Physiologically Based Pharmacokinetic Models to Predict Maternal Pharmacokinetics and Fetal Exposure to Emtricitabine and Acyclovir
Xiaomei I Liu, Jeremiah D Momper, Natella Rakhmanina, John N van den Anker, Dionna J Green, Gilbert J Burckart, Brookie M Best, Mark Mirochnick, Edmund V Capparelli, André Dallmann, Xiaomei I Liu, Jeremiah D Momper, Natella Rakhmanina, John N van den Anker, Dionna J Green, Gilbert J Burckart, Brookie M Best, Mark Mirochnick, Edmund V Capparelli, André Dallmann
Abstract
Pregnancy is associated with physiological changes that may impact drug pharmacokinetics (PK). The goals of this study were to build maternal-fetal physiologically based pharmacokinetic (PBPK) models for acyclovir and emtricitabine, 2 anti(retro)viral drugs with active renal net secretion, and to (1) evaluate the predicted maternal PK at different stages of pregnancy; (2) predict the changes in PK target parameters following the current dosing regimen of these drugs throughout pregnancy; (3) evaluate the predicted concentrations of these drugs in the umbilical vein at delivery; (4) compare the model performance for predicting maternal PK of emtricitabine in the third trimester with that of previously published PBPK models; and (5) compare different previously published approaches for estimating the placental permeability of these 2 drugs. Results showed that the pregnancy PBPK model for acyclovir predicted all maternal concentrations within a 2-fold error range, whereas the model for emtricitabine predicted 79% of the maternal concentrations values within that range. Extrapolation of these models to earlier stages of pregnancy indicated that the change in the median PK target parameters remained well above the target threshold. Concentrations of acyclovir and emtricitabine in the umbilical vein were overall adequately predicted. The comparison of different emtricitabine PBPK models suggested an overall similar predictive performance in the third trimester, but the comparison of different approaches for estimating placental drug permeability revealed large differences. These models can enhance the understanding of the PK behavior of renally excreted drugs, which may ultimately inform pharmacotherapeutic decision making in pregnant women and their fetuses.
Keywords: PBPK modeling; acyclovir; drug development; emtricitabine; pregnancy.
Conflict of interest statement
Conflicts of Interest
The authors declare no potential conflicts of interest with respect to the research, authorship, and/or publication of this article. Dr André Dallmann is an employee of Bayer AG, a company that is part of the Open Systems Pharmacology (OSP) member team and involved in OSP software development. The results from this study were presented in part at the American College of Clinical Pharmacology Annual Meeting, Washington, DC, September 2018.
© 2019, The American College of Clinical Pharmacology.
Figures
Source: PubMed