1 The effects of a single oral dose of 600 mg of
prizidilol on renal function were studied 5 to 6 h after dosing in six normal subjects and eight patients with
essential hypertension. 2 Mean arterial blood pressure was reduced to 92% of the control value in normal subjects and to 75% in hypertensive patients. Heart rate increased slightly. 3 In normal subjects, effective renal plasma flow was increased to 107% of control values while glomerular filtration rate (83%), filtration fraction (79%),
sodium (84%) and
potassium (50%) clearances were significantly decreased. 4 In hypertensive subjects, effective renal plasma flow was increased to 120% of control values, while glomerular filtration rate (67%), filtration fraction (57%),
sodium (27%) and
potassium (72%) clearances were significantly decreased. 5 Plasma
noradrenaline increased significantly in normal subjects (150%) and in patients (173%). Plasma
renin activity,
aldosterone and
epinephrine levels did not change consistently. 6 The results indicate that the acute effects of
prizidilol on blood pressure and renal function are more marked in hypertensive than in normotensive subjects.
Prizidilol increases renal plasma flow like
hydralazine and depresses glomerular filtration rate and fractional
sodium excretion like
endralazine. In addition to the fall in arterial pressure, efferent vasodilation and/or a specific effect on the glomerular ultrafiltration coefficient Kf may account for the striking decrease in filtration fraction.