The effect of nifedipine GITS on renal function in hypertensive patients with renal insufficiency

Twelve hypertensive patients with moderately severe renal dysfunction were entered into a protocol to assess the blood pressure and renal effects of the sustained release calcium antagonist, nifedipine GITS (30-180 mg/d given once a day) administered for 5 weeks. Nifedipine GITS monotherapy effectively lowered blood pressure in 50% of the patients. Glomerular filtration rate and effective renal plasma flow were increased 18% and 20%, respectively. The filtration fraction and urinary protein excretion remained unchanged. Changes that were observed in renal function were independent of the blood pressure responses of the patients; there was no correlation between the systemic and renal effect of nifedipine GITS monotherapy. Patients who had a poor systemic blood pressure response exhibited an increase in glomerular filtration rate (+11%) but had a decrease in effective renal plasma flow (-6%); patients who achieved a goal blood pressure response showed increases in both glomerular filtration rate (+35%) and effective renal plasma flow (+40%). These results show that nifedipine GITS monotherapy has the potential to improve renal function abnormalities that are encountered in hypertensive patients with renal disease; the improvement in renal function may be independent of their effect on systemic blood pressure.