Please check your internet connection and try again.
## Furosemide (Lasix)
### Overview
Furosemide is a potent loop diuretic used to treat fluid overload (edema) and high blood pressure. It works by inhibiting sodium and chloride reabsorption in the loop of Henle, leading to increased excretion of water, sodium, potassium, chloride, calcium, and magnesium.
### Primary Indications
* Edema associated with congestive heart failure (CHF), cirrhosis of the liver, and renal disease, including the nephrotic syndrome.
* Hypertension, usually in combination with other antihypertensives.
### Adult Dosing
* **Edema:** 20 mg to 80 mg orally once daily. If inadequate response, increase dose by 20 mg to 40 mg every 6 to 8 hours. Usual maintenance dose: 40 mg to 120 mg orally per day.
* **Hypertension:** 40 mg orally twice daily. Inadequate response, may increase dose. Often used in combination with other antihypertensives.
* **Maximum Oral Dose:** Generally not to exceed 600 mg/day, though higher doses have been used in severe refractory cases under close monitoring.
### Pediatric Dosing
* **Edema:**
* **Oral:** 1 mg/kg to 2 mg/kg once daily. If inadequate response, increase dose. Maximum: 6 mg/kg/day. Doses should not exceed 40 mg per dose in neonates.
* **Intravenous/Intramuscular:** 1 mg/kg once daily. If inadequate response, increase dose. Maximum: 2 mg/kg per dose. Doses should not exceed 40 mg per dose in neonates.
* **Hypertension:** Use is generally not recommended as first-line therapy in pediatric hypertension.
### Dose Adjustments
* **Renal Impairment:** Dose may need to be increased in patients with renal impairment due to reduced drug clearance and increased volume of distribution. However, caution is advised as some patients may require lower doses.
* **Hepatic Impairment:** Caution is advised; dose adjustments may be necessary.
### Contraindications
* Anuria.
* History of hypersensitivity to furosemide or sulfonamides.
### Adverse Effects
* **Common:** Dizziness, lightheadedness, dehydration, hypotension, electrolyte imbalance (hypokalemia, hyponatremia, hypochloremia), hyperuricemia.
* **Less Common:** Ototoxicity (especially with rapid IV administration or high doses), rash, photosensitivity, pancreatitis, hyperglycemia, muscle cramps.
### Key Drug Interactions
* **Aminoglycosides:** Increased risk of ototoxicity and nephrotoxicity.
* **NSAIDs:** May reduce the diuretic and antihypertensive effect of furosemide.
* **Lithium:** Furosemide can decrease lithium clearance, increasing the risk of lithium toxicity.
* **Antihypertensives:** Additive hypotensive effects.
* **Corticosteroids/ACTH:** Increased risk of electrolyte imbalance.
* **Digoxin:** Increased risk of digoxin toxicity due to furosemide-induced hypokalemia.
### Monitoring
* Electrolytes (sodium, potassium, chloride, magnesium, calcium).
* Renal function (BUN, creatinine).
* Blood pressure.
* Fluid balance (intake and output).
* Hearing (especially with high doses or IV administration).
* Blood glucose in diabetic patients.
### Clinical Pearls
* Administer the lowest effective dose to minimize adverse effects.
* Oral doses are generally less potent than equianalgesic IV doses.
* Rapid IV administration can cause ototoxicity. Infuse IV furosemide slowly (e.g., over 30-60 minutes).
* Monitor for signs and symptoms of dehydration and electrolyte imbalance.
* Patients with edema due to cirrhosis may develop hepatic encephalopathy or coma with diuretic therapy; initiate cautiously.
* In hypertensive patients, blood pressure should be monitored closely, especially when combined with other antihypertensives.
***
*Please verify current prescribing information for the most up-to-date and comprehensive details.*
