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 greater than or equal to 160 mmHg and/or a diastolic blood pressure greater than or equal to 95 mmHg. 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 1 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 1 year of treatment were 28.8 +/-2.1 mmHg and 15.8 +/-1.3 mmHg, 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 1 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 1 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(1) receptor antagonist, decreased both blood pressure and plasma angiotensin II levels.