Potassium-sparing Diuretics

Mechanism of Action

Aldosterone action is blocked in distal tubule, causing Na+ excretion in the urine; blocks K+ secretion through tubule, resul

Aldosterone action is blocked in distal tubule, causing Na+ excretion in the urine; blocks K+ secretion through tubule, resulting in retention of K+. Achieves diuretic effect by loss of Na+ to offset retention of K+ balance.

Therapeutic Effects:
* reduces BP
* reduces edema/pulmonary congestion
* decreased workload on heart

Conditions Treated:
* hypertension
* hyperaldosteronism
* adjunct to treatment with antiarrhythmics/digoxin

Side Effects/Adverse Effects

hyperkalemia, lethargy, confusion, irregular menses, hirsutism

Off label uses

treating female pattern hair loss

acne

ascites

Nursing Considerations

* do not use in pts' with hyperkalemia or anuria
* monitor K+ levels frequently
* obtain W daily, monitor UO
* avoid foods high in potassium, such as avocados, peaches, bananas, nuts, and broccoli

Med examples

amiloride (Midamor)

spironolactone (Aldactone)

triamterene (Dyrenium)

Prototype Drug

spironolactone (generic)

Aldactone (trade)