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    Disease-Specific Immunoglobulins - Antiviral

    DEA CLASS

    Rx

    DESCRIPTION

    Immune globulin containing antibodies against hepatitis B surface antigen; provides passive immunity to patients exposed to the HBV; may provide protection for up to 2 months.

    COMMON BRAND NAMES

    Hepagam B, HyperHEP S/D, Nabi-HB

    HOW SUPPLIED

    Hepagam B Intravenous Inj Sol: 1mL, 312U
    Hepagam B/HyperHEP S/D/Nabi-HB Intramuscular Inj Sol: 1mL, 5mL, 312U, 1560U

    DOSAGE & INDICATIONS

    For post-exposure hepatitis B prophylaxis.
    Following acute exposure to blood containing HBsAg including percutaneous (e.g., needlestick, bite, sharps), ocular, oral, or mucous membrane exposure to blood.
    NOTE: Receipt of HBIG is not recommended for adults either vaccinated or unvaccinated against HBV following exposure to an unknown source or to a known source at low risk for HBsAg-positivity. Unvaccinated patients are recommended to get the hepatitis B vaccine series.
    Intramuscular dosage
    Adults not yet vaccinated against HBV following exposure to known positive HBsAg source

    0.06 mL/kg IM for 1 dose as soon as possible after exposure (preferably less than 24 hours after exposure but no later than 7 days after exposure). Initiate hepatitis B vaccination series at a different site. For persons who refuse Hepatitis B vaccine or are known non-responders to the vaccine, a second dose of HBIG should be given one month after the first dose.

    Adults not yet vaccinated against HBV following exposure to known source at high risk for HBsAg-positivity

    Initiate hepatitis B vaccination series. Test source for HBsAg. If positive, give 0.06 mL/kg IM for 1 dose. For persons who refuse Hepatitis B vaccine or are known non-responders to the vaccine, a second dose of HBIG should be given one month after the first dose.

    Adults vaccinated against HBV following exposure to known positive HBsAg source

    Test exposed person for anti-HBsAg antibodies. If inadequate antibody (< 10 mIU/mL anti-HBs by radioimmunoassay or negative by enzyme immunoassay), then 0.06 mL/kg IM for 1 dose immediately and hepatitis B vaccine booster dose at a different site or a second dose of HBIG 1 month after the first dose. Two doses of HBIG are preferred if no response after at least 4 doses of vaccine.

    Adults vaccinated against HBV following exposure to known source at high risk for HBsAg-positivity

    Test source for HBsAg only if exposed person is a vaccine nonresponder; if source is HBsAg-positive, give 0.06 mL/kg IM for 1 dose immediately plus hepatitis B vaccine booster dose at a different site or a second dose of HBIG 1 month after the first dose. Two doses of HBIG are preferred if no response after at least 4 doses of vaccine.

    Perinatal exposure of infants born to HBsAg-positive mothers.
    Intramuscular dosage
    Infants born to mother known to be HBsAg-positive

    0.5 mL IM for 1 dose after physiologic stabilization of the infant and preferably within 12 hours of birth. Hepatitis B vaccination series should be initiated simultaneously, if not contraindicated, with the first dose of the vaccine given concurrently with the HBIg, but at a different site. A systematic review and meta-analysis reported that HBIg, alone or combined with hepatitis B vaccine, reduced the risk of perinatal transmission of hepatitis B to infants of mothers who are HBsAg-positive and HBeAg-positive. The study also stated that data from available randomized clinical trials could not support or refute the efficacy of HBIg use in infants of mothers who are HBsAg-positive but HBeAg-negative. A non-randomized study in such patients reported no benefit of adding HBIg to hepatitis B vaccine.

    Infants born to mother not screened for HBsAg

    If mother is found to be HBsAg positive, administer 0.5 mL IM for 1 dose as soon as possible but not later than 7 days after birth. However, the efficacy of HBIG administered after 48 hours of age is not known. Hepatitis B vaccination series should be initiated within 12 hours of birth. Testing for HBsAg and anti-HBs is recommended at 12—15 months of age.

    Sexual exposure to HBsAg-positive persons.
    Intramuscular dosage
    Adults

    0.06 mL/kg IM for 1 dose should be administered to all susceptible persons whose sexual partners have acute viral infection with hepatitis B. In addition, these persons should begin the hepatitis B vaccination series, if not contraindicated, within 14 days of the last sexual contact or if sexual contact with the infected person will continue. Administering the hepatitis B vaccine with HBIG, but at a different site, may improve the efficacy of post-exposure treatment.

    Household exposure to persons with acute HBV infection.
    Intramuscular dosage
    Adults and Children

    Prophylaxis of household contacts of persons with acute viral infection with hepatitis B is not indicated unless they have an identifiable blood exposure to the index patient such as by sharing toothbrushes or razors. These patients should be given 0.06 mL/kg IM for 1 dose and begin the hepatitis B vaccination series within 14 days of contact or if contact will continue. If the index patient becomes a carrier of hepatitis B, all household contacts should receive hepatitis B vaccine series.

    Infants

    0.5 mL IM for 1 dose and begin the hepatitis B vaccination series if the mother or primary caregiver has acute acute viral infection with hepatitis B.

    For prevention of hepatitis B infection recurrence after liver transplantation in HBsAg-positive liver transplant patients.
    NOTE: In March 2008, HepaGam B received orphan drug exclusive approval from the FDA for this indication, which provides HepaGam B seven years of market exclusivity.
    NOTE: HBIG is most effective in patients with absent or low levels of HBV replication at the time of transplantation.
    NOTE: Use of HBIG with antiviral therapy after transplantation has not been evaluated.
    NOTE: Patients with surgical bleeding, patients with abdominal fluid drainage > 500 mL, or patients undergoing plasmapheresis are particularly susceptible to extreme loss of circulated antiHBs.
    Intravenous infusion dosage (HepaGam B only)
    Adults

    20,000 units IV concurrent with grafting of the transplanted liver, then 20,000 units/day IV on days 1—7 postoperatively, then 20,000 units IV every 2 weeks starting on day 14 postoperatively, then 20,000 units IV every month starting on month 4 postoperatively. The target serum antiHBs concentration is > 500 units/L. Regularly monitor the serum antiHBs and HBsAg concentration before an infusion to track response and to allow for treatment adjustment. If the serum antiHBs concentration is < 500 units/L within the first week of transplantation, increase the dose to 10,000 units IV every 6 hours until the target antiHBs concentration is reached.

    MAXIMUM DOSAGE

    Adults

    0.06 mL/kg/dose IM for hepatitis B prophylaxis; 20,000 International Units/dose IV for prevention of hepatitis B recurrence.

    Geriatric

    0.06 mL/kg/dose IM for hepatitis B prophylaxis.

    Adolescents

    0.06 mL/kg/dose IM for hepatitis B prophylaxis.

    Children

    0.06 mL/kg/dose IM for hepatitis B prophylaxis.

    Infants

    0.5 mL/dose IM for hepatitis B prophylaxis.

    DOSING CONSIDERATIONS

    Hepatic Impairment

    Specific guidelines for dosage adjustments in hepatic impairment are not available; it appears that no dosage adjustments are needed.

    Renal Impairment

    Specific guidelines for dosage adjustments in renal impairment are not available; it appears that no dosage adjustments are needed.

    ADMINISTRATION

     
    NOTE: Each vial of HepaGam B or of Nabi-HB has at least 312 International Units anti-HBs/mL. The measured potency of each lot of HepaGam B is stamped on the vial label.

    Injectable Administration

    Hepatitis B immune globulin is administered intramuscularly for postexposure prophylaxis or intravenously for prevention of hepatitis B recurrence after liver transplantation in HBsAg-positive patients (NOTE: ONLY HepaGam B is approved for intravenous administration).
    Hepatitis B immune globulin should not be given in the same syringe or injected at the same site as hepatitis B virus vaccine.
    A separate syringe and needle should be used for each person receiving HBIG.
    Visually inspect parenteral products for particulate matter and discoloration prior to administration whenever solution and container permit. Do not use if particulate matter is present or if the product is not clear to opalescent. Do not shake vials, avoid foaming.

    Intravenous Administration

    HepaGam B only:
    Calculate the volume needed for each 20,000 IU dose by using the measured potency of the HepaGam B lot. The potency is stamped on the vial label. Aseptically prepare the dose.
    Promptly use the product after the vial has been entered; use within 6 hours of vial entry. No preservatives are in the single-dose vials; discard any unused product in a vial that has been entered.
    Administer at 2 ml/minute through a separate intravenous line using an intravenous administration set via infusion pump. Decrease the rate to 1 ml/minute or less if the patient gets uncomfortable, if the patient has infusion-related adverse events, or if concern about the infusion speed exists.

