. 2018 Apr 20;7(7):419–431. doi: 10.1002/psp4.12300

Table 2.

Summary of clearance‐specific data used in the PBPK model for metronidazole in non‐pregnant women

Parameter

Value

Unit

Reference

Dose fractions excreted unchanged in urine (

f_{e}

) and metabolized (

f_{m}

) via different enzymes

f_{m, C Y P 2 A 6}

0.25

28, 30

f_{m, C Y P 2 E 1}

0.24

28, 30

f_{m, C Y P 3 A 4}

0.27

28, 30

f_{m, U G T}

0.10

28, 30

f_{e}

0.13

28, 29

K _{m, CYP 2A6}

0.383

k _{cat, CYP 2A6}

1.45a

min⁻¹

fitted

K _{m, CYP 3A4}

33.1

µM

k _{cat, CYP 3A4}

72.5a

min⁻¹

fitted

Protein expression profile

RT‐PCR

Specific intrinsic hepatic clearance

0.0125a, b

min⁻¹

fitted

Specific renal plasma clearance

0.0222a

min⁻¹

fitted

CYP, cytochrome P450; $f_{e}$ , dose fraction excreted unchanged in urine; $f_{m}$ , dose fraction metabolized via a specific enzyme; k _cat, unimolecular rate constant; K _m, Michaelis‐Menten constant; PBPK: physiologically based pharmacokinetic; RT‐PCR, real‐time polymerase chain reaction; UGT, uridine 5′‐diphospho‐glucuronosyltransferase.

Values simultaneously fitted to in vivo PK data of non‐pregnant women29 and to the contribution of each pathway to overall elimination.28, 30

Describes elimination via CYP2E1 and UGT.