Please check your internet connection and try again.
# Furosemide
## Overview
Furosemide is a potent loop diuretic used for the management of edema associated with heart failure, liver cirrhosis, and renal disease, including the nephrotic syndrome. It is also used to treat hypertension, either alone or in combination with other antihypertensives.
## Primary Indications
* Edema (heart failure, liver cirrhosis, renal disease, nephrotic syndrome)
* Hypertension
## Adult Dosing
* **Edema:** Oral: Initial dose 20-80 mg once daily. Can increase by 20-40 mg every 6-8 hours as needed. Usual maintenance dose 40 mg once or twice daily. Maximum oral dose is 600 mg/day, but typically not to exceed 200 mg/day. IV/IM: Initial dose 20-40 mg once daily. Can increase by 20 mg every 2 hours as needed. Usual maintenance dose 40 mg once or twice daily. Maximum IV/IM dose is 200 mg in a single dose, but may be higher in severe renal failure under close supervision.
* **Hypertension:** Oral: Initial dose 40 mg twice daily. Usual maintenance dose 40 mg twice daily. May be used in combination with other antihypertensives. Higher doses may be required.
* **IV to PO Conversion:** Generally, IV furosemide is about twice the oral dose. A common strategy is to use 20 mg IV for every 40 mg oral. Monitor response carefully.
## Pediatric Dosing
* **Edema:** Oral: 1-2 mg/kg/dose once or twice daily. Maximum dose 6 mg/kg/day. IV/IM: 1 mg/kg/dose once daily. Maximum dose 20 mg/dose. If inadequate response, may increase dose by 1 mg/kg every 2 hours.
## Dose Adjustments
* **Renal Impairment:** Dose may need to be increased in patients with renal impairment due to decreased efficacy and altered pharmacokinetics. However, caution is advised as high doses can be nephrotoxic.
* **Hepatic Impairment:** Caution is advised, especially in patients with ascites, due to potential for electrolyte imbalances and hepatic encephalopathy.
## Contraindications
* Anuria
* Hypersensitivity to furosemide or sulfonamides
## Adverse Effects
* Electrolyte imbalances (hypokalemia, hyponatremia, hypochloremia, hypomagnesemia, hypocalcemia)
* Dehydration
* Hypotension
* Ototoxicity (especially with rapid IV administration or high doses)
* Hyperuricemia, hyperglycemia
* Dizziness, lightheadedness
* Rash
## Key Drug Interactions
* **Aminoglycosides:** Increased risk of ototoxicity and nephrotoxicity.
* **NSAIDs:** May decrease furosemide's diuretic and antihypertensive effects.
* **ACE inhibitors/ARBs:** Increased risk of hypotension and renal dysfunction.
* **Lithium:** Increased risk of lithium toxicity.
* **Digoxin:** Increased risk of digoxin toxicity due to furosemide-induced hypokalemia.
* **Corticosteroids:** Increased risk of hypokalemia.
## Monitoring
* Electrolytes (sodium, potassium, chloride, magnesium, calcium)
* Renal function (BUN, creatinine)
* Blood pressure
* Urine output
* Hearing (especially with high doses or risk factors for ototoxicity)
## Clinical Pearls
* Administer IV furosemide slowly (e.g., over 30-60 minutes) to minimize ototoxicity risk.
* Monitor for signs of dehydration and electrolyte depletion.
* In patients with heart failure, aim for gradual weight loss (e.g., 0.5-1 kg/day) to avoid excessive diuresis.
* Oral furosemide absorption can be variable, especially in patients with edema or ascites.
* Consider spironolactone or other potassium-sparing diuretics if hypokalemia is problematic and cannot be managed with supplementation.
***
*This information is intended for clinical use and does not replace current prescribing information. Always consult the official drug monograph and institutional protocols.*