    Intramuscular Administration

    Promptly use the product after the vial has been entered; use within 6 hours of vial entry. No preservatives are in the single-dose vials; discard any unused product in a vial that has been entered.
    In adults and children: Intramuscular injections should be made into the deltoid muscle or into the anterolateral muscles of the thigh. In order to avoid injury to the sciatic nerves, injection into the upper outer quadrant of the gluteus maximus should be used only if large volumes are administered or when large doses must be divided into multiple IM injections. If the gluteal region is used, only inject into the upper outer quadrant; avoid the central region.
    In neonates, infants, and small children: Intramuscular injections should be made into the anterolateral muscles of the thigh.
    Aspirate prior to injection to avoid injection into a blood vessel. If a vessel is penetrated, withdraw the needle, and use a new syringe and needle at a different injection site.

    STORAGE

    Hepagam B:
    - Discard product if it contains particulate matter, is cloudy, or discolored
    - Do not freeze
    - Store product in refrigerator (36 to 46 degrees F) and use within 6 hours after opening
    HyperHEP S/D:
    - Discard product if it contains particulate matter, is cloudy, or discolored
    - Protect from freezing
    - Refrigerate (between 36 and 46 degrees F)
    Nabi-HB:
    - Discard product if it contains particulate matter, is cloudy, or discolored
    - Do not freeze
    - Store product in refrigerator (36 to 46 degrees F) and use within 6 hours after opening

    CONTRAINDICATIONS / PRECAUTIONS

    Maltose hypersensitivity

    Hepatitis B immune globulin (HBIG) should be used cautiously in patients with a history of human immune globulin hypersensitivity. Do not administer HBIG to patients with known severe, potentially life-threatening reactions to human globulin. Use HepaGam B cautiously in patients with maltose hypersensitivity, as the product contains maltose.

    Intravenous administration

    Intravenous administration of hepatitis B immune globulin (HBIG) is only recommended for the prevention of hepatitis B recurrence following liver transplantation in HBsAg-positive liver transplant patients. HBIG used for other indications should only be administered intramuscularly.

    IgA deficiency

    Patients with IgA deficiency often develop antibodies against IgA and are more likely to have anaphylactic or immune-mediated adverse reactions to pooled immunoglobulin products such as hepatitis B immune globulin (HBIG). HepaGam B contains less than 40 mcg/ml of IgA. Weigh the potential benefit of HBIG receipt against the potential for hypersensitivity reactions.

    Coagulopathy, hemophilia, thrombocytopenia

    Intramuscular injections of hepatitis B immune globulin (HBIG) can cause injury at the injection site and should be used cautiously in patients with thrombocytopenia or coagulopathy (e.g., hemophilia). Use hepatitis B immune globulin, HBIG cautiously in patients who have severe thrombocytopenia or any coagulation disorder that would potentially contraindicate intramuscular administration only if the expected risks outweigh the benefits of HBIG receipt.

    Pregnancy

    Hepatitis B immune globulin (HBIG) is an FDA pregnancy category C drug. The ability of HBIG to cause fetal harm or to affect reproductive capacity is unknown. Administer HBIG to a pregnant woman only if clearly indicated. Studies concerning its effects on the fetus have not been done; however, other immunoglobulins have been used safely during pregnancy. Consult current CDC and American College of Obstetrician and Gynecology guidelines prior to use in pregnant patients; many guidelines recommend the use of HBIG during pregnancy for HBV post-exposure prophylaxis when indicated.

    Breast-feeding

    Excretion of hepatitis B immune globulin (HBIG) into breast milk is unknown; administer cautiously to women who are breast-feeding. Case reports of two nursing mothers receiving intravenous immune globulin therapy suggest transfer of IgG and IgM into the colostrum and breast milk. Consider the benefits of breast-feeding, the risk of potential infant drug exposure, and the risk of an untreated or inadequately treated condition. If a breast-feeding infant experiences an adverse effect related to a maternally administered drug, health care providers are encouraged to report the adverse effect to the FDA. 

