Exam 2 - Heart Failure Flashcards
What drug classes are used to reduce preload?
Diuretics or venodilators
What drug classes are used to reduce afterload?
Arteriodilator
What drug classes are used to increase contractility?
Inotropic drug
What drug classes are used to reduce energy expenditure?
B-adrendergic antagonist
What is the MOA of diuretics in regards to HF?
- Reduce salt and H2O retention
- Reduce venous pressure leading to reduced edema and cardiac size
What diuretics are used in HF and can reduce mortality rate?
Spironolactone and eplerenone (aldosterone antagonists)
What is the MOA for an ACE inhibitor?
Inhibits ACE, preventing the conversion of Angiotensin I to Angiotensin II
What is the MOA for an ARB?
Block Angiotensin II from binding to AT1 receptor
What is the current DOC of HF treatment today?
ACE inhibitors
What is the primary therapeutic effect of ACE inhibitors and ARBs in HF?
Diminish cardiac workload by:
- Decreasing afterload: Decrease in angiotensin II-induced vasoconstriction
- Decreasing preload: Decreased aldosterone release
What are adverse effects associated with ACE inhibitors and ARBs?
Dry cough with ACE, but not with ARB
What is the MOA for Sacubitril/Valsartan (Entresto)?
2 drugs: (ARNI: ARB + Neprilysin Inhibitor)
- ARB will block Angiotensin II from binding to AT1 receptor
- Neprilysin inhibitor will reduce the degradation of natriuretic peptides, bradykinin and others
What is the key to decreasing mortality associated with using an ARNI (Sacubitril/Valsartan)?
The neprilysin inhibitor portion will reduce cardiac remodeling as it prevents the degradation of natriuretic peptides, bradykinin and others
What are some adverse effects of Sacubitril/Valsartan (Entresto)?
- Hypotension
- Hyperkalemia (ARB portion is inhibiting aldosterone which will cause an increased K+ concentration) (will occur especially if using a K+ sparing diuretic)
- Cough and angioedema (due to increased bradykinin)
What are contraindications/precautions for Sacubitril/Valsartan (Entresto)?
- Pregnancy
- Concurrent use with ACE inhibitor due to risk of angioedema
Carvedilol and Metoprolol belong to which class of HF medications?
B-blockers - “alol”
What are the therapeutic effects of B-blockers?
- Decrease mortality
- Decrease renin secretion
- Decrease effects of high concentration of catecholamines
- Decrease HR
- Decrease remodeling
When are B-blockers effective in HF?
Only effective in early stages of HF and can be dangerous in severe or end-stage due to its negative inotropic effect
Sodium nitroprusside (Nitropress), Isosorbide dinitrate, and Hydralazine belong to what class of HF drugs?
Vasodilators
How are sodium nitroprusside (Nitropress), Isosorbide dinitrate, and Hydralazine effective in HF?
- Reduce preload
- Reduce afterload
- Reduce damaging remodeling of the heart
What is the MOA of Dobutamine and what is it used for?
- Selective B1-agonist
- Short-term treatment of severe refractory HF
What is the MOA of Dopamine and what is it used for?
- Low dose –> D1 in kidney –> vasodilation
- Mod. dose –> B1 in heart –> inotropic effect
- High dose –> a in vessels –> vasoconstriction/increase BP
Short-term treatment of severe refractory HF, especially if increase in BP is needed
What is the MOA for Digoxin (Lanoxin)?
Inhibition of membrane sodium pump Na+, K+-ATPase (digitalis receptor), ultimately leading to an increase in intracellular calcium and increased contractility. Digitalis will also directly increase vagal stimulation (baroreflex-like effect) and decrease sympathetic tone, leading to a slowed HR.
What are indications/therapeutic effects of Digoxin?
- HF (CO is increased; last agent used)
- Improves exercise intolerance in HF
- Anti-arrhythmic in non-HF
