The situation of phenobarbital is very complex, but almost certainly
safe.

1. The baby is getting this during pregnancy, in doses greater than he
will ever get it in the milk.

2. The baby is developing enzymes to metabolize phenobarbital, having
been exposed to it in utero.

3. We use phenobarb in babies in huge amounts (20 mg/kg) even very small
premature babies.

True, phenobarb has a long half life in children.  True, the
"hyperactivity" which occurs as a side effect occurs even at small
doses.  However, taken together with the above, and *the risks of
formula feeding*, I think the mother should have no hesitation.

Jack Newman, MD, FRCPC