ACE inhibitors (eg, captopril, enalapril, lisinopril) treats high blood pressure and congestive heart failure (CHF). A lower blood pressure will reduce the risk of stroke and heart attack. This medicine is also used to increase survival after a heart attack, and it is used to treat kidney problems caused by diabetes.
Mechanism of action of ACE inhibitors:
ACE Inhibitors, inhibit angiotensin converting enzyme “ACE”, reducing levels of angiotensin II and preventing inactivation of bradykinin which is a potent vasodilator and also inhibiting synthesis of Aldosterone from the adrenal glad. All this results in decreasing blood pressure. Renin release is Increased due to loss of feedback inhibition.
Clinical uses of ACE inhibitors:
- Diabetic renal disease (Drug of choice)
Toxicity of ACE inhibitors:
- Cough (due to increase of bradykinin)
- Taste changes
- Pregnancy problems (fetal renal damage)
- Increased renin
- Decreased angiotensin II
- Avoid with bilateral renal artery stenosis because ACE inhibitors significantly GFR by preventing constriction of efferent arterioles.
- Avoid in patients who have C1 esterase deficiency since they suffer from hereditary angioedema.
NOTE: Losartan, is an angiotensin II receptor antagonist. It is not an ACE inhibitor and does not cause cough, thereofor it can be used in patients on ACE inhibitors who develop cough and angioedema as an alternative.