Effect of nifedipine on renal function in patients with essential hypertension.

Twenty-six essential hypertensive patients were entered into a protocol to assess the blood pressure and renal effects of the dihydropyridine calcium antagonist nifedipine (30-120 mg/day given in divided doses) administered for 4 weeks. Nifedipine monotherapy effectively lowered blood pressure in 73% of the patients. Glomerular filtration rate and effective renal plasma flow were increased 13.3 and 19.6%, respectively. The filtration fraction and urinary albumin excretion remained unchanged. Renal vascular resistance was markedly reduced (25.2%). Changes observed in renal function were independent of the patients' initial glomerular filtration rate. Furthermore, there was no correlation between the systemic and renal effects of nifedipine monotherapy. Patients with a poor systemic blood pressure response exhibited increases in both glomerular filtration rate (+13%) and effective renal plasma flow (+20%), changes comparable with increases in glomerular filtration rate (+13%) and effective renal plasma flow (+19%) observed in patients achieving a goal blood pressure response (diastolic blood pressure less than or equal to 90 mm Hg, or a greater than or equal to 10 mm Hg decrease in diastolic blood pressure, or both). These results suggest that nifedipine monotherapy has the potential to improve renal function abnormalities encountered in the essential hypertensive state independently of its effect on systemic blood pressure.