Bumetanide

Trade Names:Bumetanide- Tablets 0.5 mg- Tablets 1 mg- Tablets 2 mg- Injection 0.25 mg/mL

Pharmacology

Inhibits reabsorption of sodium and chloride in proximal tubules and loop of Henle.

Pharmacokinetics

Distribution

Bumetanide is 72% to 96% protein bound.

Metabolism

Oxidation of the N-butyl side chain.

Elimination

The t _½ is 60 to 90 min; 81% is excreted in urine, 45% as unchanged drug, and 2% in bile.

Onset

30 to 60 min.

Within minutes.

Peak

1 to 2 h.

15 to 30 min.

Duration

4 to 6 h.

Special Populations

The t _½ is prolonged.

Elimination is considerably slower in neonates.

Indications and Usage

Treatment of edema associated with CHF, hepatic cirrhosis, and renal disease.

Unlabeled Uses

Relief of adult nocturia.

Contraindications

Hypersensitivity to other loop diuretics or to sulfonylureas; anuria; hepatic coma or states of severe electrolyte depletion until condition is improved or corrected.

Dosage and Administration

PO 0.5 to 2 mg/day as single dose. If inadequate response, give second or third dose at 4 to 5 h intervals up to max 10 mg/day.

IM / IV 0.5 to 1 mg/day over 1 to 2 min. May repeat at 2- to 3-h intervals, up to max 10 mg/day. Reserve parenteral route for situations in which GI absorption is impaired or when oral administration is not practical; replace with oral therapy as soon as possible.

Storage/Stability

If given by IV infusion, use solution within 24 h of preparation. Store at room temperature in tightly closed container.

Drug Interactions

Increased auditory toxicity.

Additive ototoxicity.

Electrolyte disturbances may predispose to digitalis-induced arrhythmias.

Increased plasma lithium levels and toxicity.

Decreased effects of bumetanide.

Impaired diuretic response in patients with cirrhosis and ascites.

Synergistic effects that may result in profound diuresis and serious electrolyte abnormalities.

Laboratory Test Interactions

None well documented.

Adverse Reactions

Cardiovascular

Hypotension; ECG changes; chest pain.

CNS

Asterixis; encephalopathy with pre-existing liver disease; vertigo; headache; dizziness.

Dermatologic

Hives; pruritus; itching; nipple tenderness; rash; photosensitivity.

EENT

Impaired hearing; ear discomfort; tinnitus; deafness.

GI

Upset stomach; dry mouth; nausea; vomiting; diarrhea; pain.

Genitourinary

Premature ejaculation; difficulty maintaining erection; renal failure.

Hematologic

Thrombocytopenia; deviations in Hgb, Hct, prothrombin time and WBC, platelets, and differential counts.

Metabolic

Glucosuria and proteinuria; hyperuricemia; gout; hypochloremia; hypokalemia; azotemia; hyponatremia; increased serum creatinine; hyperglycemia; variations in phosphorus, CO ₂ content, bicarbonate, and calcium; increases in LDL, total cholesterol, and triglycerides; decreases in HDL cholesterol.

Respiratory

Hyperventilation.

Miscellaneous

Musculoskeletal weakness; arthritic pain; pain; muscle cramps; fatigue; dehydration; sweating.

Precautions

Pregnancy

Category C .

Lactation

Undetermined.

Children

Safety and efficacy not established in children under 18 yr of age.

Renal Function

In severe chronic renal insufficiency, patients may benefit from continuous infusion (12 mg over 12 h), rather than from intermittent bolus therapy. Monitor renal function and discontinue drug if renal function decreases further.

Dehydration

Excessive diuresis may cause dehydration and decreased blood volume with circulatory collapse and possible vascular thrombosis and embolism, especially in elderly patients.

Hepatic cirrhosis and ascites

Sudden alterations of electrolyte balance may precipitate hepatic encephalopathy and coma.

Ototoxicity

Associated with rapid injection, very large doses or concurrent use of other ototoxic drugs.

Systemic lupus erythematosus

May be exacerbated or activated.

Overdosage

Symptoms

Profound water loss, volume and electrolyte depletion (characterized by weakness, dizziness, mental confusion, anorexia, lethargy, vomiting, cramps), dehydration, reduction in blood volume, circulatory collapse with possible thrombosis and embolism.

Patient Information

• Instruct patient to take as single dose early in day. Drug can be taken with food or milk to reduce GI upset.
• Advise patient to drink adequate fluids to prevent dehydration unless fluid restrictions apply.
• Caution patient to get out of bed slowly on arising, and to avoid sudden position changes to prevent orthostatic hypotension.
• If patient is not taking a potassium supplement, advise patient to increase potassium-rich foods in daily diet.
• Instruct patient to report the following symptoms to health care provider: signs of bleeding, weakness, cramps, nausea or dizziness.
• Caution patient to avoid exposure to sunlight, and to use sunscreen or wear protective clothing to avoid photosensitivity reaction.
• Advise diabetic patients to monitor blood glucose carefully because drug may cause loss of glycemic control.

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