title: The mephenytoin (cytochrome P450 2C 19) and dextromethorphan (cytochrome P450 2D6) polymorphisms in Saudi Arabians and Filipinos.
abstract: Hitherto no estimate has been available of the genetic polymorphisms of S-mephenytoin hydroxylation in the Saudi Arabian or any other Middle Eastern population. A total of 102 healthy Saudi Arabian volunteer subjects were tested simultaneously with mephenytoin and dextromethorphan. Two poor metabolizers of S-mephenytoin and two poor metabolizers of dextromethorphan were found. Also 55 healthy Filipino volunteer subjects were tested and 13 found to be poor metabolizers of S-mephenytoin, whilst none were found to be poor metabolizers of dextromethorphan. The Saudi Arabian population thus appears to resemble Europeans in the frequency of poor metabolizers of S-mephenytoin, but resembles Orientals in the frequency of poor metabolizers of dextromethorphan. The Filipino sample as expected resembles other Oriental samples in the frequencies of poor metabolizers of both drugs.
authors.affiliation: Riyadh Armed Forces Hospital, Kingdom of Saudi Arabia.
authors.forename: D A
authors.initials: DA
authors.lastname: Evans
authors.forename: P
authors.initials: P
authors.lastname: Krahn
authors.forename: N
authors.initials: N
authors.lastname: Narayanan
mesh_terms: D000293:Adolescent; D000328:Adult; D001189:Aryl Hydrocarbon Hydroxylases; D065731:Cytochrome P-450 CYP2C19; D019389:Cytochrome P-450 CYP2D6; D003577:Cytochrome P-450 Enzyme System / Q000235:genetics*; D003915:Dextromethorphan / Q000378:metabolism; D005006:Ethnicity; D005260:Female; D006801:Humans; D006900:Hydroxylation; D008297:Male; D008617:Mephenytoin / Q000378:metabolism*; D008875:Middle Aged; D006899:Mixed Function Oxygenases / Q000235:genetics*; D010679:Philippines / Q000208:ethnology; D011110:Polymorphism, Genetic; D012529:Saudi Arabia; D012727:Sex Characteristics
chemical_list: D003915:Dextromethorphan; D003577:Cytochrome P-450 Enzyme System; D006899:Mixed Function Oxygenases; D001189:Aryl Hydrocarbon Hydroxylases; C045793:CYP2C19 protein, human; D065731:Cytochrome P-450 CYP2C19; D019389:Cytochrome P-450 CYP2D6; D008617:Mephenytoin