Original article: PDF OnlyIdentification of high-impact gene–drug pairs for pharmacogenetic testing in Alberta, CanadaFan, Mikaylaa; Yarema, Mark C.b,,c,,d; Box, Adriane,,f; Hume, Staceye,,g; Aitchison, Katherine J.g,,h; Bousman, Chad A.i,,j,,kAuthor Information aBiomedical Sciences, Cumming School of Medicine, University of Calgary, Calgary bPoison and Drug Information Service, Alberta Health Services, Calgary cSection of Clinical Pharmacology and Toxicology, Alberta Health Services, Calgary dDepartment of Emergency Medicine, University of Calgary, Calgary eAlberta Precision Laboratories, Alberta Health Services, Edmonton fDepartment of Pathology and Laboratory Medicine, University of Calgary, Calgary gNeuroscience and Mental Health Institute, University of Alberta, Edmonton hDepartment of Psychiatry and Medical Genetics, University of Alberta, Edmonton iDepartment of Medical Genetics, Psychiatry, Physiology and Pharmacology, University of Calgary, Calgary jAlberta Children’s Hospital Research Institute, Calgary kMathison Centre for Mental Health Research and Education, Hotchkiss Brain Institute, Cumming School of Medicine, University of Calgary, Calgary, Alberta, Canada Received 15 May 2020 Accepted 27 July 2020 Supplemental Digital Content is available for this article. Direct URL citations appear in the printed text and are provided in the HTML and PDF versions of this article on the journal’s website, www.pharmacogeneticsandgenomics.com. Correspondence to Chad Bousman, Department of Medical Genetics, University of Calgary, 3330 Hospital Drive NW, Calgary, AB T2N 4N1, Canada, Tel: +1 403.220.7273; e-mail: firstname.lastname@example.org Pharmacogenetics and Genomics: August 20, 2020 - Volume Publish Ahead of Print - Issue - doi: 10.1097/FPC.0000000000000418 Buy SDC PAP Metrics Abstract To facilitate decision-making and priority-setting related to Alberta’s Pharmacogenomics (PGx) testing implementation strategy by identifying gene–drug pairs with the highest potential impact on prescribing practices in Alberta. Annual drug dispensing data for Alberta from 2012 to 2016 for 57 medications with PGx-based prescribing guidelines were obtained, along with population estimates and demographics (age and ethnicity). Frequencies of actionable PGx genotypes by ethnicity were obtained from the Pharmacogenomics Knowledgebase (PharmGKB). Annual dispensing activity for each of the 57 medications was calculated for the full population (all ages) and children/youth (0–19 years). Alberta ethnicity data were cross-referenced with genetic frequency data for each of the main ethnic groups from PharmGKB to estimate the proportion of individuals with actionable genotypes. Actionable genotype proportions and drug dispensing frequencies were collectively used to identify high impact gene–drug pairs. We found (a) half of the drugs with PGx-based prescribing guidelines, namely, analgesics, proton pump inhibitors, psychotropics, and cardiovascular drugs, were dispensed at high frequencies (>1% of the entire population), (b) the dispensing rate for about one-third of these drugs increased over the 5-year study period, (c) between 1.1 and 45% of recipients of these drugs carried actionable genotypes, and (d) the gene–drug pairs with greatest impact in Alberta predominatly included CYP2C19 or CYP2D6. We uncovered specific patterns in drug dispensing and identified important gene–drug pairs that will inform the planning and development of an evidenced-based PGx testing service in Alberta, Canada. Adaptation of our approach may facilitate the process of evidence-based PGx testing implementation in other jurisdictions. Copyright © 2020 Wolters Kluwer Health, Inc. All rights reserved.