Definition

A cardiac glycoside. Digoxin inhibits the sodium potassium adenosine triphosphatase (ATPase) pump, thereby increasing intracellular calcium and enhancing cardiac contractility. This agent also acts directly on the atrioventricular node to suppress conduction, thereby slowing conduction velocity. Apparently due to its effects on intracellular calcium concentrations, digoxin induces apoptosis of tumor cells via a pathway involving mitochondrial cytochrome c and caspases 8 and 3.