Pharmacology - Chapter 43 - Drugs Acting on the Renin-Angiotensin System Flashcards
What do these drugs (that act on this system) do? (3)
Regulation blood pressure, regulate blood volume, and regulation electrolyte balance.
What are the 3 types of angiotensin?
1 - Precursor of 2 - has little biological activity.
2 - very high biological activity.
3 - degradation of 2 produces 3 - has moderate activity.
Angiotensin 1 - a decline in blood pressure, a reduction in the blood volume, a decline in sodium content, a decline in renal pressure triggers the production of ___.
Renin.
Renin - produced by _____ - catalyzes ____ from _____ (a serum globuline in the liver.)
Renin - produced by juxtaglomerular cells of the kidney.
Catalyzes angiontensin 1 from angiotensinogen (a serum globuline in the liver.)
Angiotensin Converting Enzyme (ACE, also known as ___ 2.)
Kinase 2.
What does ACE do?
Catalyzes the conversion of Angiotensin 1 (inactive) to Angiotensin 2(highly active!)
Where is ACE located?
On the surface of all blood vessels (especially in the lungs!)
Action of Angiotensin 2 -
mediates all of the effects of the RAS - it acts directly on vascular smooth muscle to cause contraction, and acts indirectly on smooth muscle constriction…..also promotes synthesis and release of aldosterone.
What are the 2 drugs that act on the Renin-Angiotensin system?
Angiotensin converting enzyme (ACE) inhibitors and Angiotensin 2 receptor blockers (ARB’s)
ARB’s are only approved for ___.
Hypertension.
PRIL - ending means an….
ACE inhibitor.
ACE - treatment for….
hypertension and heart failure.
What is the 1st ace inhibitor used worldwide?
Captopril!
What does Captopril do?
Prevents formation of Angiotensin 2 - results in vasodilation.
Captopril is taken ____ and absorption is ___ % but is reduced greatly by ____ (take 1 hour prior to meals.)
Orally - 70 % - food.
Captopril - what are the Adverse effects?
COUGH (continuous!), first dose hypertension, and hyperkalemia!
Sartan - ending means ___
It is an ARB.
ARB’s - they block….
action of angiotensin 2 at receptor site. They have similar effects as Ace inhibitors.
ARB’s - may cause ____ during pregnancy.
Birth defects in the 2nd and 3rd trimesters.
Losartan (Cozaar) approved only for ____ but may be useful in heart failure.
Hypertension.
What are the adverse effects of Losartan?
Dizziness and Birth defects.
What are some new ARB? (4)
Candesartan (Atacand), Irbesartan (Avapro), Telmisartan (Micardis), Valsartan (Diovan).
