Evaluation of antihypertensive therapy with the combination of olmesartan medoxomil and hydrochlorothiazide

Most patients with hypertension require more than one agent to control blood pressure (BP). The purpose of this study was to assess the efficacy and safety of the angiotensin II receptor blocker olmesartan medoxomil in combination with hydrochlorothiazide (HCTZ). This was a randomized, double-blind, factorial design study. After a placebo run-in period, eligible patients ( n = 502) with a baseline mean seated diastolic blood pressure (SeDBP) of 100 to 115 mm Hg were randomized to one of 12 groups: placebo, olmesartan medoxomil monotherapy (10, 20, or 40 mg/day, HCTZ monotherapy (12.5 or 25 mg/day), or one of six groups of olmesartan medoxomil/HCTZ combination therapy. The primary endpoint was the change in mean trough SeDBP from baseline at week 8. Statistical analyses were conducted to determine whether at least one combination produced a larger reduction in SeDBP at week 8 than the individual corresponding component doses, but did not compare BP reductions with different combination doses. Olmesartan medoxomil plus HCTZ produced greater reductions in both SeDBP and seated systolic blood pressure (SeSBP) at week 8 than did monotherapy with either component. All olmesartan medoxomil/HCTZ combinations significantly reduced SeDBP and SeSBP compared with placebo in a dose-dependent manner. Reductions from baseline in mean trough SeSBP/SeDBP were 3.3/8.2 mm Hg, 20.1/16.4 mm Hg, and 26.8/21.9 mm Hg with placebo, olmesartan medoxomil/HCTZ 20/12.5 mg, and olmesartan medoxomil/HCTZ 40/25 mg, respectively. All treatments were well tolerated. Olmesartan medoxomil/HCTZ combination therapy produced BP reductions of up to 26.8/21.9 mm Hg and was well tolerated.