- Body system
- Cardiovascular
- Name stem
- -semide, -thiazide
- Drug cards
- 3 in this guide
Drugs in this class
Other examples: Bumetanide, Torsemide, Chlorthalidone, Metolazone, Eplerenone, Triamterene, Mannitol (osmotic).
How diuretics work
Loop diuretics block sodium reabsorption in the loop of Henle (most potent). Thiazides act in the distal tubule. Potassium-sparing diuretics block aldosterone (spironolactone, eplerenone) or sodium channels (amiloride, triamterene).
Uses
- Edema from heart failure, cirrhosis and kidney disease
- Hypertension (thiazides first-line)
- Acute pulmonary edema (IV loop diuretics)
- Heart failure and hyperaldosteronism (spironolactone)
Adverse effects
- Hypokalemia (loop, thiazide)
- Hyperkalemia (potassium-sparing)
- Dehydration and orthostatic hypotension
- Hyponatremia
- Ototoxicity (loop, high IV doses)
- Hyperglycemia and hyperuricemia (loop, thiazide)
Nursing considerations
- Monitor daily weight, intake and output, blood pressure and electrolytes.
- Check potassium before giving, especially with digoxin: low potassium raises the risk of digoxin toxicity.
- Give in the morning to avoid nighttime urination.
Patient teaching
- Weigh daily at the same time on the same scale, and report sudden gains.
- Know which foods are high in potassium and whether to eat more of them or limit them.
- Rise slowly.
Diuretics NCLEX practice questions
Answer each question to see the rationale.
3 questions. Choose an answer to see the rationale.
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A patient takes furosemide and digoxin. Which lab result is most important before giving both?
Show answer
Answer B: Potassium 3.1 mEq/L Hypokalemia from the loop diuretic increases the risk of digoxin toxicity. A potassium of 3.1 is low and should be reported.
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Which diuretic requires the patient to avoid salt substitutes?
Show answer
Answer B: Spironolactone Spironolactone is potassium-sparing. Salt substitutes contain potassium chloride and can cause hyperkalemia.
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What is the most accurate way to evaluate a diuretic's effect on fluid status at home?
Show answer
Answer B: Daily weight at the same time each day Daily weight is the most reliable indicator of fluid gain or loss: 1 kg is about 1 liter of fluid.
Frequently asked questions
What are diuretics?
Diuretics remove sodium and water. Loop and thiazide diuretics waste potassium; potassium-sparing diuretics keep it. Daily weight is the best measure of fluid balance.
How do diuretics work?
Loop diuretics block sodium reabsorption in the loop of Henle (most potent). Thiazides act in the distal tubule. Potassium-sparing diuretics block aldosterone (spironolactone, eplerenone) or sodium channels (amiloride, triamterene).
What are examples of diuretics?
Furosemide, Hydrochlorothiazide (HCTZ), Spironolactone, Bumetanide, Torsemide, Chlorthalidone, Metolazone and Eplerenone.
What are the nursing considerations for diuretics?
Monitor daily weight, intake and output, blood pressure and electrolytes. Check potassium before giving, especially with digoxin: low potassium raises the risk of digoxin toxicity.