Relationship between CYP2C8 genotypes and diclofenac 5-hydroxylation in healthy Spanish volunteers

Purpose CYP2C8 seems to be involved in diclofenac 5-hydroxylation, while, in vitro, the 4′-hydroxylation and 3′-hydroxylation seem to be mediated mainly by CYP2C9. We have demonstrated the relevance of CYP2C9 genotypes for diclofenac 4′-hydroxylation in healthy volunteers, so that the present study was aimed at analyzing the role of both CYP2C8 and CYP2C9 genotypes on diclofenac metabolism, as well as determining the CYP2C8 allele frequencies and their relationship with CYP2C9 variants.