Can albumin and furosemide (Lasix) be mixed together in the same intravenous (IV) solution?

Compatibility of Albumin and Furosemide

Albumin and furosemide should not be mixed together in the same intravenous (IV) solution as there is no evidence supporting this practice and it may compromise the efficacy of both medications.

Rationale for Keeping These Medications Separate

Pharmacological Considerations

• Furosemide is a loop diuretic that works by inhibiting sodium and chloride reabsorption in the ascending loop of Henle
• Albumin is a plasma protein that maintains oncotic pressure and serves as a carrier protein for many substances, including medications
• When mixed together, albumin may bind to furosemide, potentially altering its pharmacokinetics and reducing its availability at the site of action 1

Evidence from Guidelines

The International Collaboration for Transfusion Medicine Guidelines (2024) does not support mixing these medications, and specifically notes that:

• Albumin in conjunction with diuretics is not recommended for removal of extravascular fluid in critically ill adult patients (Conditional Recommendation, Very Low Certainty of Evidence) 1
• A systematic review evaluating albumin with furosemide compared to furosemide alone found that while urine output was higher at 6 hours with the combination, there was no difference at 24 hours 1

Administration Recommendations

When both medications are indicated:

1. Administer them separately through different IV lines
2. If using the same IV line is necessary, flush the line thoroughly between administrations
3. Allow sufficient time between administrations (typically at least 30-60 minutes)

Clinical Evidence on Combined Use (Not Mixing)

While mixing in the same solution is not recommended, the sequential or parallel administration of these medications has been studied:

Efficacy in Various Clinical Scenarios

• In critically ill patients: A retrospective study showed no significant difference in urine output between patients treated with furosemide alone versus furosemide plus albumin at 6,24, and 48 hours 2
• In cirrhotic patients: A randomized crossover study demonstrated that albumin failed to enhance the diuretic effects of furosemide in cirrhotic patients with ascites 3
• In nephrotic syndrome: A systematic review found some evidence that urine excretion was greater after treatment with furosemide and albumin versus furosemide alone, but results for sodium excretion were inconclusive 4

Specific Clinical Contexts

For patients with cirrhosis and ascites:

• Standard therapy is sodium restriction plus diuretics (spironolactone with or without furosemide) 1
• Co-administration of albumin has not consistently shown improvement in control of ascites 1
• A crossover randomized study showed albumin failed to enhance the diuretic effect of furosemide 1

Important Considerations for Clinical Practice

Albumin Binding Function

• The efficacy of furosemide is related to albumin binding capacity (ABiC)
• In patients with ABiC ≥ 60%, the free furosemide fraction was significantly lower compared to patients with lower ABiC, and a higher proportion of infused furosemide was excreted renally 5
• This suggests that albumin function, not just concentration, affects furosemide efficacy

Alternative Approaches

When diuresis is needed in hypoalbuminemic patients:

• Consider higher doses of furosemide rather than adding albumin
• In patients with cirrhosis, combination therapy with spironolactone and furosemide (maintaining a 100 mg:40 mg ratio) is recommended 1
• For tense ascites, large-volume paracentesis with albumin support (8 g/L of fluid removed) may be more appropriate than attempting diuresis 1

Conclusion

While albumin and furosemide may be used sequentially in certain clinical scenarios, they should not be mixed in the same IV solution. The evidence does not support routine co-administration of albumin to enhance furosemide's diuretic effect in most clinical situations.