Murphy- heart failure drugs Flashcards
Name the Drug treatment goal of current plan toward treating HF
- block actions of RAAS and sympathetic NS
What is the purpose of aldosterone receptor antagonist?
- antagonist of aldosterone receptor, so you block aldosterone actions and can block the renin-angiotensin system
which drugs do the best job of controlling the neurohormonal activation contributing to HF
- renin angiotensin inhibitor drugs
which drugs do the gold standard job of reducinb mortality risk in heart faiulre
ACE inhibitors (‘prils)
why choose ARB for ACE inhibitor?
when ACE inhibitors are poorly tolerated (cough, angiodema(
in terms of heart failure where are beta blockers acting?
- at the heart (failiing left ventricular muscle)
- at the kidney… blocks renin release
main indications of Beta blockers for heart failure
- stable heart failure
- heart failure with reduced LVEF
ALWAYS USED IN COMBO WITH ACEI or ARB
gibe adverse effects of beta blockers
- because of magnitude of beta receptor blockade
- if you block too much, you get decreased cardiac performance (decompensation)… bradycardia, hypoglycemia, hypotension
purpose of diuretics for HF
decrease TPR… eliminate salt and water from body..
what is effect of mortality for diuretics in HF
- not established… probably because it’s used as an adjuct to other drugs
potentially adverse effects of diuretics
- hypokalemia (excessive sodium loss in urine)
- drug interactions – hypokalmia potentiates digitalis action
- potentiates diruesis from ACEI and aldosterione receptor antagonist
What are cardiac glycosides… whats the most common formulation
- digitalis glycosides
- DIGOXIN
Mechanism of action of digoxin
- inhibits sodium potassium pump (keeping sodium inside the cell and keeping depolarization higher)
- indirectly raises intracellular calcium, giving stronger contraction and improving ventiruclar performance
what exchanger is unique to cardiomyoctes?
- Sodium calcium exchanger… sodium goes in, calcium goes out… to get rid of contraction
how does digoxin inhibit sodium potassium pump
- binds site of where potassium would bind in order to poop it into the cell for exchange with sodium
Digoxin works on what cell directly?
- myocardium, thus improving the overall neurohormonal profile
indications of Digoxin in HF
- when standard therapy is not sufficient
- to increase CO and organ perfusion while reducing neuro-hormonal activation
- INCREASES VAGAL TONE (bezold-jarisch baroreflex) – senses increased contractility
describe therapeutic index and clearance of digoxin
- low therapeutic index… cleared by kidney’s unchanged (if you’re in renal failure, you can slow clearance and cause toxicity)]
Half life is very long… makes toxicity a problem
what are the main side effects of digoxin in heart failure
- Ubiquitous drug target… causes many different side effects in different organs (because you’re targeting sodium potassium pump)
- CAUSES ARRYTHMIAS
- supraventricular (excess paraasympathetic from bezold-jarisch baroflex0
- ventricular arrythmias… too high of intracellular Na+/Ca2+, as well as low extracellular potassium
effect of digoxin on mortality
- no effect
effect of caclium channel blockers on mortality
- no effect
- effect of alpha 1 adrenergic receptors blockers on mortality
- no effect
hydrolazine is a ____ vasodilator, while isosorbide dinitrate is a ______
arteriolar; venodilator
effect of hydrolazine+isosorbide dinitrate combination on mortality for HF
- decreases mortality!
WHAT IS BIDIL
combo therapy of hydralazine + ISDN for african americans specifically
what are the two categories of positive inotropic agents
- beta adrenergic receptora agonists (induce cAMP); epinephrine and dobutamine to activate beta adrnergic receptors
- phosphodiesteras einhibitors (protect cAMP); milrinone (CARDIAC SELECTIVE and short term)
when would you use positive inotropic agents most for HF
acute and severe
