Related Experiment Videos

Pharmacogenetics of clopidogrel

Stephen A O'Connor1, Jean-Sebastien Hulot, Johanne Silvain

  • 1Institut de Cardiologie, INSERM U 937, Groupe A.C.T.I.O.N. Groupe Hospitalier Pitié-Salpêtrière, 47, boulevard de l'Hôpital, 75013 Paris, France.

Current Pharmaceutical Design
|June 26, 2012
PubMed

Insights

Genetic factors influence clopidogrel effectiveness, leading to variable patient responses. Identifying specific gene variants may personalize treatment for acute coronary syndrome patients, improving outcomes.

Area of Science:

  • Pharmacogenomics
  • Cardiovascular Medicine
  • Drug Metabolism

Background:

  • Clopidogrel and aspirin are crucial for acute coronary syndrome (ACS) and percutaneous coronary intervention (PCI) patients.
  • Variable patient responses to clopidogrel, due to genetic factors, result in high on-treatment platelet reactivity (HPR) and increased ischemic events.
  • Hepatic cytochrome P450 (CYP)-dependent metabolism is key to clopidogrel's efficacy.

Purpose of the Study:

  • To investigate the role of genetic variability, specifically CYP 2C19 loss-of-function alleles, in clopidogrel response.
  • To explore the clinical implications of identifying patients with HPR due to genetic factors.
  • To assess the potential of genotype-guided therapy in ACS patients.

Main Methods:

  • Review of pharmacogenomic studies analyzing CYP 2C19 variants and their association with clopidogrel metabolism.
  • Analysis of data linking genetic profiles to active metabolite levels, platelet inhibition, and clinical outcomes.
  • Consideration of point-of-care genetic testing development and its clinical utility.

Main Results:

  • The CYP 2C19*2 allele is a primary genetic determinant of reduced clopidogrel antiplatelet effect.
  • Carriers of loss-of-function alleles exhibit lower active metabolite levels, increased platelet reactivity, and poorer cardiovascular outcomes.
  • Current evidence suggests genetic testing is not yet recommended for routine clinical practice due to limited prospective data.

Conclusions:

  • Genetic variability significantly impacts clopidogrel efficacy, contributing to treatment variability in ACS patients.
  • While routine genetic testing is not advised, its combination with platelet function analysis may benefit select ACS patients undergoing stenting with risk factors.
  • Further prospective research is needed to establish the definitive role of genotype-guided clopidogrel therapy.

Related Concept Videos

Pharmacogenetic Phenotypes: Alterations in Pharmacokinetics, Drug Targets and Biologic Milieu01:29

Pharmacogenetic Phenotypes: Alterations in Pharmacokinetics, Drug Targets and Biologic Milieu

Genetic variations significantly influence drug response through pharmacokinetics, receptor interactions, and biologic milieu modifications. Pharmacokinetic alterations impact drug metabolism and clearance, affecting efficacy and toxicity. Variants in drug-metabolizing enzymes, such as CYP2C9 and CYP2C19, alter drug activation and elimination. For example, CYP2C9 loss-of-function variants require lower warfarin doses to prevent excessive bleeding, while CYP2C19 variants reduce clopidogrel...
Pharmacogenetics of Drug Metabolism: Overview01:27

Pharmacogenetics of Drug Metabolism: Overview

Genetic polymorphism in drug metabolism is crucial to the inter-individual variability observed in drug responses. Drug metabolism primarily involves the chemical modification of drugs and other xenobiotics to enhance their elimination by increasing their polarity. Two main classes of enzymes mediate this biotransformation process: Phase I enzymes, primarily cytochrome P450s, catalyze oxidation and reduction reactions, while other enzymes, such as esterases, mediate hydrolysis, and Phase II...
Pharmacogenetics of Phase I Enzymes: Cytochrome P450 Isozymes01:28

Pharmacogenetics of Phase I Enzymes: Cytochrome P450 Isozymes

Cytochrome P450 (CYP450) enzymes are a superfamily of heme-containing monooxygenases that play a pivotal role in Phase I drug metabolism by catalyzing oxidation and reduction reactions.These enzymes transform lipophilic xenobiotics into more hydrophilic metabolites, facilitating subsequent Phase II conjugation and eventual excretion. The CYP450 family is classified into families (e.g., CYP1–CYP3) and subfamilies (e.g., CYP2A, CYP2C), based on amino acid sequence homology.CYP450 isoenzymes,...
Pharmacogenomics: Identification of New Drug Targets01:29

Pharmacogenomics: Identification of New Drug Targets

Advances in genomics have profoundly influenced drug discovery by increasing both the speed and accuracy of pharmaceutical development. Pharmacogenomics, which examines how genetic variation influences drug response, facilitates the identification of novel therapeutic targets and enables patient stratification for personalized treatment. These strategies contribute to improved drug efficacy, minimized adverse effects, and more efficient clinical trial design.Mapping genetic differences...
Principles of Pharmacogenetics: Types of Genetic Variants01:27

Principles of Pharmacogenetics: Types of Genetic Variants

The human genome is over 99.9% identical between individuals, yet genetic differences exist at millions of bases. The human genome contains approximately 3 million variant positions per individual, many of which are heterozygous, contributing to genetic diversity and individual traits. Genetic variations include single-nucleotide polymorphisms (SNPs), insertions, deletions, and copy number variations (CNVs).SNPs, the most common variation, involve single-base changes in DNA. These can be...
Pharmacogenetics of Drug Transporters: P-Glycoprotein and Solute Carrier Transporters01:16

Pharmacogenetics of Drug Transporters: P-Glycoprotein and Solute Carrier Transporters

The pharmacogenetics of drug transporters is increasingly recognized as a critical factor influencing interindividual variability in drug absorption, distribution, and elimination. These membrane-bound proteins regulate drugs' movement across cellular barriers by actively pumping them out (efflux) or facilitating their uptake (influx). Among the major transporter families, ATP-binding cassette (ABC) and solute carrier (SLC) transporters play particularly prominent roles. Genetic polymorphisms...