Wikipedia
N-Acetylprocainamide
N-Acetylprocainamide (NAPA or acecainide) is the N-acetylated metabolite of procainamide. It is a Class III antiarrhythmic agent, whereas procainamide is a Class Ia antiarrhythmic drug. It is only partially as active as procainamide; when checking levels both must be included in the final calculation.