Human Rabies Immune Globulin (HRIG)

Action and Spectrum

Actions and Spectrum 

Human Rabies Immune Globulin (HRIG) functions by giving the body an initial passive immunity against the rabies virus. High concentrations of antibodies (immunoglobulins) found in it can neutralise the virus and stop it from spreading throughout the body. The rabies virus particles are rendered inactive by the antibodies in RIG, which improves the body’s capacity to get rid of the infection. 

All known rabies virus strains and variations are resistant to HRIG. It offers rapid defence against the virus while vaccination stimulates the body’s immune system to produce an active immunological response.

Drug Interaction

Adverse Reaction

Frequency defined  

1-10% 

Sunburn (3%) 

Joint pain (6%) 

Fatigue (6%) 

WBCs in urine (3%) 

Nausea (4%) 

Bruising (3%) 

Blood in urine (4%) 

Feeling faint (4%) 

Dizziness (6%) 

Abdominal pain (4%) 

Muscle pain (9%) 

Upper respiratory tract infection (9%) 

>10% 

Headache (15%) 

Injection site pain (33%) 

Black Box Warning

Black Box Warning 

None  

Contraindication / Caution

Contraindication/Caution: 

Contraindication: 

• People with a known history of hypersensitivity or severe allergic reactions to human immune globulins or any of its components should not be given rabies immune globulin, human (RIG). 

Caution: 

• When administering RIG to those who have a history of bleeding disorders or who are at high risk of bleeding, care should be used.  

• To reduce the possibility of spreading infectious pathogens, RIG is made from human plasma and goes through stringent screening and processing. 

Pregnancy / Lactation

Pregnancy warnings:     

Pregnancy category: N/A 

Lactation: Excretion into human milk is unknown  

Pregnancy Categories:         

Category A: well-controlled and Satisfactory studies show no risk to the fetus in the first or later trimester. 

<b>Category B: there was no evidence of risk to the fetus in animal studies, and there were not enough studies on pregnant women.  

Category C: there was evidence of risk of adverse effects in animal reproduction studies, and no adequate evidence in human studies must take care of potential risks in pregnant women. 

Category D: adequate data with sufficient evidence of human fetal risk from various platforms, but despite the potential risk, and used only in emergency cases for potential benefits. 

Category X: Drugs listed in this category outweigh the risks over benefits. Hence these categories of drugs need to be avoided by pregnant women. 

Category N: There is no data available for the drug under this category. 

Pharmacology

Pharmacology  

The rabies virus is passively protected by rabies immune globulin, human (RIG). It includes a concentrated mixture of certain immunoglobulins that have been isolated from plasma of rabies vaccine recipients.  

The rabies virus is specifically targeted by these antibodies, which neutralize it, preventing it from attaching to or entering host cells and limiting viral proliferation. 

Pharmacodynamics 

By inhibiting the virus attachment to and penetration into host cells, the antibodies neutralize the rabies virus. This reduces the viral load and helps in infection control. 

Antibodies may bind to the virus and render it dormant, stopping it from replicating and spreading throughout the body. 

Pharmacokinetics 

Absorption   

rabies immune globulin, human (RIG) is given intramuscularly (IM) or subcutaneously (SC) by injection. It slowly enters the bloodstream after being injected. The injection site and blood flow are just two examples of variables that may affect the rate and degree of absorption. 

Distribution 

rabies immune globulin, human (RIG) is present in extravascular tissues as well as other parts of the body. If given during pregnancy, RIG can give the foetus some passive immunity since the antibodies it can cross the placenta. 

Metabolism 

rabies immune globulin, human (RIG) is a biological product made from human plasma, it does not go through many key metabolic processes while within the body. The antibodies in RIG did not go through any metabolic changes, therefore they remain comparatively stable. 

Elimination and excretion 

rabies immune globulin, human (RIG) is gradually clearing from the body over period. The elimination half-life, or how long it takes for the drug’s concentration to reduce in half, can differ, although it usually lasts for a few weeks. Natural processes allow the antibodies in RIG to be removed. 

Adminstartion

Administration 

rabies immune globulin, human (RIG) is frequently given as part of post-exposure prophylaxis to those who may have been exposed to the rabies virus. RIG is administered either intramuscularly (IM) or subcutaneously (SC). 

Patient Information Leaflet

Patient information leaflet 

Generic Name: Human Rabies Immune Globulin (HRIG)

Why do we use Human Rabies Immune Globulin (HRIG)?  

Human Rabies Immune Globulin (HRIG) is recommended for people who have experienced a severe exposure to the rabies virus, such as from a bite or scratch. RIG helps prevent the establishment and progression of the rabies infection until the vaccine-induced immunity develops.