Is Gamunex Compatible with Normal Saline? A Pharmacological Guide

October 13, 2025 •

2 min read

Intravenous Immunoglobulin (IVIg) therapy is a critical treatment for various immunodeficiencies and autoimmune diseases. A primary clinical question is: Is Gamunex compatible with normal saline? The answer, according to official guidelines, is no.

Quick Summary

Gamunex is not compatible with and should not be diluted with normal saline (0.9% Sodium Chloride). If dilution is necessary, only 5% Dextrose in Water (D5W) should be used.

Key Points

Not Compatible: Gamunex-C is not compatible with normal saline (0.9% Sodium Chloride) for dilution or mixing.
Precipitation Risk: Mixing Gamunex with saline can cause the solution to form a precipitate (become cloudy or chunky), making it unsafe for infusion.
Approved Diluent: If dilution of Gamunex-C is required, the only recommended diluent is 5% Dextrose in Water (D5/W).
Separate Infusion Line: Gamunex-C should always be infused through a dedicated IV line, without mixing with other fluids or medications.
Line Flushing is Different: While you cannot dilute Gamunex with saline, the IV line can be flushed with normal saline after the infusion is complete.
Product Specificity is Key: Different IVIg products have different compatibility rules; what applies to one may not apply to another.
Check Prescribing Info: Always refer to the most current package insert for any biologic medication before administration to ensure patient safety.

The Definitive Answer on Gamunex and Saline Compatibility

According to the official prescribing information, Gamunex-C is not compatible with saline and should not be diluted or mixed with normal saline. This is because mixing can lead to the formation of a precipitate, making the solution unsafe for infusion. Gamunex-C must be infused using a separate line without mixing with other intravenous fluids or medications.

Why is Gamunex Incompatible with Normal Saline?

Gamunex-C, an immune globulin injection stabilized with glycine, has a carefully controlled pH and osmolality. Mixing with sodium chloride can disrupt this balance, potentially causing protein aggregation, altering osmolality, and decreasing efficacy. Aggregated proteins can increase the risk of adverse reactions.

The Correct Diluent and Administration Protocol

Gamunex-C is a ready-to-use solution, but if dilution is required, the only recommended diluent is 5% Dextrose in Water (D5/W). No other compatibilities have been evaluated. However, after the infusion is complete, the IV line can be flushed with either D5/W or 0.9% sodium chloride (normal saline).

Understanding Gamunex-C: Indications and Pharmacology

Gamunex-C is an IVIg product derived from pooled human plasma, providing IgG antibodies. It is FDA-approved for:

Primary Immunodeficiency (PI): Administered intravenously or subcutaneously.
Idiopathic Thrombocytopenic Purpura (ITP): To increase platelet counts.
Chronic Inflammatory Demyelinating Polyneuropathy (CIDP): For improving neuromuscular function and preventing relapse in adults.

Initial IV infusion rates vary by indication (e.g., 1 mg/kg/min for PI and ITP, 2 mg/kg/min for CIDP) and can be increased based on tolerance.

Comparison with Other IVIg Formulations

Different IVIg products have unique formulations, stabilizers, and compatibility requirements. Always consult the product-specific package insert.


Feature	Gamunex-C	Gammagard S/D	Carimune NF
Formulation	10% Liquid	Lyophilized (powder)	Lyophilized (powder)
Stabilizer	Glycine	Glycine, Albumin	N/A (requires diluent)
Saline Dilution	Not Compatible	Can be reconstituted with Sterile Water or other diluents; line can be flushed with saline	Can be reconstituted with 0.9% Sodium Chloride, D5W, or Sterile Water
Recommended Diluent	5% Dextrose in Water (D5/W)	Sterile Water for Injection (SWFI)	Sterile (0.9%) Sodium Chloride, D5W, or SWFI

This highlights the importance of checking individual product information, as compatibility with saline varies.

Risks of Improper Administration

Improper administration can lead to adverse events. Common side effects include headache and fever. Serious risks, though rare, include thromboembolic events and renal dysfunction. Gamunex-C has a boxed warning for thrombosis. Acute renal failure risk is linked to sucrose-containing products, which Gamunex-C is not, but caution is still needed in patients with renal issues. Infusion reactions can occur; slow infusion rates are recommended for at-risk patients.

Conclusion

Gamunex is not compatible with normal saline and should not be diluted or mixed with it due to the risk of precipitation. Only D5/W is an approved diluent. However, the IV line can be flushed with normal saline after the infusion. Following these guidelines is crucial for patient safety and efficacy.

For more detailed information, consult the official prescribing information. Grifols Therapeutics LLC.

Frequently Asked Questions

Mixing Gamunex with normal saline can cause the proteins in the solution to clump together and form a precipitate, which appears as cloudiness or chunks. This makes the solution unsafe for intravenous administration.

Yes. According to the FDA package insert, the Gamunex-C infusion line can be flushed with either 5% Dextrose in Water (D5/W) or 0.9% sodium chloride for injection (normal saline) after the infusion is complete.

If dilution is necessary, the only fluid that should be used to dilute Gamunex-C is 5% Dextrose in Water (D5/W).

No, Gamunex-C is a ready-to-use 10% liquid solution and does not require reconstitution. Some other IVIg products come in a powder (lyophilized) form and do require reconstitution, but Gamunex does not.

Using a separate line prevents accidental mixing with other IV fluids or medications, which could be incompatible. The manufacturer explicitly states to infuse Gamunex-C using a separate line by itself.

No. Compatibility is specific to each product's formulation. For example, Carimune NF can be reconstituted with normal saline, whereas Gamunex-C cannot. Always check the specific product's package insert.

Gamunex-C is FDA-approved for the treatment of Primary Immunodeficiency (PI), Idiopathic Thrombocytopenic Purpura (ITP), and Chronic Inflammatory Demyelinating Polyneuropathy (CIDP) in adults.