Illustrative image.
Tambocor
Flecainide
$138.00
100mg · 3 × 60 tablets · 3 months supply
GenericGeneric medicine
$46.00 per month
How long a supply?
Test mode: no payment is taken. View cart
Annual cost
$552a year at this pack size
Prescription required
Upload your prescription after ordering, or send it to our pharmacy team. We dispense only against a valid prescription.
FDA boxed warning
Mortality
The applicability of the CAST results to other populations (e.g., those without recent myocardial infarction) is uncertain, but at present, it is prudent to consider the risks of Class IC agents (including flecainide acetate), coupled with the lack of any evidence of improved survival, generally unacceptable in patients without life-threatening ventricular arrhythmias, even if the patients are experiencing unpleasant, but not life-threatening, symptoms or signs.
Ventricular Pro-arrhythmic Effects in Patients with Atrial Fibrillation/Flutter
A review of the world literature revealed reports of 568 patients treated with oral flecainide acetate for paroxysmal atrial fibrillation/flutter (PAF). Ventricular tachycardia was experienced in 0.4% (2/568) of these patients. Of 19 patients in the literature with chronic atrial fibrillation (CAF), 10.5% experienced VT or VF. FLECAINIDE IS NOT RECOMMENDED FOR USE IN PATIENTS WITH CHRONIC ATRIAL FIBRILLATION. Case reports of ventricular proarrhythmic effects in patients treated with flecainide acetate for atrial fibrillation/flutter have included increased PVCs, VT, ventricular fibrillation (VF), and death.
As with other Class I agents, patients treated with flecainide acetate for atrial flutter have been reported with 1:1 atrioventricular conduction due to slowing the atrial rate. A paradoxical increase in the ventricular rate also may occur in patients with atrial fibrillation who receive flecainide acetate. Concomitant negative chronotropic therapy such as digoxin or beta-blockers may lower the risk of this complication.
About Tambocor
Overview
Tambocor is a prescription antiarrhythmic medicine containing flecainide acetate, used to help prevent certain abnormal heart rhythms. In people without structural heart disease, it is used to prevent episodes of supraventricular tachycardia or atrial fibrillation/flutter that cause disabling symptoms. It is also used to prevent documented ventricular arrhythmias judged to be life-threatening, with treatment for sustained ventricular tachycardia started in hospital. Flecainide can cause new or worsened abnormal heart rhythms, so it is reserved for people whose prescriber judges that the benefits outweigh the risks.
What it treats
- Episodes of supraventricular tachycardia (PSVT) causing disabling symptoms, in patients without structural heart disease, to prevent recurrence. - Episodes of atrial fibrillation or flutter causing disabling symptoms, in patients without structural heart disease, to prevent recurrence. - Documented ventricular arrhythmias, such as sustained ventricular tachycardia, judged by the physician to be life-threatening, to prevent recurrence. Treatment for sustained ventricular tachycardia must begin in hospital.
Safety information
Side effects
Commonly reported side effects include dizziness or lightheadedness, blurred vision or difficulty focusing, shortness of breath, headache, nausea, tiredness, weakness, shaking, constipation, swelling and abdominal pain. Palpitations and chest pain have also been commonly reported. Flecainide can cause new or worsening abnormal heart rhythms, including life-threatening rhythms and cardiac arrest. It can also cause new or worsening heart failure, a slow heartbeat, pauses in the heartbeat or heart block. Contact a doctor immediately if you develop fainting, new or worsening palpitations, chest pain, shortness of breath or swelling. In a study of patients who had previously had a heart attack and had certain ventricular rhythm abnormalities, death or non-fatal cardiac arrest occurred more often with flecainide than with placebo. Other serious reported effects include seizures, swelling of the lips, tongue or mouth, tightening of the airways, and severe skin peeling. These warrant immediate medical attention. Rare liver problems, including liver failure, and extremely rare blood disorders have been reported after marketing, although a causal link to flecainide has not been established. Contact a doctor promptly for unexplained yellowing of the skin or eyes. The label advises discontinuing flecainide if unexplained jaundice or signs of liver or blood disorders develop.
FDA boxed warning
Mortality
The applicability of the CAST results to other populations (e.g., those without recent myocardial infarction) is uncertain, but at present, it is prudent to consider the risks of Class IC agents (including flecainide acetate), coupled with the lack of any evidence of improved survival, generally unacceptable in patients without life-threatening ventricular arrhythmias, even if the patients are experiencing unpleasant, but not life-threatening, symptoms or signs.
