Digoxin belongs to which drug family?

• A. Angiotensin-converting enzyme inhibitors
• B. Beta-blockers
• C. Angiotensin II receptor blockers
• D. Cardiac glycosides

Answer: (D)

Digoxin belongs to the cardiac glycoside family. This class increases the heart’s pumping strength by inhibiting the Na+/K+ ATPase pump on cardiac cells, which raises intracellular calcium and produces a positive inotropic effect. It also enhances vagal (parasympathetic) tone, slowing conduction through the AV node, which helps with rate control in atrial fibrillation. These actions are distinct from the other listed drug families: ACE inhibitors and ARBs are renin–angiotensin system blockers that cause vasodilation, while beta-blockers slow heart rate and reduce contractility through beta-adrenergic blockade. Cardiac glycosides like digoxin are mainly used for symptom relief in heart failure and for rate control in certain arrhythmias, with careful monitoring due to a narrow therapeutic index.