Class IC drugs: propafenone and flecainide.

Recently published clinical data on the efficacy and side-effect profiles of flecainide and propafenone are reviewed. Both compounds appear to be clinically effective for the control of a variety of cardiac arrhythmias, both ventricular as well as supraventricular. These include termination of atrial fibrillation, control of junctional tachycardias, and control of ventricular arrhythmias. While the incidence of noncardiac side effects appeared to be similar for both compounds, proarrhythmic effects appeared to be higher on flecainide than on propafenone, especially with doses higher than 400 mg.