Propafenone (Subgroup 1C)

PROPAFENONE (SUBGROUP 1C)

Propafenone has some structural similarities to propranolol and possesses weak β-blocking activity. Its spectrum of action is very similar to that of quinidine, but it does not prolong the action potential. Its sodium channel-blocking kinetics are similar to that of flecainide. Propafenone is metabolized in the liver, with an  average half-life of 5–7 hours. The usual daily dosage of propafenone is 450–900 mg in three divided doses. The drug is used primarily for supraventricular arrhythmias. The most com-mon adverse effects are a metallic taste and constipation; arrhyth-mia exacerbation can also occur.