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Implementation of In Vitro Drug Resistance Assays: Maximizing the Potential for Uncovering Clinically Relevant Resistance Mechanisms
Published on: December 9, 2015
[Clopidogrel resistance: myth or reality].
V L Serebrianyĭ1, A I Malinin, L M Makarov
1D. Hopkins University, Baltimore, USA.
Kardiologiia
|February 12, 2008
Summary
Clopidogrel is effective for acute coronary syndromes but may not work for all patients, with poor compliance potentially masking resistance. Further studies are needed to confirm "clopidogrel resistance" as a clinical issue.
Area of Science:
- Cardiology
- Pharmacology
- Clinical Trials
Background:
- Clopidogrel is a key anti-platelet drug for acute coronary syndromes and preventing clots after stenting.
- However, its efficacy is limited in some patients, including those with ischemic stroke or for primary vascular event prevention.
- The concept of "clopidogrel-resistance" has been proposed but lacks robust clinical evidence.
Purpose of the Study:
- To critically evaluate the evidence for "clopidogrel-resistance" in clinical practice.
- To explore potential confounding factors such as patient compliance.
- To discuss strategies for managing potential resistance and their associated risks.
Main Methods:
- Review of major randomized clinical trials on clopidogrel efficacy.
- Analysis of laboratory findings versus clinical study evidence regarding "clopidogrel-resistance".
- Assessment of patient compliance rates and their impact on treatment outcomes.
Main Results:
- While laboratory studies suggest "clopidogrel-resistance", large clinical trials have not consistently supported this theory.
- Low patient compliance, potentially exceeding 30% annually, may mask true resistance.
- Proposed methods to overcome resistance, like dose escalation or adding potent agents, risk increased bleeding and reduced compliance.
Conclusions:
- The clinical significance of "clopidogrel-resistance" remains uncertain, possibly being an artifact of poor compliance rather than a true pharmacological issue.
- Multicenter randomized trials with survival endpoints and detailed platelet assessments are necessary to definitively address this.
- Distinguishing true resistance from compliance issues is crucial for patient management and understanding anti-platelet therapy effectiveness.
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