The tissue
penetration of Metronidazole in pregnant wom-en of different gestation period and the excretion
of the drug in
breast milk in breast-feeding mothers were determined.The results showed that
Metronidazole penetrated through blood-placenta barrier to various tissues and body fluids
easily.Following a single intravenous infusion of 500mg of Metronidazole in pregnant and
breast-feeding women,the mean drug concentrations in various tissues and body fluids such
as chorion,endom-etrium,fetus,placenta,umbilical tissue and amniotic fluid were 29～53%f that
in maternal blood at the same time,umbilical blood being 89%. The drug concentration in breast
milk was almost equal to that in mate-rnal blood time. 1 hour after the drug admin istration,the
mean milk dr-ug concentration was7.85 mg/L,.67mg/L 12 hours later,The elimina-ion half-life in
breast milk was 6.17 ±2.19 h,Based upon the results of this study,the rational use of
Metronidazole in pregnant and breast-fee-ding women was proposed.Tbe HPLC assay of the
concentrations of Me-tronidazole in tissues and body fluids is simple、sensitive and reliable.It
can be used not only in the study of
clinical pharmacology but also in monitoring the clinical
drug concentration of Metronidazole.