Agents for treating heart failure: cardiac glycoside

Question 1

What does digoxin do?

Answer 1

inhibits the normal function of the pump, which alters the strength of of the heart contracts

• alters how fast the heart contracts and the speed of how the electrical impulses are sent through the hearts electrical conduction system
• increases intracelluar calcium and allows more calcium to enter the myocardial cell during depolarization

Question 2

What does digoxin alter in the iontropic action?

Answer 2

strength of contractions

- positive: causes the heart to squeeze or contract stronger

Question 3

what is the chronotropic action of digoxin?

Answer 3

rate the heart beats

- negative: slows down the impulses sent to the AV node

Question 4

What is the dromotropic action of digoxin?

Answer 4

• speed of electrical impulses sent through the heart

- negative: slows the impulses sent through the AV node

Question 5

What are the actions of digoxin?

Answer 5

• increased stroke volume, increased cardiac output to relive symptoms of heart failure
• increases renal blood flow
• increases urine output
• decrease peripheral edema
• decrease in renin release

Question 6

Indications for digoxin?

Answer 6

heart failure
arterial flutter
arterial fibrillation
paroxysmal atrial tachycardia

Question 7

Administration of digoxin

Answer 7

• orally
• parenteral
• rapid onset and absorption

Question 8

contraindications for digoxin

Answer 8

• allergy
• Vtach or Vfib
• heart block or sick sinus syndrome
• IHSS
• acute MI
• renal insufficiency
• electrolyte abormalities (-hypokalemia, hypomagnesemia, hypercalcemia)

Question 9

cautions for digoxin

Answer 9

• pregnancy or lactation

- pediatrics and geriatric (high risk of toxicty)

Question 10

Therapeutic range for digoxin

Answer 10

0.5-2 ng/mL

GREATER than 2 IS TOXIC

Question 11

what are the early signs of dixogin toxicty

Answer 11

N/V/ anorexia

Question 12

other signs of digoxin toxicity

Answer 12

malaise, depression, irregular heart rhythm, heart block, arterial arrhythmia, vtach

• vision changes (yellow/green vision or halo)
• bradycardia, headache, weakness, drowsiness, confusion

Question 13

Nursing considerations for digoxin

Answer 13

• monitor pluse before adminstering drug (HOLD if LESS THAN 60 bpm) - if below wait 1 hr and take again, notifity Dr.
• administer IV slowly over 5 minutes
• avoid IM injection
• weigh same time each day
• avoid administer drug with food or antacids
• assess for edema

Question 14

what emergency equipment should be on stand by for digoxin

Answer 14

• potassium salts, lidociane, phenytoin, atropine, cardiac monitor

Question 15

what is the antidote for digoxin?

Answer 15

digibind

Question 16

education for patients taking digoxin

Answer 16

signs and symptoms of toxicty

• importance of keeping appointments to have drug level monitored
• consuming foods high in potassium
• how to measure HR
• take at the same time every day
• low sodium and low fat diet
• increase PA

Question 17

A patient is taking Digoxin. What medication on the patient’s medication list increases the patient’s risk of experiencing Digoxin toxicity? 
 A. Furosemide
B. Metformin
C. Nitroglycerin
D. Coumadin

Answer 17

A. loop-diuretic (wastes potassium)

Question 18

Drug-drug interactions with digoxin

Answer 18

• potassium losing direteics
• thyroid hormones
• st.johns wort and pysllium, licorice