Please check your internet connection and try again.
# Furosemide (Lasix)
## Overview
Furosemide is a potent loop diuretic used to treat edema associated with heart failure, liver disease, and renal disease, including nephrotic syndrome. It is also used to manage hypertension, although it's not typically a first-line agent for this indication alone.
## Primary Indications
* Edema associated with congestive heart failure
* Edema associated with liver cirrhosis
* Edema associated with renal disease (including nephrotic syndrome)
* Hypertension (adjunct therapy)
## Adult Dosing
* **Edema:**
* Initial: 20-80 mg orally once daily. The dose may be increased by 20-40 mg every 6-8 hours as needed.
* Maximum daily oral dose: 600 mg (higher doses may be used in rare cases under close supervision).
* For patients with significant edema, a dose of 80-160 mg may be given initially.
* **Hypertension:**
* 20-40 mg orally twice daily.
* Maximum daily oral dose: 80 mg. Furosemide is generally not recommended as monotherapy for hypertension.
## Pediatric Dosing
* **Edema:**
* 0.5-2 mg/kg/dose orally once daily. Doses are typically given every 6-12 hours, depending on the patient's response and clinical condition.
* Maximum dose: 6 mg/kg/dose orally once daily.
* Maintenance doses are usually lower than initial doses.
* *Note: Dosing in neonates and premature infants requires careful consideration due to immature renal function and potential for prolonged drug effect.*
## Dose Adjustments
* **Renal Impairment:** Furosemide is renally excreted. Dose adjustments are often necessary in patients with impaired renal function. Higher doses may be required to achieve diuresis, but patients may also be more susceptible to electrolyte imbalances and ototoxicity.
* **Hepatic Impairment:** Monitor for fluid and electrolyte balance and worsening of hepatic encephalopathy.
## Contraindications
* Anuria
* Hypersensitivity to furosemide or sulfonamides (cross-sensitivity possible)
* Severe electrolyte depletion (e.g., hypokalemia, hyponatremia)
## Adverse Effects
* **Common:** Dizziness, lightheadedness, orthostatic hypotension, dehydration, electrolyte imbalances (hypokalemia, hyponatremia, hypochloremia, hypomagnesemia, hypocalcemia), hyperuricemia, hyperglycemia.
* **Less Common:** Ototoxicity (especially with rapid IV administration or high doses), rash, photosensitivity, gastrointestinal upset.
* **Rare:** Aplastic anemia, thrombocytopenia, agranulocytosis, pancreatitis.
## Key Drug Interactions
* **Aminoglycosides:** Increased risk of ototoxicity and nephrotoxicity.
* **NSAIDs:** May reduce the diuretic and antihypertensive effects of furosemide and increase the risk of nephrotoxicity.
* **Lithium:** Furosemide can decrease renal clearance of lithium, increasing the risk of lithium toxicity.
* **Corticosteroids (systemic):** Increased risk of hypokalemia.
* **Antihypertensives:** Additive hypotensive effects.
* **Digoxin:** Risk of digoxin toxicity is increased in the presence of furosemide-induced hypokalemia.
## Monitoring
* **Electrolytes:** Sodium, potassium, chloride, magnesium, calcium.
* **Renal function:** Serum creatinine, BUN.
* **Fluid balance:** Daily weights, intake and output.
* **Blood pressure:** Especially in hypertensive patients or those at risk of hypotension.
* **Hearing:** Monitor for tinnitus or hearing loss, particularly with high doses or rapid IV infusion.
## Clinical Pearls
* Furosemide is a potent diuretic and can cause rapid fluid and electrolyte losses.
* Administer oral furosemide preferably on an empty stomach to enhance absorption, but it can be given with food or milk if gastric irritation occurs.
* Intravenous administration should be given slowly (e.g., over 30-60 minutes) to minimize the risk of ototoxicity and hypotension.
* Monitor patients closely for signs of dehydration and electrolyte imbalances.
* Consider potassium supplementation if hypokalemia develops, especially in patients taking digoxin.
***
*Disclaimer: This information is for educational purposes only and does not constitute medical advice. Always consult with a qualified healthcare provider to determine the best course of treatment for your specific condition and to ensure the most up-to-date prescribing information.*
