I read that Plegridy contains anti-freeze, which is what makes it long lasting compared to Avonex? Wouldn't it be safer to just inject more often and use Avonex?
The generic name for Plegridy is PEGylated interferon beta 1a. PEG stands for polyethylene glycol, not to be confused with ethylene glycol or anti-freeze. While ethylene glycol (anti-freeze) has been in much demand in many parts of the country this week, especially poor Buffalo my home town, polyethylene glycol or PEG is used widely in medicinals, cosmetics and other industries because of its chemical properties and well known safety profile. In medicine PEG is well known as a laxative and is the basis of drugs like GoLYTELY and MiraLAX. When attached to proteins like interferon, the active protein is released and cleared more slowly allowing for slower rise in activity and a longer duration of action; this allows the protein to be injected less frequently and potentially with fewer side effects. Plegridy is not even the first Pegylated interferon product; PEGylated interferon alpha-2b was approved in 2001 (PEGylated interferon alpha-2a was approved in 2002) for the treatment of chronic active hepatitis C and is one of the main treatments for that disease.
Rip Kinkel MD
UCSD MS Center