Enzyme	Metabolizer phenotype	Population frequency (%)
		Asians	Blacks	Whites
CYP2C9	Poor	0.43	0.04	1.04
	Intermediate	3.54	134	334
	Ultrarapid	—	—	—
CYP2C19	Poor	18 to 233,5	1.2 to 5.35,6	2.0 to 5.03,5
	Intermediate	307	297,8	187
	Ultrarapid	—	—	—
CYP2D6	Poor	1.0 to 4.83,5,8	1.9 to 7.35,6,8	7.0 to 103,8
	Intermediate	518	309	1.0 to 2.08
	Ultrarapid	0.9 to 218	4.98	1.0 to 5.08