Please check your internet connection and try again.
## Furosemide (Lasix)
### Overview
Furosemide is a potent loop diuretic that inhibits the reabsorption of sodium and chloride in the ascending limb of the loop of Henle, leading to increased excretion of water, sodium, chloride, potassium, calcium, and magnesium.
### Primary Indications
* Edema associated with congestive heart failure (CHF)
* Edema associated with hepatic cirrhosis
* Edema associated with renal disease, including the nephrotic syndrome
* Hypertension (rarely used as a single agent)
### Adult Dosing
* **Edema:**
* Initial dose: 20-80 mg orally once a day.
* Subsequent doses: May be increased by 20-40 mg every 6-8 hours or every other day depending on response.
* Maintenance dose: Typically 20-80 mg orally daily or every other day.
* Maximum daily oral dose: Generally 600 mg, but higher doses have been used under close supervision in refractory cases.
* **Hypertension:**
* Generally not recommended as first-line therapy.
* If used, initial dose: 40 mg orally once a day.
### Pediatric Dosing
* **Edema:**
* Neonates: 1 mg/kg/dose orally every 12 hours. May increase by 1 mg/kg/dose every 12 hours. Maximum of 6 mg/kg/day.
* Infants up to 16 years: 2 mg/kg/dose orally once a day. May increase by 1-2 mg/kg/dose every 6-8 hours. Maximum of 6 mg/kg/day.
* *Note: Dosing can vary significantly in neonates due to immature renal function. Close monitoring is crucial.*
### Dose Adjustments
* **Renal Impairment:** Dose may need to be increased in renal impairment due to reduced drug clearance. However, response may be diminished, and careful titration is required.
* **Hepatic Impairment:** Dose may need to be reduced in severe hepatic impairment due to decreased metabolism and increased sensitivity.
### Contraindications
* Anuria
* Known hypersensitivity to furosemide or sulfonamides
### Adverse Effects
* Electrolyte imbalances: Hypokalemia, hyponatremia, hypochloremia, hypomagnesemia, hypocalcemia.
* Dehydration and hypotension.
* Ototoxicity (especially with rapid IV administration or high doses).
* Hyperglycemia.
* Hyperuricemia (can precipitate gout).
* Dizziness, headache, fatigue.
* Photosensitivity.
### Key Drug Interactions
* **Aminoglycosides and other ototoxic drugs:** Increased risk of ototoxicity.
* **Digoxin:** Increased risk of digoxin toxicity due to furosemide-induced hypokalemia.
* **Antihypertensives:** Additive hypotensive effect.
* **NSAIDs:** May reduce the natriuretic and diuretic effects.
* **Corticosteroids:** Increased risk of hypokalemia.
* **Lithium:** Reduced lithium clearance, leading to increased lithium levels.
### Monitoring
* Electrolytes (sodium, potassium, chloride, magnesium, calcium)
* Renal function (BUN, creatinine)
* Blood pressure
* Urine output
* Hearing (especially with high doses or IV administration)
* Blood glucose
* Uric acid levels
### Clinical Pearls
* Furosemide is a potent diuretic; rapid diuresis can lead to significant electrolyte and fluid losses.
* Oral administration may be less effective in patients with significant edema due to impaired absorption.
* For acute decompensated heart failure, intravenous administration is preferred.
* Administer IV furosemide slowly (e.g., over 20-30 minutes) to minimize ototoxicity.
* Consider potassium supplementation or potassium-sparing diuretics if significant hypokalemia occurs.
---
*This information is intended for healthcare professionals. Always consult the most current prescribing information and relevant clinical guidelines before making any treatment decisions.*
