Induction of drug metabolizing enzyme activities in the human fetus and in the newborn infant

Diazepam metabolism was followed in 5 newborns exposed to phenobarbital either during fetal life or after birth. A considerable increase of urinary metabolites and of plasma apparent K(el) was observed in comparison with newborns not exposed to the barbiturate. These findings may be considered as indirect evidence of induction of drug metabolizing enzymes during the last part of gestation and shortly after birth.