[Pharmacology of 2'-[2-hydroxy-3-(propylamino)-propoxy]-3-phenylpropiophenone (Propafenone, SA 79)-hydrochloride].

The pharmacologic actions of 2'-[2-hydroxy-3-(propylamino)-propoxy]-3-phenylpropiophenone (propafenone, SA 79) hydrochloride were investigated in animal experiments. The drug showed antiarrhythmic action in anesthetized dogs, cats and rabbits after i.v. (1 mg/kg) and oral (2-10 mg/kg) application. The model arrhythmias were induced by epinephrine infusion plus chloroform inhalation or by infusion of digoxin, calciumchloride or aconitine or by occlusion of the left coronary artery. Propafenon prolonged the refractory period in isolated atria of guinea pigs and elevated the electrical fluttering level of the ventricle in anesthetized guinea pigs or conscious rabbits. It showed local-anesthetic action on the cornea of the guinea pigs. In doses of 3-10 mg/kg i.v. it lowered blood pressure, inhibited contraction force of the heart ventricle and dilated coronary arteries. Heart rate was unchanged by anti-arrhythmic doses. With higher doses (more than 7 mg/kg i.v.) ECG was altered. The autonomic nervous system was unaffected but bronchial adrenergic beta-receptors appeared to be inhibited. The results show, that propafenon has a specific antiarrhythmic action on the heart. The doses to be used have no influences on other circulatory parameters. Propafenon acts after oral application too.