Renin-Angiotensin System

Question 1

ACE Inhibitors

Answer 1

Captopril
Enalapril
Lisinopril

Question 2

ACE Inhibitor Effects

Answer 2

Block Ang 2 formation and bradykinin degradation
Increased bradykinin causes more NO and prostaglandin from endothelial cells (vasodilation)
Orally active and treat hypertension
Reduce blood pressure without increasing Heart rate (use with caution in volume depleted patients)
Diuretics enhance actions
Improves heart failure- decrease bp (after load), left ventricular filling pressure, increase CO, decrease aldosterone (preload), and hypertrophy, and improve survival

Question 3

Enalipril and Lisinopril

Answer 3

Long duration of action because metabolized to active drug from pro drug

Question 4

ACE inhibitor Side effects

Answer 4

Lowers aldosterone causes hyperkalemia and reduces diuretic induced hypokalemia
Rash, proteinuria, neutropenia (captopril), cough, angioedema

Question 5

Renin Inhibitors

Answer 5

Aliskiren

Question 6

Aliskiren

Answer 6

Mechanism of action: binds to site where angiotensinogen would bind and blocks the site because AGT is substrate
Plasma renin activity decreases
Decreases blood pressure same amount as Losartan

Question 7

B adrenergic antagonists

Answer 7

Propranolol (B1 and B2)
Metoprolol (B1)
Both are equally effective
Treat hypertension related to lowering renin activity because B1 causes renin release and this is blocked

Question 8

Aldosterone Antagonists

Answer 8

Spironolactone

Eplerenone

Question 9

Aldosterone Antagonists Uses

Answer 9

Inhibit renal (NA and H20 retention) and extra renal (fibrosis and and inflammation) actions of aldosterone
Uses: diuretic, hypertension, heart failure
Improves mortality rates and reduce symptoms in CHF
Reduce edema, anti-arrhythmic, and decrease fibrosis in myocardium and vessels

Question 10

Losartan

Answer 10

Angiotensin receptor blocker (ARB) at AT1
3 actions: decrease aldosterone secretion, decrease vasoconstriction, decrease sympathetic activation
Decrease blood pressure without increase HR
Angiotensin 2 levels increase in the blood but feedback inhibition ability is blocked on renin but can still act on AT2 to cause vasodilation and affect apoptosis
Takes 4-6 weeks to reach maximal response and used with diuretics to enhance action
Renal function may decrease in patients with congestive heart failure or renal artery stenosis
Improves heart failure–> decrease blood pressure (after load) and left ventricular filling pressure and decrease aldosterone (preload) and improves survival
Contraindication with pregnancy
Side effects- dizziness, cough, angioedema, hyperkalemia