Persistence and adherence to antihypertensive treatment in relation to initial prescription: diuretics versus other classes of antihypertensive drugs.

Fixed combinations of antihypertensive drugs have the potentiality to improve blood pressure (BP) control. However, when pharmacokinetic parameters of the two drugs are different, both method and time of administration of the two drugs may modify the antihypertensive response. In an open-label, single-blind, randomized study we compared antihypertensive effect of four administration schemes of a combination therapy of olmesartan and amlodipine in the same group of hypertensive patients, using ambulatory blood pressure monitoring (ABPM). The olmesartan + amlodipine combination has demonstrated to provide a good control of BP, with systolic and diastolic BP constantly below 130 and 85 mmHg over the 24 h. The simultaneous or separate administration of the 2 drugs fully overlapped, suggesting that the fixed combination and the separate administration induce a similar and sustained BP control