Ventricular Pro-arrhythmic Effects in Patients with Atrial Fibrillation/Flutter
A review of the world literature revealed reports of 568 patients treated with oral flecainide acetate for paroxysmal atrial fibrillation/flutter (PAF). Ventricular tachycardia was experienced in 0.4% (2/568) of these patients. Of 19 patients in the literature with chronic atrial fibrillation (CAF), 10.5% experienced VT or VF. FLECAINIDE IS NOT RECOMMENDED FOR USE IN PATIENTS WITH CHRONIC ATRIAL FIBRILLATION. Case reports of ventricular proarrhythmic effects in patients treated with flecainide acetate for atrial fibrillation/flutter have included increased PVCs, VT, ventricular fibrillation (VF), and death.
As with other Class I agents, patients treated with flecainide acetate for atrial flutter have been reported with 1:1 atrioventricular conduction due to slowing the atrial rate. A paradoxical increase in the ventricular rate also may occur in patients with atrial fibrillation who receive flecainide acetate. Concomitant negative chronotropic therapy such as digoxin or beta-blockers may lower the risk of this complication.
A boxed warning is the strongest warning the US Food and Drug Administration requires on a medicine label. Text is taken from the official label, with internal section references removed.
When to call your doctor
If symptoms are severe or getting worse quickly, seek emergency care rather than waiting.
Before taking this medicine
Do not take Tambocor (flecainide) if you have: - Second- or third-degree atrioventricular (AV) block, unless you have a pacemaker to maintain your heart rhythm if complete heart block occurs. - Right bundle branch block together with a left hemiblock (bifascicular block), unless you have a pacemaker for the same reason. - Cardiogenic shock, a condition in which the heart cannot pump enough blood to meet the body’s needs. - A known allergy to flecainide.
Interactions
Flecainide can interact with other medicines, including: • Digoxin: flecainide can increase digoxin levels in the blood. • Beta blockers, including propranolol: taking these with flecainide may further reduce the heart’s pumping strength. Flecainide and propranolol can also increase each other’s blood levels. • Amiodarone: this can substantially increase flecainide levels in the blood. • Cimetidine and medicines that block the enzyme CYP2D6, such as quinidine: these may increase flecainide levels. • Phenytoin, phenobarbital and carbamazepine: these may make the body clear flecainide faster. • Disopyramide or verapamil: these should be used with flecainide only if the doctor decides the benefits outweigh the risks, because they also reduce the heart’s pumping strength. • Nifedipine or diltiazem: there is too little experience with these combinations to recommend using them together with flecainide. Raise any of these medicines with your doctor if you take them or are considering starting them.
Using Tambocor
Dosing
Dosing is set by your prescriber. Each health care professional may prescribe medication differently according to a patient's medical history and condition, so follow the directions on your prescription label and speak to your doctor or pharmacist before changing anything.
Storage
Store below 25°C in a dry place, in the original pack, away from direct light and moisture. Do not keep it in a bathroom. Keep all medicines out of the sight and reach of children.
Clinical information on this page is summarised from the US FDA label FLECAINIDE ACETATE TABLET [EPIC PHARMA, LLC] (DailyMed, retrieved 19 September 2026).
Patient information and references
Official and supporting information to read alongside advice from your prescriber or pharmacist.
Reviews
No reviews yet. Mail Order Drugs opened recently, and we publish reviews only from verified customers of this site, so this space stays empty until real ones arrive.
- Every prescription order is checked by a licensed pharmacist before dispensing.
- Payment pages are encrypted and card details never reach our servers.
- We ship internationally, with cold-chain packing where a medicine needs it.
Related medicines
Multaq
Dronedarone
Tablets · from 60 per pack
Also for antiarrhythmic
Brand and generic from $165.00
Norpace
Disopyramide
By Sanofi
Capsules · from 84 per pack
Also for antiarrhythmic
Brand $58.00
Betapace
Sotolol
Tablets · from 28 per pack
Also for antiarrhythmic
Generic from $15.00
Rythmol
Propafenone
Tablets · from 30 per pack
Also for antiarrhythmic
Generic from $17.00