Dextromethorphan O-demethylation polymorphism in an African-American population.
OBJECTIVE
One hundred eighty-one (97 F, 84 M) unrelated healthy African-American subjects (aged 18-41 years) were phenotyped based on their dextromethorphan (DMP) O-demethylation ability.


METHODS
Each subject was given 15 mg DMP orally and collected 8-h urine. The concentrations of DMP and its metabolite dextrophan (DOP) were determined by HPLC with ultraviolet detection. Metabolic ratio (MR) was expressed as the ratio of DMP to DOP molar amount in urine.


RESULTS
The frequency distribution histogram of the MR was bimodal, and probit analysis of this frequency gave an antimode value of 0.34. Seven subjects [3.9%, 95% confidence interval (CI) 1.1%-6.7%] were classified as poor metabolizers (PMs).


CONCLUSIONS
This deficient frequency is in complete agreement with the reported ones in two smaller investigations in the African-American populations.
He
N
N
Clinical Pharmacology Program, Department of Pharmacology, Meharry Medical College, Nashville, TN 37208, USA. henunn54@ccvax.mmc.edu
Daniel
H I
HI
Hajiloo
L
L
Shockley
D
D
D000293:Adolescent; D000328:Adult; D001741:Black or African American; D044383:Black People / Q000235:genetics*; D002851:Chromatography, High Pressure Liquid; D019389:Cytochrome P-450 CYP2D6 / Q000172:deficiency / Q000235:genetics* / Q000378:metabolism; D003915:Dextromethorphan / Q000378:metabolism*; D005260:Female; D006801:Humans; D008297:Male; D010641:Phenotype; D011110:Polymorphism, Genetic
D003915:Dextromethorphan; D019389:Cytochrome P-450 CYP2D6