What is the recommended dosage of Hepatitis B Immunoglobulin (HBIG)?

Hepatitis B Immunoglobulin (HBIG) Dosage Recommendations

The recommended dose of Hepatitis B Immunoglobulin (HBIG) is 0.06 mL/kg body weight administered intramuscularly. 1

General Dosing Guidelines

HBIG is used for post-exposure prophylaxis (PEP) against hepatitis B virus (HBV) infection. The dosing varies based on the clinical scenario:

For Adults:

• Standard dose: 0.06 mL/kg body weight IM 1, 2
• For most adults: This typically equals approximately 5 mL total dose 2

For Infants:

• Infants born to HBsAg-positive mothers: 0.5 mL IM within 12 hours of birth 2
  • Efficacy decreases markedly if delayed beyond 48 hours
  • Should be administered after physiologic stabilization of the infant

Clinical Scenarios and Administration

1. Percutaneous/Mucosal Exposure to HBsAg-Positive Blood:

• Administer 0.06 mL/kg IM as soon as possible after exposure 2
• Most effective when given within 24 hours; value beyond 7 days after exposure is unclear
• Should be followed by hepatitis B vaccine series initiation within 1 week

2. Sexual Exposure to HBsAg-Positive Person:

• Administer 0.06 mL/kg IM as a single dose 2
• Must be given within 14 days of last sexual contact
• Begin hepatitis B vaccine series concurrently (at different injection site)

3. Perinatal Exposure:

• Administer 0.5 mL IM to newborns preferably within 12 hours of birth 2
• If first dose of hepatitis B vaccine is delayed for up to 3 months, repeat 0.5 mL HBIG at 3 months
• If vaccine is refused, repeat 0.5 mL HBIG at 3 and 6 months

4. Household Exposure:

• For infants <12 months exposed to primary caregiver with acute HBV: 0.5 mL IM 2
• Other household contacts require HBIG only if they had identifiable blood exposure

Important Administration Considerations

• Route: Must be administered intramuscularly; never inject intravenously 2
• Timing: Maximum effectiveness when given as soon as possible after exposure 1, 2
• Concurrent vaccination: HBIG can be administered at the same time as hepatitis B vaccine but at a different injection site 2
• Duration of protection: HBIG provides temporary protection for 3-6 months 1

Special Considerations

• HBIG is typically used as an adjunct to hepatitis B vaccination for previously unvaccinated persons or for persons who have not responded to vaccination 1
• For non-responders to hepatitis B vaccination, HBIG administered alone is the primary means of protection after HBV exposure 1
• HBIG is prepared from plasma known to contain high concentrations of anti-HBs 1
• Visual inspection for particulate matter and discoloration is required prior to administration 2

Potential Pitfalls

• Delayed administration: Efficacy decreases significantly if administration is delayed, especially beyond 48 hours for perinatal exposure 2
• Incorrect route: HBIG must never be administered intravenously 2
• Same-site administration: HBIG and hepatitis B vaccine should be administered at different anatomical sites 3
• Inadequate dosing: Underdosing may lead to insufficient protection against HBV infection

By following these dosing recommendations, HBIG can effectively provide temporary protection against HBV infection when used appropriately for post-exposure prophylaxis.