RESUMO
PURPOSE: Fexofenadine is a well-identified in vivo probe substrate of P-glycoprotein (P-gp) and/or organic anion transporting polypeptide (OATP). This work aimed to investigate the transplacental pharmacokinetics of fexofenadine enantiomers with and without the selective P-gp inhibitor fluoxetine. METHODS: The chiral transplacental pharmacokinetics of fexofenadine-fluoxetine interaction was determined using the ex vivo human placenta perfusion model (n = 4). In the Control period, racemic fexofenadine (75 ng of each enantiomer/ml) was added in the maternal circuit. In the Interaction period, racemic fluoxetine (50 ng of each enantiomer/mL) and racemic fexofenadine (75 ng of each enantiomer/mL) were added to the maternal circulation. In both periods, maternal and fetal perfusate samples were taken over 90 min. RESULTS: The (S)-(-)- and (R)-(+)-fexofenadine fetal-to-maternal ratio values in Control and Interaction periods were similar (~0.18). The placental transfer rates were similar between (S)-(-)- and (R)-(+)-fexofenadine in both Control (0.0024 vs 0.0019 min-1) and Interaction (0.0019 vs 0.0021 min-1) periods. In both Control and Interaction periods, the enantiomeric fexofenadine ratios [R-(+)/S-(-)] were approximately 1. CONCLUSIONS: Our study showed a low extent, slow rate of non-enantioselective placental transfer of fexofenadine enantiomers, indicating a limited fetal fexofenadine exposure mediated by placental P-gp and/or OATP2B1. The fluoxetine interaction did not affect the non-enantioselective transplacental transfer of fexofenadine. The ex vivo placental perfusion model accurately predicts in vivo placental transfer of fexofenadine enantiomers with remarkably similar values (~0.17), and thus estimates the limited fetal exposure.
Assuntos
Antagonistas não Sedativos dos Receptores H1 da Histamina/farmacocinética , Troca Materno-Fetal/efeitos dos fármacos , Placenta/metabolismo , Terfenadina/análogos & derivados , Subfamília B de Transportador de Cassetes de Ligação de ATP/antagonistas & inibidores , Subfamília B de Transportador de Cassetes de Ligação de ATP/metabolismo , Área Sob a Curva , Interações Medicamentosas , Feminino , Fluoxetina/administração & dosagem , Fluoxetina/farmacocinética , Antagonistas não Sedativos dos Receptores H1 da Histamina/administração & dosagem , Humanos , Perfusão/instrumentação , Perfusão/métodos , Gravidez , Complicações na Gravidez/tratamento farmacológico , Complicações na Gravidez/imunologia , Estereoisomerismo , Terfenadina/administração & dosagem , Terfenadina/farmacocinéticaRESUMO
Secondhand smoke is associated with a myriad of adverse health outcomes. Therefore, it is essential for clinicians to ask precise questions about exposures, particularly for children. We present 4 questions that incorporate several locations of exposure and provide a more comprehensive account of children's smoke exposures than maternal smoking alone.