RAAS Medications - RM Flashcards
What does RAAS stand for?
Renin - Angiotensin - Aldosterone System
When is the RAAS activated?
When the body is hypovolemic (e.g., shock, MI, blood loss)
*because when activated, aldosterone is released causing the retention of sodium and water, which is needed during a hypovolemic situation
Angiotensinogen is a substrate secreted by the ______.
Liver
Renin is an enzyme secreted by the _______.
Kidneys
Angiotensin Converting Enzyme (ACE) is secreted by the _____ and converts ______ to _____.
Lungs & kidneys
Angiotensin-I
Angiotensin-II
When is aldosterone secreted?
It is a steroid made in the adrenal cortex (“-one” = steroid).
Secreted when Na+ is low or K+ is high.
How does aldosterone raise BP?
It causes the kidneys to retain Na+ and water…because water always follows Na+!
What is the MOA of an ACE inhibitor?
(Angiotensin Converting Enzyme Inhibitor)
Stops the conversion of Ang-1 to Ang-2 interrupting the pathway so aldosterone is never produced
What is the MOA of an ARB?
(Angiotensin-II Receptor Blocker)
Prevents the stimulation/release of aldosterone
What suffix goes with ACE inhibitors?
-pril
What suffix goes with ARBs?
-sartan
What are the therapeutic effects of ACE inhibitors & ARBs?
- decreased blood volume
- vasodilation (because angiotensin II causes vasoconstriction and angiotensin II is blocked with the ACE and ARBs)
- cardioprotection
Which conditions are RAAS meds best at treating?
- HTN
- HF
- LVD
- Acute MI
- Diabetic & non-diabetic neuropathy
- CAD
- CVD
How can ACE inhibitors help provide cardioprotection?
prevent MI, stroke, and death
What are the 4 major ACE inhibitors?
- lisinopril…most common!
- lisinopril/HCTZ
- enalapril
- ramipril
What are the 3 major ARB meds?
- losartan
- olmesartan
- valsartan
What are the adverse effects of the RAAS meds?
- First-dose HYPOtension
- Hyperkaleima
- Acute kidney injury
- Angioedema
What is “first-dose hypotension”?
The first dose of a RAAS med may have a dramatic effect on the pt. May cause significant hypotension.
Why should we watch closely pt’s starting these meds?
risk of fall due to first-dose hypotension
What is ACE-associated angioedema?
Rapid swelling of skin & mucous membranes; can obstruct airway.
Rare, but can be life-threatening!
Which ethnicity has the highest incidence of angioedema?
Highest in african-americans - 0.2%
Everyone else - 0.1%
What annoying but benign side effect is associted with ACE inhibitors?
dry cough, occurs in 10% of users
#1 cause of discontinuation
Clients with which issues should avoid RAAS meds?
- hyperkalemia
- angioedema
- pregnant
- acute kidney injury
- bilateral renal artery stenosis
When K+ levels are altered, it can cause ______ and ______.
arrhythmias
death
Which pregnancy category are RAAS meds in?
When are they most dangerous to the fetus?
Category D
2nd & 3rd trimesters
