Effect of Switching to Azilsartan From Fixed-Dose Combination of an Angiotensin II Receptor Blocker and Calcium Channel Blocker or a Thiazide in Patients With Hypertension

BACKGROUND: Despite the availability of antihypertensive treatments, fewer than half of patients who receive treatment successfully achieve blood pressure (BP) goals. The purpose of this study was to evaluate the effect of switching to azilsartan 40 mg from a fixed-dose combination tablet of an angiotensin II receptor blocker (ARB) and amlodipine at 5 mg or azelnidipine at 16 mg (ARB/CCB) or an ARB and hydrochlorothiazide (HCT) at 6.25 mg or 12.5 mg (ARB/HCT) on BP. METHODS: This prospective, multicenter, open-labeled, single-arm study included 40 patients treated with a fixed-dose combination tablet of an ARB/CCB or an ARB/HCT, which was switched to azilsartan 40 mg after enrollment. The primary outcome was the change in BP from baseline to the 24-week follow-up. RESULTS: Of the 40 patients who completed this study, 33 did not require changes in their antihypertensive medications after switching to azilsartan, and their BP did not change from baseline to follow-up. However, the systolic BP in seven patients was elevated at 12 weeks, and amlodipine at 5 mg was therefore added; these patients' baseline medications were an ARB/CCB (n = 6) and an ARB/HCT (n = 1). In all patients, the serum potassium level was slightly increased after switching to azilsartan at 6 months, while the serum creatinine, hemoblobinA1c, and lipid profile did not change. CONCLUSIONS: Azilsartan at 40 mg did not result in a greater decrease in BP than a fixed-dose combination tablet of an ARB/CCB or an ARB/HCT. However, our findings suggest a substantial BP-lowering effect of azilsartan at 40 mg in patients with hypertension.