RESUMO
Poor adherence to antihypertensive treatment is the single most important factor of unsatisfactory blood pressure (BP) control. This review focuses on therapy-related factors affecting adherence and suggests how to improve it with a wise choice of treatment schedule. Complex drug treatment schemes, poor tolerability and drug substitutions are frequent causes of poor adherence which, in turn, causes insufficient BP control, greater incidence of cardiovascular events and, finally, higher global health costs. The effects of prescribing generic drugs and of drug substitutions on adherence is also discussed. In terms of adherence, generic drugs do not seem to be better than branded drugs, unless patients have to bear very high "out of pocket" expenses to buy original drugs, suggesting no advantages in switching drug with the mere goal of reducing the cost of therapy. An important role in improving adherence (and thus cardiovascular events and health expenditure) is also played by the availability of fixed-dose combinations; among antihypertensive drugs, angiotensin receptor blockers (ARBs) are those associated with higher levels of adherence and persistence. Among ARBs, olmesartan stands out for a wide choice of effective fixed-dose combinations.