Prilocaine - barium chloride antagonism in the cardiovascular system of anesthetized dogs

The intravenous administration of BaCl2 (2 mg/kg) in dogs anesthetized with nembutal determined sharp rise of arterial blood pressure, bradycardia, enlargement of PR interval and QRS complex, and bigeminated ventricular extrasystoles. Prilocaine (20 mg/kg iv) caused only slight fall of arterial blood pressure, mild bradycardia, enlargement of PR interval and QRS complex. When the drugs were administered simultaneously, prilocaine effectively antagonized pressor and heart rhythm alterations induced by barium. However, bradycardia and PR interval enlargement were even more severe, thus indicating a synergistic action of the drugs. It is shown that the statistical analysis based on a multiple regression model is quite suitable for this kind of experimental design.