What is the recommended IVIG (Intravenous Immunoglobulin) protocol?

IVIG Administration Protocol

Standard Dosing Regimens

The recommended IVIG protocol depends on the specific indication, with the most common regimen being 2 g/kg total dose administered either as a single infusion or divided over 2 consecutive days (1 g/kg per day). 1

Dosing by Clinical Indication

Immune Thrombocytopenic Purpura (ITP):

• Initial dose: 1 g/kg as a one-time infusion 2
• May be repeated if necessary 2
• Alternative regimen: 0.4 g/kg/day for 5 days (total 2 g/kg), though the 1-2 day regimen achieves faster platelet response within 24 hours 2

Kawasaki Disease:

• 2 g/kg as a single infusion 1
• This single-dose regimen is the standard in the United States and has equivalent efficacy to divided dosing 3

Guillain-Barré Syndrome:

• 0.4 g/kg/day for 5 consecutive days (total dose 2 g/kg) 2
• Requires inpatient monitoring with ICU capability for severe cases 2

Myasthenia Gravis and Immune Checkpoint Inhibitor-Related Neurologic Toxicity:

• 2 g/kg IV over 5 days (0.4 g/kg/day) 2
• Used for Grade 3-4 toxicity with permanent discontinuation of checkpoint inhibitor 2

Idiopathic Inflammatory Myopathies:

• 1-2 g/kg over 2 consecutive days 1

Immunodeficiency Replacement Therapy:

• Initial: 300-400 mg/kg IV monthly 1
• May increase to 0.3 g/kg every 2-3 weeks if needed 4
• For Common Variable Immunodeficiency (CVID): 0.3-0.4 g/kg every 3-4 weeks after initial high-dose treatment 2

Multisystem Inflammatory Syndrome in Children (MIS-C):

• 2 g/kg based on ideal body weight 1

Pre-Administration Requirements

IgA Deficiency Screening:

• Check serum IgA level before first IVIG administration 1
• Patients with IgA deficiency and detectable IgA antibodies are at risk for severe anaphylaxis 1, 4
• Use IgA-depleted IVIG preparations if deficiency detected 1

Risk Factor Assessment:

• Evaluate renal function (serum creatinine, urine output) 1
• Assess thrombotic risk factors 1
• Review cardiac function, especially in patients with cardiac dysfunction or fluid overload risk 1
• Document history of previous infusion reactions 1

Premedication Protocol

Standard Premedication:

• Diphenhydramine 1
• Acetaminophen 1

High-Risk Patients:

• Consider corticosteroids (e.g., 20 mg prednisone) for patients with history of infusion reactions 2, 1
• Corticosteroids may enhance IVIG response and reduce infusion reactions 2

Weight-Based Dosing Considerations

Obese Patients (BMI ≥30 kg/m²):

• Use ideal body weight (IBW) or adjusted body weight (ABW) rather than actual body weight 1
• This prevents excessive dosing and reduces adverse effects 1

Cardiac Dysfunction:

• Divide total dose over 2 days (1 g/kg daily) to minimize fluid overload 1

Administration Monitoring

During Infusion:

• Monitor renal function including urine output and serum creatinine 1
• Infuse over at least several hours to reduce toxicity 2
• First infusions in previously untreated immunodeficient patients require cautious monitoring due to complement-mediated reaction risk 4

Severe Reaction Management:

• Immediately stop infusion 1
• Administer epinephrine for anaphylaxis 1
• Notify physician immediately 1

Common Adverse Effects

Frequent (dose-dependent):

• Headaches (most common, sometimes severe) 2
• Fever, chills, fatigue 2
• Nausea, diarrhea 2
• Blood pressure changes, tachycardia 2
• Transient neutropenia 2

Rare but Serious:

• Renal failure 2
• Thrombosis 2
• Aseptic meningitis 2
• Anaphylaxis (especially in IgA deficiency) 2, 1

Age-Related Considerations:

• Adverse events are significantly lower in children younger than 5 years 5

Critical Timing Considerations

Plasmapheresis Interaction:

• Do not perform plasmapheresis immediately after IVIG administration, as it will remove the immunoglobulin 2

Response Timeline:

• ITP: Many patients respond within 24 hours, typically 2-4 days 2
• Duration of response usually transient, returning to baseline 2-4 weeks after treatment 2
• Some patients maintain response for months 2