I can only share anecdotally on this one but I do see enough cases of
decreased milk supply associated with antihistamine use that I now list it as
one of the questions I will ask when treating imagined or real decrease in
milk supply.

I would like to see data on the difference between the antihistamines like
Benadryl and Chlortrimeton and perscription antihistamines like Seldane and
Clariton (the one or two dose a day antihistamines).  I understand they work
at different points in the histamine production cycle--that some are
histamine blockers and others prevent the production of histamine altogether.
 With that in mind, would one affect milk production more than others?  I
have had clients switch their antihistamines with some success.  BUT who's to
say the increase in milk supply didn't come from the other milk-increasing
techniques I suggested they employ?

I live in a community with high pollen and mold counts.  Seasonal allergies
are significant among many of my clients.

TIA for your information.

Pat Predmore