    Vaccination

    Although HGIG did not interfere with measles vaccination, it is not known whether Hepatitis B immune globulin (HBIG) may interfere with other live virus vaccines. Therefore, vaccinations should be delayed until 3 months after HBIG administration and it may be necessary to revaccinate persons who received HBIG shortly after live virus vaccination. Hepatitis B vaccine may be given at the same time, but at a different site, and may enhance the efficacy of post-exposure treatment

    Hyperglycemia

    Blood glucose testing systems based on the glucose dehydrogenase pyrroloquinolinequinone or on the glucose-dye-oxidoreductase methods falsely interpret the maltose contained in HepaGam B as glucose. Falsely elevated glucose readings (false hyperglycemia) have led to life-threatening hypoglycemia because of inappropriate administration of insulin. Falsely elevated glucose readings could also mask true cases of hypoglycemia. Measurement of blood glucose must be done with a glucose-specific method if a patient takes a parenteral product that contains maltose. Read the product information of the blood glucose testing system including the information about the test strips to determine if the system is appropriate for use with maltose-containing parenteral products. If any uncertainty exists, contact the manufacturer of the testing system.

    Viral infection

    As with other products derived from or purified with human blood components, the possibility of transmission of viral or bacterial infections exists in patients receiving hepatitis B immune globulin (HBIG). Screening plasma donors for prior exposure to certain viruses, testing for the presence of viruses, and inactivating and/or reducing viruses has reduced the risk of transmission of infectious agents. The manufacturing processes are designed to reduce the risk of transmitting viral infection; however, none of the processes are completely effective. There is also the possibility that unknown infectious agents may be present in this product. All HBIG products produced since 1985 have been tested for HIV antibody; however, some products produced between 1982 and 1985 may be positive for HIV antibody. There has been no evidence of HIV transmission from HBIG administration. Pooled antibodies may provide sufficient HIV antibodies to yield falsely positive HIV tests in individuals who received immunoglobulin before 1985, although this is unlikely. There have been no reported cases of HBV, non-A hepatitis, or non-B hepatitis infection transmission via HBIG administration, although this is a remote theoretical possibility.

    ADVERSE REACTIONS

    Moderate

    erythema / Early / Incidence not known
    hypotension / Rapid / Incidence not known

    Mild

    headache / Early / 14.0-14.0
    injection site reaction / Rapid / 4.0-12.0
    myalgia / Early / 10.0-10.0
    malaise / Early / 6.0-6.0
    nausea / Early / 4.0-4.0
    arthralgia / Delayed / 2.0-2.0
    ecchymosis / Delayed / 2.0-2.0
    vomiting / Early / 2.0-2.0
    tremor / Early / Incidence not known
    urticaria / Rapid / Incidence not known
    chills / Rapid / Incidence not known
    fatigue / Early / Incidence not known
    diarrhea / Early / Incidence not known
    back pain / Delayed / Incidence not known
    dizziness / Early / Incidence not known
    syncope / Early / Incidence not known
    fever / Early / Incidence not known
    infection / Delayed / Incidence not known

