Human Normal Immunoglobulin (HNIG) is a sterile, purified, concentrated preparation of immunoglobulin G (IgG) antibodies derived from pooled human plasma of thousands of donors. It contains a broad spectrum of IgG antibodies against common pathogens, reflecting the immune status of the donor population. In the Indian context, it is a critical therapy for primary and secondary immunodeficiencies, and for immunomodulation in autoimmune and inflammatory disorders.
Adult: **Immunodeficiency:** 300-600 mg/kg every 3-4 weeks. **ITP:** 400 mg/kg/day for 2-5 days or 1 g/kg as single dose (may repeat). **GBS/CIDP:** 2 g/kg divided over 2-5 days. **Kawasaki:** 2 g/kg as single infusion with aspirin.
Note: For IV use: Must be infused via separate line. Start at slow rate (e.g., 0.5-1 mg/kg/min) for 30 min. If tolerated, gradually increase to max 4-8 mg/kg/min. For SC use: For maintenance in PID, using pumps. Do not shake. Do not mix with other drugs. Use immediately after opening.
Mechanism is multifactorial: 1) Replacement: Provides passive immunity by supplying functional IgG antibodies to opsonize and neutralize pathogens in immunodeficient patients. 2) Immunomodulation: In autoimmune conditions, mechanisms include Fc receptor blockade on macrophages, neutralization of autoantibodies and cytokines, inhibition of complement activation, and modulation of dendritic cell and T/B cell function.
Pregnancy: Category C. Use only if clearly needed. IgG crosses placenta, increasing from 1st to 3rd trimester. May be beneficial in treating fetal conditions like neonatal alloimmune thrombocytopenia. Monitor for fluid overload.
Driving: May cause dizziness, headache, malaise. Patients should be cautioned about driving or operating machinery until they know how the infusion affects them.
| Live Attenuated Vaccines (MMR, Varicella, Yellow Fever) | Immunoglobulin may interfere with immune response to vaccine. Efficacy may be reduced. | Major |
| Other Immunosuppressants (e.g., high-dose corticosteroids, cyclophosphamide) | Additive immunosuppression may increase infection risk. | Moderate |
| Diuretics (e.g., Furosemide) | Increased risk of renal dysfunction when used with immunoglobulin. | Moderate |
| Nephrotoxic drugs (Aminoglycosides, Amphotericin B, NSAIDs) | Increased risk of acute renal failure. | Major |
Same composition (Human Normal Immunoglobulin (1000mg)), different brands: