TABLE 2

Baseline METH and AMP t_1/2 values in maternal and fetal sera and brains based on the concentration-time plots in Fig. 1

The t_1/2 values were calculated from the best-fit lines to the terminal elimination phase shown in the METH and AMP concentration-time plots in Fig. 1, A–D. All values were calculated by pharmacokinetic model-independent analysis. Data were calculated from the average maternal and fetal brain and sera values from four grouped animals per time point (see open circles in Fig. 1, A and B).

Tissue	Source	t_1/2 Values (hours)
Tissue	Source	METH (hours)	AMP (hours)
Sera	Maternal	1.7^{^a}	2.5^{^a}
	Fetal	1.2	2.0
Brain	Maternal	1.1	2.8
	Fetal	1.3	3.2

↵^a Data for these two t_1/2 values were also calculated by model-dependent analysis in Table 1 as 1.7 hours and 2.9 hours (respectively).