Table 2.

Relationships between CYP2B6 genotype levels, plasma efavirenz pharmacokinetic parameters, and hormone concentrations among the 24 efavirenz group participants.

Pharmacokinetic parameter	day	CYP2B6 Normal median (IQR)	CYP2B6 Intermediate median (IQR)	CYP2B6 Slow median (IQR)	β coefficient, P-valuea
efavirenz
AUC0–8h (log10 ng*h/mL)	0	4.67 (4.57 – 4.74)	4.87 (4.81 – 4.92)	5.17 (4.92 – 5.49)	0.27, 4.5 ×10−5
	21	4.67 (4.55 – 4.76)	4.76 (4.65 – 4.98)	5.13 (4.77 – 5.45)	0.21, 3.2 ×10−3
Cmin (log10 ng/mL)	0	3.12 (3.00 – 3.22)	3.39 (3.33 – 3.42)	3.59 (3.33 – 4.07)	0.27, 4.3 ×10−4
	21	3.09 (2.93 – 3.16)	3.30 (3.09 – 3.37)	3.42 (3.29 – 3.91)	0.32, 3.0 ×10−2
Cmax (log10 ng/mL)	0	3.49 (3.40 – 3.61)	3.68 (3.60 – 3.75)	3.91 (3.71 – 4.19)	0.21, 7.0 ×10−4
	21	3.51 (3.41 – 3.67)	3.60 (3.54 – 3.78)	3.89 (3.53 – 4.17)	0.16, 1.3 ×10−2
etonogestrel
concentration (log10 pg/mL)	21	2.70 (2.64 – 2.85)	2.64 (2.54 – 2.82)	2.10 (2.10 – 2.55)	−0.21, 1.7 ×10−3
ethinyl estradiol
concentration (log10 pg/mL)	21	1.09 (1.06 – 1.12)	1.09 (0.99 – 1.16)	0.72 (0.40 – 0.92)	−0.19, 6.7 ×10−4

Abbreviations: AUC, area under the concentration time curve; C_max, maximum concentration; C_min, minimum concentration.

^aP-values and beta coefficients were generated with linear regression models.