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. 2017 Nov 7;84(1):97–111. doi: 10.1111/bcp.13400

Table 1b.

Overview of the population pharmacokinetic models used for the evaluation of drug–drug interactions of phenobarbital, phenytoin, topiramate, valproate and zonisamide

Model Phenobarbital Phenytoin Topiramate Valproate Adults Valproate Children Zonisamide
First author Goto 20 Odani 21 Girgis 22 Blanco‐Serrano 23 Blanco‐Serrano 24 Okada 25
Population Japanese Japanese NA (Caucasian presumably) Spanish Spanish Japanese
Sample size (No. of patients) 79 116 1217 255 208 99
Sample size (No. of patients) 260 531 4640 770 534 282
Age (y) 0.8–44 1–37 2–85 14–95 0.1–14 1.36–39.24
Weight (kg) 8–80 42.4 ± 16.5 NA 4–74 27–100 10–117
Samples at TDM Peak/Trough NA TDM TDM 4.3 ± 2.8 h after dose
Graphical representation graphic file with name BCP-84-97-g012.jpg graphic file with name BCP-84-97-g013.jpg graphic file with name BCP-84-97-g014.jpg graphic file with name BCP-84-97-g015.jpg graphic file with name BCP-84-97-g016.jpg graphic file with name BCP-84-97-g017.jpg
Parameters Ka, Vc, CL Vc, CL (Vmax, Km) Ka, Vss (V1 + V2), K12, K21, CL Ka, Vc, CL Ka, Vc, CL Ka, Vc, CL
Between‐subject variability Vc, CL Vc, Vmax, Km Ka, Vc, CL CL CL CL
Covariate effects on CL WT, PHT, VPA WT, daily PHT dose, ZNS Age, WT, Inducers (CBZ/PHB/PHT), VPA, NEMD, ZNS WT, Dose, CBZ, PHT, PHB WT, Dose, CBZ WT, Dose, CYP2C19 genotype, CBZ, PHB, PHT
Covariate effects on V WT WT WT WT WT

CL, clearance; Ka, absorption rate constant; Km, Michaelis‐Menten constant; K12/K21, distribution rate constants from and to central and peripheral compartments, respectively; NA, not available; TDM, therapeutic drug monitoring; V, volume of distribution; V1 / Vc, volume of distribution of the central compartment; V2, volume of distribution of the peripheral compartment, Vmax, maximum metabolic capacity; WT, weight