IMMUNOHBs

Indications

Hepatitis B immunoglobulin (HBIG) gives immediate, short term protection against hepatitis B virus. It is used for newborn babies of mothers who carry hepatitis B, given together with the first dose of hepatitis B vaccine; after exposure to hepatitis B, such as a needle stick injury, sexual contact or blood splash, in people who are not immune; and to prevent hepatitis B returning in the new liver after a liver transplant in people with hepatitis B.

How It Works

It is made from the plasma of donors with high levels of antibodies against the hepatitis B surface antigen. These ready made antibodies bind to the virus and help stop it from infecting liver cells. This is called passive immunity: it works quickly but lasts only a few weeks to months, which is why the hepatitis B vaccine is usually given as well for long term protection.

Dosage and Administration

It is given by a doctor or nurse, usually as an injection into a muscle; some products are given into a vein, especially after liver transplant. The dose and timing are as prescribed and depend on the reason for use, age and body weight. For newborns it should be given as soon as possible after birth, ideally within 12 hours. After an exposure it works best when given as early as possible, ideally within 24 hours.

Interactions

• Live vaccines such as measles, mumps, rubella and varicella may work less well if given within about 3 months after the immunoglobulin; the doctor will advise timing.
• It does not stop the hepatitis B vaccine from working when the two are given at different sites.
• Tell the doctor about blood thinners such as Warfarin, because intramuscular injection can cause bleeding.

Contraindications

• Severe allergic reaction to human immunoglobulins or any component.
• Intramuscular forms should not be given to people with severe low platelets or serious bleeding disorders.
• Use with care in people with IgA deficiency who have antibodies to IgA.

Side Effects

Common: pain, tenderness and swelling at the injection site. Less common: headache, fever, chills, tiredness, nausea, rash and joint pain. Rare: severe allergic reaction, drop in blood pressure, and blood clots, especially with products given into a vein.

Get urgent medical help for difficulty breathing, swelling of the face or throat, fainting, chest pain, sudden leg swelling or pain, or sudden weakness on one side of the body.

Pregnancy and Lactation

It may be given in pregnancy and during breastfeeding when the doctor decides it is needed; immunoglobulins have long been used without known harm to the baby.

Precautions and Warnings

Because it is made from human blood plasma, there is a very small risk of passing on infections, although donors are screened and the product is treated to remove viruses. The person should be watched for at least 20 minutes after the injection. Tell the doctor about any earlier reaction to immunoglobulins, bleeding problems, heart disease or a history of blood clots. It does not replace the hepatitis B vaccine.

Overdose

Overdose is unlikely because it is given by health professionals. Very large amounts given into a vein may cause fluid overload or thickening of the blood; this is managed in hospital.

Therapeutic Class

Specific immunoglobulin (passive immunisation against hepatitis B)

Storage

Store in a refrigerator at 2 to 8°C. Do not freeze. Protect from light. Kept by the hospital or clinic as directed on the pack.