Effects of long-term administration of isradipine on renal hemodynamics and sodium metabolism.
The objective of this double-blind, placebo-controlled study was to evaluate the effects of isradipine on renal hemodynamics and function. Ten patients with mild-to-moderate hypertension were given isradipine at 2.5 mg twice daily for 3 months after 4 weeks of placebo washout. Renal studies were performed 2 h after the morning administration of treatment. The results of these evaluations indicate that isradipine as monotherapy significantly reduced the mean arterial pressure, while the effective renal plasma flow was increased (+16%) and glomerular filtration rate remained virtually unchanged (-8.7 ml/min). The filtration fraction and renal vascular resistance decreased significantly. There was a significant decrease in the absolute rate of proximal sodium reabsorption, and a significant increase in the distal reabsorption. Clearance of sodium remained unchanged. In conclusion, monotherapy with low-dose isradipine was not only effective in controlling blood pressure, but also decreased the renal vascular resistance while avoiding glomerular hyperfiltration, and exerted a protective effect on renal hemodynamics. Natriuresis also remained stable despite the blood pressure reduction.
Francischetti
E A
EA
Department of Medicine, Rio de Janeiro State University, Brazil.
Barroso
I
I
da Silva
A
A
Fagundes
V G
VG
D002121:Calcium Channel Blockers / Q000008:administration & dosage / Q000009:adverse effects* / Q000494:pharmacology; D004095:Dihydropyridines / Q000008:administration & dosage / Q000009:adverse effects* / Q000494:pharmacology; D004311:Double-Blind Method; D006439:Hemodynamics / Q000187:drug effects*; D006801:Humans; D017275:Isradipine; D012079:Renal Circulation / Q000187:drug effects*; D012964:Sodium / Q000378:metabolism*
D002121:Calcium Channel Blockers; D004095:Dihydropyridines; D012964:Sodium; D017275:Isradipine