Multiple oral doses of nicardipine, a calcium‐entry blocker: Effects on renal function, plasma renin activity, and aldosterone concentration in mild‐to‐moderate essential hypertension

We studied the effects of nicardipine administered in a 4-week fixed oral maintenance dosage (20 or 40 mg t.i.d.) on renal function, plasma renin activity (PRA), and plasma aldosterone concentration in seven patients with mild-to-moderate essential hypertension. Glomerular filtration rate and renal blood flow were measured by means of sodium thiosulfate and para-aminohippurate, respectively. Nicardipine increased renal blood flow by 11.5% ± 4.3% (mean ± SE; P < 0.05) and glomerular filtration rate by 16.3% ± 6.4% (P < 0.05) and decreased total renal vascular resistance by 30.0% ± 2.7% (P < 0.05), with a significant (P < 0.05) reduction in systolic and diastolic blood pressure as compared with placebo values. Nicardipine increased PRA significantly (P < 0.05), whereas plasma aldosterone concentration remained unchanged. Our results indicate that nicardipine given in a multiple oral dosage has some favorable renal effects with a concomitant hypotensive action in patients with mild-to-moderate essential hypertension. Nicardipine appears to blunt the secretion of aldosterone responding to an increased PRA possibly through its calcium-antagonizing action. Clinical Pharmacology and Therapeutics (1987) 42, 232–239; doi:10.1038/clpt.1987.137