Class: Loop diuretic
- Tablets 5 mg
- Tablets 10 mg
- Tablets 20 mg
- Tablets 100 mg
- Injection 10 mg/mL
Inhibits sodium/potassium/chloride carrier system in ascending loop of Henle, resulting in increased urinary excretion of sodium, chloride, and water. Does not significantly alter glomerular filtration rate, renal plasma flow, or acid-base balance.
Bioavailability of oral torsemide is approximately 80%, T max is 1 h, and AUC is 2.5 to 200 mg; food delays the time by approximately 30 min, but there is no effect on bioavailability.
Torsemide is more than 99% protein bound. Vd is 12 to 15 L in healthy adults or mild to moderate renal function impairment or CHF; Vd is doubled in hepatic cirrhosis.
The major metabolite is a carboxylic acid derivative and is biologically inactive.
Torsemide is cleared by hepatic metabolism (about 80%) and about 20% is excreted into urine. Torsemide t ½ is 3.5 h in healthy adults.
Special PopulationsRenal Function Impairment
Renal clearance is decreased, but total plasma clearance is not significantly altered. A diuretic response in renal failure may still be achieved if patients are given higher doses.Hepatic Function Impairment
In patients with hepatic cirrhosis, the Vd, plasma t ½ , and renal clearance are all increased, but total clearance is not changed.Elderly
There may be a decrease in renal clearance related to the decline in renal function that commonly occurs with aging.Decompensated CHF
With oral torsemide, in decompensated CHF, hepatic and renal clearances are decreased.
Indications and Usage
Management of edema associated with CHF, hepatic cirrhosis, and renal disease; treatment of hypertension.
Hypersensitivity to sulfonylureas; anuria; severe electrolyte depletion.
Dosage and AdministrationAdults
PO/IV 5 to 20 mg once daily. Titrate dose upward until desired response is obtained. Single doses greater than 200 mg have not been studied.
Store in dry area away from sunlight.
May increase ototoxicity.Anticoagulants
May enhance anticoagulant activity.Cisplatin
May cause additive ototoxicity.Digitalis glycosides
Electrolyte disturbances may predispose to digitalis-induced arrhythmias.Lithium
May increase plasma lithium levels and toxicity.Nondepolarizing muscle relaxants
May antagonize or potentiate response to muscle relaxants.NSAIDs
May decrease effects of torsemide.Probenecid
May reduce action of torsemide.Salicylates
May impair diuretic response in patients with cirrhosis and ascites.Sulfonylureas
May decrease glucose tolerance, resulting in need for increased sulfonylurea dose.Thiazide diuretics
May cause synergistic effects that may result in profound diuresis and serious electrolyte abnormalities.
Laboratory Test Interactions
None well documented.
ECG abnormality; chest pain; atrial fibrillation; orthostatic hypotension; ventricular tachycardia; shunt thrombosis.
Headache; dizziness; asthenia; insomnia; nervousness; syncope.
Hearing loss; sore throat.
Diarrhea; constipation; nausea; dyspepsia; GI hemorrhage; rectal bleeding.
Hyperglycemia; hyperuricemia; hypomagnesemia; hypokalemia; hypocalcemia; hyponatremia; hypochloremia; hypovolemia.
Rhinitis; cough increase.
Category B .
Safety and efficacy not established.
Patients with known sulfonamide sensitivity may show allergic reactions to torsemide.
Photosensitization may occur.
Hepatic cirrhosis and ascites
Sudden alterations of electrolyte balance may precipitate hepatic encephalopathy and coma.
Asymptomatic hyperuricemia or gout may occur.
Increases in LDL, total cholesterol, and triglycerides with decreases in HDL cholesterol may occur.
Associated with rapid injection or very large doses.
Dehydration, arrhythmias, decreased renal function, blood volume and electrolyte depletion, weakness, dizziness, mental confusion, anorexia, lethargy, vomiting, cramps, circulatory collapse, vascular thrombosis and embolism.
- Instruct patient to inform health care provider of all otc or prescription drugs being taken, especially NSAIDs, digitalis, or lithium.
- Advise hypertensive patient to avoid foods or medications that may increase BP, including otc drugs for appetite suppression or cold symptoms, otc drugs to help keep awake, and excessive consumption of coffee or other substances containing caffeine.
- Instruct patient to eat potassium-rich foods daily. These foods include banana, cantaloupe, and potatoes.
- Advise patient not to store drug in bathroom, but in a cool, dry place.
- Inform patient that drug may raise blood sugar levels. Instruct diabetic patients to monitor blood glucose regularly and report patterns of hyperglycemia.
- Advise patient that this drug increases urination. Advise patient to take medication early in morning to avoid disrupted sleep.
- Caution patient to notify health care provider immediately if vomiting and diarrhea occur or if signs of excessive potassium loss (eg, cramps, muscle weakness, nausea, dizziness) are noted.
- Instruct patient to report these symptoms to health care provider: chest pain, dizziness, rapid heart beat, headache, nausea, increased swelling of feet, black stools, rectal bleeding, rash, face rash, fatigue, or hearing loss.
- Caution patient to avoid sudden position changes to prevent dizziness or fainting.
- Advise patient that drug may cause dizziness and to use caution while driving or performing other tasks requiring mental alertness.
- Caution patient to avoid exposure to sunlight and to use sunscreen or wear protective clothing to avoid photosensitivity reaction.
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