A randomized, double-blind, four-arm parallel-group study of the efficacy and safety of azelnidipine and olmesartan medoxomil combination therapy compared with each monotherapy in Japanese patients with essential hypertension: the REZALT study

A 12-week randomized, double-blind, four-arm parallel-group, comparative study was conducted in patients with essential hypertension to evaluate the antihypertensive effect and safety of combination therapy with olmesartan medoxomil (OLM, an angiotensin-receptor blocker) 20 mg plus azelnidipine (AZL, a long-acting dihydropyridine calcium channel blocker) 16 mg, (O/A (20/16)), or OLM 10 mg/AZL 8 mg (O/A (10/8)) compared with those of monotherapy with OLM 20 mg (OLM (20)) or AZL 16 mg (AZL (16)). The change from baseline to week 12 in seated blood pressure (SeBP) was −23.6/−14.2 mm Hg (systolic/diastolic BP) in the O/A (20/16) group, and −20.3/−13.0 mm Hg in the O/A (10/8) group, which was a significantly greater reduction in SeBP than in the monotherapy groups (−15.7/−9.9 mm Hg in OLM (20); −15.0/−9.4 mm Hg in AZL (16)). The change from baseline in 24-h ambulatory BP was also significantly greater in the O/A (20/16) and O/A (10/8) combination groups (−22.1/−13.5 and −18.2/−10.6 mm Hg, respectively) than in the OLM (20) and AZL (16) monotherapy groups (−12.1/−6.9 and −12.0/−6.9 mm Hg). The proportion of patients achieving the SeBP goal (<130/85 mm Hg for normal BP or <140/90 mm Hg for high-normal BP) was significantly higher in the O/A (20/16) combination group than in the monotherapy groups. The incidence of adverse events was similar in the O/A combination groups and the monotherapy groups. These results showed that combination therapy with O/A was well tolerated and exerted a stronger antihypertensive effect compared with monotherapy with OLM or AZL in patients with essential hypertension.