ACE inhibitors

Mechanism of action:

They block the converting enzyme peptidyl dipeptidase that hydrolyzes and causes the conversion of (decapeptide) angiotensin I to (octapeptide) angiotensin II, resulting in the decrease of vasoconstrictor effect of angiotnesin II.

It also causes an increase of bradykinin, which has a vasodilator activity.


Actions:
1. They cause a decrease in total peripheral resistance and mean arterial blood pressure and either no change or an increase in cardiac output.

2. They do not result in reflex sympathetic stimulation and can be used safely and effectively in patients with ischemic heart disease.


Therapeutic uses:
They can be used for:
1. Mild to moderate essential hypertension and renovascular hypertension
2. Chronic congestive heart failure
3. Left ventricular systolic dysfunction
4. They can also be used in diabetic proteinuria

Adverse effects:
Headaches, dizziness, acute renal failure, hyperkalemia, dry cough, wheezing, skin rashes, angioedema

Contraindications:
1. aortic constriction
2. renal disturbance
3. pregnancy and lactation
4. bilateral renal artery constriction