Studies on the Control of Hypertension VI. Some Evidence for Reversal of the Process During Hexamethonium and Hydralazine

Because doses of antihypertensive agents necessary to control human arterial hypertension at relatively normotensive levels were observed to decrease with time, records of all patients in our series receiving oral hexamethonium chloride and hydralazine (but no other drugs) were analyzed (114 cases). After two years of therapy, those patients maintaining average diastolic pressures below 100 mm. Hg were found to require considerably less methonium ion while those unable or unwilling to control their pressures to this degree needed approximately their initial doses. Further decreases in drug requirements for the well-controlled group occurred after three years. Ten were able to discontinue all medication eventually and nine others needed only smaller doses of hydrala-zine; in these reversal of secondary changes was sometimes observed. Prolonged, continuous and adequate drug therapy is apparently associated with a change in the basic process producing hyper-tension. FTER the first consistent successes in A chronically lowering markedly ele-117k vated human diastolic pressure to normal or nearly normal values by autonomic blockade plus oral hydralazine, " 2 interest was aroused as to the permanence of the change or lack of it. Although the side effects of therapy gradually dwindled in a manner reminiscent of the tolerance characteristic for methonium compounds,3 no tolerance to the antihypertensive effect of the combined treat-ment has been observed after four years. On the contrary, a progressive diminution in drug requirement has frequently been ob-served. ' Moreover, after varying periods of induced normotension, some patients, in-cluding an occasional one who originally had severe diastolic hypertension, have been gradually able to diminish and eventually to discontinue treatment entirely, without re-elevation of blood pressure. To ascertain the magnitude of such trends, the dosage and blood pressure data for our patients orally treated with hydralazine and hexamethonium chloride have been tabulated. This paper ill