Please check your internet connection and try again.
# Furosemide
## Overview
Furosemide is a potent loop diuretic used to treat fluid overload (edema) associated with heart failure, liver disease, and kidney disease, including nephrotic syndrome. It is also used to treat high blood pressure, alone or in combination with other antihypertensives.
## Primary Indications
* Edema due to heart failure, liver cirrhosis, and renal disease.
* Hypertension.
## Adult Dosing
* **Edema:** Oral: 20 mg to 80 mg once daily. Doses may be increased by 20 mg to 40 mg every 6 to 8 hours as needed. Doses greater than 80 mg should be administered cautiously. Maximum oral dose: 600 mg/day.
* **Hypertension:** Oral: 40 mg twice daily. Not recommended as a first-line agent for hypertension.
* **Intravenous (IV) or Intramuscular (IM):** 20 mg to 40 mg once daily. Doses may be increased by 20 mg every 2 hours as needed. Maximum IV/IM dose: 200 mg in single doses or 600 mg/day in divided doses for severe cases, but usually lower doses are sufficient.
* **Acute Pulmonary Edema:** IV: 20 mg to 40 mg administered slowly.
## Pediatric Dosing
* **Edema:** Oral: 1 mg/kg to 2 mg/kg once daily, not to exceed 6 mg/kg/day.
* **IV/IM:** 1 mg/kg/dose once daily, not to exceed 6 mg/kg/day or 20 mg/dose. Higher doses may be needed in premature infants.
## Dose Adjustments
* **Renal Impairment:** Dose may need to be increased due to decreased renal excretion. However, cautious monitoring for ototoxicity is required. In patients with significant renal impairment, continuous infusion may be more effective than bolus doses.
* **Hepatic Impairment:** Use with caution.
## Contraindications
* Anuria.
* Hypersensitivity to furosemide or sulfonamides.
* Severe electrolyte depletion (e.g., hypokalemia, hyponatremia).
* Hepatic coma.
## Adverse Effects
* **Electrolyte Imbalances:** Hypokalemia, hyponatremia, hypochloremia, hypomagnesemia, hypocalcemia.
* **Ototoxicity:** Hearing impairment, tinnitus, deafness (often reversible, more common with rapid IV administration or high doses).
* **Dehydration:** Hypotension, dizziness, weakness.
* **Metabolic:** Hyperglycemia, hyperuricemia (can precipitate gout), increased cholesterol and triglycerides.
* **Renal:** Increased BUN and creatinine.
* **Dermatologic:** Photosensitivity, rash.
## Key Drug Interactions
* **Aminoglycosides:** Increased risk of ototoxicity.
* **Other Ototoxic Drugs:** Increased risk of ototoxicity.
* **Corticosteroids:** Increased risk of hypokalemia.
* **Digoxin:** Increased risk of toxicity due to furosemide-induced hypokalemia.
* **Lithium:** Reduced renal clearance, increasing lithium levels and risk of toxicity.
* **NSAIDs:** May reduce diuretic and antihypertensive effects.
* **Potassium-Sparing Diuretics:** Can be used to counteract hypokalemia, but monitor for hyperkalemia.
* **Neuromuscular Blocking Agents:** May enhance their effects.
## Monitoring
* Serum electrolytes (sodium, potassium, chloride, magnesium, calcium).
* Renal function (BUN, creatinine).
* Blood pressure.
* Fluid intake and output.
* Hearing (especially with high doses or IV administration).
* Blood glucose in diabetic patients.
* Uric acid levels.
## Clinical Pearls
* Administer oral furosemide in the morning to minimize nocturia.
* Rapid IV administration (>4 mg/min) is associated with a higher risk of ototoxicity. Administer IV doses over at least 30 to 60 minutes.
* For patients with severe edema unresponsive to oral therapy, consider switching to IV administration.
* Monitor for signs and symptoms of electrolyte depletion, especially hypokalemia. Potassium supplementation may be necessary.
* Furosemide is a potent diuretic and can lead to significant fluid and electrolyte losses. Closely monitor patients for dehydration and hemodynamic instability.
***
*Disclaimer: This information is intended for healthcare professionals. Always consult the official prescribing information and local protocols for complete and up-to-date guidance.*
