torsemide (Demadex)
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Introduction
Tradename: Demadex.
Indications
- edema associated with congestive heart failure* & hepatic or renal failure
- hypertension used alone or in combination
* torsemide is no better than furosemide in patients hospitalized with heart failure[4]
* do not change loop diuretic to thiazide diuretic for hyperkalemia in patients with systolic heart failure
Contraindications
- allergy to sulfomamide may result in cross-hypersensitivity
Dosage
Tabs: 5, 10, 20 mg, 100 mg.
Injection: 10 mg/mL (2 mL, 5 mL)
* 10-20 mg of torsemide is approximately equivalent to: furosemide 40 mg, bumetanide 1 mg
Pharmacokinetics
- bioavailablity (oral) 80-90%
- onset of diuresis 30-60 minutes, peak effect 1-4 hours
- duration 6 hours
- elimination 1/2life 2-4 hours, 7 hours with cirrhosis
- protein binding 97-99%
- metabolized in the liver by cyt P450 2C9
- 20% excreted unchanged in the urine
elimination via liver
elimination via kidney
Adverse effects
- cardiovascular: hypotension, orthostasis
- CNS: dizziness, headache, encephalopathy
- dermatologic: rash, photosensitivity
- endocrine/metabolic:
- gastrointestinal: cramps, nausea, vomiting
- genitourinary: azotemia
- hepatic: altered liver function tests
- impaired hearing
- renal:
- decreased uric acid secretion
- increased serum creatinine
- electrolyte depletion, volume depletion, hypotension, hypovolemic shock
- GI decontamination, followed by supportive treatment
- drug adverse effects of loop diuretics
- drug adverse effects of diuretics
- drug adverse effects of antihypertensive agents
Drug interactions
- any drug which inhibits cyt P450 2C9 can increase torsemide levels
- any drug which induces cyt P450 2C9 can diminish torsemide levels
- torsemide increases effects of NSAIDs
- torsemide increases hypotensive effects of antihypertensive agents
- torsemide increases lithium levels
- increases risk of ototoxicity when used in combination with aminoglycosides, other loop diurectis, vancomycin
- diuretic-induced hypokalemia increases risk of digoxin-associated arrhythmia
- drug interaction(s) SGLT2 inhibitors (flozins) with diuretics
- drug interaction(s) of diuretics in combination with Zn+2
- drug interaction(s) of antiarrhythmic agents in combination with diuretics
- drug interaction(s) of beta-2 adrenergic receptor agonists with loop diuretics
- drug interaction(s) of calcium channel blockers with diuretics
- drug interaction(s) of lithium carbonate with loopt diuretics
- drug interaction(s) of beta-adrenergic receptor antagonists with loop diuretics
- drug interaction(s) of diuretics with angiotensin II receptor antagonists
- drug interaction(s) of diuretics with ACE inhibitors
- drug interaction(s) of loop diuretics with alpha-1 adrenergic receptor antagonist
- drug interaction(s) of NSAIDs, diuretics & angiotensin II receptor antagonists
- drug interaction(s) of NSAIDs, diuretics & ACE inhibitors
- drug interaction(s) of NSAIDs & antihypertensives
- drug interaction(s) of NSAIDs & loop diuretics
Mechanism of action
- site of action: ascending loop of Henle, distal tubule
- inhibits tubular reabsorption of Na+, Cl-
- interferes with Cl- binding co-transport system
More general terms
Additional terms
References
- ↑ The Pharmacological Basis of Therapeutics, 9th ed. Gilman et al, eds. Permagon Press/McGraw Hill, 1996
- ↑ Geriatric Dosage Handbook, 6th edition, Selma et al eds, Lexi-Comp, Cleveland, 2001
- ↑ Medical Knowledge Self Assessment Program (MKSAP) 15, American College of Physicians, Philadelphia 2009
- ↑ 4.0 4.1 Mentz RJ, Anstrom KJ, Eisenstein EL et al Effect of Torsemide vs Furosemide After Discharge on All-Cause Mortality in Patients Hospitalized With Heart Failure. The TRANSFORM-HF Randomized Clinical Trial. JAMA. 2023;329(3):214-223 PMID: https://www.ncbi.nlm.nih.gov/pubmed/36648467 https://jamanetwork.com/journals/jama/fullarticle/2800428
- ↑ NEJM Knowledge+