mode of action

Last reviewed 01/2018

Digoxin raises intracellular sodium concentration in cardiac myocytes by partial inhibition of membrane sodium/potassium activated ATPase and indirectly increases intracellular calcium availability by sodium/calcium exchange.

The increased intracellular calcium leads to:

  • positive inotropism
  • disturbance of rhythm by:
    • blocking the AV conduction
    • increasing ectopic pacemaker activity
  • negative chronotropy, mediated via increased vagal activity