👤 By the CinnaRN Clinical Content Team🕐 Updated 2026-08-23🏷️ Pharmacological Therapies🔖 Free to read, print, and share
Also known as: Lasix · water pill · loop diuretic
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Use this quick-reference guide to spot, treat, and prevent Furosemide on the NCLEX. Keep it handy during review and on exam day!
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📒 The 1-minute cheat sheet
✅ Action
Loop diuretic, ↓preload
Use: HF, edema, HTN
🧪 Labs
Hypokalemia: K+ < 3.5 → hold
Monitor Na, Mg, glucose, BUN
🩺 Watch
Ototoxic if IV pushed fast
Orthostatic ↓BP, dehydration
🎓 Teach
Eat high-K foods: banana, OJ
Take in morning, daily weight
📚 Furosemide — full study notes
The cheat sheet above is your quick recall card. These notes go deeper — what it is, what to do first, what must be reported, and what to teach.
Furosemide is a loop diuretic that blocks sodium and chloride reabsorption in the loop of Henle, producing rapid, potent diuresis. It is used for edema in heart failure, pulmonary edema, renal disease, and hypertension. Memory aid: 'Lasix LASTS 6 hours and makes you LOSe fluid and K+.' Key principle: it wastes potassium, so monitor for hypokalemia.
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Key points
Understand these first
Loop diuretics are the most potent diuretics and work even in renal impairment.
Causes loss of potassium, magnesium, calcium, and sodium, leading to hypokalemia and hypomagnesemia.
IV furosemide must be pushed slowly (no faster than 20 mg/min) to prevent ototoxicity and hearing loss.
It is a sulfa-based drug, so cross-sensitivity can occur in sulfa-allergic patients.
Loop diuretics potentiate digoxin toxicity because hypokalemia increases digoxin binding.
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Nursing priorities
What to do, in order
Monitor potassium and replace as ordered; report levels below 3.5 mEq/L before giving more.
Weigh the patient daily at the same time and track strict intake and output.
Monitor blood pressure and assess for orthostatic hypotension before ambulation.
Assess lung sounds and edema to evaluate therapeutic response.
Push IV doses slowly and monitor hearing, especially with renal impairment.
Report new tinnitus or hearing changes (ototoxicity).
Hold and report systolic BP below parameters or signs of dehydration.
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Labs & values
Numbers to know
Potassium 3.5-5.0 mEq/L
Sodium 135-145 mEq/L
Magnesium 1.3-2.1 mEq/L
BUN 10-20 mg/dL
Creatinine 0.6-1.2 mg/dL
Digoxin therapeutic 0.5-2.0 ng/mL
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Patient teaching
What patients must know
Take in the morning to avoid nighttime urination.
Eat potassium-rich foods such as bananas, oranges, and potatoes.
Rise slowly to prevent dizziness and report weight gain over 2-3 lb in a day.
❓ Furosemide: NCLEX FAQs
What are the priority nursing interventions for Furosemide?
Monitor potassium and replace as ordered; report levels below 3.5 mEq/L before giving more. Weigh the patient daily at the same time and track strict intake and output. Monitor blood pressure and assess for orthostatic hypotension before ambulation. Assess lung sounds and edema to evaluate therapeutic response.
What are the warning signs of Furosemide a nurse must report?
Report potassium below 3.5 mEq/L, muscle cramps, or irregular pulse (hypokalemia risk). Report new tinnitus or hearing changes (ototoxicity). Hold and report systolic BP below parameters or signs of dehydration.
What do I need to know about Furosemide for the NCLEX?
Loop diuretics are the most potent diuretics and work even in renal impairment. Causes loss of potassium, magnesium, calcium, and sodium, leading to hypokalemia and hypomagnesemia. IV furosemide must be pushed slowly (no faster than 20 mg/min) to prevent ototoxicity and hearing loss. It is a sulfa-based drug, so cross-sensitivity can occur in sulfa-allergic patients.
What patient teaching is important for Furosemide?
Take in the morning to avoid nighttime urination. Eat potassium-rich foods such as bananas, oranges, and potatoes. Rise slowly to prevent dizziness and report weight gain over 2-3 lb in a day.
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Quick Tip
Loop diuretics are the most potent diuretics and work even in renal impairment.