LONG-TERM EFFECTS OF FELODIPINE IN PATIENTS WITH REDUCED RENAL-FUNCTION

To characterize the long-term effects of calcium antagonists on renal function in hypertension felodipine was used to treat 14 patients with severe uncontrolled hypertension associated with renal functional impairment: six patients had renal parenchymal hypertension, six had essential hypertension and two had renovascular hypertension. Mean blood pressure was 197 +/- 2/115 +/- 3 mm Hg despite treatment with three or more antihypertensive drugs. Mean glomerular filtration rate (GFR) was 39 +/- 6 ml/min (Cr-EDTA clearance) before initiation of felodipine treatment. All patients experienced a blood pressure reduction after starting felodipine treatment, which persisted during long-term therapy in combination with previous medication except former vasodilating drugs. Blood pressure after 12 and 24 months was 152 +/- 7/89 +/- 2 and 157 +/- 5/90 +/- 2 mm Hg, respectively. Patients with moderately impaired GFR and absence of progressive renal disease (N = 8) manifested an increase in GFR after 6 and 12 months on felodipine (59 +/- 10 to 63 +/- 7 and 70 +/- 6 ml/min, respectively, P < 0.05). Renal plasma flow (PAH clearance) exhibited only a slight increase (315 +/- 68 to 340 +/- 63 and 314 +/- 69 ml/min) with a consequent increase in filtration fraction (18 +/- 1 to 21 +/- 1 and 20 +/- 1%, NS). At follow-up after six to eight years patients with initial GFR greater-than-or-equal-to 50 ml/min had a maintained renal function. In five patients a progressive deterioration of renal function had been documented. After initiation of felodipine treatment the rate of decline in kidney function, expressed as decrease in GFR (ml/min/year), decreased from 9.6 +/- 2.3 to 4.3 +/- 1.4 ml/min/year. We conclude that felodipine decreases blood pressure in patients with previously refractory hypertension, and that the drug has beneficial effects on renal function.