Medical Management of Primary Hypertension

Abstract

GuanethidineActionsGuanethidine, like reserpine and methyldopa, exerts its antihypertensive action by interfering with neurotransmission at the adrenergic postganglionic nerve terminals, and thereby decreasing arteriolar vasoconstriction. Guanethidine acts both by preventing the release of norepinephrine from the postganglionic nerve terminals and by depleting norepinephrine stores at these terminals. 180–184 Guanethidine also partially depletes the myocardium of its catecholamine stores.185 Unlike methyldopa, guanethidine does not interfere with the synthesis of norepinephrine or result in the synthesis of a false neurotransmitter.Guanethidine decreases heart rate, stroke volume and cardiac output, probably owing to its sympatholytic action on the heart.145, 185 , 186 The decrease in . . .