Table 2.

Phenoconversion for CYP2C19 and CYP2D6 phenotypes.

Enzyme	Genotype-predicted phenotype	Phenotype predicted following drug-induced phenoconversion
In the presence of a strong inhibitor
CYP2C19	PM	PM a
CYP2C19	IM, NM	PM
CYP2C19	UM	IM
CYP2D6	PM	PM a
CYP2D6	IM, NM	PM
CYP2D6	UM	PM
In the presence of a moderate inhibitor
CYP2C19	PM	PM a
CYP2C19	IM, NM	PM
CYP2C19	UM	IM
CYP2D6	PM	PM a
CYP2D6	IM, NM	IM
CYP2D6	UM	NM or UM b
In the presence of an inducer c
CYP2C19	PM	PM a
CYP2C19	IM	NM
CYP2C19	NM	UM
CYP2C19	UM	UM d

^aGenotype-predicted CYP2C19 and CYP2D6 PMs are not affected by inhibitors or inducers and the phenotype remains as PM.

^bDependent on the adjusted genotype activity score.

^cThere are no known moderate or strong inducers for CYP2D6.

^dGenotype-predicted UMs are likely to be further induced; however, the phenotype remains as UM.

IM, intermediate metabolizer; NM, normal metabolizer; PM, poor metabolizer; UM, ultra-rapid metabolizer.