What are the indications for furosemide (Lasix) in adults with various medical conditions, including congestive heart failure, cirrhosis of the liver, nephrotic syndrome, hypertension, and impaired renal function?

Indications for Furosemide

Furosemide is indicated for the treatment of edema associated with congestive heart failure, cirrhosis of the liver, renal disease (including nephrotic syndrome), and for hypertension in adults, with specific dosing protocols varying by underlying condition. 1

FDA-Approved Indications

Edema Management

• Furosemide is approved for treating edema in adults and pediatric patients associated with congestive heart failure, cirrhosis of the liver, and renal disease including nephrotic syndrome, particularly when an agent with greater diuretic potential is needed. 1

Hypertension

• Furosemide may be used in adults for hypertension treatment, either alone or combined with other antihypertensive agents, though patients inadequately controlled with thiazides will likely not respond adequately to furosemide monotherapy. 1

Disease-Specific Applications and Dosing

Congestive Heart Failure

• In acute decompensated heart failure with pulmonary edema, initiate furosemide 20-40 mg IV bolus over 1-2 minutes when systolic blood pressure is ≥90-100 mmHg and there is no marked hypovolemia. 2
• For patients already on chronic oral diuretics, the IV dose should equal or exceed their home oral dose. 2
• Total furosemide dose should not exceed 100 mg in the first 6 hours and 240 mg in the first 24 hours during acute heart failure management. 2
• Doses exceeding 160 mg/day indicate advanced disease requiring treatment escalation beyond diuretics alone. 2

Cirrhosis with Ascites

• Start with oral furosemide 40 mg combined with spironolactone 100 mg as a single morning dose for first-line management of ascites in cirrhosis. 3, 2
• Increase both drugs simultaneously every 3-5 days (furosemide in 40 mg steps, spironolactone in 100 mg steps) if weight loss is inadequate, maintaining the 100:40 ratio. 3
• Maximum furosemide dose is 160 mg/day in cirrhotic patients; exceeding this threshold indicates diuretic-resistant ascites requiring large-volume paracentesis. 3, 2
• Target weight loss should not exceed 0.5 kg/day in patients without peripheral edema and 1 kg/day in those with edema. 3

Nephrotic Syndrome

• Administer IV furosemide 0.5-2 mg/kg at the end of albumin infusions in the absence of marked hypovolemia or hyponatremia for congenital nephrotic syndrome. 2
• For severe edema, commence furosemide at 0.5-2 mg/kg per dose IV or orally up to six times daily (maximum 10 mg/kg per day). 2
• High doses (>6 mg/kg/day) should not be given for periods longer than 1 week. 2
• Infusions should be administered over 5-30 minutes to avoid ototoxicity. 2

Renal Disease and Acute Kidney Injury

• Furosemide should NOT be used to prevent or treat acute kidney injury itself—only to manage volume overload that complicates AKI. 2
• In hemodynamically stable, volume-overloaded AKI patients, furosemide may be beneficial for fluid balance management. 2
• The drug does not prevent AKI and may increase mortality when used for this purpose. 2

Acute Respiratory Distress Syndrome (ARDS)

• Administer furosemide when central venous pressure >8 mmHg with urine output <0.5 mL/kg/h or central venous pressure >4 mmHg with urine output ≥0.5 mL/kg/h in ARDS patients with fluid overload. 2

Critical Contraindications and Precautions

Absolute Contraindications

• Discontinue all diuretics immediately if severe hyponatremia (serum sodium <120-125 mmol/L), progressive renal failure, worsening hepatic encephalopathy, or incapacitating muscle cramps develop. 3
• Stop furosemide specifically if severe hypokalemia (<3 mmol/L) occurs. 3
• Do not administer furosemide when systolic blood pressure is <90 mmHg without circulatory support, or in the presence of marked hypovolemia or anuria. 2

Special Monitoring Requirements

• Patients should undergo frequent clinical and biochemical monitoring, particularly during the first month of treatment. 3
• Monitor electrolytes (sodium, potassium), renal function, and daily weights every 3-7 days during initial titration. 3, 2
• In acute settings, place a bladder catheter to monitor urinary output and rapidly assess treatment response. 2

Common Clinical Pitfalls

• Never administer furosemide to hypotensive patients expecting it to improve hemodynamics—it causes further volume depletion and worsens tissue perfusion. 2
• In acute pulmonary edema, furosemide should not be used as monotherapy; IV nitroglycerin is superior and should be started concurrently. 2
• Oral administration is preferred in cirrhotic patients due to good bioavailability and avoidance of acute GFR reductions associated with IV administration. 2
• When standard doses fail, combination therapy with thiazides or aldosterone antagonists is preferred over escalating furosemide alone. 3, 2