Table 2.

Concentrations of efavirenz and its metabolites in plasma and CSF

	Plasma (ng/mL), total concentration	Plasma (ng/mL), protein corrected	CSF concentration (ng/mL)	CSF:plasma ratio, total concentration	CSF:plasma ratio, protein corrected
Efavirenz pharmacokinetics (N = 47)
undetectable samples, n/N (%)	0	0	1/47 (2.1%)	1/47 (2.1%)	1/47 (2.1%)
median (IQR)	1960 (1390–3200)	4.31 (3.06–7.04)	17.25 (10.7–19.9)	0.71 (0.61–0.78)	324.34 (278.29–356.44)
range	55–18 100	0.12–39.82	1.73–119	0.31–1.12	142.82–508.66
geometric mean concentration (95% CI)	2081.5 (1557.8–2781.4)	4.58 (3.43–6.12)	15.64 (12.08–20.24)	0.69 (0.64–0.75)	315.54 (291.90–341.10)
8-Hydroxy-efavirenz pharmacokinetics (N = 47)
undetectable samples, n/N (%)	0	unknown	30/47 (63.8%)	30/47 (63.8%)	unknown
median (IQR)	1808 (1325.5–2498.7)		4.17 (3.80–5.79)	0.20 (0.14–0.24)
range	68.81–4887.5		3.15–9.56	0.10–0.72
geometric mean concentration (95% CI)	1570.7 (1255–1965.9)		4.69 (3.93–5.60)	0.21 (0.16–0.26)
7-Hydroxy-efavirenz pharmacokinetics (N = 47)
undetectable samples, n/N (%)	2/47 (4.3%)	unknown	not measured	not applicable	not applicable
median (IQR)	216.71 (122.91–375.43)
range	11.45–2181.73
geometric mean concentration (95% CI)	229.17 (166.51–315.41)