What is the maximum daily dose of furosemide (Lasix)?

Maximum Daily Dose of Furosemide

The maximum daily dose of furosemide is 600 mg/day according to the FDA label, though this should be carefully titrated and requires close clinical observation and laboratory monitoring when exceeding 80 mg/day. 1

Context-Specific Maximum Doses

The maximum dose varies significantly by clinical indication:

Cirrhosis with Ascites

• The maximum recommended dose is 160 mg/day in patients with cirrhosis and ascites, typically combined with spironolactone 2, 3
• Exceeding 160 mg/day in cirrhotic patients is considered a marker of diuretic resistance and indicates the need for alternative strategies such as large volume paracentesis rather than further dose escalation 2, 3
• Start at 40 mg/day combined with spironolactone 100 mg as a single morning dose, increasing in 40 mg steps every 3-5 days if inadequate response 2

Acute Heart Failure

• Total furosemide dose should remain <100 mg in the first 6 hours and <240 mg during the first 24 hours in acute heart failure 3
• Initial IV bolus of 20-40 mg for new-onset heart failure, or equivalent to oral dose for patients on chronic diuretics 3
• Continuous infusion at 5-10 mg/hour may be used, with maximum rates not exceeding 4 mg/min 3

Severe Edematous States

• The FDA label permits careful titration up to 600 mg/day in patients with clinically severe edematous states 1
• When doses exceeding 80 mg/day are given for prolonged periods, careful clinical observation and laboratory monitoring are particularly advisable 1

Critical Monitoring Requirements

When using higher doses (>80 mg/day), you must monitor:

• Electrolytes (sodium, potassium, chloride) - check daily initially, then regularly throughout treatment 2, 3
• Renal function (serum creatinine, BUN, urine output) - assess frequently as high doses can precipitate acute kidney injury 2, 3
• Daily weights - target 0.5 kg/day loss without peripheral edema, 1 kg/day with edema 2
• Blood pressure and perfusion status - ensure SBP ≥90-100 mmHg before continuing therapy 3

Absolute Contraindications to Dose Escalation

Stop furosemide immediately if any of the following develop:

• Severe hyponatremia (serum sodium <120-125 mmol/L) 2, 3
• Severe hypokalemia (<3 mmol/L) 2
• Progressive renal failure or acute kidney injury 2, 3
• Marked hypotension (SBP <90 mmHg without circulatory support) 2, 3
• Anuria 3, 1
• Worsening hepatic encephalopathy in cirrhotic patients 2
• Incapacitating muscle cramps 2

Special Populations

Pediatric Patients

• Maximum dose is 6 mg/kg/day - doses greater than this are not recommended 1, 4
• In nephrotic syndrome, may use 0.5-2 mg/kg per dose up to six times daily (maximum 10 mg/kg/day) 3
• High doses (>6 mg/kg/day) should not be given for periods longer than 1 week 3

Geriatric Patients

• Start at the low end of the dosing range (20-40 mg/day) 1
• Dose selection should be cautious with careful titration 1

Common Pitfalls to Avoid

• Do not escalate furosemide doses in cirrhotic patients beyond 160 mg/day - this indicates diuretic resistance requiring alternative management 2, 3
• Do not administer furosemide in hypotensive patients (SBP <90 mmHg) without circulatory support - it will worsen hypoperfusion and precipitate shock 3
• Do not use rapid IV administration at very high doses - infuse over 5-30 minutes to avoid ototoxicity 3
• Do not continue high-dose therapy without addressing underlying diuretic resistance - consider combination therapy with thiazides (hydrochlorothiazide 25 mg) or aldosterone antagonists (spironolactone 25-50 mg) rather than escalating furosemide alone 3

Evidence from Extreme Dosing

While the FDA maximum is 600 mg/day 1, research has documented safe use of much higher doses in specific refractory cases:

• One study successfully used up to 8 g/day (8000 mg) in severe cardiac failure, though this is exceptional 5
• High-dose furosemide (500-1000 mg twice daily) combined with hypertonic saline has been used in refractory heart failure with improved outcomes 6
• In hemodialysis patients with residual function, doses of 250-2000 mg daily have been studied 7

However, these extreme doses are not recommended for routine practice and should only be considered in highly specialized settings with intensive monitoring.