Candesartan cilexetil and renal hemodynamics in hypertensive patients

This randomized, double-blind, placebo-controlled crossover study evaluated the effects of the angiotensin II type 1 (AT(1))-receptor blocker candesar tan cilexetil on renal blood perfusion and glomerular filtration in patient s with primary hypertension with diastolic blood pressure of 100 to 114 mm Hg. After a 4-week placebo run-in period, patients were randomized to recei ve either 16 mg candesartan cilexetil or placebo once daily for 6 weeks, af ter which they were switched to the alternative treatment. At the end of ea ch period, 24 h after the last dose, renal assessments were made and the pl asma renin activity, plasma concentrations of angiotensin II, aldosterone, and catecholamines were measured. Compared with placebo, candesartan cilexetil significantly reduced mean art erial pressure, by 8 mm Hg (95% confidence interval [CI], 3;12). Renal vasc ular resistance was significantly reduced by 0.03 mm Hg/mL min(-1) (95% CI, 0.01;0.06). There was a small nonsignificant increase in renal plasma now. The filtration fraction fell slightly from 0.24 to 0.22 (95% CI, -0.00, 0. 04). As expected, angiotensin II concentrations and plasma renin activity w ere increased and the aldosterone concentrations were reduced. Catecholamin e concentrations were unaffected. In conclusion, 6 weeks' treatment with 16 mg candesartan cilexetil once dai ly induced a reduction of renal vascular resistance and a trend toward incr eased renal plasma now despite a reduction in mean arterial pressure. Becau se the glomerular filtration rate was maintained the filtration fraction wa s reduced, indicating a decreased glomerular capillary pressure. Am J Hyper tens 2000;13:1045-1048 (C) 2000 American Journal of Hypertension, Ltd.