Which diuretic is known to potentially cause digoxin toxicity?

The diuretic that can potentially cause digoxin toxicity is hydrochlorothiazide (HCTZ). This occurs because thiazide diuretics, like HCTZ, can lead to electrolyte imbalances, particularly hypokalemia (low potassium levels). Potassium is essential for maintaining normal heart function, and when its levels drop, the risk of digoxin toxicity increases due to the way digoxin works on the potassium channels.

Digoxin has a narrow therapeutic window, meaning that the difference between a therapeutic dose and a toxic dose is very small. When potassium levels decrease, digoxin's effects can be amplified, leading to toxicity.

In contrast, furosemide (a loop diuretic) can also cause electrolyte imbalances, but it may lead to hypomagnesemia rather than a direct relationship to digoxin toxicity as significantly as thiazides do. Spironolactone (a potassium-sparing diuretic) generally does not cause low potassium levels, which helps protect against digoxin toxicity. Amiloride, also a potassium-sparing diuretic, functions similarly, retaining potassium in the body. Thus, the specific risk of digoxin toxicity is most directly associated with hydrochlorothiazide due to its