How we set up the UK’s first clopidogrel genomics testing system

“Out of the realms of science fiction” was one patient’s remark, which made me think about the perception of pharmacogenomics, not only among patients but also some healthcare professionals.

Before I joined NHS Tayside as the specialist clinical pharmacist for stroke in 2020, I would not have given pharmacogenomics much thought. Maybe I thought I did not have the necessary knowledge to consider it, or maybe the real-life applications of such a concept never crossed my mind. However, since then, as a clinical pharmacist, I became involved in the P4Me project — a partnership between the University of Dundee and NHS Tayside that is aimed to incorporate precision medicine into daily routine and give it real-world applications. 

Now I use pharmacogenomics daily, as I would any other blood test, to guide me in my decision making.

Earlier in 2022, I was privileged to be invited by the Royal Pharmaceutical Society in Scotland to attend the ‘Pharmacy 2030: celebrating and sharing best practice’ event in Glasgow, where I presented NHS Tayside’s current work on implementing pharmacogenomics in the stroke service. 

During this event I had the opportunity to speak with many colleagues from different backgrounds and their responses were overwhelmingly positive. Pharmacists want to know more and they want to be involved. Pharmacogenomic testings has been in practice for a long time, and oncology colleagues in particular will be well aware of its applications. However, what raised the most interest from my presentation at the event was not only seeing the potential benefits of pharmacogenomics, it was seeing the concept applied to common drugs, such as clopidogrel, and how it can impact daily decision making.

Clopidogrel is an antiplatelet medication widely used in stroke prevention, which requires hepatic bioactivation. Owing to mutations to the CYP2C19, not all individuals will metabolise clopidogrel to the same extent and gain the same benefit and antiplatelet protection. This can potentially leave some patients at a higher risk of strokes and thrombo-occlusive events than those who are normal metabolisers of clopidogrel. Research has revealed that a staggering 25% of patients may not receive the same benefit from this medication in the first months after a stroke as normal metabolisers do.

I was overwhelmed by the reaction and interest from my peers and humbled by winning the 2022 RPS Best Practice Award for my presentation at the event. This recognition was not only a great honour and responsibility, given the quality of the other examples and presentations at the event, but it also shows unequivocally that the pharmacist community is interested in this area and is willing to develop the required skillset to be a part of the development and implementation of pharmacogenomics in their own specialist areas.

Led by Alex Doney, a senior clinical lecturer at the University of Dundee, and through collaborative work across several teams, the P4Me project was developed to be where it is today, from technical and clinical challenges to funding and pathway development. As a specialist clinical pharmacist in stroke, my main role in this project has been implementing pharmacogenomics in daily use on the acute stroke ward. This allows me to identify patients who are impaired metabolisers of clopidogrel and may not receive the necessary protection from it in stroke prevention. 

When I carry out daily patient reviews and explain what I am doing, patients’ reactions have been phenomenal. Following the shocking and life-changing news of an acute stroke, some people do struggle to comprehend the concept, but many are amazed at the possibilities that pharmacogenomics can offer.

Following a diagnosis and indication for clopidogrel, I will request the CYP2C19 genotyping test from the East of Scotland Regional Genetic Laboratory, based in Ninewells Hospital, Dundee. Once reported I will review these results, discuss them with the medical team, consider the patients unique characteristics, optimise and communicate the antiplatelet plan — thus delivering personalised medicine.

These are exciting times, where we have an opportunity to move from reactive to predictive medicine. Instead of giving a specific drug to a patient and evaluate expected and unexpected reactions caused by that drug, we can now aim to predict its efficacy before we subject the patient to a specific treatment. Advancing from ‘one size fits all’ treatments to personalised medicine can be not only safer, but also more cost effective. 

As pharmacists and medicine experts, we are ideally placed to champion and promote the rational use of pharmacogenomics testing, interpret results, optimise medication and communicate with patients and other healthcare professionals. 

This approach to medicine will be embedded into common practice in a not so distant future, where pharmacogenomics will be one of the many tools healthcare professionals will have at their disposal when treating patients.