Comparison of effects of angiotensin II receptor blocker on morning home blood pressure and cardiorenal protection between morning administration and evening administration in hypertensive patients: the COMPATIBLE study.

Whether the time of administering the angiotensin receptor antagonist olmesartan influences antihypertensive and renoprotective effectiveness remains unclear. This study compared the effects of olmesartan on morning home blood pressure (MHBP), office BP (OBP) and renoprotective parameters between morning and evening administration. A total of 218 patients with primary hypertension were randomly assigned to receive olmesartan once daily in the morning (morning-dose group) or evening (evening-dose group), and 188 completed the study protocol (morning-dose group, n=95; evening-dose group, n=93). In both groups, morning home systolic BP, morning home diastolic BP, office systolic BP and office diastolic BP decreased significantly. There was no significant difference between the groups in MHBP or OBP after 6 months of treatment. The urinary albumin-to-creatinine ratio (UACR) decreased from 13.9 to 6.9 mg g(-1) (geometric means, P<0.001) in the morning-dose group and from 14.4 to 9.1 mg g(-1) (P<0.001) in the evening-dose group. The changes in UACR after treatment did not differ significantly between the groups. SV1+RV5 decreased significantly from baseline to 6 months in the morning-dose group (P<0.001) and the evening-dose group (P<0.01), and did not differ significantly between the groups. In conclusion, olmesartan effectively decreased MHBP, OBP, SV1+RV5 and UACR regardless of whether the drug was administered in the morning or in the evening. Our results suggest that olmesartan can be prescribed once daily, either in the morning or in the evening.