Blood Pressure-lowering Efficacy of the Fixed-dose Combination of Azilsartan Medoxomil and Chlorthalidone: a Factorial Study

This study compared the efficacy and safety of fixed-dose combinations (FDCs) of the angiotensin II receptor blocker azilsartan medoxomil (AZL-M) and the thiazide-like diuretic chlorthalidone (CLD) with the individual monotherapies in a double-blind factorial study. A total of 1714 patients with clinic systolic blood pressure (SBP) 160 mm Hg to 190 mm Hg inclusive were randomized to AZL-M 0 mg, 20 mg, 40 mg, or 80 mg and/or chlorthalidone 0 mg, 12.5 mg, or 25 mg. The primary efficacy end point was change from baseline to 8 weeks in trough (hour 22-24) SBP by ambulatory blood pressure (BP) monitoring (ABPM). Patients' mean age was 57 years; 47% were men and 20% were black. Baseline trough BP was approximately 165/95 mm Hg and 151/91 mm Hg by clinic and ABPM measurements, respectively. For the pooled AZL-M/CLD 40/25-mg and 80/25-mg FDC groups, SBP reduction by ABPM at trough was 28.9 mm Hg and exceeded AZL-M 80 mg and CLD 25 mg monotherapies by 13.8 mm Hg and 13 mm Hg, respectively (P<.001 for both comparisons). Discontinuation rates and elevations in serum creatinine were dose-dependent and occurred more often in the AZL-M/CLD groups. In patients with stage 2 hypertension, treatment with the combination of AZL-M and CLD resulted in substantially greater SBP reduction compared with either agent alone.