Renal effects of losartan and amlodipine in hypertensive patients with non-diabetic nephropathy

Background. The objective of this study was to examine the effects of angio tensin II receptor blocker losartan versus the calcium channel blocker amlo dipine on proteinuria, renal haemodynamics, glomerular sieving and tubular function in hypertensive patients with nondiabetic nephropathy. Methods. The study design was a prospective, double blind, placebo controll ed, randomized crossover trial with amlodipine and losartan. Renal paramete rs were measured at baseline and at the end of each 4-week active treatment period. Fifteen patients with a diagnosis of non-diabetic renal disease an d hypertension were included. Results. Mean arterial blood pressure decreased from 123 +/- 13 mmHg at bas eline to 113 +/- 10 mmHg (P < 0.01) on losartan and to 114+/-10 mmHg on aml odipine (P < 0.01). Urinary albumin excretion significantly decreased from 3510 +/- 2586 mg/24 h at baseline to 2684 +/- 2051 mg/24 h (P < 0.01) on lo sartan and increased non-significantly to 3748 +/- 3355 mg/24 h on amlodipi ne. Filtration fraction significantly decreased from a baseline value of 22 .8 +/- 9.3% to 21.2 +/- 10.2% (P < 0.05) on losartan and increased to 23.6 +/- 8.9% (ns) on amlodipine. Either drug did not significantly alter glomer ular sieving of neutral dextrans. Conclusion. Our results demonstrate that losartan, but not amlodipine, decr eased albumin excretion in hypertensive patients with non-diabetic nephropa thy.