The Renal Function and Blood Pressure Effects of Dilevalol in the Normotensive and Hypertensive Elderly

Dilevalol, the R-R optical isomer of labetalol, is a nonselective beta adrenergic blocking drug with selective beta-2 agonist properties. In a double-blind, crossover study the renal function effects of dilevalol were compared to placebo in 12 normotensive elderly volunteers before and after single dose administration. In addition, chronic treatment (>4 weeks) effects of dilevalol were determined in eight elderly patients with mild to moderate essential hypertension. Renal function was determined by plasma disappearance curves from single injections of 99mTc-DTPA and 131I-orthohippurate. In both study populations renal function tests commenced two hours after dosing at expected peak plasma levels of dilevalol. Normotensive volunteers had an acute decrease in glomerular filtration rate of 10.3 ml/min, which was significant (P < 0.05), while hypertensive patients had no change in glomerular filtration rate. There were no significant changes in other parameters of renal function measured. In the hypertensive elderly dilevalol treatment resulted in significant reductions, 18 and 19 mmHg respectively, of systolic (P < 0.01) and diastolic (P < 0.001) blood pressure. Heart rate was reduced by 5 beats per minute, and the change was not statistically significant. Dilevalol appears to be an excellent agent for treatment of hypertension in the elderly hypertensive patient, and does not change renal function when administered chronically to the hypertensive patient. Small but significant decrements in glomerular filtration rate occur with acute administration to normotensive volunteers.