[Pharmacokinetic variations in anticonvulsants in Mexican epileptic women during different stages of the postpartum period].

During pregnancy, there are several physiological changes that influence the kinetics of medication administrated during this time. These physiological changes are not reestablished immediately during delivery; so, its concentration in biologic fluids is different when is administered immediately after delivery, than several weeks after. The purpose in this work was to identify the changes of pharmacocinetics constants for fenitoin and carbamacepine, in epileptic patients. When the same dose is maintained, during different times of postpartum. In 20 Mexican epileptic women, the plasma and milk concentrations of fenitoina during 60 day postpartum and in 14 carbamacepine was determined. In all the patients pharmakocinetics of anticonvulsivant, in each study period (5, 15, 30, 45 y 60 days postpartum). Excretion index of maternal milk was determined. Maximal plasmatic concentration of fentoine had no variation; however, carbamacepine was higher during the late period. There were no differences in the areas under curve and life all the middle of elimination and in excretion index.