I have not been able to find out much information about triamterene. It
is a significant omission in Hale's book. The CPS (Canadian PDR) also
has almost no information about it. Perhaps Frank Nice could offer some
information.
I believe that formula is guilty until proved otherwise, and that it is
almost always safer to continue breastfeeding when taking medication.
The decision is the mother's. I would encourage her to breastfeed.
Jack Newman, MD, FRCPC