Ultraschnelle metabolisierer - Grundlogen und klinische bedeutung

Psychotropic drugs are metabolised at different rates in the liver, where the polymorphic isozyme cytochrome P450 2D6 (CYP2D6) plays an important role. This explains some of the great interindividual differences in their plasma concentrations. Phenotypically, poor, intermediate, extensive and ultrarapid metabolisers have been described. Using genotyping, it is partly possible to explain these different phenotypes, in that in the investigated populations, individuals have been observed who have either 'normally' functional and/or not functional genes, deleted genes, or gene duplications/amplifications with functional or non-functional alleles. In psychiatry, the existence of gene duplication/multiplication of CYP2D6 is of clinical relevance, as patients concerned do not respond to even high doses, as a consequence of an ultrarapid metabolism of drugs which are metabolised by CYP2D6.