[Pharmacokinetic of piracetam during labour influence to acid-base-status in maternal and fetal blood (author's transl)].

PIRACETAM concentrations in fetal and maternal blood were measured during the first and second stage of labor and the elimination in maternal and fetal blood was studied. Fetal heart-rate, pH- and base-excess of the maternal and fetal blood were investigated to evaluate the influence of PIRACETAM on the acid-base-status of mother and child. PIRACETAM was administered intravenously to 43 patients in a dosage 2 g, 4 g and 6 g. The concentration in the maternal and fetal plasma was measured by gaschromatography. Before and after the injection of PIRACETAM and at delivery, blood was sampled from the mother's earlobe and the umbilical artery and vein, respectively. The results were compared with a control group. There was an exponential fall of PIRACETAM concentration in maternal and fetal blood. Maternal and fetal elimination half-life of PIRACETAM was about 112-98 minutes and 200 minutes, respectively. A fairly good correlation between the concentration of PIRACETAM in maternal and fetal blood was found. The fetal PIRACETAM concentration was about 50% below the maternal values. Fetal heart-rate, maternal and fetal pH- and base-excess-values were not significantly altered following PIRACETAM infusion. It may be concluded, that there exists a transfer of PIRACETAM across the placental barrier. However, the cytoprotective effect of PIRACETAM, as described in animal observations and by investigations in human, could not be verified by the methods and technology used in this study.