Long-term effects of olmesartan, an Ang II receptor antagonist, on blood pressure and the renin-angiotensin-aldosterone system in hypertensive patients

The object of this study is to evaluate the long-term effects of olmesartan on hypertension and the renin-angiotensin-aldosterone system in hypertensive patients. This study evaluated 26 hypertensive male and female outpatients, 38-69 years of age, with a systolic blood pressure >= 160 mm Hg and/or a diastolic blood pressure >= 95 mm Hg. Oral doses of 5 to 40 mg olmesartan were administered once daily. Blood pressure and renin-angiotensin-aldosterone parameters (plasma renin activity and plasma angiotensin I, II, and aldosterone concentrations) were evaluated at 12-16 weeks, 6 months, and I year after the start of olmesartan administration. Systolic and diastolic blood pressures were significantly decreased following the administration of olmesartan. The observed decreases in systolic and diastolic blood pressures after I year of treatment were 28,8 +/- 2,1 mm Hg and 15,8 +/- 1,3 mm Hg, respectively. No change was observed in the pulse rate. The plasma renin activity increased significantly from a baseline premedication mean of 1,26 +/- 0,31 ng/ml/h to a mean of 2,58 +/- 0,74 ng/ml/h and 2,87 +/- 0,72 ng/ml/h after 6 months and I year of treatment, respectively. Angiotensin II levels decreased significantly from a baseline of 20,4 +/- 3,2 pg/ml to a mean of 8,6 +/- 2,1 pg/ml and 6,8 +/- 1,8 pg/ml after 6 months and I year of treatment, respectively. The plasma aldosterone level also decreased significantly after 6 months of treatment. In hypertensive patients, the long-term administration of olmesartan, a novel AT, receptor antagonist, decreased both blood pressure and plasma angiotensin II levels.