CARDIOVASCULAR ACTION OF HYDROXYZINE (ATARAX)

Abstract

Hydroxyzine in doses of 1.2 - 20 mgm./kgm. intravenously caused a transient fall in arterial blood pressure and inhibited the pressor response to epinephrine in cats under pentobarbital anesthesia. Hydroxyzine reduced the incidence and duration of ventricular arrhythmias in cats treated with harman methosulfate and epinephrine. Hydroxyzine increased the coronary flow in the perfused cat's heart and in the hearts of dogs under anesthesia. The femoral blood vessels were also dilated by hydroxyzine. Epinephrine-induced automaticity of papillary muscles and isolated auricular strips was prevented by hydroxyzine in concentrations which did not significantly affect the threshold of electrical excitability.