Torasemide
A longer-acting loop diuretic of the pyridine-sulfonylurea type, used for edema in heart failure, kidney or liver disease, and for hypertension.
Also called torsemide (US name).
Drug card
- Class
- Loop diuretic
- How it works
- Blocking NKCC2 in the loop of Henle, so much more salt and water is lost
- Used for
- Edema in heart failure
- Edema from kidney or liver disease
- High blood pressure
- Known for
- Low potassium
- Tinnitus and hearing loss, usually reversible
- Its name
- -semide means a loop diuretic (furosemide type)
Study it as a flashcard, and it comes back before you forget it.
Mechanism of action
How does torasemide work?
Acts from inside the tubule lumen on the Na-K-2Cl carrier of the thick ascending limb, so its effect tracks how much drug is secreted into the urine. About 80% of an oral dose is absorbed, the liver clears most of it through CYP2C9, and one oral dose keeps the diuresis going for about 6 to 8 hours.
Like other loop diuretics: They block the Na-K-2Cl cotransporter (NKCC2) in the thick ascending limb of Henle's loop, reaching it from inside the tubule. Sodium, chloride and water are lost in large amounts, along with potassium, magnesium and calcium. The diuresis is strong and quick, and it still works when kidney function is poor.
Uses
What is torasemide used for?
- Edema in heart failure
- Edema from kidney or liver disease
- High blood pressure
Side effects
Side effects of torasemide
- Low potassiumKnown forSerious
- Tinnitus and hearing loss, usually reversibleKnown forSerious
- Passing more urine than usual
- Low blood pressure and dehydration
- Worsening kidney functionSerious
- Low sodium, magnesium or calcium
- Raised blood sugar
- Raised uric acid, rarely gout
- PancreatitisSerious
- Severe skin reactions (Stevens-Johnson syndrome, TEN)Serious
- Sensitivity to sunlight
- Acute urinary retention
Known for marks what an exam expects you to know it for.
Watch for
Cautions and what sets it apart
- Contraindicated in anuria and hepatic coma.
- CYP2C9 inhibitors such as fluconazole or amiodarone raise its levels, and it can alter warfarin and phenytoin.
- NSAIDs blunt its effect and, together with it, can cause acute kidney injury.
- Lithium toxicity becomes more likely.
Good to know: Chemically a pyridine-sulfonylurea, yet it is a loop diuretic, not a diabetes drug; it lasts longer than furosemide.
Remember it
A way to remember it
OH DANG
- O
- Ototoxicity
- H
- Hypokalemia
- D
- Dehydration
- A
- Allergy to sulfonamides
- N
- Nephritis (interstitial)
- G
- Gout
A mnemonic widely used in teaching
Its name
-semide means loop diuretic (furosemide type)
Furosemide and torasemide (US name torsemide) share it. Bumetanide, another loop diuretic, carries the stem -etanide instead.
- Every drug name stem
Its class
Loop diuretics
Other loop diuretics with a card:
Easily mixed up with thiazide and thiazide-like diuretics and mineralocorticoid receptor antagonists.
Sources
Checked against
Written for biofideX in plain words, after checking these references:
For learning pharmacology, not for treatment decisions: no doses are given, and a prescriber, pharmacist or the product's own label is the word on any one patient. Spotted a mistake? Tell us and we'll correct it.
Heart failure, rhythm and angina
Torasemide is one of 10 drugs practiced together here: their classes, how they work, what they treat and what they're known for.
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