Immunorho Mechanism of Action

Pharmacotherapeutic group: Immune sera and immunoglobulins, immunoglobulins, specific immunoglobulins: Anti-D (Rh) immunoglobulin. ATC code: J06BB01.
Pharmacology: Pharmacodynamics: Anti-D immunoglobulin contains specific antibodies (IgG) against the D (Rh) antigen of human erythrocytes.
During pregnancy, and especially at the time of childbirth, fetal red blood cells may enter the maternal circulation. When the woman is Rh(D) negative and the fetus Rh(D) positive, the woman may become immunised to the Rh(D) antigen and produce anti-Rh(D) antibodies which cross the placenta and may cause haemolytic disease of the newborn. Passive immunisation with anti-D immunoglobulin prevents Rh(D) immunisation in more than 99% of cases provided that a sufficient dose of anti-D immunoglobulin is administered soon enough after exposure to Rh(D) positive fetal red blood cells.
The mechanism by which anti-D immunoglobulin suppresses immunisation to Rh(D) positive red cell is not known. Suppression may be related to the clearance of the red cells from the circulation before they reach immunocompetent sites or, it may be due to more complex mechanisms involving recognition of foreign antigen and antigen presentation by the appropriate cells at the appropriate sites in the presence or absence of antibody.
Paediatric population: No specific studies of efficacy and safety are available on paediatric population.
Pharmacokinetics: Human anti-D immunoglobulins for intramuscular administration is slowly absorbed into the recipient's circulation and reaches a maximum after a delay of 2-3 days.
Human anti-D immunoglobulin has a half-life of about 3-4 weeks. This half-life may vary from patient to patient.
IgG and IgG-complexes are broken down in cells of the reticuloendothelial system.
Paediatric population: No specific studies of efficacy and safety are available on paediatric population.
Toxicology: Preclinical safety data: Immunoglobulins are normal constituents of the human body.
In animals single dose toxicity testing is of no relevance since higher doses result in overloading. Repeated dose toxicity testing and embryo-fetal toxicity studies are not practicable due to the induction of and interference with antibodies. Effects of the product on the immune system of the newborn have not been studied.
Since clinical experience provides no hint for carcinogenic and mutagenic effects of immunoglobulins, experimental studies, particularly in heterologous species, are not considered necessary.