What is the principal nursing consideration with potassium-sparing diuretics such as spironolactone?

• A. They cause dehydration; ensure fluids.
• B. They act on the distal tubule to block sodium reabsorption.
• C. They commonly cause hyperkalemia; monitor potassium.
• D. Monitor for hyperkalemia, especially with ACE inhibitors or K+ supplements; assess renal function and electrolytes.

Answer: (D)

Potassium-sparing diuretics raise potassium levels because they block aldosterone’s action in the collecting ducts, reducing potassium excretion. The main nursing consideration is the risk of hyperkalemia, especially when the patient is also taking ACE inhibitors or potassium supplements, or has impaired kidney function. This requires checking renal function and serum potassium before starting therapy, then monitoring electrolytes regularly after initiation or dose changes. Be vigilant for signs of hyperkalemia such as muscle weakness or palpitations, and educate about avoiding high-potassium foods or salt substitutes unless advised. The focus on hyperkalemia distinguishes this drug from others that primarily cause dehydration; its action is in the collecting ducts, not the distal tubule, which helps explain the potassium-sparing effect.