Screening test for: Metabolism of Warfarin CYP2C9, one of the members of the family of cytochrome P-450, is responsible for the metabolism of approximately 16% of the drugs currently on the market. It is important for the metabolism of many drugs with a narrow therapeutic range, such as phenytoin (antiepileptic) or anticoagulants Warfarin and Sintrom, and blockers (angiotensin II), non-steroidal anti-inflammatory drugs, some antidepressants and many other drugs. There are several allelic variants of CYP2C9, the most common are the CYP2C9 * 2 (C430T) and CYP2C9 * 3 (A1075C), with an allele frequency in the Caucasian population respectively of 8-18% and 4-10%. Several studies of patients treated with warfarin showed that individuals with alleles CYP2C9 * 2 and CYP2C9 * 3 metabolize drugs more slowly (low-metabolizers) and therefore require a lower dose of the drug.
These alleles were strongly associated with an increased sensitivity to warfarin and risk of bleeding during treatment anticoagulante. There are genotype-phenotype correlations for a better management of the patient: - subjects with genotype CYP2C9 *1/*1 (frequency of 70% in the Caucasian population) are considered normal metabolizers; - individuals CYP2C9 *1/*2 (frequency of 16% in Caucasian populations), and *1/*3 (frequency of 10% in the Caucasian population) are considered poor metabolizers; - finally, there is a class of very poor metabolizer genotype grouping subjects at *2/*2 (frequency of 1%), *2/*3 (frequency 1%), *3/*3 (frequency of 0.3%). The kit is available in sizes from 24, 48 or 72 reactions.