Ch 21 Cardiac Glycosides & HF Flashcards
What are the meds for choice for HF
ACE INHIBITORS
ARBs
Beta blockers
What is a secondary med given if the choice of meds for HF Are unaffected
Cardiac glycosides
What is the prototype drug of cardiac glycosides
Digoxin ( lanoxin, lanoxicaps, digitek)
What is the pharmalogical action of cardiac glycosides
Positive inotropic effect= increased force of myocardial contraction this improves SV and cardiac output
Neg inotropic effect= decreased HR
at therapeutic levels, digoxin slows the rate of SA NODE depolarization and the rate of of impulses thru the conduction system of the heart
A decreased HR gives the ventricle more time to fill with blood coming from the atria, which leads to increased SV and increased CO
What are the therapeutic uses of cardiac glycosides
Treatment of HF
dysrhythmias ( atrial fibrillation)
What are the adverse effects of cardiac glycosides
Dysrhythmias
Cardio toxicity
GI effects include anorexia, nausea, vomiting and abdominal pain
CNS effects include fatigue, weakness, vision changes,
What are serum K+ levels
3.5-5
What are therapeutic serum levels of digoxin
0.5-2
Cardiac glycosides are contraindicated in what
Pregnancy category C
cilents who have disturbances in ventricular rhythm, including ventricular fibrillation, ventricular tachycardia and 2nd and 3rd degree heart block.
Use cautiously in ppl who have hypokalemia, partial AV block, advanced HF and renal insufficiency
What are medication food interactions of cardiac glycosides
Thiazides diuretics and loop diuretics may lead to hypokalemia,which increases the risk of developing dysrhythmias
Ace inhibitors and ARBs increase the risk of hyperkalemia which can lead to decreased effects of digoxin
Sympathomimetic meds such as dopamine
Quinidine increases the risk of digoxin toxicity
Verapamil increases plasma levels of digoxin
Antacids decrease absorption of digoxin
What are indications of digoxin toxicity
Fatigue, weakness, vision changes, GI effects
When administering digoxin via IV what is a priority
Infuse over at least 5 min and monitor for dysrhythmias
How can a nurse manage digoxin toxicity
- Digoxin and K+”sparing meds should be stopped immediately
- Monitor k+ levels… For levels less than 3.5 administer k+ IV or PO
- Treat dysrhythmias with phenytoin or lidocaine
- Treat bradycardia with atropine
- For excessive overdose, activated charcoal, cholestyramine, or digiblind can b used to bind digoxin
How can a nurse tell if digoxin therapy is effective
Control of HF
Absence of cardiac dysrhythmias
What is the prototype drug of ADRENERGIC AGONISTS
Catecholamines
- epinephrine ( adrenaline)
- dopamine ( Inotropic)
- dobutamine
Other meds:
* Isoprotenerol: Catecholamine
Terbutaline: noncatecholamine