Randomized trial comparing the velocities of the antihypertensive effects on home blood pressure of candesartan and candesartan with hydrochlorothiazide

Abstract

We aimed to evaluate the hypotensive effect and the time to attain the maximal antihypertensive effect (stabilization time) of 8 mg candesartan/6.25 mg hydrochlorothiazide (HCTZ) combination therapy (combination regimen) and therapy with an increased candesartan dose (12 mg; maximum dose regimen) using home blood pressure (BP) measurements. A prospective, multicenter, open-label, randomized, comparative trial was conducted. Essential hypertensive patients who failed to achieve adequate BP control (systolic BP (SBP) ≤135 mm Hg) on 8 mg candesartan alone were randomized to two groups: the combination regimen (n=103) and the maximum dose regimen (n=103). Home morning SBP reduction at 8 weeks after randomization was 11.4±1.3 mm Hg in the combination regimen and 7.8±1.2 mm Hg in the maximum dose regimen. The combination regimen provided additional reduction of 4.0 mm Hg (95% confidence interval (CI): 0.8-7.2 mm Hg, P=0.01) in home morning SBP over the maximum dose regimen at 8 weeks after randomization. The maximal antihypertensive effect and stabilization time for home SBP were 9.4 mm Hg and 37.1 days (P<0.0001), respectively, with the combination regimen. The maximum dose regimen decreased home SBP with a very gentle slope, and estimated maximal effect and estimated stabilization time were not significant (P>0.2). The rate of achieving target BP (home morning SBP <135 mm Hg) was significantly higher with the combination regimen than with the maximum dose regimen (52.4 vs. 30.1%, P=0.002). In conclusion, changing from 8 mg candesartan to combination therapy was more effective in reducing home SBP and achieving goal BP more rapidly than increasing the candesartan dose.