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Polymorphism of dextromethorphan oxidation in South Indian subjects
Author(s) -
Mamidi Rao N.V.S.,
Satyavageeswaran Shreeram,
Vakkalanka Swaroopkumar V.S.,
Chaluvadi Madhusudana R.,
Katneni Kasiram,
Brahmadevara Nataraj,
Damodarram Govindadas,
Subramaniam Swaminathan
Publication year - 1999
Publication title -
clinical pharmacology and therapeutics
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.941
H-Index - 188
eISSN - 1532-6535
pISSN - 0009-9236
DOI - 10.1053/cp.1999.v66.99989
Subject(s) - dextrorphan , dextromethorphan , metabolite , urine , volunteer , chemistry , pharmacology , medicine , biology , biochemistry , agronomy
One hundred fifty‐six unrelated healthy South Indian subjects were phenotyped according to their ability to metabolize dextromethorphan to its O ‐demethylated metabolite dextrorphan. Each volunteer was administered 25 mg oral dextromethorphan hydrobromide (19.3 mg dextromethorphan). Urine was collected during an 8‐hour period after drug administration and was analyzed for dextromethorphan and dextrorphan by HPLC with fluorescence detection. This analysis was performed with and without previous deconjugation. The log 10 (metabolic ratio), calculated as the ratio of dextromethorphan to dextrorphan, was bimodally distributed, and it was inferred that the frequency of occurrence of poor metabolizers of dextromethorphan in South Indian subjects is 3.2%. Phenotype assignment remained the same with both methods of analysis. Furthermore, a fairly good correlation (Spearman rank order correlation coefficient [ r s ] = 0.61; P < .0001) was observed between the log‐transformed metabolic ratio derived from both methods. Clinical Pharmacology & Therapeutics (1999) 66 , 193–200; doi: 10.1053/cp.1999.v66.99989