Digoxin

• Digoxin

• Digitoxin (similar with longer lasting effects)

Classification:

• Cardiac Glycoside

Mechanism of Action:

• Positive inotropic effect
  • Increases the contractile force of the heart
  • Ventricular emptying is more complete
  • Increase stroke volume
• Negative chronotropic effect
  • Decreases the heart rate by increasing the refractory period at the AV node
• Decreases heart size with cardiomegaly and heart failure
  • Increases stroke volume and improves ventricular emptying
  • Decreases cardiac workload
• Mild indirect diuretic effect
  • Due to increase cardiac output and renal perfusion
• Indirect effect on ECG
  • Shorter T wave
  • ST segment dips below the baseline
  • PR interval is prolonged
  • Shorter QT interval

Indications:

• CHF
• AFib/Aflutter/SVT

Contraindications:

• Acute myocardial infarction
• Heart block
• Ventricular tachycardia
• Bradycardia
• Acute or chronic renal failure

Precautions:

• Digitalis toxicity
  • History suggesting change in dosage
  • History of any other new medications
  • Fatigue, blurred vision, disturbed color perception, N/V, anorexia, diarrhea, abdominal pain, headache, dizziness, confusion, delirium, hallucinations
  • Bradycardia
  • Occasional tachycardia
  • Hypotension in severe cases