Efficacy of an angiotensin II receptor antagonist in managing hyperaldosteronism

Objective To determine whether an angiotensin II receptor antagonist decrea ses blood pressure in patients with hyperaldosteronism and hypertension who are taking other antihypertensive agents. Design A double-blind randomized placebo-controlled crossover study. Patients and methods Blood pressure and hormonal responses to 2-week course s of placebo/irbesartan (150 mg/day given by mouth at 08.05 h) were assesse d in 10 patients with hyperaldosteronism. Clinic blood pressure was measure d by sphygmomanometer, and plasma concentrations of aldosterone, cortisol, angiotensin II, electrolytes and renin activity (PRA) were determined weekl y. Automated 24 h ambulatory blood pressure recordings were made at the end of the active and placebo phases. Results Irbesartan caused a post-dose decrease in ambulatory blood pressure (systolic, P = 0.02; diastolic, P = 0.05) in the period from 10.00 h to 20 .00 h. Clinic blood pressure, measured at trough, was not significantly dec reased. Plasma aldosterone decreased (P < 0.03) and PRA increased (P < 0.04 ) in the first week of active treatment with irbesartan, but differences be tween the placebo and active-treatment groups were not significant in the s econd week. There were no significant changes in plasma concentrations of a ngiotensin II, cortisol or potassium in either week. In the second week of irbesartan treatment, there were associations between change in plasma aldo sterone and maximal change in ambulatory blood pressure (systolic and diast olic). Conclusion Irbesartan has a role in combination antihypertensive treatment of patients with hyperaldosteronism. (C) 2001 Lippincott Williams & Wilkins .