Hypertensive Responses to Methyldopa

SEVERAL of the drugs currently employed in the management of arterial hypertension interfere with either the binding or the catabolism of norepinephrine in tissues. Administration of these drugs occasionally results in dangerous paradoxical pressor reactions. Thus, parenteral administration of guanethidine or, less commonly, of reserpine may, by suddenly releasing large amounts of norepinephrine from tissue stores, increase blood pressure.1 This is particularly apt to occur when tissue stores of norepinephrine are abnormally large, as in patients with pheochromocytomas or in those taking drugs that inhibit monoamine oxidase activity. Patients treated with such inhibitors are also susceptible to severe hypertensive attacks . . .