Potassium-sparing diuretics are vital medications that help manage fluid balance and blood pressure. They work by blocking sodium reabsorption in the kidneys, increasing urine output while preserving potassium levels. This unique action makes them useful for treating edema, hypertension, and preventing hypokalemia.

These drugs come in several forms, including spironolactone, eplerenone, amiloride, and triamterene. Each has its own benefits and potential side effects. Nurses play a crucial role in monitoring patients on these medications, checking electrolyte levels, and educating patients about proper use and dietary considerations.

Potassium-Sparing Diuretics

Mechanism of action and primary uses

• Block sodium reabsorption in distal tubule and collecting duct of nephron prevents sodium from being reabsorbed back into the bloodstream, increasing urinary excretion of sodium and water (natriuresis and diuresis)
• Reduce potassium excretion by inhibiting sodium-potassium exchange in distal tubule helps maintain normal serum potassium levels (normokalemia) and prevents potassium loss (hypokalemia)
• Treat fluid volume excess conditions (edema, hypertension) by reducing total body fluid volume through increased urinary output
• Manage renal disorders (chronic kidney disease, nephrotic syndrome) by promoting fluid and sodium excretion to alleviate strain on kidneys and prevent fluid overload complications
• Prevent hypokalemia in patients taking other diuretics (loop diuretics, thiazides) that cause potassium loss by counteracting their potassium-wasting effects

Common potassium-sparing diuretics

• Spironolactone (Aldactone)
  • Treats edema, hypertension, heart failure, hyperaldosteronism by blocking aldosterone receptors in distal tubule and collecting duct
  • Increases sodium and water excretion, reduces potassium excretion
  • May cause gynecomastia (breast enlargement in males), menstrual irregularities, hyperkalemia (elevated serum potassium)
• Eplerenone (Inspra)
  • Similar indications and effects as spironolactone for heart failure, hypertension, hyperaldosteronism
  • Lower incidence of endocrine-related side effects (gynecomastia, menstrual irregularities) due to higher selectivity for aldosterone receptors
  • Risk of hyperkalemia, dizziness, fatigue
• Amiloride (Midamor)
  • Treats edema, hypertension, often combined with other diuretics (loop diuretics, thiazides) to prevent hypokalemia
  • Increases sodium and water excretion, reduces potassium excretion by directly blocking sodium channels in distal tubule and collecting duct
  • May cause hyperkalemia, nausea, diarrhea, headache
• Triamterene (Dyrenium)
  • Similar indications and effects as amiloride for edema, hypertension, prevention of hypokalemia when combined with other diuretics
  • Increases sodium and water excretion, reduces potassium excretion by directly blocking sodium channels in distal tubule and collecting duct
  • Risk of hyperkalemia, nausea, vomiting, dizziness, photosensitivity (increased skin sensitivity to sunlight)

Nursing considerations

• Monitoring
  • Assess fluid balance by measuring intake and output (I&O) to ensure adequate hydration and prevent fluid overload or dehydration
  • Monitor serum electrolytes (potassium, sodium) regularly to detect and prevent electrolyte imbalances (hyperkalemia, hyponatremia)
  • Regularly check blood pressure and weight to evaluate effectiveness of therapy and detect fluid retention or excessive fluid loss
  • Observe for signs and symptoms of electrolyte imbalances (muscle weakness, irregular heartbeat) to promptly identify and treat complications
• Safety precautions
  • Use caution in patients with renal impairment due to higher risk for hyperkalemia from reduced potassium excretion
  • Avoid concurrent use with medications that increase serum potassium (ACE inhibitors, potassium supplements) to prevent severe hyperkalemia
  • Adjust dosage based on renal function and serum potassium levels to maintain therapeutic effect while minimizing risk of adverse effects
  • Educate patients about importance of follow-up appointments and laboratory monitoring to ensure safe and effective use of medication

Patient education plan

• Medication administration
  • Instruct patients to take medication as prescribed at same time each day for consistent therapeutic effect
  • Advise patients not to stop taking medication without consulting healthcare provider to prevent rebound fluid retention or hypertension
• Dietary considerations
  • Encourage balanced diet with moderate potassium intake to maintain normal serum potassium levels
  • Provide list of high-potassium foods (bananas, oranges, potatoes) to be consumed in moderation to prevent hyperkalemia
  • Advise patients to avoid salt substitutes containing potassium chloride which can significantly increase potassium intake and risk of hyperkalemia
• Self-monitoring
  • Teach patients to monitor weight daily and report significant changes ($>$2 lbs in a day or $>$5 lbs in a week) which may indicate fluid retention or excessive fluid loss
  • Instruct patients to be aware of signs and symptoms of electrolyte imbalances (muscle cramps, weakness, irregular heartbeat) and report them promptly to healthcare provider
  • Emphasize importance of keeping follow-up appointments and completing recommended laboratory tests to ensure safe and effective use of medication
• Lifestyle modifications
  • Encourage regular exercise (30 minutes per day, 5 days per week) and stress management techniques (deep breathing, meditation) to help control blood pressure and improve overall health
  • Advise patients to limit alcohol consumption ($\leq$1 drink per day for women, $\leq$2 drinks per day for men) and quit smoking to enhance effectiveness of medication and reduce cardiovascular risk factors