Varizig® for Chickenpox Symptoms

By: Steve Soman, Co-Editor-in-Chief

–

Varicella Zoster Immune Globulin (Varizig®) was approved by the FDA on December 21^st of 2012. The Canadian pharmaceutical company Cangene Corporation, which is owned in-part by Apotex Inc., markets the new product.  The drug was approved by the Food and Drug Administration (FDA) to reduce “the severity of chicken pox (varicella zoster virus) infections in high risk individuals when given within four days after exposure.”¹

The Varicella Zoster immune globulin  is prepared from harvested plasma of healthy donors who exhibited high levels of anti-varicella zoster virus antibodies.  The donated plasma was collected via FDA-licensed collection facilities around United States and Canada and purified by the anion-exchange column chromatography method.  According to the manufacturer, the manufacturing process includes both a Planova 20 nm virus filter that effectively removes lipid-enveloped and non-enveloped viruses based on size and a solvent/detergent treatment step (using tri-n-butyl phosphate and Triton X-1007)that effectively inactivates lipid-enveloped viruses.²  Despite these precautions, this product can still potentially transmit disease diseases such as human immunodeficiency virus (HIV), hepatitis B and hepatitis C.

The product is manufactured as a powder for injection 125 IU/vial with no preservatives. The route of administration will determine how the product should be reconstituted. For Intravenous administration, 2.5 mL of a sterile diluent should be added to the 6 mL Varizig® vial to get a drug concentration of 50 IU/mL.  For Intramuscular administration, 1.25 mL of a sterile diluent should be added to the 6 ml Varizig® vial to get a drug concentration of 100 IU/mL.²  To insure proper dilution of the powder, you can gently tilt and rotate the vial or gently swirl the vial upright until the powder is dissolved.  When reconstituting the product, it is important to remember that you should not shake the vial.  Reconstituted product can be stored for up to 12 hours at 2-8°C prior to use.²

There are no geriatric or specific pediatric clinical data for Varizig®.  Varizig is approved for immunocompromised children and adults, newborns, pregnant women, premature infants, children younger than 1 year, and adults with no immunity to VZV®.³  The drug is contraindicated in patients with known immunity to varicella zoster virus such as previous varicella infections or varicella vaccination.  Individuals who are deficient in IgA may have the potential to develop IgA antibodies and have an anaphylactoid reaction. Patients who had such reactions in the past to other immunoglobulin products should refrain from using Varizig®. The most common adverse reactions to the Varizig® was injection site reactions (17%), headache (7%), and rash (5%).²

SOURCES:

1. U.S. Food and Drug Administration press release. Available at: http://www.fda.gov/NewsEvents/Newsroom/PressAnnouncements/ucm333233.htm. Accessed December 26, 2012
2. Varizig® Package Insert. Cangene Corporation, Winnipeg, Canada. Available at: http://www.cangene.com/_uploads/documents/VariZIG_approved PM_Jan 2008_English. Accessed December 26, 2012.
3. Medscape Pharmacists News. FDA Approves Varizig to Reduce Chickenpox Symptoms. Available at: http://www.medscape.com/viewarticle/776569. Accessed December 26, 2012.