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flecainide vs propranolol

Side-by-side comparison of flecainide and propranolol. Data from FDA drug databases (Orange Book, NDC Directory, recalls, shortages) covering 20,000+ approved drugs, plus CMS pricing; see our methodology.

minor Known Drug Interaction

In a study involving healthy subjects receiving flecainide acetate and propranolol concurrently, plasma flecainide levels were increased about 20% and propranolol levels were increased about 30% compared to control values. In this formal interaction study, flecainide acetate and propranolol were each found to have negative inotropic effects; when the drugs were administered together, the effects were additive. The effects of concomitant administration of flecainide acetate and propranolol on the PR interval were less than additive.

Recommendation: Your doctor should watch your heart health closely and may need to change your medication doses.

Drug Class
flecainide Class IC Antiarrhythmic
propranolol Non-Selective Beta-Blocker
Type
flecainide Prescription
propranolol Prescription
Summary
flecainide

Flecainide is a medicine used to prevent irregular heartbeats. It helps your heart beat normally.

propranolol

Propranolol is a medicine that can help with high blood pressure, chest pain, and other conditions. It works by blocking the effects of certain natural chemicals in your body, like adrenaline, that affect the heart and blood vessels.

What It Treats
flecainide

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.

propranolol

Propranolol tablets can treat high blood pressure. It can be used alone or with other medicines. Propranolol can also help with chest pain (angina), control fast heart rate with atrial fibrillation, improve survival after a heart attack, prevent migraine headaches, and reduce tremors. It can also help with symptoms of some tumors.

How It Works
flecainide

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.

propranolol

Propranolol is a beta-blocker. It works by blocking the effects of adrenaline on your heart and blood vessels. This helps to slow down your heart rate and lower your blood pressure.

Common Side Effects
flecainide
  • Dizziness
  • Vision problems
  • Difficulty breathing
  • Headache
  • Nausea
propranolol
  • Tiredness
  • Dizziness
  • Nausea
  • Vomiting
  • Diarrhea
FAERS Reports
flecainide
  • Irregular heartbeat in the upper chambers 337
  • Feeling tired 276
  • Difficulty breathing 270
  • Feeling lightheaded 255
  • Feeling sick to your stomach 244
propranolol
  • Feeling sick to your stomach 4,279
  • Pain in your head 3,784
  • Feeling very tired 3,752
  • Loose, watery stools 3,121
  • Feeling lightheaded or unsteady 3,102
Serious Warnings
flecainide

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.

propranolol

Propranolol is contraindicated in people with cardiogenic shock, very slow heart rate, asthma, or those who are allergic to it.

Pregnancy
flecainide

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.

propranolol

Tell your doctor if you are pregnant or plan to become pregnant. Propranolol may affect your baby. Talk to your doctor about the risks and benefits of taking propranolol during pregnancy or while breastfeeding.

Also Compare, Nearby Drugs

Compare flecainide with

Compare propranolol with

How to Read This flecainide vs propranolol Comparison

flecainide is classified in the Class IC Antiarrhythmic drug class, while propranolol sits within the Non-Selective Beta-Blocker class. Drugs from different classes work through distinct mechanisms, so a head-to-head comparison illustrates trade-offs rather than equivalence. 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 propranolol has 18,038. Those figures reflect cumulative reporting volume, not per-patient risk, so older, widely dispensed drugs typically look worse on count alone. These two drugs have a known minor interaction flagged in FDA labeling, attributed to taking these drugs together increases the amount of medicine in your blood and can further weaken the heart's ability to pump.. 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 propranolol - 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.