Comprehensive Guide to Diuretics

Oct 15, 2024

Diuretics Lecture Notes

Overview of Diuretics

  • Purpose: Remove excess fluid by stimulating kidneys to produce urine.
  • Types of Diuretics:
    • Loop Diuretics
    • Thiazide Diuretics
    • Potassium-Sparing Diuretics
    • Osmotic Diuretics

Why Diuretics Are Given

  • Heart Failure: Fluid retention due to weakened heart, causing edema and hypertension.
  • Chronic Kidney Disease (CKD): Helps kidneys excrete excess fluid and regulate potassium.

Loop Diuretics

  • Examples: Furosemide (Lasix), Bumetanide, Torsemide.
  • Mechanism: Inhibits reabsorption of sodium and chloride in kidneys; affects distal and proximal tubules & loop of Henle.
  • Effects: Potent; causes potassium to be excreted (potassium-wasting).
  • Side Effects: Hypokalemia; need to monitor and replace potassium.
  • Nursing Considerations:
    • Monitor potassium levels.
    • Administer potassium carefully (do not crush oral forms; avoid IV push).
    • Administer furosemide slowly to avoid ototoxicity.

Thiazide Diuretics

  • Examples: Hydrochlorothiazide, Chlorothiazide.
  • Mechanism: Inhibits sodium and chloride reabsorption in the ascending loop of Henle and early distal tubule.
  • Effects: Less potent than loop diuretics; also potassium-wasting.
  • Side Effects: Hypokalemia.
  • Nursing Considerations:
    • Monitor potassium levels.
    • Avoid in patients with gout or sulfa allergies.

Potassium-Sparing Diuretics

  • Example: Spironolactone (Aldactone).
  • Mechanism: Blocks aldosterone, preventing sodium and water retention, retains potassium.
  • Effects: Monitor for hyperkalemia.
  • Nursing Considerations:
    • Avoid high-potassium foods (leafy greens, bananas, etc.) and potassium supplements/salt substitutes.

Osmotic Diuretics

  • Example: Mannitol (Osmitrol).
  • Mechanism: Increases filtrate thickness; prevents water reabsorption.
  • Uses: Treat cerebral edema, decrease intraocular pressure, not for typical hypertension/edema.
  • Nursing Considerations:
    • Administer IV only, check for crystallization.
    • Perform neuro assessments.

General Nursing Considerations for Diuretics

  • Administer in the morning to avoid nocturia.
  • Educate patient on orthostatic hypotension and low-sodium diet.
  • Monitor daily weights and intake/output.

Potassium Levels and Diuretics

  • Potassium Wasting: Loop and Thiazide Diuretics.
  • Potassium Sparing: Spironolactone (Aldactone).

Practice Question Recap

  • Spironolactone should be avoided if potassium is high (hyperkalemia risk).
  • Correct option is to report a potassium level of 5.3 mEq/L.

Additional Resources

  • Recommended NCLEX study materials and practice questions.

Remember, this is a summary of key points regarding diuretics, their types, mechanisms, uses, side effects, and nursing considerations. Use this guide to aid in your study of diuretic medications.