Table 2.
Key Model Parameters for Fentanyl Simulation
| parametera | value | source |
|---|---|---|
| PhysChem and Blood Binding | ||
| MW (g/mol) | 336.47 | b |
| log P | 2.8 | b |
| pKa | 8.06 | b |
| B/P | 0.963 | ref 92c |
| f u | 0.297 | d |
| Distribution | ||
| Vss (L/kg) | 4.089 | d |
| Elimination | ||
| Clint 3A4 (μL·min–1·pmol–1) | 0.496 | ref 93c |
| C1R (L/h) | 4.6 | ref 94c |
| Interaction | ||
| Ki (μM) | 24.2 | ref 95c |
a
Abbreviations: MW, molecule weight; log P, log of the octanol–water partition coefficient for the neutral compound; pKa, dissociation constant; B/P, blood/plasma concentration ratio; fu, fraction of drug unbound in plasma; Vss, steady-state volume of distribution; Clint 3A4, in vivo clearance of acetaminophen; ClR, renal clearance; Ki, inhibition constant of fentanyl on CYP3A4.
b
From PubChem (PubChem CID 3345) (https://pubchem.ncbi.nlm.nih.gov).
c
Derived from published data and then optimized based on observed data.
d
Predicted by Simcyp.