Furosemide
- Class: Loop diuretic
- Used for: fluid overload
- Say it: fyoor-OH-seh-mide
- Forms: tablet, oral liquid, injection
Remember the name – FURO → furious, SEMIDE → sea
FUROSEMIDE = a FURIOUS SEA. It rushes out of the swollen legs and waterlogged lungs and takes the flood with it.
The sea rushing out is literal. Blocking the loop transporter makes the kidney dump salt and water, and the flood leaves in the urine.
FUROSEMIDE = a FURIOUS SEA. It rushes out of the swollen legs and waterlogged lungs and takes the flood with it.
The sea rushing out is literal. Blocking the loop transporter makes the kidney dump salt and water, and the flood leaves in the urine.
Mnemonic: FUROsemide is a furious flush of the LOOP
Loop diuretics hit the loop of Henle, where the largest share of filtered salt is reabsorbed — which is why they are the strongest. Potassium and calcium go out with it.
Loop diuretics hit the loop of Henle, where the largest share of filtered salt is reabsorbed — which is why they are the strongest. Potassium and calcium go out with it.
Side effects
Common: low potassium, dehydration, dizziness
Serious: hearing loss, kidney injury
Typical dose
20–80 mg once or twice daily
Oral absorption is erratic; 40 mg orally is roughly 20 mg intravenously. Avoid late doses — the patient will be up all night.
Check yourself
Why is Furosemide a stronger diuretic than hydrochlorothiazide?
- It blocks reabsorption in the loop, where the largest share of filtered salt is taken back
- It is simply given at a higher dose
- It blocks aldosterone as well
- It acts on the glomerulus rather than the tubule
Show answer
A. It blocks reabsorption in the loop, where the largest share of filtered salt is taken back
Position along the tubule decides potency. The loop reclaims far more salt than the distal tubule does, so blocking it moves far more water.
See it, don't memorize it
The app has the mechanism comic and a patient case for Furosemide – plus the name link, the class mnemonic, pronunciation you can hear, and a self-check, for the top 100 drugs. One purchase, no subscription, no account.