Digoxin

Question 1

What is Digoxin and where is it extracted from?

Answer 1

Positively inotropic cardiac glycoside

Extracted from foxglove Digitalis lanata

Question 2

What is Digoxin’s MoA?

Answer 2

Positive inotrope
1 - Blocks Na/K exchange, increasing intracellular Na
2 - Na/Ca exchange takes place, increasing intracellular Ca
3 - Contractility is increased, AV node delay increased, HR reduced (secondary negative chronotropic effect)

Question 3

What is Digoxin used for and why?

Answer 3

Symptomatic relief in heart failure

• has been shown to be effective in doing so, without improving mortality
• but is the only inotrope that doesn’t increase mortality