    DRUG INTERACTIONS

    Diphtheria Toxoid, Tetanus Toxoid, Acellular Pertussis Vaccine, DTaP; Hepatitis B Vaccine, Recombinant; Inactivated Poliovirus Vaccine, IPV : (Minor) Administration of hepatitis B virus vaccines (e.g., hepatitis B vaccine, recombinant) at the same site or in the same syringe as hepatitis B immune globulin, HBIG can result in neutralization. Hepatitis B Immune Globulin (human) may be administered at the same time (but at a different site) or up to one month preceding hepatitis B vaccination without impairing the active immune response to hepatitis B vaccine.
    Haemophilus influenzae type b Conjugate Vaccine; Hepatitis B Vaccine, Recombinant: (Minor) Administration of hepatitis B virus vaccines (e.g., hepatitis B vaccine, recombinant) at the same site or in the same syringe as hepatitis B immune globulin, HBIG can result in neutralization. Hepatitis B Immune Globulin (human) may be administered at the same time (but at a different site) or up to one month preceding hepatitis B vaccination without impairing the active immune response to hepatitis B vaccine.
    Hepatitis A Vaccine, Inactivated; Hepatitis B Vaccine, Recombinant: (Minor) Administration of hepatitis B virus vaccines (e.g., hepatitis B vaccine, recombinant) at the same site or in the same syringe as hepatitis B immune globulin, HBIG can result in neutralization. Hepatitis B Immune Globulin (human) may be administered at the same time (but at a different site) or up to one month preceding hepatitis B vaccination without impairing the active immune response to hepatitis B vaccine.
    Hepatitis B Vaccine, Recombinant: (Minor) Administration of hepatitis B virus vaccines (e.g., hepatitis B vaccine, recombinant) at the same site or in the same syringe as hepatitis B immune globulin, HBIG can result in neutralization. Hepatitis B Immune Globulin (human) may be administered at the same time (but at a different site) or up to one month preceding hepatitis B vaccination without impairing the active immune response to hepatitis B vaccine.
    Measles Virus; Mumps Virus; Rubella Virus; Varicella Virus Vaccine, Live: (Major) Do not give immune globulin including concurrently with the varicella-zoster virus vaccine, live. Because of the potential inhibition of the immune response to vaccination by passively transferred antibodies, it is advisable not to give varicella-zoster virus vaccine, live to any patient who has received blood (except washed red blood cells), plasma transfusions, or immunoglobulins within the previous 5 months. After varicella vaccination, the CDC recommends that immune globulin products should not be given for 3 weeks, unless the benefit outweighs the risk; the manufacturer recommends waiting 2 months before administering immunoglobulins. In the case that IgG products are administered within 3 weeks of vaccination, the vaccinee should be either revaccinated at 5 months or tested for immunity and revaccinated if seronegative. Consult current CDC guidelines for recommendations. (Major) The manufacturers advise deferral of live virus vaccine receipt such as measles/mumps/rubella vaccines, MMR and varicella virus vaccine live until approximately 3 months after hepatitis B immune globulin, HBIG administration. Of note, the Advisory Committee on Immunization Practices states that Ty21a typhoid; yellow fever; live, attenuated influenza vaccine; zoster; and rotavirus vaccines may be administered at any time before, concurrent with, or after administration of HBIG. For all other live vaccines, do not administer simultaneously with HBIG, as HBIG may interfere with live virus vaccines. If simultaneous administration of measles-containing vaccine or varicella-containing vaccine (except zoster) is unavoidable, administer the products at different sites and revaccinate or test for seroconversion after recommended interval of at least 3 months between HBIG administration and any measles or varicella-containing vaccine except the zoster vaccine. It may be necessary to revaccinate persons who received HBIG shortly after live virus vaccination. If HBIG was administered less than 14 days after live virus vaccination, revaccinate 3 months after HBIG administration unless serologic test results indicate antibody production. Administering inactivated vaccines and toxoids either simultaneously with or at any interval before or after receipt of an antibody-containing product should not substantially impair development of a protective antibody response. Administer the inactivated vaccine or toxoid and HBIG at different sites using the standard recommended doses.
    Measles/Mumps/Rubella Vaccines, MMR: (Major) The manufacturers advise deferral of live virus vaccine receipt such as measles/mumps/rubella vaccines, MMR and varicella virus vaccine live until approximately 3 months after hepatitis B immune globulin, HBIG administration. Of note, the Advisory Committee on Immunization Practices states that Ty21a typhoid; yellow fever; live, attenuated influenza vaccine; zoster; and rotavirus vaccines may be administered at any time before, concurrent with, or after administration of HBIG. For all other live vaccines, do not administer simultaneously with HBIG, as HBIG may interfere with live virus vaccines. If simultaneous administration of measles-containing vaccine or varicella-containing vaccine (except zoster) is unavoidable, administer the products at different sites and revaccinate or test for seroconversion after recommended interval of at least 3 months between HBIG administration and any measles or varicella-containing vaccine except the zoster vaccine. It may be necessary to revaccinate persons who received HBIG shortly after live virus vaccination. If HBIG was administered less than 14 days after live virus vaccination, revaccinate 3 months after HBIG administration unless serologic test results indicate antibody production. Administering inactivated vaccines and toxoids either simultaneously with or at any interval before or after receipt of an antibody-containing product should not substantially impair development of a protective antibody response. Administer the inactivated vaccine or toxoid and HBIG at different sites using the standard recommended doses.
    Rotavirus Vaccine: (Major) Defer vaccination with live virus vaccines such as Rotavirus Vaccine until approximately 3 months after Hepatitis B immune globulin administration. Inform the immunizing physician of recent therapy with the immune globulin so that appropriate measures can be taken. The efficacy of live attenuated virus vaccines such as Rotavirus Vaccine may be impaired by Hepatitis B immune globulin administration; revaccination may be necessary. The passive transfer of antibodies from the immune globulin may impair the efficacy of live attenuated virus vaccines.
    Rubella Virus Vaccine Live: (Major) The manufacturers advise deferral of live virus vaccine receipt such as measles/mumps/rubella vaccines, MMR and varicella virus vaccine live until approximately 3 months after hepatitis B immune globulin, HBIG administration. Of note, the Advisory Committee on Immunization Practices states that Ty21a typhoid; yellow fever; live, attenuated influenza vaccine; zoster; and rotavirus vaccines may be administered at any time before, concurrent with, or after administration of HBIG. For all other live vaccines, do not administer simultaneously with HBIG, as HBIG may interfere with live virus vaccines. If simultaneous administration of measles-containing vaccine or varicella-containing vaccine (except zoster) is unavoidable, administer the products at different sites and revaccinate or test for seroconversion after recommended interval of at least 3 months between HBIG administration and any measles or varicella-containing vaccine except the zoster vaccine. It may be necessary to revaccinate persons who received HBIG shortly after live virus vaccination. If HBIG was administered less than 14 days after live virus vaccination, revaccinate 3 months after HBIG administration unless serologic test results indicate antibody production. Administering inactivated vaccines and toxoids either simultaneously with or at any interval before or after receipt of an antibody-containing product should not substantially impair development of a protective antibody response. Administer the inactivated vaccine or toxoid and HBIG at different sites using the standard recommended doses.
    Varicella-Zoster Virus Vaccine, Live: (Major) Do not give immune globulin including concurrently with the varicella-zoster virus vaccine, live. Because of the potential inhibition of the immune response to vaccination by passively transferred antibodies, it is advisable not to give varicella-zoster virus vaccine, live to any patient who has received blood (except washed red blood cells), plasma transfusions, or immunoglobulins within the previous 5 months. After varicella vaccination, the CDC recommends that immune globulin products should not be given for 3 weeks, unless the benefit outweighs the risk; the manufacturer recommends waiting 2 months before administering immunoglobulins. In the case that IgG products are administered within 3 weeks of vaccination, the vaccinee should be either revaccinated at 5 months or tested for immunity and revaccinated if seronegative. Consult current CDC guidelines for recommendations.

