Abstract
The aim of this study was to evaluate the medium-term effects of the selective AT 1 -blocker irbesartan on atrial natriuretic peptide (ANP) levels in patients with moderate essential hypertension. The drug was given orally in a daily dose of 300 mg for 30 days. Plasma ANP levels increased by 15.7% despite the drop in blood pressure and the slight decrease of atrial and ventricular diameters. These findings indicate that AT 1 -blockers like irbesartan exert part of their antihypertensive action by increasing ANP plasma levels.