📋 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.

💊 Dosage & Administration

Adult: 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.

Note: 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.

⚠️ Contraindications

History of severe systemic hypersensitivity reactions (anaphylaxis) to human immunoglobulin preparations or any component (e.g., glycine, polysorbate).
Patients with selective IgA deficiency who have known antibodies against IgA (risk of anaphylaxis).

🔬 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.

🤕 Side Effects

Pain, tenderness, erythema, and induration at the injection site.
Low-grade fever, malaise, headache.
Mild arthralgia or myalgia.

🤰 Special Populations

Pregnancy: Pregnancy Category C (US FDA). No well-controlled studies. Use only if clearly needed, such as for post-exposure prophylaxis in a pregnant healthcare worker. Benefits generally outweigh risks. Anti-HBs antibodies can cross the placenta.

Driving: Unlikely to affect ability. Patients should be advised about potential for dizziness or malaise.

🔄 Drug Interactions

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

HepaGam