type of medicine | An anti-arrhythmic medicine |
|---|---|
| Used for | Irregular heartbeats |
| Also called | Arythmol® |
| Available as | Tablets and extended-release capsules |
An arrhythmia is an irregularity in the heartbeat where the heart may skip beats, beat unevenly, too fast (tachycardia), or too slowly (bradycardia). Propafenone corrects these by stabilizing electrical signals in the heart.
Key facts
- Propafenone is typically prescribed for paroxysmal atrial fibrillation/flutter (PAF) associated with disabling symptoms in patients without structural heart disease.
- It prolongs the time to recurrence of AF and helps maintain sinus rhythm post-cardioversion.
- Commonly used for PSVT and some ventricular arrhythmias, but only for serious cases.
- Dosage forms include 150 mg, 225 mg, 300 mg immediate-release tablets (three times daily) and 225 mg, 325 mg, 425 mg extended-release capsules (twice daily).
- Treatment often starts in a hospital for monitoring due to potential proarrhythmic effects.
Before taking propafenone
Allergy
Do not take propafenone if you are allergic to it or any similar medicines. Inform your doctor of any allergic reactions.
Pregnancy and breastfeeding
Propafenone is not usually recommended during pregnancy unless benefits outweigh risks. It may pass into breast milk, so discuss with your doctor.
Blood tests
Your doctor may perform blood tests to monitor liver and kidney function, electrolytes, and heart rhythm via ECG before and during treatment.
Other medicines
Inform your doctor of all medications, as propafenone interacts with many, including blood thinners (e.g., warfarin), beta-blockers, calcium channel blockers, antidepressants, and CYP2D6 inhibitors. It can increase levels of digoxin or theophylline.
How and when to take propafenone
Take propafenone just after a meal to improve absorption and reduce dizziness. Swallow tablets whole with water; do not chew or crush. The usual adult dose is 150-300 mg three times daily for immediate-release, adjusted based on response up to 900 mg/day. Extended-release is 225-425 mg twice daily.
- Pill-in-the-pocket approach: For paroxysmal AF, some take higher doses as needed under medical supervision.
- Do not stop suddenly without consulting your doctor, as it may worsen arrhythmias.
- If you miss a dose, take it as soon as remembered unless near the next dose; do not double up.
Common questions about propafenone
How long does propafenone take to work?
It may take days to weeks for full effect on rhythm control. Acute conversion of AF can occur within hours.
How long do you take propafenone for?
Long-term for maintenance, as directed. Regular monitoring is required.
Is propafenone safe long-term?
Generally yes in suitable patients, but requires ECG and blood monitoring due to proarrhythmic risk.
Can you drink alcohol with propafenone?
Avoid or limit alcohol, as it may increase dizziness and side effects.
Side effects
Propafenone side effects are usually mild but can include dizziness (most common), nausea, vomiting, constipation, headache, fatigue, metallic taste, and blurred vision. Serious effects include new/worsened arrhythmias (proarrhythmia), heart failure worsening, severe dizziness, fainting, or breathing difficulties.
| Common side effects | How to manage |
|---|---|
| Dizziness, lightheadedness | Avoid driving; rise slowly from sitting/lying. |
| Nausea, bitter taste | Take with food; report if persistent. |
| Fatigue, tremor | May improve over time; contact doctor if severe. |
| Proarrhythmia (rare but serious) | Seek immediate medical help for chest pain, palpitations. |
When to seek urgent help: Fast/irregular heartbeat, shortness of breath, swelling, fainting, seizures, or allergic reactions (rash, swelling). Call emergency services.
How to cope with side effects of propafenone
- Dizziness: Sit or lie down; avoid alcohol and hot baths. Do not drive until adjusted.
- Nausea: Take with meals; eat smaller, frequent meals.
- Constipation: Increase fiber, water, and exercise.
- Blurred vision: Avoid tasks needing sharp vision; report to doctor.
- Most side effects lessen over time; discuss alternatives if intolerable.
Pregnancy and breastfeeding with propafenone
Use only if essential during pregnancy (Category C). Limited data; potential fetal risks. Not recommended breastfeeding due to excretion in milk. Consult specialist.
Other medicines, food, drink and propafenone
Propafenone has many interactions:
- Grapefruit juice: Avoid, as it affects metabolism.
- Warfarin, digoxin: Monitor levels closely.
- Cimetidine, fluoxetine: Increase propafenone levels.
- Quinidine: Avoid combination.
- Always check with pharmacist or doctor.
Frequently asked questions (FAQs)
Who should not take propafenone?
Patients with structural heart disease, heart failure, bradycardia, hypotension, asthma/COPD, electrolyte imbalances, or certain conduction disorders (e.g., sick sinus syndrome without pacemaker).
Can propafenone cause weight gain?
Not commonly reported; fatigue may reduce activity leading to minor gain. Monitor diet and exercise.
Does propafenone lower blood pressure?
It can cause hypotension, especially initially. Rise slowly and monitor.
Is propafenone a beta-blocker?
No, it’s primarily a Class IC antiarrhythmic with mild beta-blocking properties.
What if propafenone doesn’t work?
Your doctor may adjust dose, switch medications (e.g., flecainide, amiodarone), or consider ablation.
Guideline recommendations
US AHA/ACC/HRS guidelines consider propafenone for rhythm control in patients without structural heart disease. ESC recommends it for long-term rhythm control in those with normal LV function. CCS leaves choice to physician.
Propafenone is effective for supraventricular arrhythmias, including AF, PSVT, and WPW-related issues, with good short- and long-term tolerability, especially in children for ectopic tachycardias.
References
- Guidelines for the use of propafenone in treating supraventricular… — PubMed/NCBI. 1995-11-01. https://pubmed.ncbi.nlm.nih.gov/8521758/
- Propafenone (Rythmol) – Uses, Side Effects, and More — WebMD. 2026 (accessed). https://www.webmd.com/drugs/2/drug-8838-4070/propafenone-oral/propafenone-oral/details
- Propafenone for irregular heartbeats; Arythmol®tablets — Patient.info. 2026 (accessed). https://patient.info/medicine/propafenone-for-irregular-heartbeats-arythmol
- Propafenone (oral route) – Side effects & dosage — Mayo Clinic. 2026 (accessed). https://www.mayoclinic.org/drugs-supplements/propafenone-oral-route/description/drg-20065687
- Propafenone: Uses & Side Effects — Cleveland Clinic. 2026 (accessed). https://my.clevelandclinic.org/health/drugs/17390-antiarrhythmic-medication-propafenone
- Propafenone (Rythmol) for Afib Rhythm Control — StopAfib.org. 2026 (accessed). https://www.stopafib.org/managing-afib/medication-for-afib/control-afib/rhythm-control-medication/propafenone-rythmol/
- RYTHMOL (propafenone hydrochloride tablets), for oral use — FDA. 2018-01-01. https://www.accessdata.fda.gov/drugsatfda_docs/label/2018/019151s015lbl.pdf
