Table 1

Correlation between the etoposide 3′-demethylation activities (i.e., Vmax/Km) with microsomes obtained from six human livers and metabolic reactions of seven selective substrates of distinct human CYP isoforms

Metabolic Reaction of SubstrateCYP IsoformCorrelation Coefficients with Etoposide 3′-Demethylation
Coumarin 7-hydroxylationCYP2A60.598
Diclofenac 4′-hydroxylationCYP2C90.017
S-Mephenytoin 4′-hydroxylationCYP2C190.652
Desipramine 2-hydroxylationCYP2D60.290
Chlorzoxazone 6-hydroxylationCYP2E10.254
Testosterone 6β-hydroxylationCYP3A40.9321-a
  • 1-a P < .01.