Why administer Furosemide (Lasix) after albumin infusion?

From the Guidelines

Lasix (furosemide) should be administered after albumin in patients with conditions like cirrhosis, nephrotic syndrome, or volume overload to enhance diuresis and improve morbidity, mortality, and quality of life outcomes. The typical approach involves giving albumin (usually 25g or 1g/kg) followed by Lasix (20-40mg IV or higher depending on renal function and clinical scenario) about 1-2 hours later, as recommended by recent guidelines 1. This sequential administration works because albumin first expands the intravascular volume by increasing oncotic pressure, drawing fluid from extravascular spaces into the bloodstream. When Lasix is then administered, this mobilized fluid can be more effectively eliminated through the kidneys. Without the preceding albumin, Lasix alone might be less effective in hypovolemic patients as it would have less fluid to work with and could potentially worsen intravascular depletion.

Key Considerations

• The use of albumin before Lasix is supported by studies showing improved outcomes in patients with cirrhosis and ascites 1.
• The dose of albumin and Lasix may vary depending on the patient's condition, renal function, and clinical scenario.
• The timing between administrations is crucial to allow albumin to fully distribute and perform its volume-expanding function before the diuretic effect begins.
• Patients with hypoalbuminemia may benefit from this combination therapy, as the infused albumin temporarily corrects this deficiency, improving the hemodynamic response to the diuretic.

Clinical Implications

• The administration of Lasix after albumin can help prevent the re-accumulation of ascites in patients with cirrhosis.
• This combination therapy may also be beneficial in patients with nephrotic syndrome or volume overload.
• However, the use of Lasix and albumin should be tailored to the individual patient's needs and monitored closely to avoid potential complications, such as hypovolemia or electrolyte imbalances, as highlighted in recent studies 1.

From the FDA Drug Label

Furosemide is extensively bound to plasma proteins, mainly to albumin Plasma concentrations ranging from 1 to 400 mcg/mL are 91 to 99% bound in healthy individuals. Furosemide binding to albumin may be reduced in elderly patients.

The administration of Lasix (furosemide) after albumin may be considered to increase the effectiveness of furosemide, as albumin can bind to furosemide, potentially increasing its plasma concentrations. However, the exact reason for administering Lasix after albumin is not explicitly stated in the provided drug label. Key points to consider:

• Binding of furosemide to albumin: Furosemide is extensively bound to plasma proteins, mainly to albumin.
• Potential increased effectiveness: Administering Lasix after albumin may increase the effectiveness of furosemide by increasing its plasma concentrations 2.

From the Research

Rationale for Administering Lasix after Albumin

• The administration of Lasix (furosemide) after albumin is a common practice in the treatment of edema, particularly in patients with hypoalbuminemia 3, 4, 5, 6.
• Hypoalbuminemia can lead to decreased diuretic efficacy, and the co-administration of albumin with furosemide can enhance the therapeutic effect by increasing oncotic pressure and promoting diuresis 4, 5, 6.
• Studies have shown that the combination of furosemide and albumin can improve urine volume and sodium excretion in patients with nephrotic syndrome and cirrhosis 4, 5, 6.
• The use of albumin and furosemide has also been explored in the treatment of pulmonary edema in COVID-19 patients, with promising results 7.

Mechanism of Action

• Furosemide works by inhibiting the sodium-potassium-chloride cotransporter in the thick ascending limb of the loop of Henle, leading to increased urine production 3, 4, 5, 6.
• Albumin helps to increase oncotic pressure, which can enhance the effect of furosemide by increasing the amount of fluid returned to the bloodstream and subsequently excreted in the urine 4, 5, 6.

Clinical Implications

• The co-administration of albumin and furosemide may be beneficial in patients with hypoalbuminemia and edema, particularly those who are resistant to diuretic therapy alone 3, 4, 5, 6.
• Further studies are needed to fully understand the clinical implications of this treatment approach and to determine the optimal dosing and timing of albumin and furosemide administration 3, 4, 5, 6, 7.