Please check your internet connection and try again.
# Furosemide (Lasix)
## Overview
Furosemide is a potent loop diuretic used to treat fluid overload (edema) and high blood pressure. It works by inhibiting the reabsorption of sodium, chloride, and water in the kidneys.
## Primary Indications
* Edema associated with congestive heart failure (CHF)
* Edema associated with hepatic cirrhosis
* Edema associated with renal disease, including nephrotic syndrome
* Hypertension (used alone or in combination with other antihypertensives)
* Acute pulmonary edema
## Adult Dosing
* **Edema:**
* **Oral:** Initial dose is typically 20-80 mg once daily. Higher doses may be needed for severe edema, up to 600 mg daily in divided doses. Doses greater than 80 mg are usually given in two or more divided doses.
* **Intravenous (IV) / Intramuscular (IM):** Initial dose is typically 20-40 mg once daily. If a satisfactory response is not obtained, the dose may be increased by 20 mg every 2 hours until the desired diuresis is achieved. For patients resistant to conventional doses, doses up to 80-200 mg may be required in a single dose.
* **Hypertension:**
* **Oral:** Initial dose is typically 40 mg twice daily. Dose may be adjusted based on response.
* **Acute Pulmonary Edema:**
* **IV:** 20-40 mg. May be followed by an additional 40 mg if response is inadequate within 2 hours.
## Pediatric Dosing
Dosing is highly individualized and depends on the indication and patient response. Consult specific pediatric guidelines or protocols.
* **Oral:** Generally 1-2 mg/kg/dose once or twice daily. Maximum: 6 mg/kg/dose.
* **IV/IM:** Generally 1 mg/kg/dose. Maximum: 20 mg/dose for premature infants and newborns; 40 mg/dose for older infants and children. Higher doses may be administered in specific situations, but close monitoring is essential.
## Dose Adjustments
* **Renal Impairment:** Dose may need to be increased due to reduced renal excretion and impaired drug effect. However, careful titration is required as excessive diuresis can worsen renal function.
* **Hepatic Impairment:** Dose may need to be reduced, especially in patients with ascites, due to increased bioavailability and altered drug metabolism.
## Contraindications
* Anuria
* Known hypersensitivity to furosemide or sulfonamides
## Adverse Effects
* **Electrolyte imbalances:** Hypokalemia, hyponatremia, hypochloremia, hypomagnesemia, hypocalcemia.
* **Dehydration and hypotension.**
* **Ototoxicity:** Tinnitus, hearing impairment (especially with rapid IV administration or high doses).
* **Metabolic:** Hyperglycemia, hyperuricemia (can precipitate gout).
* **Renal:** Increased BUN, azotemia.
* **Other:** Dizziness, lightheadedness, rash, photosensitivity.
## Key Drug Interactions
* **Aminoglycosides, other ototoxic drugs:** Increased risk of ototoxicity.
* **Corticosteroids:** Increased risk of hypokalemia.
* **Digoxin:** Increased risk of digoxin toxicity due to furosemide-induced hypokalemia.
* **NSAIDs:** May reduce diuretic and antihypertensive effect, and increase risk of renal impairment.
* **Lithium:** Reduced lithium clearance, increased risk of lithium toxicity.
* **Antihypertensives:** Additive hypotensive effect.
## Monitoring
* **Fluid and electrolytes:** Serum electrolytes (sodium, potassium, chloride, magnesium, calcium), BUN, creatinine, and intake/output.
* **Blood pressure:** Especially with antihypertensive use.
* **Auditory function:** If high doses or rapid IV administration.
* **Blood glucose and uric acid levels:** In susceptible patients.
## Clinical Pearls
* Furosemide is a potent diuretic; rapid or excessive diuresis can lead to dehydration, electrolyte depletion, and hypotension.
* Administer IV furosemide slowly to reduce the risk of ototoxicity.
* Oral administration is generally preferred for chronic management.
* For patients with severe edema, continuous IV infusion or frequent dosing may be necessary.
* Potassium supplementation may be required to prevent or treat hypokalemia.
***
*This information is intended for healthcare professionals. Always consult the current prescribing information and local protocols for the most up-to-date and complete details before initiating or modifying therapy.*
