Family of enzymes with 10 isoforms responsible for the oxidative metabolism of most drugs.
The activity of these enzymes and the interaction of environmental factors and genetic and non-genetic host factors account for the variability of drug metabolism among patients.
CYP2C9, CYP2C19 and CYP2D6 isoforms account for 40% of cytochrome P-450 mediated drug metabolism.
Cytochrome P-450-CYP2D6 is involved with the metabolism of about 100 drugs including beta-blockers, antiarrhythmic, antidepressant, antiseizure and opioid analgesics.
CYP2D6 associated with variations in serum levels of medications and in clinical responses.
Antidepressants frequently require dose modifications because of the presence of CYP450 polymorphic mutations.
Patients who lack 2 fully active alleles for 2D6 gene are less able to tolerate drugs metabolized primarily by 2D6.
Decreased activity of CYP2D6 associated with cardiovascular toxicity.
Following stem cell hematopoietic transplantation the use of multiple drugs can affect the system.
CYP2C19 isoenzyme exhibits significant genetic polymorphism.
CYP2C9 is the enzyme primarily responsible for the metabolic clearance of the S-enatiomer of warfarin.