CHF Pharm Flashcards
According to ACC/AHA guidelines, a patient who is stage A can be characterized by what?
AT RISK for CHF
According to ACC/AHA guidelines, a patient who is stage B can be characterized by what?
Low EF but no symptoms
According to ACC/AHA guidelines, a patient who is stage C can be characterized by what?
edema and dyspnea
According to ACC/AHA guidelines, a patient who is stage D can be characterized by what?
advanced heart failure
How do you treat a stage A CHF patient?
1) Preventive Measures (treating hypertension, dyslipidemia, diabetes, stopping smoking and alcohol intake)
2) ACE inhibitor or ARB
What do you add on to the treatment of a stage B CHF patient?
Other than preventative measures and ACEI/ARB, you use a beta blocker
What do you add on to the treatment of a stage C CHF patient?
Preventative measures, ACEI/ARB, Beta blocker and add on diuretic/digoxin/spironolactone
How do you treat a stage D CHF patient?
you need to give IV inotropes and transplant along with the other therapy
What is the MOA of ACE inhibitors?
block angiotensin I to angiotensin II conversion in the lung
Which ACE inhibitors are NOT prodrugs?
captopril and lisinopril
What is the MOA of ARBs?
block AT1 receptors to induce vasodilation and increase Na+ and water excretion
What is the ending to ARBs?
-tans (ex. losartan)
What is the MOA of aliskiren?
directly inhibits the protease activity of renin
Renin is released from the kidney to act on what chemical? What is this released from?
REnin is released from the kidney and converts angiotensinogen (from liver) to angiotensin
ACE inhibitors lead to what effects?
- Decrease TRP (prevent vasoconstriction)
- Decrease aldosterone (natriuresis, loss of Na and fluids)
- Increase Bradykinin levels
- Increase prostaglandin production (increased vasorelaxation)
What are the specs of ACE inhibitor use. (who do these work on, who do they not work on, contraindications)
- Not good for African Americans
- Not good for low-renin HTN
- Decreases mortality post MI
- Preserves renal function in diabetics
- Little effect on lipids/sexual function
- FETOTOXIC
What are the 2 most common adverse effects of ACE inhibitors?
1) first dose HTN
2) Na+ depletion
What are the other common adverse effects of ACE inhibitors?
- Dry cough
- Hyperkalemia
- Angioedema (allergic skin/mucosa disease)
- Renal insufficiency
ARBs have basically the same effects of ACE inhibitors, except they do not have what side effect?
dry cough
What are the side effects of ARBs?
- 1st does hypotension
- Hyperkalemia
- Hepatic dysfunciton
- Fetotoxicity
- Spruelike enteropathy (from olmesartan)
Aliskiren has DDIs with what drugs?
drugs that inhibit p-glycoprotein (because aliskiren does too): erythromycin, amiodarone, etc.
What are the mitogenic effects of angiotensin II that ACE inhibitors and ARBs inhibit?
1) Hypertrophy of cardiac myocytes
2) Hypertrophy of vascular SM
3) Cardiac and vascular fibrosis (remodeling)
4) Atherosclerosis
Which drug has the phenomenon of aldosterone “escape”?
ACE inhibitors, over time, can no longer prevent the synthesis of aldosterone synthesis and this begins to increase
When would you use an ARB over an ACE inhibitor?
if you cannot tolerote an ACE inhibitor (due to dry cough, etc.)
Why were beta-blockers once contraindicated in CHF therapy?
becasue beta activation increases inotrophy needed when you have CHF
Beta blockers mainly treat CHF by attenuating the deleterious effects of chronic high levels of what?
norepinephrine and epinephrine
How do chronic high levels of NE and Epinephrine influence CHF?
- Beta receptor down regulation
- Arrhythmias (cause of death in CHF)
- Increased myocardial oxygen consumption (ischemia)
- Myocyte apoptosis followed by fibrosis
What are the short-term hemodynamic effects of beta blockers in CHF?
reduced CO and BP (may see initial worsening of symptoms before they get better)
What are the long-term hemodynamic effects of beta blockers in CHF?
increased CO, decreased LVEDP
When do you want to start beta blockers?
early in CHF to slow disease progression
List the beta blockers approved for CHF treatment.
Metoprolol
Crvedilol
Bisoprolol
What are the major molecular effects of beta blockers in CHF?
1) reverse desensitization of beta receptors
2) increase receptor number
3) restore fast signaling modes (contractility) over slow signaling modes (gene expression)
What is unique about the chemical structure of digitalis?
CARDIAC GLYCOSIDE
- Steroid nucleus
- Unsaturated lactone ring
- Glycoside residues
What are the sources of digitalis?
plants and toad venom
Why is digoxin almost exclusively used now?