    PREGNANCY AND LACTATION

    Pregnancy

    Hepatitis B immune globulin (HBIG) is an FDA pregnancy category C drug. The ability of HBIG to cause fetal harm or to affect reproductive capacity is unknown. Administer HBIG to a pregnant woman only if clearly indicated. Studies concerning its effects on the fetus have not been done; however, other immunoglobulins have been used safely during pregnancy. Consult current CDC and American College of Obstetrician and Gynecology guidelines prior to use in pregnant patients; many guidelines recommend the use of HBIG during pregnancy for HBV post-exposure prophylaxis when indicated.

    Excretion of hepatitis B immune globulin (HBIG) into breast milk is unknown; administer cautiously to women who are breast-feeding. Case reports of two nursing mothers receiving intravenous immune globulin therapy suggest transfer of IgG and IgM into the colostrum and breast milk. Consider the benefits of breast-feeding, the risk of potential infant drug exposure, and the risk of an untreated or inadequately treated condition. If a breast-feeding infant experiences an adverse effect related to a maternally administered drug, health care providers are encouraged to report the adverse effect to the FDA. 

    MECHANISM OF ACTION

    The pooled monomeric IgG present in HBIg provides a variety of antibodies capable of neutralizing the hepatitis B virus by opsonization, resulting in complement activation and stimulation of cell-mediated immunity. The passive immunity imparted by HBIg is capable of attenuating or preventing HBV infection.

    PHARMACOKINETICS

    Hepatitis B Immune Globulin, HBIG is administered intramuscularly or intravenously. The distribution of HBIG has not been described; however, it is probable that HBIG crosses the placenta and may be distributed into breast milk. The half-life of Nabi-HB is 23.1 +/- 5.5 days. The mean half-life of HepaGam B after intramuscular administration is 22—25 days. The exact fate of HBIG is not well defined.

    Intramuscular Route

    Following intramuscular injection, Hepatitis B Immune Globulin, HBIG is slowly absorbed, with anti-HBs appearing in 1—6 days and peak concentrations attained in about 3—9 days. Anti-HBs remain in the serum for up to 2 months.