Flecainide is a drug used to prevent several irregular heart rhythms, most commonly paroxysmal atrial fibrillation. It is usually commenced by a Cardiologist and may be taken either on a regular basis or in a ‘pill-in-the-pocket’ fashion. 

Mechanism of action

Flecainide acts by preventing the passage of sodium into heart muscle cells thereby slowing electrical conduction.

Potential side-effects

Flecainide is a very useful drug but it should be used with caution. Common side effects include visual disturbance (5-16%) and dizziness (10-19%). If you are started on Flecainide and experience any untoward effects it is essential that you seek medical advice.


Its use should also be avoided in patients with a history of cardiac failure or significant coronary artery disease as well as severe kidney failure. Potential side effects include other abnormal heart rhythms.