Please check your internet connection and try again.
# Furosemide (Lasix)
## Overview
Furosemide is a potent loop diuretic used to treat edema associated with congestive heart failure, liver cirrhosis, and renal disease, including in patients with chronic kidney disease or acute kidney injury. It is also used to treat hypertension, typically in combination with other antihypertensives.
## Primary Indications
* Edema associated with congestive heart failure (CHF)
* Edema associated with liver cirrhosis
* Edema associated with renal disease
* Hypertension
## Adult Dosing
**Edema:**
* **Oral:** Starting dose: 20-80 mg once daily. May be given as a single dose or divided doses. Dose can be increased by 20-40 mg every 6-8 hours until desired diuresis is achieved. Usual maintenance dose: 40-80 mg once daily. Doses up to 600 mg daily have been used in severe cases.
* **Intravenous (IV) or Intramuscular (IM):** Starting dose: 20-40 mg once daily. May be given as a single dose or divided doses. Dose can be increased by 20 mg every 2 hours until desired diuresis is achieved. Usual maintenance dose: 40-80 mg once daily. Doses up to 200 mg in a single IV dose have been used in severe cases.
* **Continuous IV Infusion:** 4 mg/hour initially. May be increased by 1-2 mg/hour every 2 hours.
**Hypertension:**
* **Oral:** Starting dose: 40 mg twice daily. Dose adjusted based on response.
## Pediatric Dosing
**Edema:**
* **Oral:** 1-2 mg/kg/dose once daily. Maximum dose: 6 mg/kg/day.
* **Intravenous (IV) or Intramuscular (IM):** 1 mg/kg/dose once daily. Maximum dose: 20 mg/dose. May be increased by 1 mg/kg/dose every 2 hours if needed.
## Dose Adjustments
* **Renal Impairment:** Higher doses may be required due to reduced GFR. However, monitor closely for electrolyte imbalances and worsening renal function. In patients with severe renal impairment, continuous IV infusion may be more effective.
* **Hepatic Impairment:** Use with caution. Monitor for electrolyte imbalances.
## Contraindications
* Anuria
* Hypersensitivity to furosemide or sulfonamides
## Adverse Effects
* **Electrolyte disturbances:** Hypokalemia, hyponatremia, hypochloremia, hypocalcemia, hypomagnesemia.
* **Dehydration and hypotension.**
* **Ototoxicity:** Hearing loss, tinnitus (especially with rapid IV administration or high doses).
* **Hyperglycemia.**
* **Hyperuricemia:** May precipitate gout.
* **Aplastic anemia, thrombocytopenia, agranulocytosis.**
* **Rash, photosensitivity.**
## Key Drug Interactions
* **Aminoglycosides, other ototoxic drugs:** Increased risk of ototoxicity.
* **ACE inhibitors, ARBs, other antihypertensives:** Additive hypotensive effect. Risk of significant hypotension, especially with initial doses.
* **Digoxin:** Increased risk of digoxin toxicity due to furosemide-induced hypokalemia.
* **NSAIDs:** May reduce diuretic and antihypertensive effects and increase risk of nephrotoxicity.
* **Lithium:** Reduced renal clearance of lithium, increasing risk of lithium toxicity.
* **Corticosteroids:** Increased risk of hypokalemia.
## Monitoring
* Electrolytes (sodium, potassium, chloride, magnesium, calcium)
* Renal function (BUN, creatinine)
* Blood pressure
* Urine output
* Blood glucose (in diabetic patients)
* Serum uric acid
## Clinical Pearls
* Furosemide's diuretic effect is dose-dependent.
* Oral absorption can be variable, especially in edematous states. IV administration may be preferred for rapid diuresis.
* To minimize ototoxicity, administer IV furosemide slowly (e.g., over 30-60 minutes) or as a continuous infusion.
* Hypokalemia is a common and important adverse effect. Consider potassium supplementation or a potassium-sparing diuretic if needed.
* For edema, timing of diuretic administration can impact nocturia.
***
**Disclaimer:** This information is intended for healthcare professionals. Always consult the most current prescribing information and institutional protocols before making clinical decisions.
