[Changes in the effects of verapamil in sensitized dogs]

The cardiovascular effects of verapamil were studied on anesthetized dogs with the intact chest, control ones and those sensitized with horse serum. Verapamil dose inducing the minimal cardio- and hemodynamic effects in the sensitized dogs was 2-3 times less that used in the controls. In addition, in contrast to the control dogs, the sensitized dogs exhibited the cardiotoxic effects of verapamil-a disorder of atrioventricular conductivity and a deterioration of the cardiac muscle relaxation. The cardiovascular effects of verapamil are modified by sensitization of the organism by heterologous serum proteins.