When to Administer Furosemide
Furosemide should be administered in patients with evidence of fluid overload, particularly in conditions like heart failure, nephrotic syndrome, cirrhosis with ascites, and acute respiratory distress syndrome (ARDS), while carefully monitoring for hypovolemia and electrolyte disturbances. 1
Specific Clinical Indications
Heart Failure
- Administer IV furosemide 20-40 mg bolus in acute heart failure patients with symptoms of congestion and volume overload 1
- For patients with evidence of significant volume overload, the dose may be increased based on renal function and history of chronic diuretic use 1
- Total furosemide dose should remain <100 mg in first 6 hours and <240 mg during first 24 hours in acute heart failure 1
- For refractory cardiac failure, higher doses (≥0.5 g/day) may be considered with careful monitoring 2
Nephrotic Syndrome
- In congenital nephrotic syndrome, administer IV furosemide 0.5-2 mg/kg at the end of albumin infusions in the absence of marked hypovolemia or hyponatremia 1
- 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) 1
- In stable patients, oral furosemide at 2-5 mg/kg per day can be given in combination with a thiazide or potassium-sparing diuretic 1
Cirrhosis with Ascites
- Start with oral furosemide 40 mg combined with spironolactone 100 mg as a single morning dose 1
- Doses can be increased simultaneously every 3-5 days (maintaining 100 mg:40 mg ratio of spironolactone:furosemide) if weight loss is inadequate 1
- Maximum doses are typically 400 mg/day of spironolactone and 160 mg/day of furosemide 1
ARDS
- In ARDS patients with fluid overload (without shock), administer furosemide when:
- Begin with 20 mg bolus or 3 mg/h infusion, doubling subsequent doses until goal achieved or maximum infusion rate of 24 mg/h reached 1
Dosing Considerations
General Adult Dosing
- Initial dose: 20-80 mg as a single dose 3
- Same dose can be administered 6-8 hours later or increased if needed 3
- Dose may be increased by 20-40 mg increments, given no sooner than 6-8 hours after previous dose 3
- For severe edematous states, doses may be carefully titrated up to 600 mg/day 3
Pediatric Dosing
- Initial dose: 2 mg/kg body weight as a single dose 3, 4
- If response is inadequate, dosage may be increased by 1-2 mg/kg no sooner than 6-8 hours after previous dose 3
- Doses greater than 6 mg/kg are not recommended for routine use 3
Monitoring and Precautions
Required Monitoring
- Fluid status assessment (peripheral perfusion, blood pressure) 1
- Electrolytes (particularly potassium and sodium) 1
- Kidney function (urine output, estimated glomerular filtration rate) 1
- Urine output should be assessed frequently when administering furosemide 1
Important Precautions
Avoid furosemide in patients with:
High doses of furosemide (>6 mg/kg/day) should not be given for periods longer than 1 week 1
Infusions should be administered over 5-30 minutes to avoid hearing loss 1
Special Situations
Combination Therapy
- In diuretic resistance, combine with thiazides (hydrochlorothiazide 25 mg) or aldosterone antagonists (spironolactone 25-50 mg) 1
- In nephrotic syndrome, amiloride is preferable to spironolactone when potassium-sparing diuretics are needed 1
- In cirrhosis, combination therapy with spironolactone from the beginning is the preferred approach 1
Route of Administration
- Oral administration is preferred in cirrhotic patients due to good bioavailability and avoidance of acute reductions in GFR associated with IV administration 1
- IV administration is preferred in acute situations requiring rapid diuresis 1
- Continuous infusion may be considered after initial bolus in patients with volume overload 1