The effect of spironolactone versus eplerenone on blood pressure targets in resistant hypertension patients

Abstract Objective to evaluate different effects on blood pressure (BP) control in two treatment options spironolactone (SPIR) versus eplerenone (EPL) as an add-on therapy in resistant hypertensive (RAH) patients. Design and methods: We studied 208 patients with true RAH confirmed by the office and ambulatory BP monitoring (ABPM) despite the use of 3 antihypertensive medications including a calcium channel blocker, a blocker of the renin-angiotensin system, and a thiazide diuretic with maximally tolerated doses for at least 3 months. Patients were randomized into 2 groups throughout 12 weeks of once-daily treatment with SPIR (25–50 mg) or EPL (25-50 mg) in addition to their baseline triple-combination and then rotated with drugs. BP was measured in the office and by ABPM. Changes in laboratory tests were also studied. The predictive values of plasma aldosterone, active renin concentration (ARC), aldosterone-renin ratio (ARR), and serum potassium were analyzed to determine the antihypertensive response. Results There were no significant differences in the reduction of average office BP, average systolic 24-h, daytime, and nighttime BP by SPIR and EPL. SPIR reduced average diastolic 24-h BP by 7.3 mm Hg, diastolic daytime BP by 7.2 mm Hg, and diastolic nighttime BP by 7.5 mm Hg compared with a reduction of 5.6 mm Hg (P = 0.01), 5.6 mm Hg (P = 0.03) and 4.2 mm Hg (P = 0.0001) with EPL, respectively. Overall, 40.7 % RAH patients achieved targets of clinical BP and 24-h ABPM levels on SPIR and 33.3 % on EPL (Р = 0.002). After 12 weeks of treatment mean plasma potassium concentrations increased by 7.1 (P = 0.0001) on SPIR and by 5.0 % (Р = 0.0001) on EPL, but eGFR did not significantly change on the two drugs. Plasma aldosterone (β = 0.498, Р = 0.02) and ARC (β= -0.374, Р = 0.04) were predictors of the BP-lowering effect of SPIR and plasma aldosterone (β = 0.453, Р = 0.04) was a predictor of reduction BP for EPL in multivariate modeling. Breast pain or tenderness, changes in sex drive, and irregular menstrual cycles or spotting were more often by SPIR than by EPL (5.2 % vs 1.9 %, respectively, P = 0.04). Conclusions The greater antihypertensive effect of SPIR is related to aldosterone status, ARS level in resistant hypertension. EPL may be recommended for RAH patients who have high serum potassium levels that cannot tolerate spironolactone and for people with systolic resistant hypertension.