Table 3.

Estimates of oral clearance and AUC at steady state for isoniazid and acetyl-isoniazid for slow and fast acetylators when given with or without efavirenz-based ART^a

Scenario	Intrinsic CL of isoniazid (L/h)	Hepatic extraction of isoniazid (EH) (%)	Oral CL of isoniazid (L/h)	Change in isoniazid oral CL (%)	Isoniazid AUC (mg·h/L)b	Acetyl-isoniazid AUC (mg·h/L)c
Slow acetylator	18.0	26	17.1	reference	17.5	5.44
Fast acetylator not on efavirenz-based ART	47.3	47	44.9	+162	6.68	20.8
Fast acetylator on efavirenz-based ART	66.7	56	63.4	+270	4.73	26.8

^aThe estimates reported here refer to an individual with an FFM of 43.3 kg (the median in our cohort). These are calculated using population parameter estimates from the fixed effects component of the final model.

^bAUC for a dose of 300 mg.

^c$\text{AUC}\text{=}\left({\mathrm{E}}_{\mathrm{H}}\text{·}{\text{DOSE}}_{\text{isoniazid}}\text{·}{\text{FRACTION}}_{\text{acetylation}}\text{·}\frac{{\text{Molecular}\text{weight}}_{\text{acetyl}-\text{isoniazid}}}{{\text{Molecular}\text{weight}}_{\text{isoniazid}}}\right)/{\text{CLEARANCE}}_{\text{acetyl}-\text{isoniazid}}$