Please check your internet connection and try again.
## Furosemide
### Overview
Furosemide is a potent loop diuretic used for managing fluid overload.
### Primary Indications
* Edema associated with congestive heart failure (CHF), cirrhosis, and renal disease.
* Hypertension (less common, usually in combination).
### Adult Dosing
* **Edema:** Typically initiated at 20-80 mg orally once or twice daily. Doses can be increased by 20-40 mg every 6-8 hours as needed. The maximum single oral dose is generally 600 mg, but higher doses have been used cautiously in specific inpatient settings. For chronic use, the lowest effective dose should be employed.
* **Hypertension:** Usually 40 mg orally twice daily (given as adjunct therapy).
### Pediatric Dosing
* **Edema:**
* Oral: 1-2 mg/kg/dose every 6-12 hours. Maximum single dose: 40 mg.
* IV/IM: 1 mg/kg/dose every 6-12 hours. Maximum single dose: 20 mg.
* For very premature infants, lower doses may be necessary.
* **Note:** Dosing in neonates and infants can be highly variable and may require careful titration based on response and electrolytes.
### Dose Adjustments
* **Renal Impairment:** Furosemide is renally excreted. Dose may need to be adjusted based on the degree of renal impairment. Higher doses may be required in severe renal impairment due to decreased potency and altered absorption.
* **Hepatic Impairment:** Use with caution; may precipitate hepatic coma. Dose adjustment is often not explicitly defined but requires careful monitoring.
### Contraindications
* Anuria.
* Known hypersensitivity to furosemide or sulfonamides (cross-sensitivity possible).
* Severe electrolyte depletion (e.g., hypokalemia, hyponatremia).
### Adverse Effects
* **Common:** Dizziness, lightheadedness, electrolyte imbalances (hypokalemia, hyponatremia, hypochloremia), dehydration, hypotension, hyperglycemia.
* **Serious:** Ototoxicity (especially with rapid IV administration or high doses), severe dehydration, acute kidney injury, Stevens-Johnson syndrome.
### Key Drug Interactions
* **Aminoglycosides & other ototoxic drugs:** Increased risk of ototoxicity.
* **NSAIDs:** May reduce the natriuretic and diuretic effects of furosemide.
* **Antihypertensives:** Additive hypotensive effect.
* **Digoxin:** Increased risk of digoxin toxicity if hypokalemia occurs.
* **Lithium:** Reduced renal clearance of lithium, increasing risk of lithium toxicity.
* **Corticosteroids:** Increased risk of electrolyte depletion, particularly hypokalemia.
### Monitoring
* **Electrolytes:** Sodium, potassium, chloride, magnesium, calcium (frequently, especially with dose changes).
* **Renal function:** BUN, creatinine.
* **Fluid status:** Daily weights, intake/output, signs of edema.
* **Blood pressure:** Especially with initial dosing and dose changes.
* **Hearing:** Assess for tinnitus or hearing loss.
### Clinical Pearls
* Administer oral furosemide with food or milk to minimize GI upset.
* IV administration is generally 50% to 100% bioavailable compared to oral.
* Rapid IV infusion (e.g., > 4 mg/min) can increase the risk of ototoxicity. Consider continuous infusion or slower intermittent dosing in critically ill patients.
* Potassium supplementation or potassium-sparing diuretics may be necessary to prevent or manage hypokalemia.
* Monitor for signs of dehydration, especially in elderly patients.
***
*Disclaimer: This information is intended for clinical professionals. Always consult the current prescribing information and relevant guidelines for complete details and to ensure patient-specific appropriateness.*
