CVS: Digoxin Flashcards
What class of Meds is Digoxin?
Cardiac glycosides
What does Digoxin treat? (3 things)
- AF
- Atrial flutter
- HF
What is the MOA of Digoxin? (2 things)
- Increases force of Myocardial Contraction
- Decreases Heart Rate
How does Digoxin increase force of Myocardial Contraction @ a receptor level? (4 steps)
- Induces an increase in IC Na
- Drives influx of Ca in heart
- Increased contractility
- Improved Left Ventricular Ejection Fraction (LVEF)
How does Digoxin decrease the Heart Rate @ a receptor level? (4 steps)
- Activates PNS
- Decreases Norepinephrine levels
- Reduces AV node conductivity
- Decreases Heart Rate
What is the pathophysiological aspect of HF that Digoxin clarts? (3 steps)
- HF
- Increases Norepinephrine levels
- Increased Heart Rate
What are the Monitoring Requirements for Digoxin? (2 things)
- Plasma-Digoxin conc assay: Take blood 6+ hours after dose
- Toxicity: Monitor Electrolytes + Renal function
What are the Side fx of Digoxin? (5 things)
- Dizziness
- Mental disturbance
- Diarrhoea
- Headache
- Arrhythmia (consider toxicity)
What are the CI for taking Digoxin? (5 things)
- Constrictive pericarditis
- Hypertrophic cardiomyopathy
- Heart Block
- SVT (e.g WPW syndrome)
- VT / VF
When should Digoxin be used with Caution? (7 things)
- Hypercalcaemia (risk of toxicity)
- Hypokalaemia (risk of toxicity)
- Hypoxia (risk of toxicity)
- Recent MI
- Severe Resp disease
- Sick Sinus Syndrome
- Thyroid disease
What do you need to take into account when switching Digoxin from IV to Oral route?
Increase dose by 20-33% to maintain same Plasma-Digoxin conc