Card Set Information
Pharm exam heart failure
Pharm exam 2
What are the goals of therapy for heart failure?
Decrease signs and symptoms of congestion.
Maintain normal lifestyle.
What causes heart failure?
Systolic dysfunction (most commom); results in reduced contractility
Diastolic dysfunction; results in reduced ventricular filling
decreased ejection fraction
increased left vent end diastolic volume
ventricular hypertrophy r/t pressure or volume overload
reduced vent filling
normal ejection fraction
decreased left vent end diastolic volume
How is the renal system involved in heart failure?
heart failure leads to decreased cardiac output
decreased CO leads to release of renin, angiotensin II, and aldosterone and stimulation of symp NS
release of aldosterone increases reabsoption of water and sodium
increased reabsoprtion increases plasma volume, preload, and edema
stim of symp NS increases HR, contractility and vasoconstriction resulting in increased afterload and decreased CO
compensatory mechanism activating the renin/angiotensin/aldosterone system, increasing stroke volume
may result in volume overload, increased myocardial oxygen demand
Compensatory mechamisms in heart failure:
increased heart rate
: r/t SNS activation; increases oxygen demand, ischemia, arrhythmias, and decreases filling time
: decreases stroke volume
ventricular hypertrophy and remodeling
: increases myocardial cell death, ischemia, arrhythmias
How does reducing preload affect heart failure?
reducing preload decreases the amount of blood returning to heart, therefore helping to alleviate symptoms of pumonary congestion
How does reducing afterload affect heart failure?
reducing afterload reduces the force that the heart must contract against, therefore allowing an increase in CO
What types of drugs decrease preload?
diuretics, NSAIDS, nitrates, ACEI, nitroprusside, nesiritide
What types of drugs decrease afterload?
nitrates, ACEI, nitroprusside, nesiritide, hydralazine
What types of drugs reverse remodeling of the heart?
beta blockers (metoprolol, carvedilol, bosoprolol), ACEI, ARBs, aldosterone antagonists (spironolactone)
What do you monitor for when givine heart failure medications?
Left-sided heart failure
Right-sided heart failure
Excessive fluid loss
How do you respond to a person with high CO and low PCWP (end diastolic pressure)?
Do nothing, this is normal.
How do you respond to a patient with low CO and low PCWP (end diastolic pressure)?
Give fluids, patient is experiencing hypoperfusion.
How do you respond to a patient experiencing high CO and high PCWP (end diastolic pressure)?
Administer loop diuretics and vasodilators, pt is experiencing pumonary congestion.
How do you resond to a pt experiencing low CO and high PCWP (end diastolic pressure)?
Administer diuretics, vasodilators, pt is experiencing pulmonary congestion and hypoperfusion.
Action of diuretics (general)
decrease preload, do no effect CO (decreases symptoms)
Meds that are vasodilators
nitroglycerin, nitroprusside, nesiritide
induces smooth muscle relaxation in veins and arteries (mainly venodilator)
: HA, hypotension, tachycardia
tolerance can develope w/i 12hrs (tachyphylaxis)
potent, dilates veins and arteries
decreases preload and afterload
can become toxic quickly, usually short term med
antagonizes renin/agiotensin/aldosterone system and SNS
: excessive hypotension
Drugs that are inotropic agents (increase force of contraction).
milrinone, dobutamine, dopamine
positive inotropic effect and vasodilation
decreases preload and afterload
used short term (long term increases mortality rate)
beta 1 agonist leading to increased HR and contractility
beta 2 agonist results in vasodilation
increases MAP by stimulating alpha 1 receptors
chronic treatment of diastolic HF
: relax heart so that it fills better, increase diastole
low sodium diet (2g/day)
beta blockers or nondihydropyridine CCBs (not nifedipine)
chronic treatment of systolic HF
diuretic plus ACEI and beta blocker
hydralazine plus nitrates and/or digoxin in AA
control symptoms of pumonary congestion and fluid overload
do not increase survival (exceptions
: spironolactone and inspra)
ACEI and ARBs
mild to severe HF
reduce mortality rate, esp in pts with CHF
ACEI cough generall improves after several weeks
correct dose is important
Hydralazine plus nitrates
often used for AA or pts who cannot tolerate ACEI or ARBs
when used with diuretics and digoxin, reduces mortality (not as much asn ACEI)
beta blockers (in HF)
used in all stable HF pts
protects heart from chronic toxicity of high norepinephrine levels (ischemia, remodeling)
used in combo with ACEI
contraindicated in symptomatic bradycardia, hypotension, 2/3 degree heart block
aldosterone antagonist in HF
major risk is hyperkalemia
monitor serum creatinin and potassium before and after therapy initiation
digoxin in HF
positive inotropic effect (direct) - inhibits Na-K pump increasing intracellular Na and Ca resulting in increased force of contraction
vagotonic effect (take apical pulse and EKG before admin)
high renal elimination
dose based on IBW
: bradycardia, arrhythmias, AV block, fatigue, vision probs, weakness, anorexia, nausea, hallucinations/confusion/insomnia
not been shown to increase survival
reduces risk of hospitalization when used with diuretic and ACEI
Factors that alter digoxin effects:
increase effect w/o increasing levels
: hypokalemia, hypomagnesemia (prob w/alcoholics), vagal stim, hyperstimulation
: renal failure, amiodarone, verapamil, basing dose on actual wt instead of IBW, erythromycin (in some pts)
: antacids (binds w/dig in stomach) and rifampin (stims metabolism)
Drugs to avoid in HF
NSAIDS (increases Na and H2O retention)
drugs that cause adrenergic stimulation (decongestants, some beta blockers)
TZDs (used to treat DM, can cause fluid retention)
antiarrhythmics with negative inotropic activity (quinidine, procainamid) - good for diastolic HF, bad for systolic HF
antiarrhythmics that prolong QTc interval (increases r/o arrhythmias)
CCBs (may increase r/o death in systolic HF; nondihydropyridines like verapamil and diltiazam may be helpful in treating diastolic HF however)