TABLE 2.
Warfarin drug property–specific parameters
| S-Warfarin | R-Warfarin | Definitions | |
|---|---|---|---|
| MW | 308.3 (Simcyp, 2020) | Molecular weight | |
| Compound type | Monoprotic acid (Simcyp, 2020) | ||
| Log Po:w | 0.27 (Simcyp, 2020) | Logarithmic neutral species octanol:buffer partition coefficient | |
| pKa | 5.1 (Simcyp, 2020) | Acid dissociation constant | |
| CL (L/hour) | 0.260 (Cheng et al., 2022a) | 0.119 (Cheng et al., 2022a) | Total clearance |
| If *1B/*1B | × 0.885 (Cheng et al., 2022a) | Fractional multipliers of CL if other CYP2C9 genotypes | |
| If *1/*3 | × 0.607 (Cheng et al., 2022a) | ||
| If *2/*3 | × 0.277 (Cheng et al., 2022a) | ||
| If *3/*3 | × 0.215 (Cheng et al., 2022a) | ||
| CLR (L/hour) | 0.00369 (Cheng et al., 2022a) | 0.00436 (Cheng et al., 2022a) | Renal clearance |
| Kon (L/(µg*hour)) | 0.00494 (Cheng et al., 2022a) | 0.00137 (Cheng et al., 2022a) | Association rate constant |
| If *2/*3 | × 0.837 (Cheng et al., 2022a) | Fractional multipliers of Kon if other CYP2C9 genotypes | |
| If *3/*3 | × 0.518 (Cheng et al., 2022a) | ||
| Koff (/hour) | 0.0405 (Cheng et al., 2022a) | 0.0405 (Cheng et al., 2022a) | Dissociation rate constant |
| Rmax (µg/L) | 182 (Cheng et al., 2022a) | 188 (Cheng et al., 2022a) | Total receptor levels |
| If *1/*3 | × 0.479 (Cheng et al., 2022a) | Fractional multipliers of Rmax if other CYP2C9 genotypes | |
| If *2/*3 | × 2.51 (Cheng et al., 2022a) | × 0.506 (Cheng et al., 2022a) | |
| If *3/*3 | × 1.89 (Cheng et al., 2022a) | × 0.21 (Cheng et al., 2022a) | |
| Fa (%) | 100 (Simcyp, 2020) | Bioavailability | |
| Ka (/hour) | 1.85 (Simcyp, 2020) | Absorption rate constant | |
| Lag time (hour) | 0 (Simcyp, 2020) | Absorption lag time | |
| BP | 0.59 (Simcyp, 2020) | Blood-to-plasma ratio | |
| fup | 0.009 (Simcyp, 2020) | Fraction of unbound drug in plasma | |