flecainide vs propafenone
Side-by-side comparison of flecainide and propafenone Data from FDA drug databases (Orange Book, NDC Directory, recalls, shortages) covering 20,000+ approved drugs, plus CMS pricing; see our methodology.
Tambocor
Rythmol
Flecainide is a medicine used to prevent irregular heartbeats. It helps your heart beat normally.
Propafenone (Rythmol) is a medicine that helps control irregular heartbeats. It works by slowing down electrical signals in the heart.
This medicine can prevent fast heart rates in the upper chambers of the heart. This includes supraventricular tachycardia and atrial fibrillation/flutter. Flecainide can also prevent life-threatening fast heartbeats in the lower chambers (ventricles). It is usually started in the hospital for these serious ventricular problems.
This medicine is used to help keep your heart rhythm normal if you have atrial fibrillation or supraventricular tachycardia. These are types of fast or irregular heartbeats that can cause problems. It can also treat life-threatening ventricular arrhythmias. Propafenone is for people without structural heart disease.
Flecainide works by slowing down electrical signals in the heart. This helps to stabilize your heart rhythm. It belongs to a class of drugs called Class IC antiarrhythmics.
Propafenone works by affecting the electrical activity in your heart. It slows down the signals that cause irregular heartbeats. This helps your heart beat more regularly.
- • Dizziness
- • Vision problems
- • Difficulty breathing
- • Headache
- • Nausea
- • Unusual taste
- • Nausea
- • Vomiting
- • Dizziness
- • Constipation
- Irregular heartbeat in the upper chambers 337
- Feeling tired 276
- Difficulty breathing 270
- Feeling lightheaded 255
- Feeling sick to your stomach 244
- Irregular heartbeat in the upper chambers of the heart 347
- Medicine not working 330
- Medicine interacting with another medicine 320
- Feeling lightheaded or unsteady 261
- Harmful effect from different substances 231
Flecainide can increase the risk of death or cardiac arrest in some patients who have had a heart attack. It is generally not recommended for people with less serious, but unpleasant, heart rhythm problems. Flecainide is also not recommended if you have chronic atrial fibrillation.
This medicine may increase the risk of death in people with heart problems. Do not take this medicine if you have structural heart disease and non-life-threatening ventricular arrhythmias. Talk to your doctor about the risks and benefits of taking this medicine.
Tell your doctor if you are pregnant or plan to become pregnant. It is not known if flecainide can harm an unborn baby. Talk to your doctor about the risks and benefits of taking flecainide while breastfeeding.
Tell your doctor if you are pregnant or plan to become pregnant. This medicine can cross the placenta, and may affect the baby. Your doctor will monitor you and your baby for any problems.
How to Read This flecainide vs propafenone Comparison
flecainide is classified in the Class IC Antiarrhythmic drug class, while propafenone sits within the Class IC Antiarrhythmic class. Because both drugs share the same classification, they are often considered interchangeable in theory — but clinical outcomes rarely track that cleanly. Both drugs are prescription-only, so a licensed provider must authorize use.
Adverse event totals above are pulled from the FDA's Adverse Event Reporting System (FAERS). For these top-ranked reactions alone, flecainide has 1,382 submissions while propafenone has 1,489. Those figures reflect cumulative reporting volume — not per-patient risk — so older, widely dispensed drugs typically look worse on count alone. No direct interaction between these two drugs is listed in our FDA-derived dataset, though co-prescription still warrants pharmacist review. Serious warnings, pregnancy guidance, and contraindications can differ even when indications overlap.
A table cannot substitute for clinical judgment. Effectiveness, tolerability, drug-drug interactions with your other medications, kidney and liver function, pregnancy status, insurance formulary, and price all feed into a decision that only a licensed prescriber can make responsibly. Data here is sourced from FDA Structured Product Labels (SPL) and FAERS, both of which update as manufacturers and clinicians submit new information. This page is for educational purposes only, is not medical advice, and should not be used to self-switch between flecainide and propafenone — always consult your physician or pharmacist first.
Important: This comparison is for informational purposes only. Drug effects vary between individuals. Always consult your doctor or pharmacist for personalized medical advice.