PHARMACOGENOMICS AND PRESCRIBING RATES IN NORTHERN IRELAND

Background: Pharmacogenomic-considerate practice represents the next phase of quality healthcare provision.
However, identification of drug-gene interactions that exist among currently prescribed medicines is the first critical step
towards fully understanding prescribing behaviour and ultimate integration of pharmacogenomic-considerate practice into
Northern Ireland.
Aim: The aim of this research is to identify the most commonly prescribed medicines that are deemed to be
pharmacogenomically relevant with actionable drug-gene interactions, and to determine the prescribing rates of these
medicines in Northern Ireland across a 24 month period between January 2021 to December 2022.
Method: Medicines with actionable drug-gene interactions were identified by interrogation of pharmacogenomic
databases including Pharmacogenomics Knowledge Base and the Clinical Pharmacogenetics Implementation
Consortium. Following compilation of the actionable medicines list, quantitative retrospective analysis of Northern Ireland
prescribing data from January 2021 to December 2022 was undertaken. This enabled prescribing rates of medicines in
Northern Ireland with actionable drug-gene interactions to be determined. This data was analysed using Microsoft® Excel®
(Version 2309) and statistical analysis conducted using IBM SPSS® Statistics (Version 29.0.1.0).
Results: Of the 38,847,653 medicinal items prescribed in Northern Ireland from January 2021 to December 2021,
20.71% (n = 8,046,666) were medicines that are known to have actionable drug-gene interactions, with 1,170 different
medicines prescribed in Northern Ireland during this period. Interrogation of pharmacogenomic databases identified 108
medicines classified as having actionable drug-gene interactions. An average of 75.46% (n = 82) were medicines
prescribed in Northern Ireland from January 2021 to December 2022. Of all medicinal items prescribed in Northern
Ireland during this two-year period, 20.53% (n = 8,096,189) were medicines with actionable pharmacogenomic status.
Analysis showed that the largest category of medicines included Central Nervous System medicine (43.21%; n = 35). The
remaining 56.79% of actionable pharmacogenomic medicines prescribed in this period are distributed among 11 other
therapeutic areas including Obstetrics & Gynaecology, Cardiovascular disease and immunosuppression, and
Musculoskeletal disorders and joint disease.
Conclusion: This study highlights that medicines with actionable drug-gene interactions are being prescribed in Northern
Ireland without consideration of interpatient genetic variation. One-fifth of all medicinal items prescribed in Northern
Ireland had actionable drug-gene interactions, validating the necessity for pharmacogenomic services in Northern Ireland.
This work supports the need for widespread pharmacogenomic analysis to become a staple of prescribing
considerations, given such vast prescirbing practice is already in place.
References/Acknowledgments: Bowel Cancer UK. (2021) Bowel cancer patients in Northern Ireland join England and
Wales in receiving DPYD test to screen for serious reactions to chemotherapy. London: Bowel Cancer UK. Available at:
https://www.bowelcanceruk.org.uk/news-and-blogs/research-blog/bowel-cancer-patients-in-england-to-receive-test-to-screen-for-serious-reactions-to-chemotherapy/#:~:text=Testing%20people%20with%20bowel%20cancer,chose%20a%20different%