Search results for "CYP2C19"

LE VARIANTI DEL GENE CYP2C19 NELLA FARMACO-GENOMICA DEL CLOPIDOGREL

2010

Il clopidogrel per espletare la propria funzione di antiaggregante piastrinica necessita l’intervento di diversi citocromi epatici. Le varianti del gene CYP2C19 sembrano influenzarne sensibilmente l’attivazione e pertanto l’azione farmacologica. Sono stati identificati tre alleli principali. L’allele CYP2C19*1 è il wild type e codifica per un enzima costituzionalmente attivo. Gli alleli CYP2C9*2 e CYP2C9*3 codificano invece per forme enzimatiche parzialmente funzionanti e sono responsabili sia in eterozigosi che in omozigosi della variazione di attività farmacologica. La valutazione delle varianti è stata eseguita mediante le metodiche PCR-RFLP e sequenziamento diretto. Abbiamo allestito du…

Role of genetic factors on the effect of additional loading doses and two maintenance doses used to overcome clopidogrel hyporesponsiveness.

2014

Background and objective: Additional loading doses and higher maintenance doses (MDs) have been used to overcome hyporesponsiveness of clopidogrel. We aimed to investigate whether genetic polymorphisms of two cytochromes (CYP2C19 and CYP2C9) and ABCB1 modify effect of such dose-adjustment strategy.Materials and methods: We enrolled 118 patients undergoing elective or acute percutaneous coronary intervention (PCI) with drug eluting stent (DES). Platelet reactivity index (PRI) was measured using the vasodilator-stimulated phosphoprotein (VASP) index and a cut-off value of ≥60% was defined as hyporesponsiveness. Polymorphism of two cytochromes (CYP2C19, CYP2C9) and gene ABCB1 were determined. …

Cytochrome P450 enzymes as human autoantigens

1991

Genotype and Allele Frequencies of Drug-Metabolizing Enzymes and Drug Transporter Genes Affecting Immunosuppressants in the Spanish White Population

2013

Interpatient variability in drug response can be widely explained by genetically determined differences in metabolizing enzymes, drug transporters, and drug targets, leading to different pharmacokinetic and/or pharmacodynamic behaviors of drugs. Genetic variations affect or do not affect drug responses depending on their influence on protein activity and the relevance of such proteins in the pathway of the drug. Also, the frequency of such genetic variations differs among populations, so the clinical relevance of a specific variation is not the same in all of them. In this study, a panel of 33 single nucleotide polymorphisms in 14 different genes (ABCB1, ABCC2, ABCG2, CYP2B6, CYP2C19, CYP2C…

Increased Hospital Stay and Allograft Disfunction in Renal Transplant Recipients with Cyp2c19 AA Variant in SNP rs4244285

2012

Pharmacogenetics correlates certain genetic variants, such as single nucleotide polymorphisms (SNPs), with blood drug levels, efficacy, and adverse effects of the treatment. Tacrolimus is mainly metabolized via CYP3A4/5, whereas CYP2C19 and CYP3A4/5 are responsible for omeprazole metabolism. Omeprazole inhibits tacrolimus metabolism via CYP3A5 in patients carrying variant alleles of CYP2C19, increasing tacrolimus blood concentrations. Seventy-five renal transplant recipients treated with tacrolimus and concomitant omeprazole were genotyped in a panel of 37 SNPs with use of Sequenom MassArray. The patients with CYP2C19*2/*2 genotype (n = 4) showed a median posttransplantation hospital stay o…

Voriconazole and the liver.

2015

Voriconazole is an azole useful for the prophylaxis and the treatment of aspergillosis and other fungal infections in immunosuppressed subjects, as those found in aplasia after aggressive polychemotherapy treatments, after hematopoietic stem cell, liver or lung transplantation. Its administration in therapeutic doses lead to extremely varied serum levels from patient to patient and even to the same patient. The explanations are varied: nonlinear pharmacokinetics, certain patient-related factors, including genetic polymorphisms in the cytochrome P450 2C19 gene, the kidney and liver function, simultaneous administration with other drugs metabolised by the same cytochrome. It is recommended to…

Severe Tremor After Cotrimoxazole-Induced Elevation of Venlafaxine Serum Concentrations in a Patient With Major Depressive Disorder

2013

: We describe a female patient who was an extensive metabolizer of cytochrome P450 isoenzyme (CYP) 2D6 and an intermediate metabolizer of CYP2C19 (genotype: CYP2C19 *1/*2). She exhibited high serum concentrations of venlafaxine and O-desmethylvenlafaxine and developed severe tremor after comedication with cotrimoxazole (sulfamethazole/trimethoprim). Venlafaxine is mainly metabolized by O- and N-demethylation. O-demethylation is catalyzed by the highly polymorphic CYP2D6 and N-demethylation by several enzymes, CYP2C19, CYP2C9, and CYP3A4. The observed overall pharmacokinetic effect was most probably the result of decreased N-demethylation of venlafaxine by (1) reduced expression of CYP2C19 d…