4.5 Heart Failure Drugs Flashcards
Reduced contractility along with decreased ejection fraction (pumping less blood)
Systolic failure
-
Reduced Filling + CO, due to:
- Stiffness
- Loss of adequate relaxation
Heart is not stretching enough to fill up
Diastolic Failure
What is the effect of CHF on contracility, HR, preload + afterload?
-
Decreased:
- Contractility
-
Increased:
- HR
- Preload
- Afterload
Why is HR increased in congestive heart failure?
Sympathetic activation of beta-adrenergic receptors
Why is preload increased in congestive heart failure?
Increased BV + venous tone
Why is afterload increased in congestive heart failure?
Increased systemic vascular resistance
What problem is associated with pts taking ACE Inhibitors?
- ACE is also responsible for the breakdown of bradykinin
- ACE converts Angiotensin I to Angiotensin II
- Pts taking ACE Inhibitors get an acculumation of bradykinin resulting in persistent cough , etc.
Are beta-adrenergic blockers or agonists used for Chronic or Acute CHF?
-
Chronic CHF
- beta-adrenergic blockers
- metoprolol
- beta-adrenergic blockers
-
Acute CHF
- beta-adrenergic agonists
- dobutamine, dopamine
- beta-adrenergic agonists
What are the ACE Inhibitors used in the tx of Chronic CHF? (4)
- prili = ACE Inhibitors
- Benazepril
- Captopril
- Enalapril
- Lisinopril
What are the cardiac effects of ACE Inhibitors? (2)
-
Reduce:
- Peripheral Resistance
- Afterload
- Aldosterone secretion
- Sympatethic activity
- via inhibition of angiotensin
- Prevent Myocardial Remodeling
What are the Angiotensin II Type-1 Receptor Blockers? (3)
- sartan
- Losartan
- Velsartan
- Olmesartan
What drugs are considered in pts intolerant to ACE Inhibitors due to incessant cough?
Angiotensin II Type-1 Receptor Blockers
Losartan, velsartan, olmesartan
What is a plant derived cardiac glycoside (only cardiac glycoside used in USA)?
Digitalis/Digoxin
In what form is digitalis/digoxin active, and what is the half life?
- Orally active
- Long 1/2 life = 36-40 hrs
How is digitalis/digoxin excreted?
excreted in kidneys
What is the mechanism of action of Digoxin?
- Inhibits the Na+/K+ ATPase
- Thus increases intracellular Na+, which in turn inhibits Na+/Ca2+ exchanger (NCX)
- Which leads to the retention of intracellular calcium, causing increases myocardial contractility
What effect does Digitalis have on the CNS?
- Disorientation
- hallucinations
What effect does Digitalis have on the GI tract?
- Anorexia
- Nausea
- Vomiting
- Diarrhea
Gynecomastia may occur in men who take …
Digitalis