HAeMODYNAMIC STUDIES WITH METHYLDOPA: EFFECT ON CARDIAC OUTPUT AND RESPONSE TO PRESSOR AMINES

Abstract

After 4 to 10 days'' treatment with methyldopa, the reduction in blood pressure in hypertensive patients was accompanied by a bradycardia, by a slight fall in supine cardiac output, and also by a fall in calculated total peripheral resistance. On tilting feet downwards, some postural hypotension occurred, accompanied by a further reduction in cardiac output. A small increase in sensitivity to the pressor effect of norepineph-rine was seen in patients receiving methyldopa; the duration of action of a single dose of norepinephrine was greatly prolonged. The pressor action of tyramine was increased after methyldopa.