Story Highlight
– UK CERSI-PGx releases first clopidogrel clinical guideline.
– Focus on CYP2C19 genotyping for personalized treatment.
– Addresses variability in clopidogrel effectiveness among patients.
– Guidelines enhance integration of pharmacogenomics into healthcare.
– Collaboration includes multiple universities and health organizations.
Full Story
The University of Liverpool has spearheaded the establishment of the UK Centre of Excellence in Regulatory Science and Innovation in Pharmacogenomics (UK CERSI-PGx), which recently unveiled its inaugural clinical guideline relating to the antiplatelet drug clopidogrel. This medication is routinely dispensed in the UK as a preventative measure against blood clot formations. The field of pharmacogenomics investigates the influence of genetic variations on individual responses to medications.
This newly released guideline emphasises the importance of CYP2C19 genotyping for patients undergoing treatment with clopidogrel, particularly those suffering from coronary artery disease, cerebrovascular disease, and peripheral arterial disease. The necessity for such guidelines arises from the observation that clopidogrel’s effectiveness is not consistent across all patients.
The CYP2C19 enzyme plays a pivotal role in the liver’s processing of clopidogrel, converting it into its active form. However, levels of this enzyme can vary significantly between individuals due to genetic differences. For instance, patients with diminished levels of CYP2C19 may experience less effective activation of clopidogrel compared to those with standard enzyme levels. Such variability can be assessed through a straightforward genetic test. Research indicates that approximately 20% to 30% of individuals of European descent exhibit lower enzyme activity, while this percentage may increase to between 50% and 60% among individuals of Asian heritage.
In contrast to existing international pharmacogenomic protocols from the Clinical Pharmacogenetics Implementation Consortium (CPIC) and the Dutch Pharmacogenetics Working Group (DPWG), the UK CERSI-PGx guideline prioritises a more clinically oriented approach. It delivers actionable recommendations regarding:
– Criteria for patient testing
– Methods for incorporating testing into existing clinical workflows
– Specific genetic variants to analyse and expected response times
– Treatment strategies based on genetic outcomes
– Economic considerations related to health
– Identified research gaps and directions for future inquiries
This guideline represents a significant milestone as the first of its kind in the UK, developed by a collaborative committee comprising a diverse array of specialists. Its importance extends to regulators, industry stakeholders, and the National Health Service (NHS). The NHS’s decade-long strategy highlights an aim to weave pharmacogenomics into daily clinical practice. The current guideline, along with others that are planned for development, will play a critical role in actualising this vision.
Funding for UK CERSI-PGx comes from Innovate UK and the Medical Research Council, in partnership with the Medicines and Healthcare products Regulatory Agency (MHRA). It forms part of a network consisting of seven Centres of Excellence aimed at advancing Regulatory Science and Innovation. Key partners in the CERSI-PGx initiative include various academic institutions such as The University of Manchester, Queen Mary University of London, and Bangor University, alongside organisations like The Office of Health Economics and the British Pharmacological Society.
Professor Sir Munir Pirmohamed, who leads the initiative at the University of Liverpool, stated, “With the new CERSI-PGx guideline for clopidogrel, we aim to ensure patients are prescribed the right treatment at the right dose, based on their genetics. By integrating CYP2C19 testing into routine pathways, we can improve efficacy, reduce adverse drug reactions, ease pressure on the NHS, and support cost-effective, precision prescribing.”
Professor Dame Sue Hill, Chief Scientific Officer for England, described the guidelines as a crucial advancement in employing genomics to shape treatment strategies and circumvent unnecessary side effects. She expressed her satisfaction with the inclusive, multidisciplinary approach adopted during the guidelines’ formulation, which she hopes will be replicated for other clinical scenarios. The emergence of UK-specific clinical guidelines for pharmacogenomics is expected to facilitate a systematic introduction into standard healthcare practices.
Dr Alison Cave, Chief Safety Officer of the MHRA, remarked on the significance of the CERSI-PGx’s first clinical guideline concerning clopidogrel, highlighting its role in expediting the integration of pharmacogenomics into everyday healthcare. By utilising genetic assessments, this approach aims to guarantee that patients receive medications and dosages tailored to their unique genetic configurations, thereby mitigating the potential for adverse reactions. Such methodologies are aligned with the long-term aspirations of the MHRA, advocating for a transition towards more personalised medication strategies, which would greatly enhance patient safety and well-being.
The comprehensive guidelines and an accompanying editorial have been published on 4 December 2025 in the British Journal of Clinical Pharmacology. As these guidelines take effect, there is growing optimism regarding their impact on patient care and the move towards more precise and effective treatment protocols in the UK healthcare system, marking a new chapter in the application of pharmacogenomics in clinical practice.
Our Thoughts
The article outlines the publication of clinical guidelines for the antiplatelet medication clopidogrel, emphasizing the importance of CYP2C19 genotyping for patient safety. To prevent potential adverse reactions associated with clopidogrel, healthcare practices should ensure routine genetic testing is performed before prescribing. This aligns with the Health and Safety at Work Act 1974, which mandates employers to ensure, as far as is reasonably practicable, the health and safety of employees and patients.
Key safety lessons include the necessity of integrating pharmacogenomics into standard clinical pathways to tailor medication effectively based on individual genetic profiles. Although the article does not specify any breaches of regulations, the failure to implement personalized medicine could compromise patient safety, infringing upon the General Pharmaceutical Council’s standards for safe and effective patient care.
To mitigate future incidents, healthcare providers must adopt these guidelines universally, ensuring that healthcare professionals are trained in pharmacogenomics. Regular audits and monitoring should be instituted to reinforce compliance and evaluate the effectiveness of these interventions, maintaining a focus on patient-centered care within NHS guidelines.




















