1. Clinical Overview
Human Hepatitis B Immunoglobulin (HBIG) is a sterile, concentrated solution of immunoglobulins, primarily immunoglobulin G (IgG), containing high titers of antibodies against Hepatitis B surface antigen (anti-HBs). It is prepared from pooled human plasma from screened donors with high anti-HBs titers. It provides passive immunity against Hepatitis B virus (HBV) infection. In the Indian context, it is a critical component of post-exposure prophylaxis (PEP) and for prevention of HBV recurrence post-liver transplantation.
| Onset | Duration | Bioavailability |
|---|---|---|
| Rapid, with detectable antibody levels within hours of intramuscular administration. | Approximately 3 to 6 months. The half-life of passively administered IgG is about 21-24 days. | 100% following intravenous infusion. Intramuscular bioavailability is variable but considered complete over time as the protein is absorbed from the injection site. |
2. Mechanism of Action
HBIG provides immediate, passive immunity by delivering high titers of neutralizing antibodies (anti-HBs) against the Hepatitis B surface antigen (HBsAg). These antibodies bind to circulating HBV particles, facilitating their opsonization and clearance by the reticuloendothelial system, thereby preventing the virus from infecting hepatocytes.
3. Indications & Uses
- Post-exposure prophylaxis (PEP) for percutaneous (needlestick), ocular, or mucous membrane exposure to HBsAg-positive blood/body fluids.
- Prevention of Hepatitis B re-infection following liver transplantation in HBsAg-positive recipients.
- Prophylaxis for infants born to HBsAg-positive mothers (given within 12 hours of birth along with Hepatitis B vaccine).
4. Dosage & Administration
Adult Dosage: Post-exposure Prophylaxis: 100 IU (0.06 mL/kg) intramuscularly, preferably within 24 hours (max 7 days) of exposure. For liver transplant: Dosing is peri-operative and maintenance-based, often 500-10,000 IU IV as per protocol.
Administration: For IM use: Administer by DEEP INTRAMUSCULAR injection into the anterolateral aspect of the thigh (infants) or deltoid muscle (adults). Do NOT administer intravenously or subcutaneously unless specified for an IV formulation. Do not mix with other medications. Use a separate syringe and needle. Observe patient for at least 30 minutes post-injection.
5. Side Effects
Common side effects may include:
- Pain, tenderness, erythema, and induration at the injection site.
- Low-grade fever, chills, headache.
- Malaise, fatigue.
6. Drug Interactions
| Drug | Effect | Severity |
|---|---|---|
| Live Virus Vaccines (e.g., MMR, Varicella, Yellow Fever) | HBIG may interfere with the immune response to live virus vaccines. Administration should be deferred for at least 3 months after HBIG, or vaccine given at least 2 weeks before HBIG. | Major |
| Other Immunoglobulin Preparations | May increase the risk of systemic adverse reactions and volume overload. | Moderate |
7. Patient Counselling
- DO complete the full course of Hepatitis B vaccine series as prescribed, even after receiving HBIG.
- DO inform all healthcare providers (including dentists) about this injection, especially before any future vaccinations.
- DO report any signs of allergic reaction (rash, itching, swelling, dizziness) immediately.
- DON'T miss the timing; administration is most effective when given as soon as possible after exposure.
- DON'T share needles or have unprotected sex until Hepatitis B vaccination is confirmed effective.
8. Toxicology & Storage
Overdose: Overdose is unlikely with standard IM doses. With massive IV overdose, symptoms may relate to volume overload, hyperviscosity (headache, blurred vision, thromboembolism), and aseptic meningitis.
Storage: Store at +2°C to +8°C (in a refrigerator). DO NOT FREEZE. Protect from light. Keep the vial in the outer carton. The product should be administered as soon as possible after withdrawal from the vial. Do not use if the solution is cloudy or contains particulate matter. Do not use after the expiry date.