THE EFFECTS OF ISRADIPINE AND SPIRAPRIL AS MONOTHERAPY AND COMBINED THERAPY ON BLOOD-PRESSURE, RENAL HEMODYNAMICS, NATRIURESIS, AND URINARYKALLIKREIN IN HYPERTENSIVE NEPHROPATHY

In this cross-over, double-blind study, 12 essential hypertensive pati ents (stage I, II, and III) with glomerular filtration rate (GFR) betw een 50 to 80 mL/min/1.73 m(2), were submitted to 4 weeks of placebo fo llowed by 12 weeks with isradipine SRO (IS) 5 mg, spirapril(SP) 6 mg, and isradipine plus spirapril(IS + SE). The study evaluated the effect s of these drugs on GFR (Tc-99m DTPA), effective renal plasma now (ERP F) (I-131-orthoiodohippurate), urinary sodium excretion (UNaV), urinar y kallikrein excretion (UKa1), urinary albumin excretion (UAE), and pl asma renin activity (PRA). The three protocols significantly reduced m ean blood pressure (128 v 107 mm Hg; 126 v 112 mm Hg; 129 v 104 mm Hg with IS, SP and IS + SP, respectively). ERPF and GFR did not change. U NaV increased significantly after IS (0.17 v 0.22 mEq/min) and IS + SP (0.18 v 0.24 mEq/min). UKa1 increased significantly after IS (58.6%) and IS + SP (53.6%). UAE decreased significantly only after SP. PRA in creased significantly after IS (1.31 v 2.84 ng/mL/h), SP (1.10 v 2.15 ng/mL/h), and after IS + SP (1.23 v 3.21 ng/mL/min). In conclusion, IS , SP and IS + SP were effective in reducing blood pressure while keepi ng renal function stable. Only SP significantly decreased UAE. Enhance d UKa1 may have played a role in natriuresis observed after IS and IS + SP. (C) 1997 American Journal of Hypertension, Ltd.