Flecainide (Tambocor) to Control Heart Rhythm

Unless otherwise noted, the following information about flecainide (Tambocor®) comes from the package insert.1


Flecainide is an antiarrhythmic drug used to convert paroxysmal afib and/or atrial flutter that are associated with disabling symptoms to normal sinus rhythm and maintain it.

How to Use

Hospitalization for three days is required to start flecainide. It comes in 50, 100, or 150 mg tablets for taking by mouth. It may be taken when needed (called “pill-in-the-pocket”), such as when having an afib episode.


Flecainide can cause other types of heart rhythm disorders or worsen heart failure. Thus, it should not be used by those with:

  • Cardiovascular disease
  • Heart failure
  • Persistent afib

Common Side Effects

These are common side effects of flecainide.

  • Dizziness
  • Visual disturbances
  • Shortness of breath
  • Headache

Serious Side Effects

Contact your doctor immediately if you experience any of the following serious side effects:

  • Difficult or labored breathing
  • Dizziness, fainting, or lightheadedness
  • Fast, irregular, pounding, or racing heartbeat or pulse
  • Shortness of breath
  • Tightness in the chest
  • Wheezing

Drug Interactions

Talk with your doctor about any prescription or over-the-counter drugs, nutritional supplements, or herbal remedies you are taking. Flecainide may have possible interactions with the following medications:

  • Beta blockers, which are often used to treat afib
  • Quinidine, which may be used to treat afib


You may need periodic tests to assess the levels of flecainide in your bloodstream.


The various guidelines have specific recommendations related to flecainide.

  • US guidelines (AHA/ACC/HRS) recommend flecainide as a long-term rhythm control medication for those with normal left ventricular function and no structural heart disease such as valvular disease.2
  • European guidelines (ESC) list flecainide as a medication that can be used to maintain normal sinus rhythm depending on any underlying cardiovascular or other health conditions.3
  • Canadian guidelines (CCS) leave the choice of which antiarrhythmic to use for maintenance rhythm control up to the physician based on patient characteristics.4