What is the recommended dosage and administration of Intravenous Immunoglobulin (IVIG)?

Recommended Dosage and Administration of Intravenous Immunoglobulin (IVIG)

The recommended IVIG dosage varies by indication, with standard replacement therapy for immunodeficiency requiring 300-400 mg/kg IV monthly, while treatment of autoimmune conditions typically requires higher doses of 1-2 g/kg divided over multiple days. 1

Dosage by Indication

Primary and Secondary Immunodeficiency

• Replacement therapy: 300-400 mg/kg IV monthly 1
• Target IgG trough levels: >500 mg/dL 2
• May require dose adjustment to 0.3 g/kg and increased frequency (every 2-3 weeks) based on clinical response 3
• For HIV-infected patients with recurrent bacterial infections: 200-400 mg/kg every 2-4 weeks 4

Autoimmune/Inflammatory Conditions

• Kawasaki Disease: 2 g/kg as a single infusion over 10-12 hours 5

  • Higher doses in single infusions show greater efficacy based on meta-analyses 5
  • For children weighing ≥25 kg, evidence suggests 1 g/kg may be similarly effective with lower cost 6

• Immune Thrombocytopenic Purpura (ITP):

  • 400 mg/kg daily for 2-5 consecutive days 3
  • Maintenance therapy: repeat doses of 400 mg/kg as needed 3
  • For life-threatening bleeding in HIV-associated ITP: 1-2 g/kg 4

• Pemphigus Vulgaris:

  • 2 g/kg divided over 5 days, administered monthly 5
  • Single cycle (2 g/kg divided over 5 days) has shown significant improvement in disease activity 5

• Inflammatory Myopathies:

  • 1 g/kg (divided over 1-2 days) monthly for 1-6 months for refractory cases 1

• Immune Checkpoint Inhibitor-Related Toxicities:

  • 2 g/kg administered in divided doses for management of severe neurological adverse events 5

Post-Exposure Prophylaxis

• Measles exposure in susceptible contacts:
  • Standard (non-immunocompromised): 0.25 mL/kg (40 mg IgG/kg) IM 5
  • Immunocompromised: 0.50 mL/kg (80 mg IgG/kg) IM 5

Administration Guidelines

Infusion Rate

• Initial infusions should proceed with caution, especially in previously untreated immunodeficient patients 3
• Standard infusion: typically over 10-12 hours for high-dose regimens (e.g., 2 g/kg for Kawasaki disease) 5

Monitoring During Administration

• Monitor vital signs regularly during infusion
• Watch for common adverse reactions:
  • Headache, fever, nausea, myalgia, and infusion-related reactions 1
  • Serious but rare complications: thromboembolic events, aseptic meningitis, renal dysfunction, hemolytic anemia 1

Special Considerations

• IgA-deficient patients: IVIG is contraindicated in patients with selective IgA deficiency who have detectable anti-IgA antibodies 3
• Vaccination timing: Measles, mumps, and varicella immunizations should be deferred for 11 months after receiving high-dose IVIG 5
• Product differences: IVIG is a biological product made from pooled donor plasma with potentially important manufacturing differences affecting adverse effect profiles 5

Practical Considerations

Product Selection

• Consider product-specific characteristics as adverse effects vary considerably among products 5
• Coombs-positive hemolytic anemia risk is higher in individuals with AB blood type 5

Cost Considerations

• For certain indications like Kawasaki disease in larger children (≥25 kg), lower doses (1 g/kg) may be equally effective with significantly lower costs 6

Follow-up Monitoring

• For replacement therapy: monitor IgG trough levels (target >500 mg/dL) 2
• For autoimmune conditions: monitor disease-specific markers and clinical response

IVIG therapy should be administered in settings equipped to manage potential adverse reactions, with particular caution in patients receiving their first infusion or those with risk factors for complications.