- Convenient pharmacokinetics
- Multiple ROA
- Assay for measurements of serum levels
What is the MOA of digoxin?
Increased intracellular availability of calcium for contractile apparatus via inhibition of sodium potassium pump (increase intracellular Na+. decrease intracellular K+)
What does digoxin do to the pressure-volume curve?
shifts the curve upward and to the left
Because digoxin is excreted unchanged by the kidney, how should you alter the dose in renal disease?
reduce it!
How do you monitor the therapeutic action of digoxin?
plasma concentrations correlate roughly with theraapeutic effect and toxicity
What are the adverse effects of digoxin?
- Atrial and ventricular arrhythmias
- Visual changes (blurring, yellow-green halo)
- Headache, fatigue, drowsiness, confusion, seizures
How can you reverse the toxicity of digoxin?
Digibind (antibody to digoxin)
List the DDIs of digoxin?
- Quinidine and Amiodarone increases plasma digoxin levels by decreasing elimination
- Verapamil slow HR and digoxin toxicity
- Diuretic can increase potential for arrhythmias due to hypokalemia
Why does digoxin have so many DDIs?
it has a very narrow therapeutic window
Long-term digoxin therapy may have what effect?
arrhythmias and worsened ventricular function
What SYMPTOMS of CHF do diuretics treat?
promote Na+ and water excretion to reverse edema and pulmonary congestion
Do diuretics really have an effect on CHF?
no, they just treat symptoms (reduce preload but do not increase CO)
What 2 “high ceiling” diuretics are commonly used to treat CHF symptoms?
furosemide (“loop”)
Bumetanide
What is typically used in combination with loop diuretics?
potassium sparing diuretics (like aldosterone antagonists)
What is an example of an aldosterone antagonist?
spironolactone
What are the adverse effects of diuretics?
Electrolyte disturbances Hypokalemia Hyponatremia Metabolic alkalosis Dehydration, hypotension Ototoxicity (tinnitus and hearing loss from loop diuretics)
What type of drugs reduce efficacy of diuretics by promoting fluid retention?
NSAIDs
What drugs mimic the effects of diuretics but have a suboptimal effect that is not sufficient enough to prevent edema?
ACE inhibitors and ARBs by reducing sodium retention by preventing aldosterone release)
What effects does spironolactone and eplerenone (aldosterone inhibitors) have other than diuretic effect?
Stop the direct mitogenic and fibrogenic effects of aldosterone (combined with AngII) on the myocardium that often leads to worsened LV function
What effect do direct arterial vasodilators have in CHF? Name an example used in CHF.
reduce afterload to improve ventricular performance and increase CO. Hydralazine
What must you combine with a arterial vasodilator to reduce both afterload and preload?
a venodilator (nitrate)
When would you give a patient hydralazine?
only if they are unable to tolerate ACE inhibitors (ex. renal insufficiency or angioedema)
What are the adverse effects of hydralazine?
nausea
anorexia
+FANA
drug induced lupus (rare)
How to nitrates reduce preload?
Veno and Vasodilation!!
- Reduce pulmonary arterial pressure (pulmonary congestion)
- Reduces left ventricular filling pressure and wall stress
- these decrease preload and afterload
Name the 2 IV inotropic agents.
dobutamine
milrinone
What is the MOA of dobutamine.
Beta agonist and alpha agonist that vasodilates and serves as a “bridge” until the patient is stable enough for digoxin
What drug should not be used with dobutamine?
beta-blocker therapy prevents the vasodilator effect of dobutamine and may actually cause vasoconstriction (from alpha 1 effect)
What is a problem with dobutamine release?
desensitizaiton
What drug works in the path of dobutamine but will not have the problem of desensitizaiton?
milrinone
What is the MOA of milrinone?
PDE inhibitor to stop the breakdown of cAMP. This will lead to increased HR and increase contraction speed!
When are ANP and BNP released from the atria and ventricles?
in response to volume/pressure expansion
What are the levels of ANP and BNP like in CHF? Why?
they are naturally elevated to promote vasodilation, venodilation, and natriuresis
What are the hemodynamic effects of ANP and BNP?
- Reduce preload
- Inhibit renin/aldosterone release
- Inhibits sodium reabsorption in proximal convoluted tubule
- Selective afferent arteriolar vasodilation
What is nesiritide? What is it approved for?
Nesiritide is recombinant human BNP approved for IV treatment of Class IV CHF
What is the MOA of nesiritide?
- Binds to BNP receptor in vascular smooth muscle, increases cGMP to promote veno-and vasodilation: this reduces preload and afterload
- Increases GFR by dilating renal arterioles, natriuresis (decreases Na resorption)
- Suppresses R-A-A and SNS
Who should be given nesiritide?
Class IV CHF in patients who do not respond to nitroglycerin
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