Drugs for Heart Failure Flashcards
What are currently the drugs of chronic management for CHF? What are the primary drugs?
ACEIs and ARBs
ACEIs, ARBs, beta blockers, diuretics loop or thiazide or spironolactone or eplerenone, hydralazine + isosorbide dinitrate
Why may hydralazine and isosorbide dinitrate be used as a therapy for CHF?
preferred for chronic therapy in patients who cannot tolerate an ACEI or ARB
What major factor can be linked to stopping cardiac remodeling?
stopping secretion of aldosterone
Does digoxin improve survival of a patient with CHF?
no
Describe chronotropy, dromotropy, and inotropy of digoxin.
+ inotropy (FOC)
- dromotropy (conduction velocity)
-chronotropy (HR) (SA node)
What are the direct effects of digoxin?
inhibition of cardiac Na+/K+ ATPase
What are the direct effects (MOA) of digoxin?
Inhibition of Na+ -K+ ATPase
inc. intracellular Na+
Dec Na+/Ca2+ exchange
Inc intracellular Ca 2+
Increases Ca2+ release from sarcoplasmic reticulum
Inc. actin-myosin interaction
Inc. contractile force
Indirect effect: inhibition of neuronal Na+/K+ ATPase (results in inc. vagal activity)
Describe 1/2 life of Digoxin.
long 1/2 life
Which groups of people should you use digoxin in with caution?
in those with renal impairment
Describe Vd of Digoxin?
large Vd
Uses of digoxin.
CHF
supra ventricular tachycardias, except Wolff-Parkinson-White syndrome
What are the S/E of using Digoxin?
early signs include anorexia, nausea, ECG changes
later signs include disorientation, visual effects (yellow-green color disturbances, blurry vision)
in toxic doses, any cardiac arrythmias
How do you manage Digoxin toxicity?
use Fab antibodies towards digoxin; supportive therapy (electrolytes and antiarrhythmics class 1B)
Some drug interactions to be on the lookout for when using with Digoxin?
dec. K+, dec Mg2+, inc. Ca2+
quinidine and verapamil
CHF that is caused by diastolic dysfunction (CHF with preserved ejection fraction) is best treated with what drugs?
beta blockers and diuretics
What are the phosphodiesterase inhibitors discussed that treat CHF?
inamrinone and milrinone
What do inamrinone and Milrinone treat?
acute CHF only
Do phosphdiesterase inhibitors increase cAMP or decrease it?
increase it
How does increased cAMP affect the heart and smooth muscles?
increase inotropy
decreased TPR (respectively)
MOA of Dobutamine.
Stim. B1 which inc. contractility of the heart
also stim B2 receptors but more effect on B1
B1> B2
Uses of Dobutamine and Dopamine?
acute CHF only
What is a S/E of Dobutamine and Dopamine?
can lead to tachyphylaxis which is rapid tolerance w/i one day
Compare tachyphylaxis to true tolerance.
True tolerance takes days or weeks
MOA of Sacubitril.
ARNI angiotensin receptor neprolysin inhibitor that inhibits breakdown of these peptides >inc. ANP and BNP which are 2 BP lowering peptides
What is Sacubitril usu. given in combo with?
valsartan
MOA of Ivabridine
heart rate lowering by blocking funny Na+ channels which causes SA nodes that controls the spontaneous depolarization in the sinoatrial (SA) node and hence regulates the heart rate.
This SA node activity is unregulated in CHF patients
S/E of Ivabridine.
bradycardia
blurred vision
What is a benefit of using Ivabridine?
can slow HR without dir. effects on contractility
Why should you limit doses of B blockers in CHF?
can depress contractility
What are methods of management of Wolff-Parkinson-White Syndrome? What should you and what should you not do?
Do block accessory pathway with IA or III
Do not slow AV conduction (avoid digoxin, B-blocker, Ca2+ channel blocker, adenosine)
