Mechanism of action
Digoxin inhibits the
Na-K-ATPase membrane pump, resulting in an increase in intracellular sodium.
The sodium calcium exchanger (NCX)in turn tries to extrude the sodium and in so
doing, pumps in more calcium. Increased intracellular concentrations of calcium
may promote activation of contractile proteins (e.g., actin, myosin). Digoxin
also acts on the electrical activity of the heart, increasing the slope of
phase 4 depolarization, shortening the action potential duration, and
decreasing the maximal diastolic potential.
No comments:
Post a Comment