Dosage, Plasma Concentration and Antiarrhythmic Effect of Procainamide in Sustained-Release Tablets

. A new sustained-release tablet of procainamide has been found to have a mean biological half-life of 6.7 hours as compared with 3.2 hours in ordinary tablet form. The dosage of 1.2 g t.i.d. yielded averaged plasma concentrations of 3.2–5.4 mg/1 after 24 hours. Ventricular premature beats were abolished for about 5 hours in most of the 47 patients studied. These findings suggest 1.0 g q.i.d. to be the optimum for an average patient. Because of great individual differences the determination of procainamide plasma levels in clinical use is recommended.