Lecture 3: RAAS- Antihypertensives Flashcards
Which commonly used drugs have been associated with the induction of HTN?
Oral contraceptives
Angiotensin II formed from RAAS is a potent _________.
Angiotensin II formed from RAAS is a potent vasoconstrictor.
Angiotensin II acts to increase what 2 things?
1) Total peripheral resistance
2) Extracellular fluid volume
What 3 things are stimulated by angiotensin II?
- Stimulates thirst
- Aldosterone secretion (causes retention of Na+)
- ADH secretion (retention of H2O)
What is the MOA of Captopril?
- Competitive inhibitor of ACE
- Prevents conversion of angiotensin I —> angiotensin II
- Increases plasma renin and decreases aldosterone secretion = lower BP
Why is enalapril significant?
Is a prodrug, w/ active form being enalaprilat
What are ACE inhibitors used for clinically?
- HTN, can combo w/ thiazide or loop diuretic
- Acute HTN (urgency/emergency)
- HF w/ reduced ejection fraction
- Diabetic nephropathy
What are the adverse effects associated w/ ACE inhibitors?
Which AE is the reason most people stop taking the drug and what is a potentially deadly AE?
- Cough = #1 reason people stop taking
- Hypotension, HA, drowsiness
- Angioedema = can be fatal
- Loss of/altered taste
ACE inhibitor drugs have what suffix?
-pril
What is the MOA of the -sartans?
- Competitive nonpeptide angiotensin II receptor antagonist
- Blocks the vasocontrictor and aldosterone-secreting effects
What is the clinical application of the -sartans (i.e., losartan)?
- Diabetic nephropathy w/ ↑ Scr and proteinuria
- HTN, alone or in combo
- Heart failure if intolerant of ACE inhibitors
What is the big advantage of the -sartans for HTN and other clinical applications?
Doesn’t produce as much of a cough as the ACE inhibitors so is better tolerated
What is the significance of Valsartan and Candesartan?
- Valsartan = is NOT a prodrug requring activation
- Candesartan = has irreversible binding of the angiotensin II receptor
Which drug is often used in people w/ heart failure that are intolerant to ACE inhibitors (i.e., too much cough)?
Losartan
Which drug used for the tx of HTN is a direct renin inhibitor?
Aliskiren
What are the effects of Aliskiren?
Direct renin inhibitor –> blocks conversion of angiotensinogen to angiotensin I
What is the clinical application of Aliskiren?
How often is it used?
- Tx of HTN, alone or in combo w/ others
- New, expensive, no obvious benefits, some evidence of increased risk of AE’s
What are some of the AE’s associated w/ Aliskiren?
- Skin rash
- Diarrhea
- >300% increase in creatine phosphokinase (1%)
- Hyperkalemia, especially if combined or pt has renal dysf. or DM
You should NOT use a β-blocker, like propranolol, in patients with what 2 disorders?
1) Asthma
2) Diabetes
Which drugs work well in combo when treating an African American for HTN?
- Diuretics and Ca2+ channel blockers
- β-blockers, ACE inhibitors and ARBS work well when added to diuretic, but NOT as monotherapy
Which HTN drugs should not be given to sexually active girls?
- ACE inhibitors
- ARBs
Which drug used for HTN is contraindicated throughout pregnancy?
ACE inhibitors