1. Clinical Overview
Human Hepatitis B Immunoglobulin (HBIG) is a sterile, concentrated solution of immunoglobulin G (IgG) antibodies specific to the Hepatitis B surface antigen (HBsAg). It is prepared from pooled human plasma of donors with high titers of anti-HBs antibodies. It provides passive immunity against Hepatitis B virus (HBV) infection by neutralizing the virus. In India, it is a critical component of post-exposure prophylaxis (PEP) and for the prevention of HBV re-infection in liver transplant patients.
| Onset | Duration | Bioavailability |
|---|---|---|
| Rapid, with detectable anti-HBs antibodies in serum within minutes to hours after intramuscular administration. | Approximately 3 to 6 months, depending on the dose administered. The half-life of passively administered IgG is about 21-24 days. | Approximately 100% via intramuscular route as it is administered directly into systemic circulation via the muscle. Intravenous formulations have immediate 100% bioavailability. |
2. Mechanism of Action
HBIG provides immediate, passive immunity by delivering high titers of pre-formed antibodies against Hepatitis B surface antigen (HBsAg). These antibodies bind to circulating HBsAg, forming immune complexes that are cleared by the reticuloendothelial system, thereby neutralizing the virus and preventing its attachment and entry into hepatocytes.
3. Indications & Uses
- Post-exposure prophylaxis (PEP) for percutaneous (needlestick), ocular, or mucous membrane exposure to HBsAg-positive blood or body fluids.
- Prevention of Hepatitis B re-infection in HBsAg-positive patients undergoing liver transplantation.
4. Dosage & Administration
Adult Dosage: Post-exposure Prophylaxis: 0.06 mL/kg body weight, intramuscularly, as a single dose. Usual adult dose is 3-5 mL (200-400 IU). For liver transplant patients: Dosing is protocol-based, often 10,000 IU IV during anhepatic phase and continued post-op.
Administration: For IM use: Administer by DEEP INTRAMUSCULAR injection into the gluteal muscle or anterolateral thigh. DO NOT administer intravenously unless product is specifically labeled for IV use. For PEP, administer concurrently with the first dose of Hepatitis B vaccine at a DIFFERENT anatomical site. Shake vial gently before use. Do not mix with other products. Use within 4 hours of vial puncture.
5. Side Effects
Common side effects may include:
- Pain, tenderness, erythema, and induration at the injection site.
- Low-grade fever, malaise, headache.
- Mild arthralgia or myalgia.
6. Drug Interactions
| Drug | Effect | Severity |
|---|---|---|
| Live Attenuated Vaccines (e.g., MMR, Varicella, Yellow Fever) | HBIG may interfere with the immune response to live vaccines. Administration should be deferred for at least 3 months after HBIG, or HBIG should be given at least 2 weeks after the vaccine. | Major |
| Other Immunoglobulin Preparations | May increase the risk of systemic adverse reactions and volume overload. | Moderate |
7. Patient Counselling
- Do inform your doctor if you have ever had a severe reaction to a blood transfusion or immunoglobulin injection.
- Do receive the Hepatitis B vaccine series if prescribed, at a different injection site.
- Do report any signs of infection at the injection site (increasing redness, swelling, pus).
- Don't skip any recommended follow-up doses of Hepatitis B vaccine.
- Don't receive any live vaccines for at least 3 months without consulting your doctor.
8. Toxicology & Storage
Overdose: Unlikely with standard IM doses due to volume constraints. With high-dose IV administration, symptoms may relate to volume overload: headache, dizziness, flushing, chills, chest tightness, and in severe cases, pulmonary edema or 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. Do not use if the solution is cloudy or contains particulate matter. During transport, maintain cold chain. Do not shake vigorously.