Practical efficacy of olmesartan versus azilsartan in patients with hypertension: a multicenter randomized-controlled trial (MUSCAT-4 study).

Background: Olmesartan and azilsartan, angiotensin II receptor blockers (ARBs), are expected to decrease blood pressure more than the other ARBs. We conducted randomized-controlled trials to compare the practical efficacy of olmesartan with azilsartan.

Methods: Eighty-four patients treated with the conventional ARBs for more than 3 months were assigned randomly to receive either 20 mg of olmesartan (olmesartan medoxomil, OL group) or 20 mg of azilsartan (azilsartan, not azilsartan medoxomil, AZ group) once daily for 16 weeks. The practical efficacy on blood pressure was compared between the OL and AZ groups.

Results: Office blood pressure of both groups decreased significantly (OL group: 152/86-141/79 mmHg, P<0.05, AZ group: 149/83-135/75 mmHg; P<0.05). Diastolic home blood pressure in the AZ group decreased significantly (79±9-74±7 mmHg; P<0.05), but not in the OL group (79±11-75±10 mmHg; P=0.068). However, there were no significant differences between the groups. The dosage of olmesartan and azilsartan increased significantly and slightly for 16 weeks (OL group: 20.3-23.1 mg; P<0.05, AZ group: 20.5-23.2 mg; P<0.05), without a significant difference between groups. Furthermore, there were no significant differences in renal function, lipid profiles, brain natriuretic peptide, soluble fms-like tyrosine kinase-1, and urinary L-type fatty acid-binding protein between the two groups.

Conclusion: Both olmesartan and azilsartan equally reduced blood pressures. Both olmesartan and azilsartan showed a renoprotective effect and were well tolerated without any major adverse events.