any of a class of drugs that prevent the stimulation of alpha adrenoceptors, a type of receptor in the sympathetic nervous system, by adrenaline and noradrenaline and that therefore cause widening of blood vessels: used in the treatment of high blood pressure and prostatic hyperplasia
A drug that opposes the excitatory effects of norepinephrine released from sympathetic nerve endings at alpha-adrenergic receptors and causes vasodilation and a decrease in blood pressure.alpha-adrenergic blocking agent
