Renal effects of nicardipine, a calcium entry blocker, in hypertensive type II diabetic patients with nephropathy.

We studied the renal effects of nicardipine, a calcium entry blocker, in eight patients with essential hypertension (group A, WHO I or II), six hypertensive type II diabetics with mild-to-moderate nephropathy (group B, urinary albumin 200-789 mg/day), and six hypertensive type II diabetics with severe or advanced nephropathy (group C, urinary albumin 1,596-4,300 mg/day). The patients received an intravenous dose of nicardipine hydrochloride (0.5 mg) or saline placebo in a random order. Glomerular filtration rate (GFR) and renal blood flow (RBF) were measured by means of thiosulfate sodium and p-aminohippurate, respectively, during the 30 min after the nicardipine or saline injection. Blood pressures were serially monitored during the study. Nicardipine reduced both systolic and diastolic blood pressures significantly (P less than .05 to .01) at all measurement periods in all study groups compared with the respective placebo. Nicardipine increased RBF (P less than .01), GFR (P less than .05), and urinary Na+ excretion (P less than .01) and decreased total renal vascular resistance (P less than .01) in groups A and B, but these parameters remain unchanged in group C. The filtration fraction remained unaltered in all groups. The results indicate that nicardipine has several favorable renal effects with a concomitant hypotensive action in hypertensive type II diabetics with mild-to-moderate nephropathy, as observed in patients with uncomplicated essential hypertension, and the renal pharmacological responsiveness appears to be related to the severity of nephropathy.(ABSTRACT TRUNCATED AT 250 WORDS)