Please check your internet connection and try again.
# Furosemide (Lasix)
## Overview
Furosemide is a potent loop diuretic that inhibits the reabsorption of sodium, chloride, and potassium in the ascending limb of the loop of Henle, leading to increased excretion of these electrolytes and water.
## Primary Indications
* Edema associated with heart failure, liver cirrhosis, and renal disease (including nephrotic syndrome).
* Hypertension (typically as adjunctive therapy).
* Acute pulmonary edema.
## Adult Dosing
* **Edema:** Oral: 20-80 mg once daily. May be increased by 20-40 mg every 6-8 hours as needed. Usual maintenance dose: 40-80 mg once or twice daily. Intravenous/Intramuscular: 20-40 mg once daily. May be increased by 20 mg every 2 hours as needed.
* **Hypertension:** Oral: 40 mg twice daily (adjunctive).
* **Acute Pulmonary Edema:** Intravenous: 20-40 mg. If response is inadequate after 20 mg IV, may administer 40 mg IV.
* **Maximum Daily Dose:** Oral: 600 mg. Intravenous: 600 mg (however, higher doses may be used in specific, closely monitored situations, often with continuous infusion).
## Pediatric Dosing
* **Edema:** Oral: 1-2 mg/kg/dose once or twice daily. Maximum: 6 mg/kg/day.
* **Acute Pulmonary Edema:** Intravenous/Intramuscular: 1 mg/kg/dose once daily. Maximum: 20 mg/dose. Higher doses may be used in specific, closely monitored situations.
## Dose Adjustments
* **Renal Impairment:** Patients with severe renal impairment may require lower initial doses and gradual titration. Some may require higher doses to achieve diuresis. Careful monitoring is crucial.
* **Hepatic Impairment:** Monitor for electrolyte imbalances and hepatic encephalopathy. Dose adjustments may be necessary.
## Contraindications
* Anuria.
* Known hypersensitivity to furosemide or sulfonamides.
## Adverse Effects
* **Electrolyte abnormalities:** Hypokalemia, hyponatremia, hypochloremia, hypomagnesemia, hypocalcemia.
* **Dehydration and hypotension.**
* **Ototoxicity:** Especially with rapid IV administration or in patients with renal impairment.
* **Hyperuricemia:** May precipitate gout.
* **Hyperglycemia.**
* **Dizziness, lightheadedness.**
* **Rash, photosensitivity.**
* **Aplastic anemia, thrombocytopenia, agranulocytosis** (rare).
## Key Drug Interactions
* **Aminoglycosides/Other Ototoxic Drugs:** Increased risk of ototoxicity.
* **ACE Inhibitors/ARBs:** Increased risk of hypotension and renal dysfunction.
* **NSAIDs:** May decrease diuretic and antihypertensive effect, and increase risk of renal impairment.
* **Lithium:** Reduced renal clearance, increased risk of lithium toxicity.
* **Corticosteroids/ACTH:** Increased risk of electrolyte depletion.
* **Digoxin:** Increased risk of digoxin toxicity due to furosemide-induced hypokalemia.
## Monitoring
* **Renal function (BUN, creatinine).**
* **Electrolytes (sodium, potassium, chloride, magnesium, calcium).**
* **Fluid status (weight, intake/output, edema).**
* **Blood pressure.**
* **Hearing function** (especially with high doses or risk factors).
* **Blood glucose and uric acid levels** (in susceptible individuals).
## Clinical Pearls
* Administer oral furosemide at least 6 hours before bedtime to minimize nocturia.
* Rapid IV administration can increase the risk of ototoxicity. Infuse slowly or use a continuous infusion.
* Monitor for signs of electrolyte depletion, especially hypokalemia, which can lead to arrhythmias.
* For patients with resistant edema, consider continuous infusion or alternating dosing regimens, often guided by specialist protocol.
***
*This information is intended for healthcare professionals. It is essential to consult the most current prescribing information and institutional protocols for definitive guidance.*
