Human placental perfusion method in the assessment of transplacental passage of antiepileptic drugs.

Epilepsy is one of the most common neurological diseases, affecting about 0.5 to 1% of pregnant women. It is commonly accepted that older antiepileptic drugs bear teratogenic potential. So far, no agreement has been reached about the safest antiepileptic drug during pregnancy. It is known that nearly all drugs cross the placenta at least to some extent. Nowadays, there is very little information available of the pharmacokinetics of drugs in the feto-placental unit. Detailed information about drug transport across the placenta would be valuable for the development of safe and effective treatments. For reasons of safety, human studies on placental transfer are restricted to a limited number of drugs. Interspecies differences limit the extrapolation of animal data to humans. Several in vitro methods for the study of placental transfer have been developed over the past decades. The placental perfusion method is the only experimental method that has been used to study human placental transfer of substances in organized placental tissue. The aim of this article is to review human placental perfusion data on antiepileptic drugs. According to perfusion data, it seems that most of the antiepileptic drugs are transferred across the placenta meaning significant fetal exposure.