[Determination of the oxidation phenotype in the Czechoslovak population using metoprolol]

The authors assessed the oxidative phenotype type debrisochin/spartein in 97 healthy volunteers aged 23 to 56 years (45 men and 52 women). After metoprolol administration which served as a model substance, in doses of 100 mg p. o. at night, the authors collected urine during 8 hours. In the urine specimens they assessed by gas chromatography with detection of the electron capture (fig. 1) the metabolic ratio of metoprolol/alpha-hydroxymetoprolol (M/HM). The distribution of logM/HM on the frequency histogram was bimodal and made it possible to divide the group into extensive and poor metabolizers (fig. 2). The authors detected 6 poor metabolizers which corresponds to the results in the white population. The authors discuss the clinical impact of oxidative polymorphism in the treatment with metoprolol, diltiazem, quinidine and other drugs.