Brands, Medical Use, Clinical Data
Drug Category
Dosage Forms
Brands / Synonyms
Bumetanida [INN-Spanish]; Bumetanide; Bumetanide [USAN:BAN:INN:JAN]; Bumetanidum [INN-Latin]; Bumex; Burine; Burinex; Fontego; Fordiuran; Lixil; Lunetoron; Segurex
Indications
For the treatment of edema associated with congestive heart failure, hepatic and renal disease including the nephrotic syndrome.
Pharmacology
Bumetanide is a loop diuretic of the sulfamyl category to treat heart failure. It is often used in patients in whom high doses of furosemide are ineffective. There is however no reason not to use bumetanide as a first choice drug. The main difference between the two substances is in bioavailability. It is said to be a more predictable diuretic, meaning that the predictable absorption is reflected in a more predictable effect. Bumetanide is 40 times more potent than furosemide (for patients with normal renal function).
Mechanism of Action
Bumetanide interferes with renal cAMP and/or inhibits the sodium-potassium ATPase pump. Bumetanide appears to block the active reabsorption of chloride and possibly sodium in the ascending loop of Henle, altering electrolyte transfer in the proximal tubule. This results in excretion of sodium, chloride, and water and, hence, diuresis.
Absorption
Bumetanide is completely absorbed (80%), and the absorption is not altered when taken with food. Bioavailability is almost complete.
Toxicity
Overdosage can lead to acute profound water loss, volume and electrolyte depletion, dehydration, reduction of blood volume and circulatory collapse with a possibility of vascular thrombosis and embolism. Electrolyte depletion may be manifested by weakness, dizziness, mental confusion, anorexia, lethargy, vomiting and cramps. Treatment consists of replacement of fluid and electrolyte losses by careful monitoring of the urine and electrolyte output and serum electrolyte levels.
Biotrnasformation / Drug Metabolism
45% is secreted unchanged. Urinary and biliary metabolites are formed by oxidation of the N-butyl side chain.
Contraindications
Bumetanide is contraindicated in anuria. Although bumetanide can be used to induce diuresis in renal
insufficiency, any marked increase in blood urea nitrogen or creatinine, or the development of oliguria during
therapy of patients with progressive renal disease, is an indication for discontinuation of treatment with
bumetanide. Bumetanide is also contraindicated in patients in hepatic coma or in states of severe electrolyte
depletion until the condition is improved or corrected. Bumetanide is contraindicated in patients hypersensitive to
this drug.
Drug Interactions
1. Drugs with ototoxic potential: Especially in the presence of impaired renal function, the use of
parenterally administered bumetanide in patients to whom aminoglycoside antibiotics are also being given should be
avoided, except in life-threatening conditions.
2. Drugs with nephrotoxic potential: There has been no experience on the concurrent use of
bumetanide with drugs known to have a nephrotoxic potential. Therefore, the simultaneous administration of these
drugs should be avoided.
3. Lithium: Lithium should generally not be given with diuretics (such as bumetanide) because they
reduce its renal clearance and add a high risk of lithium toxicity.
4. Probenecid: Pretreatment with probenecid reduces both the natriuresis and hyperreninemia produced
by bumetanide. This antagonistic effect of probenecid on bu-metanide natriuresis is not due to a direct action on
sodium excretion but is probably secondary to its inhibitory effect on renal tubular secretion of bumetanide. Thus,
probenecid should not be administered concurrently with bumetanide.
5. Indomethacin: Indomethacin blunts the increases in urine volume and sodium excretion seen during
bumetanide treatment and inhibits the bumetanide-induced increase in plasma renin activity. Concurrent therapy with
bumetanide is thus not recommended.
6. Antihypertensives: Bumetanide may potentiate the effect of various antihypertensive drugs,
necessitating a reduction in the dosage of these drugs.
7. Digoxin: Interaction studies in humans have shown no effect on digoxin blood levels.
8. Anticoagulants: Interaction studies in humans have shown bumetanide to have no effect on warfarin
metabolism or on plasma prothrombin activity.
|