Figure 3.

Sensitivity analysis of obstetric semi-mechanistic metabolism model. The solid line indicates predicted maternal plasma drug concentration based on the initial obstetric semi-mechanistic metabolism model. Broken and dotted lines represent twofold decreases and increases, respectively, in (a) hepatic blood flow, Q_H; (b) absorption rate constant, k_a; (c) fraction unbound, f_u; (d) intestinal rate of metabolism, V_max,GW; and (e) hepatic rate of metabolism, V_max,H. (f) Effect of fetal metabolism on maternal plasma concentrations as predicted by the initial model (solid line), assuming no contribution from fetal metabolism (dotted line), and with a 20-fold increase in cytochrome P450 3A7 (CYP3A7) V_max (dashed line).