[Use of angiotensin-II-antagonists in hypertension]

Angiotensin-II antagonists act on the terminus of the renin-angiotensin cascade, i.c. the angiotensin II subtype I (AT1) receptor. As a result, the receptor is reversibly blocked for the action of circulating angiotensin II, usually for 24 hours after a single dose. The consequence of this is that the blood pressure decreases, to the extent that this is dependent upon the action of this hormone. This action has various components, namely, vasoconstriction, sodium retention (mainly via aldosterone) and the promotion of cell growth in the cardiovascular system. The decrease in blood pressure is comparable to that achieved with the conventional antihypertensive drugs. The most striking difference is the almost total absence of the adverse effects know to be produced by the established agents. In vivo, there is no significant difference between the activity of the various AT1-receptor blockers. Their ultimate effect on the cardiovascular prognosis in the hypertensive population is still under investigation.