DEXTROMETHORPHAN METABOLIC PHENOTYPING IN A CHINESE POPULATION

AIM: To establish a phenotyping of dextromethorphan (DM) oxidation pol ymorphism in a native Chinese population. METHODS: The urine concentra tions of DM and its metabolite dextrophan (DX) were assayed by HPLC an d metabolic ratios (MR) were calculated in 120 unrelated native Chines e subjects after ingestion of DM 20 mg. RESULTS: The incidence of poor metabolizers was 0.8 % (one in 120 subjects). There were distinct dim odal distributions which divided extensive metabolizers into 43 interm ediate metabolizers and 76 very extensive metabolizers. The 0 - 8 h ur inary recoveries of DM and DX were 0.4 % +/- s 0.5 % and 26 % +/- s 13 %, respectively. There was no difference in 0 - 8 h urinary recoverie s between male and female subjects. CONCLUSION: DM metabolic phenotypi ng provides a new information for debrisoquine 4-hydroxylation (CYP2D6 ) polymorphism in native Chinese.