Cytochrome P-450: Difference between revisions

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===CYP2D6===
===CYP2D6===
3-10% of anglos are poor metabolizers of drugs that use the CYP2D6 [[isoenzyme]].<ref name="pmid11710893">{{cite journal |author=Phillips KA, Veenstra DL, Oren E, Lee JK, Sadee W |title=Potential role of pharmacogenomics in reducing adverse drug reactions: a systematic review |journal=JAMA |volume=286 |issue=18 |pages=2270–9 |year=2001 |month=November |pmid=11710893 |doi= |url=http://jama.ama-assn.org/cgi/pmidlookup?view=long&pmid=11710893 |issn=}}</ref> This affects [[antidepressant]]s.
3-10% of anglos are poor metabolizers of drugs that use the CYP2D6 [[isoenzyme]].<ref name="pmid11710893">{{cite journal |author=Phillips KA, Veenstra DL, Oren E, Lee JK, Sadee W |title=Potential role of pharmacogenomics in reducing adverse drug reactions: a systematic review |journal=JAMA |volume=286 |issue=18 |pages=2270–9 |year=2001 |month=November |pmid=11710893 |doi= |url=http://jama.ama-assn.org/cgi/pmidlookup?view=long&pmid=11710893 |issn=}}</ref> This affects many [[antidepressant]]s, [[metoprolol]] and other drugs that use this [[isoenzyme]]. More information is available at Entrez Gene.<ref name="urlGene Home">{{cite web |url=http://www.ncbi.nlm.nih.gov/sites/entrez?Db=gene&Cmd=ShowDetailView&TermToSearch=1565 |title=Entrez Gene: CYP2D6 cytochrome P450, family 2, subfamily D, polypeptide 6 [ Homo sapiens ] |author=Anonymous |authorlink= |coauthors= |date= |format= |work= |publisher=National Library of Medicine |pages= |language= |archiveurl= |archivedate= |quote= |accessdate=2009-01-03}}</ref>


==References==
==References==

Revision as of 10:28, 3 January 2009

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Cytochrome P-450 is a "superfamily of hundreds of closely related hemeproteins found throughout the phylogenetic spectrum, from animals, plants, fungi, to bacteria. They include numerous complex monooxygenases (mixed function oxygenases). In animals, these P-450 enzymes serve two major functions: (1) biosynthesis of steroids, fatty acids, and bile acids; (2) metabolism of endogenous and a wide variety of exogenous substrates, such as toxins and drugs (biotransformation). They are classified, according to their sequence similarities rather than functions, into CYP gene families (>40% homology) and subfamilies (>59% homology). For example, enzymes from the CYP1, CYP2, and CYP3 gene families are responsible for most drug metabolism."[1]

Common abnormal alleles

CYP2C9

CYP2C9 is an isoenzyme of cytochrome P-450. Polymorphisms of CYP2C9 explain 10% of variation in warfarin dosing[2], mainly among Caucasian patients as these variants are rare in African American and most Asian populations.[3] A meta-analysis of mainly Caucasian patients found[3]:

  • CYP2C9*2 allele:
    • present in 12.2% of patients
    • mean reduction was in warfarin dose was 0.85 mg (17% reduction)
    • relative bleeding risk was 1.91
  • CYP2C9*3 allele:
    • present in 7.9% of patients
    • mean reduction was in warfarin dose was 1.92 mg (37% reduction)
    • relative bleeding risk was 1.77


CYP2D6

3-10% of anglos are poor metabolizers of drugs that use the CYP2D6 isoenzyme.[4] This affects many antidepressants, metoprolol and other drugs that use this isoenzyme. More information is available at Entrez Gene.[5]

References

  1. Anonymous (2024), Cytochrome P-450 (English). Medical Subject Headings. U.S. National Library of Medicine.
  2. Wadelius M, Chen LY, Downes K, et al (2005). "Common VKORC1 and GGCX polymorphisms associated with warfarin dose". Pharmacogenomics J. 5 (4): 262-70. DOI:10.1038/sj.tpj.6500313. PMID 15883587. Research Blogging.
  3. 3.0 3.1 Sanderson S, Emery J, Higgins J (2005). "CYP2C9 gene variants, drug dose, and bleeding risk in warfarin-treated patients: a HuGEnet systematic review and meta-analysis". Genet. Med. 7 (2): 97-104. PMID 15714076[e]
  4. Phillips KA, Veenstra DL, Oren E, Lee JK, Sadee W (November 2001). "Potential role of pharmacogenomics in reducing adverse drug reactions: a systematic review". JAMA 286 (18): 2270–9. PMID 11710893[e]
  5. Anonymous. Entrez Gene: CYP2D6 cytochrome P450, family 2, subfamily D, polypeptide 6 [ Homo sapiens ]. National Library of Medicine. Retrieved on 2009-01-03.

External links