Furosemide

Oral and selected injection labels cover adult/pediatric edema with heart failure, cirrhosis or renal disease including nephrotic syndrome. Oral products also cover adult hypertension; injection is adjunctive therapy for acute pulmonary edema.

The AHA/ACC/HFSA guideline recommends diuretics for fluid retention to relieve congestion and prevent worsening heart failure. Reserve addition of a thiazide to a loop diuretic for inadequate response to moderate/high loop doses, to limit electrolyte abnormalities.

Edema: 20–40 mg IV/IM initially; IV over 1–2 minutes. Repeat/increase by 20 mg no sooner than 2 hours, then once/twice daily as individualized. Acute pulmonary edema: 40 mg IV over 1–2 minutes; if inadequate after 1 hour, 80 mg IV over 1–2 minutes. Continuous infusion must not exceed 4 mg/min; high-dose therapy requires controlled infusion.

Oral edema: 2 mg/kg once initially; increase 1–2 mg/kg no sooner than 6–8 hours. IV/IM: 1 mg/kg initially over 1–2 minutes; increase 1 mg/kg no sooner than 2 hours. Both labels advise against doses above 6 mg/kg. Selected injection limits premature infants to 1 mg/kg/day.

Anuria is contraindicated. Stop for increasing azotemia plus oliguria in progressive severe renal disease. Cirrhosis/ascites warrants hospital initiation and careful titration; correct hepatic coma/electrolyte depletion first. Oral solutions are 8 or 10 mg/mL; verify concentration and measuring device. No automatic oral-to-IV conversion is supplied here.

Anuria or prior hypersensitivity to furosemide.

Selected oral labels prominently warn of profound diuresis and water/electrolyte depletion requiring medical supervision. The selected modern injection PI has no boxed warning; its serious volume/electrolyte and hearing warnings still apply.

Dizziness, orthostasis, GI upset, cramps and photosensitivity occur. Serious reports include hearing loss, severe allergy/skin reactions, blood disorders and renal injury. Overdose requires urgent supportive fluid/electrolyte correction and BP monitoring; dialysis does not speed elimination.

• Avoid lithium; avoid ethacrynic acid and aminoglycosides except life-threatening indications.
• Cisplatin/nephrotoxic drugs require renal/hearing review.
• ACE inhibitors/ARBs and other antihypertensives: monitor BP/renal function; doses may need reduction.
• NSAIDs/phenytoin may reduce response. Methotrexate/tubularly secreted drugs can increase toxicity.
• Potassium-depleting medicines increase risk; hypokalemia enhances digoxin toxicity.
• Separate oral tablets and sucralfate by at least 2 hours.
• Review high-dose salicylates, cyclosporine, chloral hydrate and perioperative muscle relaxants against the full label.

Use requires individualized maternal/fetal assessment. The newer injection PI reports no demonstrated major-malformation signal from available observational data; this does not establish absence of risk. Furosemide enters milk and significant diuresis may impair supply.

Premature infants have hearing, nephrocalcinosis and nephrolithiasis risks; assess renal function/ultrasound as labeled. Oral labeling notes possible persistent ductus risk early in premature life. Older adults often need lower starting doses and renal assessment.

Inhibits renal sodium/chloride reabsorption, particularly in the loop of Henle, producing diuresis.

Oral effect

Onset within 1 hour; duration 6–8 hours.

IV effect

Onset within 5 minutes; duration approximately 2 hours.

Disposition

Highly albumin-bound; predominantly urinary elimination.

Half-life

Approximately 2 hours; patient factors alter clearance.

• Assess BP, hydration, urine output and edema response.
• Check sodium/potassium, CO₂, BUN/creatinine; assess magnesium/calcium, glucose and uric acid as appropriate.
• Check hearing symptoms and urinary retention.
• Infant renal function/ultrasound and high-dose treatment require additional surveillance.

Rise slowly. Report fainting, cramps, marked thirst, reduced urine or hearing changes. Follow the prescribed fluid/potassium plan and sun protection. Measure liquid with the supplied calibrated device; verify strength every refill.

Strength / appearance

40 mg white, round, scored tablet.

Imprint

Lasix 40.

Distributor

Validus Pharmaceuticals LLC.

Example NDC

30698-060-01 ·100 tablets.

U. S. status

Prescription medicine.

Selected oral products

20/40/80 mg tablets; 10 mg/mL and 40 mg/5 mL solutions.

Selected IV/IM product

40 mg/4 mL(10 mg/mL), single-dose vial.

Scope boundary

Subcutaneous on-body products require separate labels and are outside these dosing directions.

Lasix: 20–25°C, excursions 15–30°C; protect from light and reject discolored tablets. Hikma 10 mg/mL: original bottle; discard 90 days after opening; 60 mL package uses its supplied syringe. Injection: 20–25°C, light protection; discard unused contents and reject particles/discoloration.