Furosemide ototoxicity

Bumetanide (Bumex) Most potent. Orally for edema, IV for pulmonary edema. Similar to furosemide. Ototoxicity has not been reported. Large doses may cause severe myalgia. 

Ototoxicity, as evidenced by transient or permanent hearing loss, is a serious side effect of ethacrynic acid, and occurs less frequently with furosemide. Bumetanide is claimed to have only 20% of the ototoxic potential of furosemide (43). It has been reported that patients treated with torasemide at high doses for four weeks did not suffer hearing loss (36). 

Loop diuretics (furosemide, bumetanide, torsemide, and ethacrynic acid) are all equally effective when given in equivalent doses. Therefore, selection is based on the side-effect profile, cost, and pharmacokinetics of the agents. The incidence of ototoxicity is significantly higher with ethacrynic acid compared to the other loop diuretics therefore, its use is limited to patients who are allergic to the sulfa component in the other loop diuretics.15 While ototoxicity is a well-established side effect of furosemide, its incidence is greater when administered by the intravenous route at a rate exceeding 4 mg per minute.16 Torsemide has not been reported to cause ototoxicity. 

The ototoxic effects of streptomycin are potentiated by the coadministration of ethacrynic acid, furosemide, mannitol, and possibly other diuretics. 

Uses Edema, HTN, CHF, h atic cirrhosis Action Loop diuretic -1- reabsorption of Na Cr in ascending loop of Henle distal tubule Dose 5-20 mg/d PO or IV 200 mg/d max Caution [B, ] Contra Sulfonylurea sensitivity Disp Tabs, inj SE Orthostatic -1- BP, HA, dizziness, photosens, electrolyte imbalance, blurred vision, renal impair Notes 20 mg torsemide = 40 mg furosemide Interactions t Risk of ototox W/ aminoglycosides, cisplatin t effects W/ thiazides t effects OF anticoagulants, antih5rpCTtensives, Li, salicylates X effects IT/barbiturates, carbamaz ine, cholestyramine, NSAIDs, phenytoin, phenobarbital, probenecid, dandehon EMS t Effects of anticoagulants monitor for S/Sxs tinnitus, monitor ECG for hypokalemia (flattened T waves) OD May cause HA, hypotension, hypovolemia, and hypokalemia give IV fluids symptomatic and supportive... 

Aminoglycosides e.g. Ethacrynic acid, furosemide, skeletal Increased ototoxicity, increased... 

It is highly effective in pulmonary edema. Adverse effects such as hyperuricaemia, potassium loss and ototoxicity are less than furosemide. 

Furosemide Loop diuretic Decreases NaCI and KCI reabsorption in thick ascending limb of the loop of Henle in the nephron (see Chapter 15) Increased excretion of salt and water reduces cardiac preload and afterload reduces pulmonary and peripheral edema Acute and chronic heart failure severe hypertension edematous conditions Oral and IV duration 2-4 h Toxicity Hypovolemia, hypokalemia, orthostatic hypotension, ototoxicity, sulfonamide allergy... 

Ototoxicity Ototoxicity (vestibular and cochlear) is directly related to high peak plasma levels and duration of treatment. Deafness may be irreversible and has been known to affect fetuses in utero. Patients simultaneously receiving another ototoxic drug such as the loop diuretics furosemide, bumetanide, ethacrynic acid (see p. 227) or cisplatin (see p. 396), are particulary at risk. Vertigo and loss of balance may also occur because these drugs affect the vestibular apparatus. 

Furosemide is eliminated in equal portions by renal and non-renal (glucuronidation) routes. Its half-life is prolonged in renal failure, but hepatic failure has little effect, Bumetanide and torasemide are eliminated via CYP isoenzymes and so their half-life is affected by hepatic disease more than renal disease. They are known to cause thrombocytopenia (hut decrease activity of oral anticoagulants), ototoxicity and nephrotoxicity. 

LOOP DIURETICS AMINOGLYCOSIDES t risk of ototoxicity and possible deafness as a result of concomitant use of furosemide and gentamicin Both furosemide and gentamicin are associated with ototoxicity this risk is t if they are used together If used concurrently patients should be monitored for any hearing impairment... 

A 60-year-old white woman developed ototoxicity after only 5 days of gentamicin therapy (500 mg, 6.8 mg/kg/ day) and one dose of furosemide 20 mg (180). 

Bates DE, Beaumont SJ, Baylis BW. Ototoxicity induced by gentamicin and furosemide. Ann Pharmacother... 

One advantage of bumetanide is that it is less ototoxic than furosemide (1-3). It is sensible to prefer bumetanide to furosemide in patients with hearing problems or who concurrently need ototoxic drugs, such as an aminoglycoside antibiotic. 

High doses of furosemide in uremia are potentially ototoxic (26). 

Furosemide increases the ototoxic risks of aminoglycoside antibiotics (30,31) by reducing their clearance by about 35% (32) permanent deafness has resulted from the use of this combination. 

The cumulative dose and duration of aminoglycoside therapy are more important than serum concentrations in the development of gentamicin ototoxicity, except when interacting medications such as furosemide are co-administered. 

Furosemide 40-80 mg/day 120 mg t.i.d. 70% 100% 100% 100% Ototoxicity increased in ESRD, especially in combination with aminoglycosides high doses effective in ESRD NC NC No data... 

Ototoxicity may occur with furosemide at high infusion rates. 

KC is a 45-year-old man receiving ampicillin and gentamicin for endocarditis due to Enterococcus faecalis. He has a baseline serum Cr of 1.5 mg/dL secondary to uncontrolled diabetes mellitus. His other medications include furosemide, aspirin, and captopril. During his second week of therapy KC complains of ringing in his ears and a sensation of fullness. Risk factors for ototoxicity in KC include ... 

B Unlike other diuretics, furosemide at high infusion rates is associated with ototoxicity. Ototoxicity may occur with all loop diuretics, but the frequency is less with bumetanide and it has not been reported with torsemide. In addition, hypocalcemia is a side effect also experienced with loop diuretics and not with thiazide diuretics. In contrast, hydrochlorothiazide decreases urinary excretion of calcium, which may result in an elevation of serum calcium levels. Thus, thiazide diuretics may potentially reduce the risk of osteoporosis and be beneficial in postmenopausal women. 

In general, furosemide nr bumetanide is preferred over tihacrynic acid (another site 2 diuretic) because (hey have a broader dose-response curve, less ototoxicity, and le.ss gastrointestinal (oxicity. ... 

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