Vasodilating antihypertensive drugs that prevent the convertion of angiotensin I, an inactive ocapeptide, to angiotensin II, which is a potent vasoconstrictor and aldosterone stimulator. In addition, ACE inhibitors prevent the degradation of bradykinin ( a vasodilating substance).
The antihypertensive response to ACE inhibitors is greatest in those patients whose hypertension is being generated by high levels of angiotensin II such as those with renovascular hypertension.