Do calcium antagonists (nifedipine and nitrendipine) improve renal haemodynamics and reduce blood pressure in patients with stable chronic renal failure?
Short-term use of calcium antagonists in patients with chronic renal failure reduces systemic blood pressure and renal vascular resistance without compromising glomerular filtration rate or effective renal plasma flow.
Experimental evidence suggests that pharmacological manipulations of glomerular haemodynamics may affect the progression of chronic renal insufficiency and scarring. In this study, we have investigated the short-term (4 weeks) renal haemodynamic effects of nifedipine and nitrendipine (10 mg/thrice daily) in two separate groups of 6 patients with stable chronic renal failure (CRF) (glomerular filtration rate, GFR: 9.7-47.8 ml/min/1.73 m2). Patients were studied on three occasions: (1) before the administration of the calcium antagonist, (2) after 4 weeks of treatment and (3) 4 weeks after the discontinuation of the drug. Mean arterial pressure fell significantly on nifedipine: from 116.33 +/- 12.25 to 107.22 +/- 18.67 mm Hg, p less than 0.05, and on nitrendipine: from 112.22 +/- 10.04 to 102.22 +/- 13.77 mm Hg, p less than 0.05. There was no significant effect of either calcium antagonist on GFR, effective renal plasma flow (ERPF), proteinuria or natriuresis. Consequently, renal vascular resistance (RVR) fell in both experimental groups, nifedipine: from 51.40 +/- 28.77 to 44.97 +/- 30 dyn s cm-5 x 10(3) (mean +/- SD), and nitrendipine: from 37.04 +/- 18.46 to 30.47 +/- 15.56 dyns s cm-5 x 10(3), p less than 0.05. These results show that calcium antagonists reduce systemic blood pressure whilst GFR and ERPF are maintained. The fall in the RVR of patients with CRF treated with calcium antagonists may confer on these agents a therapeutic advantage in the management of progressive renal insufficiency.
Wight et al. (2008) studied this question.