Effects of adrenaline on circulatory dynamics and cardiac function in rats administered chlorpromazine.

We aimed to elucidate changes in circulatory dynamics and cardiac function during concomitant use of chlorpromazine (CPZ) and adrenaline (AD). An arterial line and left intraventricular pressure-volume measurement catheter were inserted in rats. CPZ 10 mg/kg was administered to the left great adductor muscle, followed by normal saline (NS) or AD 50 µg/kg through the tongue 20 min later. End-diastolic volume (V ed), end-systolic pressure (P es), stroke volume (SV), stroke work (SW), end-systolic volume elastance (E es), systolic blood pressure (SBP), diastolic blood pressure (DBP), and pulse rate (PR) were measured. Following AD administration, V ed significantly decreased at 2-4 and 10 min than that in control rats; P es significantly decreased at 1 min; E es significantly increased from 2 to 10 min; SV did not change significantly, and SW significantly reduced at 1 and 2 min; SBP and DBP were lower at 1-3 min than in the control; and PR increased at 10 min. These findings suggest that when AD-containing local anesthetics are administered during dental treatment of patients taking CPZ, there is a risk of a temporary drop in blood pressure. However, the blood pressure is recovered a few minutes later by the increase in afterload and the myocardial contractile force.