[Problems of pharmacokinetics in pregnancy. A bibliographic review]

Drug prescription in pregnancy for the treatment of maternal diseases and the first attempts to obtain therapeutic effects even on the product of conception make necessary to know the pharmacokinetics of drugs in pregnancy. The Authors discuss how changes of physiological maternal parameters and the presence of the placenta and of the foetus can affect drug pharmacokinetics in a clinically important way. The possibility that the unique multicompartmental structure of the maternal-placental-foetal unit can "trap" drugs in the foetus is highlighted. Methodological, ethical and legal problems make the acquisition of data on these changes difficult, but their knowledge is needed in order to prevent adverse and toxic effects both in the pregnant woman and in the foetus and to attempt a therapy of foetus diseases in intrauterine life.