Renal effects of amlodipine

The effects of a new dihydropyridine calcium channel blocker, amlodipine, on blood pressure (BP) and renal function were studied in spontaneously hypertensive rats (SHR). These effects were compared with those of an angiotensin-converting enzyme (ACE) inhibitor, enalapril. In addition, the effects of amlodipine on BP and renal function were studied in hypertensive patients with renal impairment. In five of six nephrectomised salt-loaded SHR, increases in BP, urinary excretion of protein and serum creatinine were attenuated by the administration of 2 mg/kg/day of amlodipine. The progression of renal histological damage was also markedly decreased. The protective effects of amlodipine against renal damage were similar to those of enalapril. However, the mechanisms of action of these two agents seem to differ as, unlike enalapril, amlodipine did not significantly dilate the efferent arteriole in hydronephrotic perfused rat kidney. In a clinical study, 2.5-5 mg/day of amlodipine was administered once a day for 8-10 weeks to 39 hypertensive patients with renal impairment (serum creatinine ≥ 1.5 mg/dl to < 5 mg/dl) or renal parenchymal disease (serum creatinine < 5 mg/dl). A significant reduction in BP (reduction of mean BP ≥ 13 mm Hg) was observed in 28 patients (80%). Headache was experienced as a side-effect in one of 35 patients (2.9%). With respect to the influence of amlodipine on renal function, mean values of blood urea nitrogen and serum creatinine were unchanged for the total group whereas a slight elevation of serum creatinine was observed in four of 35 patients (11.4%). From these results it is suggested that amlodipine has a beneficial action on hypertension-induced renal damage and that this is similar to that of enalapril. Amlodipine is a useful and well-tolerated drug for the control of BP in hypertensive patients with renal impairment (serum creatinine < 5 mg/dl).