Flecainide (Tambocor, Amarhyton)

Mechanism of action

  • Antiarrhythmic (Class Ic)
  • Blocks sodium channels on cardiomyocytes which leads to their reduced excitation. This reduces myocardial automaticity and slows down the impulse conduction as well as prolongs refractory period of cardiomyocytes. 
  • Second effect is a block of potassium channels which lengthens the action potential in cardiomyocytes.

Indications and dose


Onset of action: 2–4 hours

Half-life of elimination

  • 13 hours after single dose
  • 16 hours after multiple doses

Metabolism: Hepatic

Elimination: Kidneys (86 %), liver

Directions for administration

Should be taken at least one hour before food since food undesirably affects the absorption of the drug.

Medicinal forms

Pills – 50 mg, 100 mg


Arrhythmias (high risk in patients with structural heart disease)


Blurred vision



  1. Pharm 101: Flecainide • LITFL • Top 200 Drugs
  2. Flecainide Acetate 100 mg tablets - Summary of Product Characteristics (SmPC) - (emc) (medicines.org.uk)
  3. Flecainide: Uses, Interactions, Mechanism of Action | DrugBank Online