TABLE 1

Summary of enzyme kinetic parameters for linezolid metabolismd

2-HydroxylinezolidDesethylenelinezolid
EnzymeKMbVmaxcCLintcKMbVmaxcCLintc
CYP1A1NDaND0.120233 (154-370)0.550 (0.449-0.710)2.36
CYP1B1NDND0.383196 (159-243)0.868 (0.786-0.969)4.43
CYP2C8NDND1.55NDND0.544
CYP2D6NDND0.391NDND2.91
CYP2J2124 (109–141)2.66 (2.52–2.80)21.423.7 (20.1–27.8)2.28 (2.19-2.39)96.2
CYP3A4NDND0.294258 (211–320)1.12 (1.01-1.26)4.34
CYP3A5NDND0.0485NDND1.32
CYP4F2NDND3.52NDND0.288
Human Liver Microsomes270 (213–349)67.3 (59.4–77.9)0.249NDND0.257
Human Intestine MicrosomesNDND0.0071NDND0.0757
  • aND, individual enzyme kinetic parameters were not able to be determined since estimated KM was greater than the highest substrate concentration evaluated.

  • bAll KM units are µM.

  • cFor recombinant P450 data, Vmax units are pmol/min/pmol P450 and CLint units are µL/min/nmol P450. For microsomal data, Vmax units are pmol/min/mg protein and CLint units are µL/min/mg protein.

  • dValues in parentheses are the 95% confidence intervals. All data were rounded to three significant digits.