A comment was voiced concerning the use of Propylthiouracil(PTU) and
methimazole(Tapazol)  in hyperthyroid patients.  I know that the AAP
considers both to be safe for breastfeeding infants.  However,  if one
reviews the literature, we generally find that methimazole levels in
breastmilk(M:P ratio = > 1.0)  are considerably higher than
propylthiouracil(M:P ratio = 0.1 ).  Although they might not be detremental
to most infants,  I think it would be safer to use PTU.  Its just as
effective as methimazole,  and in breastfeeding situations is probably
preferred.

tom hale