Comparison of the therapeutic effectiveness of aprindine, procainamide and quinidine in chronic ventricular dysrhythmias.

1 A cross-over study with aprindine (100 mg daily after a loading dose of 200 mg), procainamide (4 × 1000 mg daily) and quinidine bisulphate (2 × 750 mg daily), all given orally, was performed in seventeen patients with stable chronic premature ventricular contractions following healed myocardial infarction. 2 The effectiveness of the treatment was evaluated during three consecutive weeks by continuous ambulatory tape recording of the electrocardiogram and repeated determinations of plasma levels were done. 3 The results showed that aprindine was more effective than procainamide and quinidine. 4 For the three drugs the therapeutic plasma levels varied markedly from patient to patient, but for each patient taken individually, the therapeutic activity could be correlated with the plasma levels.