Pharmacogenetics of cytochrome p4502D6: genetic background and clinical implication

Eur J Clin Invest. 2003 Nov:33 Suppl 2:17-22. doi: 10.1046/j.1365-2362.33.s2.3.x.


Interindividual differences in the pharmacokinetics of a number of drugs are often due to hereditary polymorphisms of drug-metabolizing enzymes. Most important is cytochrome p4502D6 (CYP2D6), also known as debrisoquine/sparteine hydroxylase. It catalyzes hydroxylation or demethylation of more than 20% of drugs metabolized in the human liver, such as neuroleptics, antidepressants, some beta-blockers and many others like codeine. About 7%-10% of Caucasians lack any CYP2D6 activity due to deletions and frame-shift or splice-site mutations of the gene. About 1%-3% of Middle-Europeans, but up to 29% of Ethiopians display gene duplications, leading to elevated so-called ultrarapid metabolization rates. Meanwhile there is now a much better understanding of the genetic background of poor, intermediate, extensive and ultrarapid metabolizers, enabling a more precise DNA genotyping-based prediction of plasma levels. Since there is evidence that deteriorated drug elimination partly accounts for drug side-effects, CYP2D6 genotyping could contribute to an individualized and therefore optimized drug therapy.

Publication types

  • Review

MeSH terms

  • Cytochrome P-450 CYP2D6 / genetics*
  • Cytochrome P-450 CYP2D6 / physiology
  • Ethnicity
  • Humans
  • Pharmacokinetics*
  • Polymorphism, Genetic


  • Cytochrome P-450 CYP2D6