Monika Szewczuk-Bogusławska, Magdalena Grzesiak, Jan Aleksander Beszłej, Andrzej Kiejna
Badanie aktywności CYP2D6 jako forma optymalizacji terapii lekami przeciwdepresyjnymi  1093
Assessment of CYP2D6 activity as a form of optimizing antidepressant therapy  1093
Summary
Cytochrome 2D6 catalyzes oxidation processes of many antidepressants (TCAs, SSRIs, maprotyline, mianserine, nefazodon, trazodon, venlafaxine). CYP2D6 is characterized by genetically determined polymorphism which may lead to serious clinical consequences. Based on CYP2D6 activity four phenotypes are distinguished: poor metabolism (PM), intermediate (IM), extensive (normal) EM and ultrarapid (UM). In case of PM and IM increased plasma concentration of a drug and adverse events or toxicity may appear. Decreased plasma level and lack of clinical effect may be connected with ultrarapid phenotype. CYP2D6 activity may be assessed by phenotyping or genotyping . Model drugs such as sparteine, debrisoquine, dextrometorhan and metoprolol are used in the phenotyping method. Based on metabolic ratio of model drug the phenotype status is established. Genotyping consists in an assessment of genotype i.e. an identification of alleles coding the CYP2D6 protein. The environmental factors may modify the CYP2D6 activity and influence on phenotyping but not genotyping results. The knowledge of CYP2D6 phenotype is of special value when drugs characterized by a narrow therapeutic index are used and in polymedicated and older patients.