Flunitrazepam metabolism by cytochrome P450S 2C19 and 3A4.

  title={Flunitrazepam metabolism by cytochrome P450S 2C19 and 3A4.},
  author={Tansel Kilicarslan and Robert L Haining and Allan E Rettie and Usoa E. Busto and Rachel F. Tyndale and Edward M. Sellers},
  journal={Drug metabolism and disposition: the biological fate of chemicals},
  volume={29 4 Pt 1},
We have identified CYP2C19 and CYP3A4 as the principal cytochrome P450s involved in the metabolism of flunitrazepam to its major metabolites desmethylflunitrazepam and 3-hydroxyflunitrazepam. Human CYP2C19 and CYP3A4 mediated the formation of desmethylflunitrazepam with Km values of 11.1 and 108 microM, respectively, and 3-hydroxyflunitrazepam with Km values of 642 and 34.0 microM, respectively. In human liver microsomes (n = 4) formation of both metabolites followed biphasic kinetics… CONTINUE READING