Table 3.
Genotype-based prediction of CYP2C9 metabolizer phenotypes and phenoconversion by non-genetic factors.
| CYP2C9 genotype | Phenotype predicted from genotype | Phenoconversion | |||
|---|---|---|---|---|---|
| Classification according to Mostafa et al.34 | Activity scoring according to CPIC guideline35 | Medication with CYP2C9 inducera | Medication with CYP2C9 inhibitorb | Non-specific non-genetic factorsc | |
| *1/*1 | Normal (high IM–EM) | 2 | EM | IM–PM | IM–PM |
| *1/*2 | High IM | 1.5 | EM | IM–PM | IM–PM |
| *1/*3 | IM | 1 | High IM–EM | PM | PM |
| *2/*2 | PM | 1 | IM | PM | PM |
| *2/*3 | PM | 0.5 | IM | PM | PM |
| *3/*3 | PM | 0 | IM | PM | PM |
PM poor metabolizer, IM intermediate metabolizer, EM extensive metabolizer, CPIC Clinical Pharmacogenetics Implementation Consortium.
aCYP2C9 inducers: dexamethasone, methylprednisolone, midazolam.
bCYP2C9 inhibitors: amlodipine, tamoxifen.
cNon-specific factors: chronic alcohol consumption, amoxicillin + clavulanic acid therapy.