FIG. 1.
Population pharmacokinetic model for the simultaneous prediction of FTC concentrations in the mother, the cord blood (top), and the neonate (bottom). A two-compartment model with first-order absorption and elimination best described maternal data. For cord blood FTC concentrations, an “effect” compartment is modeled as a virtual compartment linked to the maternal plasma compartment by a first-order process. After delivery, the fetal compartment is disconnected, and the neonate has his own elimination. F denotes bioavailability, D the maternal FTC dose, ka the absorption rate constant, CL the maternal elimination clearance from the central compartment, V1 the volume of the central maternal compartment, Q2 the maternal intercompartmental clearance, V2 the volume of the peripheral maternal compartment, k1F the mother-to-fetus transfer rate constant, kF1 the fetus-to-mother transfer rate constant, kF0 neonate elimination rate constant, VF the neonate volume of distribution, BWM the maternal BW, and BWF the neonatal BW.