To      : Kathy Parkes
Re      : Avonex

I'm not sure this is the medication your interested in, but Avonex is
Interferon Beta 1 Alpha.  It is used for treatment of multiple sclerosis.  It
has a half-life of roughly 10 hours,  and a time-to-peak interval of 3-15 hours
following injection.  It is generally used once weekly but this may vary.

Interferons are glycoproteins with antiviral, antiproliferative, and
immunomodulatory activity. We know that some interferons are transferred into
milk and may account for some of the antiviral activity of human milk.  We do
not know if injected interferons are subsequently transferred into milk, but I
suspect that they are to some degree.  It is reasonably agreed that oral
interferons may be absorbed in the oropharynx and can produce immune changes in
the patient.

As a family,  the interferons are normal glycoproteins present in all mammals,
they rise during viral infections, and in general are very non toxic although
they can produce uncomfortable side effects in some patients.  In certain
diseases(ITP),  they are used in doses of many millions of units largely
without toxicity.  I do not think that enough would pass into milk to be
dangerous,  but I do not know this for sure.

Regards
Tom Hale