CYP2B6*6, CYP2B6*18, Body weight and sex are predictors of efavirenz pharmacokinetics and treatment response: population pharmacokinetic modeling in an HIV/AIDS and TB cohort in Zimbabwe

Table 3 Parameter estimates for the final pharmacokinetic model for daily 600 mg EFV

Parameter	Estimate (% RSE)^a	^bIIV (%RSE)
CL/F_TT (L/hr)	7.01 (10)	70.3 (7)
CL/F_TC (L/hr)	2.26 (12)	70.3 (7)
C/FL_CC (L/hr)	0.539 (24)	70.3 (7)
V/F (L/hr)	150 FIX
ka (hr ⁻¹)	0.18 FIX
PROP_ERR	0.12
Effect on CL/F _TT , CL/F _TC and CL/F _CC
CYP2B6_GG (%)	+93.1 (24%)
CYP2B6_TT (%)	−63.4 (9)
CYP2B6_GT (%)	0
10 kg increase body weight (%)	+21.1 (21)
Females (%)	+22.2 (67)

^aRSE, relative standard error (how precise the model is estimating the IIV). ^bIIV, inter-individual variability reported as percent coefficient of variation. CL/F, oral clearance; CYP2B6*18 TT, extensive metabolizer; TC, Intermediate metabolizer; CC, poor metabolizer; V/F, volume of distribution; ka, first-order absorption rate constant; PROP_ERR, proportional error; CYP2B6 GG, extensive metabolizer; GT, Intermediate metabolizer; TT, poor metabolizer.

ISSN: 2050-6511