metabolic capacity of cyp2d6 within an iranian population (mazandaran province)

background: cyp2d6 is polymorphically expressed enzyme that show marked interindividual and interethnic variation. phenotyping of cyp2d6 provides valuable information about real-time activity of this important drug-metabolizing enzymes through the use of specific probe drugs. the aim of this study was to identify the cyp2d6 oxidation phenotype with dextromethorphan (dex) as a probe drug in mazandarani ethnic group among iranian population. methods: the study included 71 unrelated healthy volunteers. dextromethorphan hydrobromide (30 mg) was given orally to healthy subjects and peripheral venous blood samples (10 ml) were taken at 3 hr post-dose. dextromethorphan and the metabolite dextrorphan (dor) were analyzed by the hplc method. the log dex/dor metabolic ratio (mr) at 3 hr plasma sample was used as the index of cyp2d6 activity and a value of 0.3 was used as the antimode separating extensive metabolizers (em) and poor metabolizers (pm) phenotypes. results: a 560-fold interindividual variation in dextromethorphan mrs was observed in this study. considering the antimode 0.3 in log scale, 7.04% (5/71) volunteers were identified as pms.conclusion: the result showed that the frequency of cyp2d6 pm phenotypes accounted for 7.04% of subjects in our samples. despite these findings, we propose a further study in larger samples to provide a wider image and to get more valuable information upon pharmacogenetic basis for individual therapy and personalized medicine.