CVS: Digoxin

Question 1

What class of Meds is Digoxin?

Answer 1

Cardiac glycosides

Question 2

What does Digoxin treat? (3 things)

Answer 2

1. AF
2. Atrial flutter
3. HF

Question 3

What is the MOA of Digoxin? (2 things)

Answer 3

1. Increases force of Myocardial Contraction
2. Decreases Heart Rate

Question 4

How does Digoxin increase force of Myocardial Contraction @ a receptor level? (4 steps)

Answer 4

1. Induces an increase in IC Na
2. Drives influx of Ca in heart
3. Increased contractility
4. Improved Left Ventricular Ejection Fraction (LVEF)

Question 5

How does Digoxin decrease the Heart Rate @ a receptor level? (4 steps)

Answer 5

1. Activates PNS
2. Decreases Norepinephrine levels
3. Reduces AV node conductivity
4. Decreases Heart Rate

Question 6

What is the pathophysiological aspect of HF that Digoxin clarts? (3 steps)

Answer 6

1. HF
2. Increases Norepinephrine levels
3. Increased Heart Rate

Question 7

What are the Monitoring Requirements for Digoxin? (2 things)

Answer 7

1. Plasma-Digoxin conc assay: Take blood 6+ hours after dose
2. Toxicity: Monitor Electrolytes + Renal function

Question 8

What are the Side fx of Digoxin? (5 things)

Answer 8

1. Dizziness
2. Mental disturbance
3. Diarrhoea
4. Headache
5. Arrhythmia (consider toxicity)

Question 9

What are the CI for taking Digoxin? (5 things)

Answer 9

1. Constrictive pericarditis
2. Hypertrophic cardiomyopathy
3. Heart Block
4. SVT (e.g WPW syndrome)
5. VT / VF

Question 10

When should Digoxin be used with Caution? (7 things)

Answer 10

1. Hypercalcaemia (risk of toxicity)
2. Hypokalaemia (risk of toxicity)
3. Hypoxia (risk of toxicity)
4. Recent MI
5. Severe Resp disease
6. Sick Sinus Syndrome
7. Thyroid disease

Question 11

What do you need to take into account when switching Digoxin from IV to Oral route?

Answer 11

Increase dose by 20-33% to maintain same Plasma-Digoxin conc