Flecainide
Flecainide is a Class Ic antiarrhythmic medication used to treat various heart rhythm disorders, including atrial fibrillation, atrial flutter, and certain types of ventricular arrhythmias. It works by blocking sodium channels in the heart, which slows electrical conduction and helps restore normal heart rhythm. This medication is typically prescribed when other treatments have not been effective.
Flecainide is a heart rhythm medication used to treat abnormal heartbeats including atrial fibrillation and certain ventricular arrhythmias.
This medication carries a boxed (black box) warning — the strongest type of FDA warning. Review the full prescribing information before use.
Key facts at a glance
- ATC
- C01BC04
- RxNorm
- 4441
- Generic
- Flecainide
- Class
- atc-c01
- Brands
- —
- Availability
- rx
- Pregnancy
- C
- Lactation
- caution
- Routes
- oral
- Forms
- solution, tablet
- Regions
- US, EU, CN, JP
- Monitoring
- —
This page is for informational purposes only.
Do not use this information to diagnose yourself or to replace a physician's advice. Always consult a qualified healthcare provider before starting, stopping, or changing any medication. If you believe you are experiencing a medical emergency, call your local emergency number immediately.
Treatment of tachyarrhythmias including Wolff-Parkinson-White syndrome, paroxysmal atrial fibrillation/flutter, and life-threatening ventricular arrhythmias when other therapies are ineffective or not tolerated.
As a Class Ic antiarrhythmic, flecainide blocks voltage-gated sodium channels, which slows conduction velocity in the heart tissue and prolongs the refractory period, helping to stabilize irregular electrical activity.
May cause new or worsened arrhythmias (proarrhythmic effect); requires careful monitoring with ECG and serum level checks. Contraindicated in patients with structural heart disease, heart failure, or cardiogenic shock. Avoid abrupt discontinuation. Regular cardiac monitoring essential during treatment.
Official drug label
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This information is for educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment.
This content is for general informational and educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment. Always seek the guidance of a qualified healthcare provider with any questions you have about a medical condition, and never disregard professional medical advice or delay seeking it because of something you read here.
If you think you may have a medical emergency, call your local emergency number or go to the nearest emergency department immediately.
Medically reviewed by WellAlly Editorial Team Last reviewed August 25, 2026. · Read our editorial policy