Comparative Effects of Losartan and Amlodipine on Activities of Sympathetic Nerve, Renin-angiotensin-aldosterone System and Brain Natriuretic Peptide in the Elderly Hypertensive Patients.

Abstract

This study investigated the comparative effects of losartan and amlodipine on the activation of the sympathetic nervous system, renin-angiotensin-aldosterone system (R-A-A system) and brain natriuretic peptide (BNP) in patients with essential hypertension. Twenty-four elderly patients who had received more than 12 months of antihypertensive treatment with amlodipine participated in this study. The treatment regimen of 5 mg/day amlodipine was changed to 50 mg/day losartan. Plasma catecholamines (norepinephrine, epinephrine and dopamine), active renin, aldosterone and BNP concentration were measured before and after an average of 5 months of losartan treatment. After losartan treatment, blood pressures were not changed, suggesting the comparable effect of 50 mg losartan and 5 mg amlodipine on elevated blood pressure. Losartan significantly reduced norepinephrine (799 +/- 277 pg/mL vs. 692 +/- 268 pg/mL, p < 0.05) and aldosterone concentration (81.2 +/- 35.3 pg/mL vs. 55.2 +/- 17.7 pg/mL, p < 0.01), whereas there were not any changes in BNP concentrations. These findings suggested that losartan might be superior to amlodipine in prevention of chronic or intermittent sympathetic hyperactivity and enhanced R-A-A system.