IVIG Administration Route
Intravenous Immunoglobulin (IVIG) must be administered via the intravenous route, as the name explicitly indicates—this is the standard and only FDA-approved route for IVIG products. 1, 2
Standard Intravenous Administration
- IVIG is administered intravenously as an infusion, typically over 10-12 hours for high-dose regimens (2 g/kg), though infusion times can be shortened to 2-3 hours in ambulatory settings for replacement therapy 1, 3
- The intravenous route delivers immunoglobulin directly into the bloodstream, achieving immediate peak serum concentrations necessary for therapeutic effect 4
- Permanent central venous access solely for IVIG administration should be discouraged due to infection risks and catheter-related complications 1
Dosing Varies by Indication
- For Kawasaki Disease: 2 g/kg as a single IV infusion over 10-12 hours 1, 2
- For primary immunodeficiency replacement therapy: 300-400 mg/kg IV monthly, or 400-800 mg/kg every 3-4 weeks 2, 3
- For autoimmune conditions (pemphigus vulgaris, idiopathic inflammatory myopathies): 2 g/kg divided over 2-5 consecutive days 1, 2
- For immune thrombocytopenic purpura: 1 g/kg as a one-time dose, repeatable if necessary 2
Critical Pre-Administration Assessment
- Check serum IgA levels before first IVIG administration to identify IgA-deficient patients at risk for anaphylaxis 1, 2
- If IgA deficiency is detected (<7 mg/dL), use IVIG preparations with reduced IgA content, as anaphylaxis can occur in rare cases with high levels of anti-IgA antibodies 1, 2
- Assess renal function, thrombotic risk factors, and cardiac function (especially in patients with cardiac dysfunction who may require divided dosing to prevent fluid overload) 2
Monitoring During IV Infusion
- Monitor renal function including urine output and serum creatinine during and after administration 2
- Observe for systemic adverse effects including headache, aseptic meningitis, and anaphylaxis, which are more common with IV administration compared to subcutaneous routes 1, 4
- Most adverse effects occur in approximately 12.9% of infusions, with severe reactions in less than 1% of patients 3
Alternative Route: Subcutaneous Administration
- Subcutaneous immunoglobulin (SCIG) is an alternative route available specifically for primary immunodeficiency diseases and chronic inflammatory demyelinating polyneuropathy, but this uses different products than IVIG 4, 5
- SCIG products and IVIG products are not interchangeable—they are distinct formulations designed for their respective routes 4, 5
- Some patients who experienced anaphylaxis with IVIG have tolerated subcutaneous infusions without reactions 1
- SCIG requires more frequent administration (weekly to daily) but avoids venous access requirements and reduces systemic adverse effects 4, 5
Common Pitfall to Avoid
Do not confuse IVIG with SCIG—these are separate therapeutic modalities with different products, pharmacokinetics, and administration protocols. When a patient requires "IVIG," this specifically means intravenous administration unless subcutaneous immunoglobulin is explicitly being considered as an alternative therapy for eligible conditions 4, 5.