Highly potent and selective CYP2C19 inhibitors are not currently available. In the present study, N-3-benzyl derivatives of nirvanol and phenobarbital were synthesized, their respective (+)- and (-)-enantiomers resolved chromatographically, and inhibitor potencies determined for these compounds toward CYP2C19 and other human liver cytochromes P450 (P450s). (-)-N-3-Benzyl-phenobarbital and (+)-N...

Dual antiplatelet therapy with clopidogrel and aspirin has become the mainstay of therapy for patients with acute coronary syndrome (ACS) undergoing percutaneous coronary interventions (PCI). Many pharmacokinetic and pharmacodynamic studies have demonstrated substantial interindividual variation in antiplatelet response with clopidogrel, a significant proportion of which is explained by the var...

Cytochrome P450 enzymes from the CYP2C subfamily play a prominent role in the metabolic clearance of many drugs. CYP2C enzymes have also been implicated in the metabolism of arachidonic acid to vasoactive epoxyeicosatrienoic acids. CYP2C8, CYP2C9, and CYP2C19 are expressed in the adult liver at significant levels; however, the expression of CYP2C enzymes in extrahepatic tissues such as the brai...

Antiretroviral therapy for human immunodeficiency virus (HIV) infection includes treatment with both reverse transcriptase inhibitors and protease inhibitors, which markedly suppress viral replication and circulating HIV RNA levels. Cytochrome P450 (P450) enzymes in human liver, chiefly CYP3A4, play a pivotal role in protease inhibitor biotransformation, converting these agents to largely inact...

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 coronar...

AIMS In clopidogrel-treated patients undergoing coronary stenting, high on-treatment platelet reactivity was linked to a higher risk of stent thrombosis (ST). Platelet response to clopidogrel is significantly influenced by genetic factors. Recently published findings showed a highly significant impact of a common polymorphism (Q192R) within the paraoxonase-1 (PON1) gene on clopidogrel treatment...

Clopidogrel decreases the morbidity and mortality associated with several cardiovascular diseases. However, clopidogrel is a prodrug that needs to be metabolized to the active thiol metabolite by the cytochrome P450 (CYP) system. This activation is a source of significant interindividual variability in clopidogrel responsiveness. Drug interactions with and genetic variation in CYP3A4, CYP3A5, a...

BACKGROUND High platelet reactivity (HPR) after clopidogrel treatment is linked to an increased risk of periprocedural myocardial infarction (PMI). The occurrence of PMI that could be associated with CYP2C19 genotype status was our hypothesis. METHODS AND RESULTS A total of 233 patients with non-ST elevation acute coronary syndromes (NSTACS) undergoing uneventful elective percutaneous coronar...

Several in vitro criteria were used to assess whether three methylenedioxyphenyl (MDP) compounds, the isoquinoline alkaloids bulbocapnine, canadine, and protopine, are mechanism-based inactivators of CYP2C19. The recently reported fluorometric CYP2C19 progress curve analysis approach was applied first to determine whether these alkaloids demonstrate time-dependent inhibition. In this experiment...

The evidence for testing for CYP2C19 metabolizer status by CYP2C19 genotyping in patients with need for antiplatelet therapy who are undergoing or being considered for clopidogrel therapy includes 1 randomized controlled trial (RCT) of CYP2C19 genotype-directed antiplatelet therapy, observational studies, and analyses or RCTs of clopidogrel therapy, and meta-analyses of these studies. Relevant ...