B - 19. Drugs used for the treatment of hypertension III: Drugs acting on the renin-angiotensin-aldosterone system Flashcards
ACE inihibitors mode of action
Blocks ACE (angiotensin converting enzyme), inhibiting release of AT II (vasoconstrictor) and aldosterone (retains Na+ and water) -> lowered blood volume and vasodilation
Also increases bradykinin levels -> more vasodilation and capillary permeability. can cause edema
ACE inihibitor names
First group: prodrugs
enalapril
perindopril
ramipril
Second group: not prodrugs
captopril - first ever ACEi, not much use anymore
ACE inihibitor indications
- First line drug for hypertension, even in young people
- —> 6 first weeks: fluctuating BP
- CHF
- Post-myocardial infarction (inhibits fast remodelling)
primary, secondary indications of hypertension treatment with ACE inhibitors and thiazide diuretics
Primary
- new patient with new diagnosis of HTN
Secondary
- patients monotherapy is not sufficient, thiazide diuretics must be added
ACE inihibitor SE
Hyperkalemia (aldosterone inhibition causes K+ retention)
Dry cough (due to bradykinin increase!)
Hypotension
Acute renal failure
Angiotensin II receptor blockers: names
Losartan (also lowers uric acid and cholesterol)
Valsartan
Valsartan + sacubitril
Irbesartan
Angiotensin II receptor blockers: function
Functions pretty much like ACEi, except they do not increase bradykinin, and thus no dry coughing
Newer and more expensive than ACEi
Aldosterone Antagonists: names
Spironolactone
Eplerenone
Aldosterone Antagonists: indication
Needed when aldosterone levels are high, e.g. conns syndrome
Aldosterone Antagonists: SE
o hyperkalemia: these are the MOST hyperkalemia-causing drugs
o hyponatremia
o metabolic acidosis from hyperkalemia
o spironolactone may cause gynecomastia bc antagonizes androgen receptors
