Glucophage (metformin) and Rezulin (troglitizone) are both oral
anti-diabetic drugs for Type 2 diabetes. I have researched them both
somewhat, and yes, there is a greater likelihood of metformin passing into
the milk as it is a small molecule that has low protein binding. Rezulin,
however, is a large molecule that is highly protein bound and is unlikely to
pass in significant amounts into the milk. If diabetes is the only issue,
rezulin may be a viable option; the only caution is that some risks have
been recently identified with rezulin which necessitate a good health
screening first. As I understand it, both of these drugs work by reducing
*insulin resistance*, and I do believe that neither induce hypoglycemia in
non-diabetics, thus I wonder why the concern for babies on that level.

I have had two moms now on metformin. One mom has been on it for over a
year, having taken it since the baby was newborn, and the pediatrician has
been monitoring baby's health-- no ill effects noted. I lost track of the
second mom, so have less to say there.

I think that a lot of the concern is due to the newness and lack of
experience with these medications more than absolute risk--- only time will
tell,though.

Lisa Marasco, BA, IBCLC
Santa Maria, CA