Propafenone: a novel type Ic antiarrhythmic agent

Propafenone is an investigational type Ic anti-arrhythmic agent that markedly slows conduction velocity in all cardiac tissues. Propafenone also possesses weak beta- and calcium-channel blocking properties. The bioavailability of propafenone is dose-dependent. Hepatic metabolism of this agent is polymorphic and appears to correlate with the ability of the liver to oxidize debrisoquin sulfate. Propafenone is effective in suppressing spontaneous ventricular ectopy; however, the drug may be less effective in patients with sustained ventricular tachycardia or ventricular fibrillation when evaluated using programmed stimulation. Propafenone is also useful in the treatment of supraventricular tachycardias including atrioventricular (AV) nodal reentrant tachycardia, AV reentrant tachycardia associated with the Wolff-Parkinson-White syndrome, and atrial fibrillation. Adverse reactions seen with propafenone affect the gastrointestinal, central nervous, and cardiovascular systems. Comparative studies with currently available type Ic agents are needed to better define propafenone's place in therapy.