Oxidative phenotype status in related subjects.

Human population varies with regard to the rate of drug metabolism. Differences in pharmacological activity of a drug in patients who belong to the same population result from a different enzymatic activity and different genotypes of those subjects. The aim of the study was to assess the incidence of extensive (EM) and poor (PM) oxidative phenotypes in related persons and to establish whether any associations exist between an individual, genetically conditioned drug oxidation capacity and a family relationship. The study comprised 61 healthy subjects including 39 females and 22 males aged between 18 and 77 years (mean age 39.02 +/- 16.55 years). The persons belonged to 20 families and were first degree relatives. The oxidative phenotype status was established based on the metabolic ratio (MR); the amounts of urinary output of dextromethorphan and dextrorphan in the 10 h urine were determined using the HPLC method. Prevalence of poor metabolizers in the group of relatives reached 16.4%. The percentage of poor metabolizers was higher in the group of relatives than in the control group (9.6%), however, the difference was not statistically significant. Inheritance of the oxidative phenotype among relatives is mainly associated with mothers and their daughters.