IMMUNOHBs

• Approved Indications:
• Post-exposure prophylaxis for individuals exposed to Hepatitis B virus (HBV), including:
• Neonates born to HBsAg-positive mothers to prevent perinatal transmission.
• Individuals with percutaneous or mucosal exposure to HBV-infected blood or body fluids (e.g., healthcare workers with needle-stick injuries).
• Sexual partners or household contacts of HBsAg-positive persons.
• Recipients of liver transplantation from HBV-infected donors to prevent graft reinfection.
• Adjunct to hepatitis B vaccination to provide passive immunity in exposed individuals.
• Clinically Accepted Off-Label Uses:
• Immediate passive immunization for high-risk individuals with unknown vaccination or immune status after potential HBV exposure.
• Protection in immunocompromised patients undergoing invasive procedures with HBV exposure risk.

• Adults and Pediatrics:
• Post-exposure prophylaxis: 0.06 mL/kg intramuscular (IM) injection as soon as possible, ideally within 24 hours but up to 7 days post-exposure.
• For neonates born to HBsAg-positive mothers: 0.5 mL IM within 12 hours of birth, ideally in the anterolateral thigh.
• May be repeated at 1-month intervals depending on exposure risk or ongoing risk.
• Concurrent hepatitis B vaccination is recommended for sustained active immunity.
• Elderly:
• No specific dose adjustment; follow standard dosing.
• Special Populations:
• Use with caution in patients with bleeding disorders or thrombocytopenia due to intramuscular administration route.
• Avoid intravenous administration unless under specific clinical protocols.
• Route:
• Intramuscular injection only; do not administer intravenously.
• Frequency:
• Single dose post-exposure; may require additional doses if exposure continues.

Hepatitis B Immune Globulin provides immediate passive immunity by supplying high titers of anti-HBs antibodies. These antibodies bind to circulating hepatitis B virus particles and hepatitis B surface antigen (HBsAg), neutralizing the virus and preventing its attachment and entry into hepatocytes. This action reduces viral replication and establishment of infection. Passive immunity offered by HBIG is temporary, typically lasting 3 to 6 months, which is why it is used alongside active vaccination for long-term protection.

• Absorption:
• Rapidly absorbed after intramuscular injection, with peak plasma antibody concentrations within 2 to 4 days.
• Distribution:
• Distributed primarily in the intravascular and extracellular fluid compartments.
• Metabolism:
• Immunoglobulin catabolized via reticuloendothelial system and proteolytic degradation.
• Excretion:
• Catabolites are eliminated mainly by the kidneys.
• Half-life:
• Approximately 3 to 4 weeks, depending on individual patient factors.

• Pregnancy:
• Category C (FDA classification). No evidence of harm in animal studies; clinical data in pregnant women is limited.
• Considered safe during pregnancy when indicated, especially to prevent vertical transmission of HBV.
• Lactation:
• Safe to use during breastfeeding; antibodies may pass into breast milk and could provide passive immunity to the infant.
• Data: Limited controlled data; clinical judgment advised.

• Primary Class: Immune globulin, passive immunizing agent
• Subclass: Hepatitis B specific immune globulin

• Known hypersensitivity to human immune globulin preparations.
• History of severe allergic reactions or anaphylaxis to immune globulin or blood products.
• IgA deficiency with antibodies against IgA and history of hypersensitivity.

• Administer via intramuscular route only to minimize risk of systemic reactions.
• Use caution in patients with bleeding disorders or on anticoagulants due to IM injection bleeding risk.
• Monitor for hypersensitivity reactions, including anaphylaxis; have emergency equipment ready.
• Transmission of infectious agents is extremely rare but possible despite screening and manufacturing safeguards.
• Use in neonates with care; ensure correct dose and injection technique.
• Avoid intravenous administration outside specialized protocols.
• Assess vaccination status; HBIG does not replace active immunization.

• Common:
• Injection site pain, redness, swelling.
• Mild fever or malaise.
• Rare/Serious:
• Allergic reactions including rash, urticaria.
• Anaphylaxis (rare).
• Headache or dizziness.
• Possible transient changes in blood pressure or heart rate.

• No significant CYP450 enzyme interactions.
• Concurrent vaccination with hepatitis B vaccine is standard; no adverse interactions.
• May interfere with live vaccines; avoid administering live vaccines simultaneously.
• No known interactions with food or alcohol.

• Current guidelines recommend HBIG administration combined with hepatitis B vaccination for all perinatal exposures.
• Updated CDC and WHO guidelines emphasize early administration (within 24 hours of exposure) for maximum efficacy.
• Recent protocols include HBIG use in combination with antiviral therapy for liver transplant recipients.
• Emphasis on screening high-risk populations for HBV and timely prophylaxis.

• Store at 2°C to 8°C (36°F to 46°F); do not freeze.
• Protect from light; keep in original packaging until use.
• Do not use if solution is discolored or contains particulate matter.
• Use aseptic technique; discard unused portions.