Agents for treating heart failure ch 44

Question 1

What is heart failure?

Answer 1

Inability of heart to function efficiently

Question 2

Describe left sided heart failure?

Answer 2

Tachypnea, dyspnea, orthopnea, PND, crackles, pulmonary edema risk

Question 3

Describe right sided heart failure?

Answer 3

JVD, hepatomegaly, dependent edema, GI

Question 4

What are manifestations of heart failure?

Answer 4

Atrial flutter/fib
Ventricular irregularities
RHF
LHF

Question 5

What are drugs used for heartfailure?

Answer 5

Diuretics
ACE inhibitors and ARBs
Vasodilators
Beta adrenergic agonists

Question 6

What is Cardiotonic (Inotropic) drugs

Answer 6

Cardiac glycosides
Increase contractility of heart muscle
Help heart contract more efficiently

Question 7

What is digoxin (Lanoxin)

Answer 7

Cardiotonic Agents: Cardiac glycoside
Originally derived from foxglove or digitalis plant

Question 8

What is therapeutic actions of digoxin (Lanoxin)

Answer 8

Cardiotonic Agents: Cardiac glycoside

Improves cardiac contraction and pumping ability
Increases force of contraction (positive inotropic effect)
Increases cardiac output and renal perfusion
Decreases electrical impulses allowed to reach ventricles
Slooows heart rate by slowing repolarization (negative chronotropic effect)
-Allows more calcium to enter muscles of cardiac system so it can pump more

Question 9

What is antidote for Cardiotonic Agents: Cardiac glycoside toxicity?

Answer 9

Antidote: digoxin immune Fab (Digibind/Digifab) (Can be given)

Question 10

What is pharmacokinetics of digoxin (Lanoxin)

Answer 10

Cardiotonic Agents: Cardiac glycoside

Oral or IV
Narrow therapeutic index  0.5-2.0 ng/mL

Question 11

What are adverse effects of digoxin (Lanoxin)?

Answer 11

Cardiotonic Agents: Cardiac glycoside
HA, weakness, drowsiness
Vision changes (yellow halo)**
Arrhythmias

Question 12

What are contras of digoxin (Lanoxin)?

Answer 12

Cardiotonic Agents: Cardiac glycoside
Allergies
Ventricular irregularities
Bradycardia, heart block

Question 13

What are cautions of digoxin (Lanoxin)?

Answer 13

Cardiotonic Agents: Cardiac glycoside
-Pregnancy: unknown effects
-Watch for renal failure –> drug excreted unchanged in kidney, dose reduce

because the drug is excreted through the kidneys and toxic levels could develop; and electrolyte abnormalities

Question 14

What are drug to drug interactions of digoxin (Lanoxin)?

Answer 14

Cardiotonic Agents: Cardiac glycoside

-Cardiac meds, anti-infectives —> increased risk of toxicity

-Herbs:
St John’s Wort (decrease effectiveness) &
ginseng, hawthorn, licorice (increased effectiveness)

cardiac arrhythmias could increase if these drugs are taken with potassium-losing diuretic

Question 15

Cardiotonic Agents: Cardiac glycoside
What are nursing considerations with these?

Answer 15

-Check AP for one full minute before admin – hold for <60 bpm (adult)
-Monitor electrolytes b/c low electrolytes can increase dig toxixity
-Do not administer with antacids, cold remedies, diet pills – decrease dig absorption (separate by 2-4hrs)

Question 16

Cardiotonic Agents: Cardiac glycoside
What to monitor for signs and symptoms of toxicity?

Answer 16

N/V, visual changes, rhythm disturbances – fast or slow
-blood level; when the level is over 1.2 ng/mL, there is increased potential for adverse effects.
-toxicity include anorexia, nausea, vomiting, visual changes, alteration in color vision, fatigue, weakness, dizziness, and cardiac arrhythmias.
-The first sign of toxicity in infants and children is sinus bradycardia or any other cardiac arrhythmia. Any change in cardiac conduction that occurs after the child is taking digoxin should be first suspected to be related to digoxin toxicity. Other common signs in infants and children are weight loss and/or failure to thrive, abdominal pain, drowsiness, and behavioral disturbances.