Does taking the IgG sub-cu make it act differently in my body?
No: Once they are adsorbed into the bloodstream, the antibody molecules basically act the same way. Studies with antibodies to the Rh blood group (given to Rh negative pregnant women to prevent them from making antibodies that might harm future Rh+ babies) have shown that giving them by different routes is equally effective.
However, IgG molecules which are clumped together, and/or impurities in the preparations, may cause side effects when they are given directly into the blood stream. These clumps (called “aggregates”) or impurities may react differently under the skin. This may be one of the reasons there seem to be fewer reactions when IgG is given sub-cutaneously rather than intravenously
Are there preservatives containing mercury (Thimerosal) in the 16% ISG ? No: Neither VivaglobinR (CSL Behring) nor the only other16% ISG currently sold in the USA, (GammastanR) (Talecris) contains thimerosal or any other preservative containing mercury. Therefore, once the bottle is opened by putting a syringe through the stopper, the IgG must be used within hours. Partial doses should not be saved, even in the refrigerator. These products are treated the same way as the IV preparations (solvent/detergent (S/D) treatment or pasteurization and alcohol treatment) to inactivate potential viruses.
How does the cost of sub-cutaneous IgG compare with intravenous IGIV ?For most patients other than small children, the main part of the cost is for the product itself.
Since subcutaneous and IV products come from the same blood donors and are made by similar processes, the cost per gram is about the same. Therefore, the overall costs for both routes are likely to be pretty similar.
If the sub-cutaneous route is used at home, without participation of a nurse, costs that would be associated with a home-infusion nurse or which might be charged in a hospital or infusion center will be saved. In that case, there is less traveling time and the infusions will usually be given at times that do not interfere with work or school. That may be important to certain patients, and may preserve “sick days” or income.