By Derrek Blake, RN, IgCN, and Joe DiStefano, RPh.
Intravenous immune globulin (IVIG) is available as either a liquid or lyophilized (freeze-dried) powder. Initially only powder products were available, requiring reconstitution before administration. Over time, manufacturers changed their manufacturing process to achieve stability of the IgG molecules in a suspended or liquid state. By doing so, the task of reconstitution has been eliminated, making the powder products relatively obsolete. Depending on the brand, IVIG liquid is available in 5% and 10% concentrations. Depending on the brand, IVIG powder is reconstituted to yield a concentration between 3% and 12%.
Today in home infusion, we are starting to see resurgence in the use of powder products. This could be due to the physician’s preference or even the patient’s insurance requiring us to use a certain formulary-choice drug. Currently there are two commercially available IVIG powder products: Carimune NF, manufactured by CSL Behring, and Gammagard S/D, manufactured by Shire. Carimune NF is the only sucrose-containing IVIG brand, liquid or powder. Sucrose-containing IVIG has been implicated in renal failure and should be used in caution with at-risk patients. Gammagard S/D has the lowest IgA content of any IVIG brand, liquid or powder, and is often used in patients with low serum IgA or in the presence of anti-IgA antibodies. Although IVIG powders are not as common as liquids, nurses must be prepared to enter the home, skillfully prepare IVIG powder and administer the prescribed dose. In this blog we will describe how to reconstitute IVIG powder properly and transfer these products into a pooling bag before administration. NuFACTOR typically discourages pooling IVIG. However when it comes to IVIG powder, we prefer the IVIG be pooled prior to administration. Although both Carimune NF and Gammagard S/D are powders, reconstitution is different.
Gammagard S/D and Carimune NF Reconstitution
Gammagard S/D is commercially available in 5 gm and 10 gm vials and is packaged with a 100 ml or 200 ml vial of sterile water for injection (SWFI), respectively. Gammagard S/D can be reconstituted to a final concentration of 5% or 10%. For example, a Gammagard S/D 5 gm vial reconstituted with SWFI 50 ml yields a 10% concentration, but reconstituted with 100 ml SWFI yields a 5% concentration. This is very critical to understand as we do not want to over dilute or under dilute the powder. To dilute Gammagard S/D to a 5% solution, the transfer device included in the box is used to transfer the entire contents of the accompanying SWFI 100 ml vial. To dilute Gammagard S/D to a 10% solution, the transfer device cannot be used. Half the amount of SWFI in the vial would need to be drawn up using a syringe and needle. To reconstitute a Gammagard S/D 5 gm vial to a 5% solution, gather the 100 mL vial of SWFI and Gammagard S/D vial. Insert the transfer device into the SWFI vial first. Then quickly insert the other end of the transfer device into the Gammagard S/D vial and invert so the SWFI is on top. The Gammagard S/D will have negative pressure, allowing the SWFI to flow into the Gammagard S/D vial. Once the SWFI 100 mL is added, remove the transfer device and swirl to dissolve the Gammagard S/D. To reconstitute a Gammagard S/D 5 gm vial to a 10% solution, using a needle and a 60mL syringe draw up SWFI 50 mL and add it directly into the 5 gm vial of Gammagard S/D slowly, aimed toward the wall of the vial. Never shake the solution. Instead, slowly swirl the contents to prevent breakdown of the IgG protein and avoid foam. Typically this takes 20 - 40 minutes for complete dissolution. Use the transfer device and accompanying 200 ml SWFI to reconstitute Gammagard S/D 10 gm to a 5% solution or a syringe and needle using 100 ml SWFI to yield a 10% solution.
Carimune NF is commercially available in 6 gm and 12 gm vials and does not include a diluent such as SWFI. Carimune NF can be reconstituted to a final concentration of 3%, 6%, 9% or 12%. Reconstituting Carimune NF is done similar to Gammagard S/D using a syringe and needle to draw up the volume of SWFI indicated in the package insert. It typically takes 30 - 60 minutes for complete dissolution. Reconstituting a Carimune NF 6 gm vial with 50 ml SWFI yields a 12% solution and 100 ml yields a 6% solution. Reconstituting a Carimune NF 12 gm vial with 100 ml SWFI yields a 12% solution and 200 ml yields a 6% solution.
Before pooling, check to make sure the solution is clear and free of undissolved particles. There is a specific way we prefer the nurse in the home to pool the medication. Locate the pooling bag and gravity fill set tubing. Clamp the gravity set tubing and then attach it to the pooling bag. Insert the vented end of the gravity fill set tubing into the IVIG vial and then invert the vial. Unclamp the gravity fill set tubing, open vented spike and transfer the IVIG into the pooling bag. Close the clamp and vented spike and repeat steps again as needed for any additional vials. Once the contents of all vials have been transferred into the pooling bag, clamp the port on the bag, remove the gravity fill set tubing, attach the pooling bag cap and close the wings. You will now be ready to spike to pooling bag and prepare for the infusion.