Alpha 1-blockers in hypertension.

Hypertension is a heterogeneous disease and this is reflected in the marked variability in response to monotherapy. Co-administering antihypertensive therapies has several theoretical benefits, namely enhanced efficacy, improved tolerability, increased compliance and, in some cases, potentially beneficial changes in biochemical variables associated with increased cardiovascular risk, such as improvements in lipid profiles. alpha 1-Blockers, such as doxazosin, have several favourable properties which should be advantageous when used with other agents. Their mechanism of action is complementary to that of each of the other four main groups of antihypertensive drugs and, in each case, enhanced efficacy has been observed when alpha 1-blockade has been added to monotherapy with other drug classes. Synergistic effects have been seen when an alpha 1-blocker is administered together with either a calcium channel blocker or angiotensin-converting enzyme inhibitor. While alpha 1-blockers induce regression of left ventricular hypertrophy, the possibility of enhanced effects during multiple therapy has not been explored. alpha 1-Blockers exert positive effects on lipids (limited data suggest that they are able to reverse the deleterious lipid effects of diuretics and beta-blockers) and exert neutral or positive effects on glucose homeostasis. Further studies are needed to determine whether alpha 1-blockers can alleviate the adverse effects of beta-blockers or diuretics on glucose homeostasis. alpha 1-Blockers, when given concomitantly with other antihypertensive drugs, are well tolerated, conferring advantages with respect to patient compliance. The current data favour the use of alpha 1-blockers as an additional component of antihypertensive therapy, but further studies are needed to address the metabolic and end-organ effects of such treatment regimens.