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Review article: the prevalence and clinical relevance of cytochrome P450 polymorphisms
Author(s) -
WIJNEN P. A. H. M.,
OP DEN BUIJSCH R. A. M.,
DRENT M.,
KUIPERS P. M. J. C.,
NEEF C.,
BAST A.,
BEKERS O.,
KOEK G. H.
Publication year - 2007
Publication title -
alimentary pharmacology and therapeutics
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 3.308
H-Index - 177
eISSN - 1365-2036
pISSN - 0269-2813
DOI - 10.1111/j.1365-2036.2007.03490.x
Subject(s) - cyp2c19 , medicine , cyp1a2 , cyp2d6 , genotyping , cyp2c9 , pharmacology , drug , clinical significance , cytochrome p450 , cyp2e1 , adverse effect , adverse drug reaction , cyp3a , pharmacogenetics , intensive care medicine , genotype , biology , genetics , gene , metabolism
Summary Background Most drugs currently used in clinical practice are effective in only 25% to 60% of patients, while adverse drug reactions (ADRs) as a consequence of treatment are estimated to cost billions of US dollars and tens of thousands of deaths. Aim To review the prevalence and clinical significance of cytochrome P450 polymorphisms. Results The cytochrome P450 enzyme families 1–3 are responsible for 70 to 80% of all phase I dependent drug metabolisms. In 90% metabolic activity dependents on six enzymes: CYP1A2, CYP3A, CYP2C9, CYP2C19, CYP2D6 and CYP2E1. Polymorphisms in the CYP450 gene can influence metabolic activity of the subsequent enzymes. A poor metabolizer (PM) has no or very poor enzyme activity. A consequence of PM is drug toxicity if no other metabolic route is available, or when multiple drugs are metabolized by the same cytochrome. In that case dose reduction is an option to prevent toxic effects. Conclusions In the future genotyping should be considered to identify patients who might be at risk of severe toxic responses, in order to guide appropriate individual dosage. Medical therapy should be a close cooperation between clinicians, pharmacologists and laboratory specialists, leading to reduced therapeutic errors, ADRs and health care costs.