Which potassium-sparing diuretics are commonly used?
Potassium-sparing diuretics include the following drug types, with typical examples in each group:
- Aldosterone antagonists (also called mineralocorticoid receptor antagonists): spironolactone, eplerenone.
- Direct epithelial sodium channel (ENaC) blockers: amiloride, triamterene.
- Aldosterone synthesis inhibitors: (not commonly used in standard “potassium-sparing diuretic” lists in many references).
What’s the difference between aldosterone blockers and ENaC blockers?
Aldosterone antagonists (spironolactone, eplerenone) reduce sodium reabsorption and potassium excretion by blocking aldosterone’s effect in the kidney’s distal nephron. ENaC blockers (amiloride, triamterene) directly reduce sodium entry through the epithelial sodium channel in the distal tubule/collecting duct, which also helps limit potassium loss.
Why are these called “potassium-sparing,” and what risk do they carry?
They tend to lower potassium excretion, which helps prevent hypokalemia (low potassium) compared with loop or thiazide diuretics. The main risk is hyperkalemia (high potassium), especially in people with kidney disease, diabetes, older adults, or those taking other medications that raise potassium.
How are they usually used?
Potassium-sparing diuretics are commonly used for:
- Heart failure and edema, often including spironolactone or eplerenone
- Resistant hypertension (often with spironolactone in practice)
- Conditions where avoiding low potassium matters
Are there combo products that include a potassium-sparing diuretic?
Yes. Some products combine a potassium-sparing diuretic with a thiazide (for example, triamterene with hydrochlorothiazide) to balance diuresis while reducing thiazide-related potassium loss.
Quick reference list (names)
Spironolactone; Eplerenone; Amiloride; Triamterene.