Hexamethonium in the Chronic Treatment of Hyper-

Neurogenic (autonomic) factors in hypertensive vascular disease (1, 2) may be studied with hexamethonium 2 which reduces arterial blood pressure by blockade of the sympathetic ganglia. When the blood pressure is reduced acutely in this manner, alterations in renal hemodynamics have been observed. Following a single dose of hexamethonium administered parenterally to patients with hypertension, the glomerular filtration rate and renal plasma flow are immediately depressed but within one hour renal hemodynamic readjustment occurs and both functions return to or towards control values, although the arterial blood pressure remains depressed (3, 4) for two to six hours. The present study was designed to evaluate the effects of prolonged reduction of blood pressure in hypertensive patients, with and without renal damage, during the therapeutic oral administration of hexamethonium. In addition to studies in the supine position, observations on renal hemodynamics were made during ambulation before and during therapy. The latter observations were made in order to evaluate the effect of ganglionic blockade on the renal vasoconstriction which normally is associated with changing from the supine to the upright position (either static tilt or ambulation) in the untreated patient (5).