Notes: Cytochrome P450 enzymes function to metabolize both endogenous and exogenous compounds. Both the 3A and 2C isoforms are present in human liver of which CYP2C9 seems most highly expressed.{14151} Tienilic acid is a specific suicide substrate for CYP2C9 and CYP2C10 whereby its oxidation inactivates the enzyme.{14150,14152} The time required to inactivate one half of the CYP2C10 enzyme at the maximal rate (t½max) is 3.4 minutes, with a dissociation constant (Kd) value of 4.3 µM.{14152}