Potassium Sparing Diuretics

Summary

Potassium sparing diuretics include spironolactone, eplerenone, triamterene, and amiloride. They work by either directly blocking sodium channels in the kidneys, or blocking aldosterone receptors. This leads to an increased loss of both sodium and water in the urine while retaining potassium in the body.

These drugs are used to treat conditions associated with fluid overload, such as edema, hypertension, and heart failure.

Side effects of potassium sparing diuretics can include hormonal effects such as gynecomastia, menstrual irregularities, and erectile dysfunction. The retention of potassium and excretion of sodium can also cause electrolyte imbalances such as hyperkalemia and hyponatremia.

Key Points

• Potassium Sparing Diuretics
  • Drug Names
    • Spironolactone (Aldactone)
    • Triamterene (Dyrenium)
    • Amiloride (Midamor)
    • Eplerenone (Inspra)
  • Mechanism
    • Blocks aldosterone
      • Also called aldosterone antagonists
    • Blocks sodium channels in the kidneys
      • Less sodium is reabsorbed back into the kidneys → more sodium is excreted in the urine
  • Clinical Use
    • Hypertension
    • Edema
    • Heart Failure
    • Weak diuretic
      • Given alongside other stronger diuretics (i.e. loop diuretics, thiazide diuretics) to counteract their potassium loss
  • Side Effects
    • Hyperkalemia
      • Monitor potassium levels and hold medication and notify provider if patient becomes hyperkalemic
      • Patient should not take additional potassium supplements
      • Avoid foods high in potassium
      • Use other potassium sparing medications with caution (ACE Inhibitors, ARBs, etc.)
    • Hyponatremia
    • Endocrine Effects
      • Due to blocking of the sex hormone (androgen) receptors
        • Irregular menstrual cycle (female)
        • Gynecomastia (male)
        • Erectile dysfunction (male)
          • Also called impotence
        • Hirsutism (female)
        • Breast tenderness
        • Decreased libido
        • Deepened voice