Pharmacogenomics in the United States Community Pharmacy Setting: The Clopidogrel-CYP2C19 Example

Abstract

Pharmacogenomics (PGx) is expanding across health-care practice settings, including the community pharmacy. In the United States, models of implementation of PGx in the community pharmacy have described independent services and those layered on to medication therapy management. The drug-gene pair of clopidogrel-CYP2C19 has been a focus of implementation of PGx in community pharmacy and serves as an example of the evolution of the application of drug-gene interaction information to help optimize drug therapy. Expanded information related to this drug-gene pair has been provided by the US Food and Drug Administration and clinical PGx guidelines have and continue to be updated to support clinical decision-making. Most recently direct-to-consumer (DTC) PGx has resulted in patient generated sample collection and submission to a genetic testing-related company for analysis, with reporting of genotype and related phenotype information directly to the patient without a health-care professional guiding or even being involved in the process. The DTC testing approach needs to be considered in the development or modification of PGx service models in the community pharmacy setting. The example of clopidogrel-CYP2C19 is discussed and current models of PGx implementation in the community pharmacy in the United States are presented. New approaches to PGx services are offered as implementation continues to evolve and may now include DTC information.

Independent Community Pharmacists’ Experience in Offering Pharmacogenetic Testing

“… 14 , 51 , 52 Direct-to-consumer PGx testing may also significantly increase the role of pharmacists as patients may consult with them to better understand their test results and how it impacts their current medications. 53 , 54 …”

Knowledge, attitude and perception of community pharmacists towards pharmacogenomics services in northern Nigeria: a cross-sectional study

“…Pharmacogenomics testing services are used to optimize drug therapy and the results can be used to change drug therapy, adjust doses of medications, discontinue drug therapy and for monitoring treatment [ 2 ]. Initially, pharmacogenomics-tailored drug therapy was implemented in hospital settings [ 3 ] and hospital pharmacists played an important role in the implementation of the services in healthcare facilities [ 4 ]. Community pharmacists, the third largest healthcare professional group in the world after physicians and nurses [ 5 ], have the potentials to become the first healthcare professional that the public will contact for pharmacogenomics testing services [ 4 ].…”

“…Initially, pharmacogenomics-tailored drug therapy was implemented in hospital settings [ 3 ] and hospital pharmacists played an important role in the implementation of the services in healthcare facilities [ 4 ]. Community pharmacists, the third largest healthcare professional group in the world after physicians and nurses [ 5 ], have the potentials to become the first healthcare professional that the public will contact for pharmacogenomics testing services [ 4 ]. The increasing public awareness regarding pharmacogenomics testing, continuous decrease in the cost of pharmacogenomics testing, and the implementation of direct-to-consumer testing have provided an opportunity for community pharmacists to incorporate pharmacogenomics services into patient care [ 4 , 6 ].…”

“…Community pharmacists, the third largest healthcare professional group in the world after physicians and nurses [ 5 ], have the potentials to become the first healthcare professional that the public will contact for pharmacogenomics testing services [ 4 ]. The increasing public awareness regarding pharmacogenomics testing, continuous decrease in the cost of pharmacogenomics testing, and the implementation of direct-to-consumer testing have provided an opportunity for community pharmacists to incorporate pharmacogenomics services into patient care [ 4 , 6 ]. Studies conducted in the United States (US), Canada and the Netherlands have demonstrated successful implementation of pharmacogenomics testing services in community pharmacy among post-myocardial infarction patients and patients taking antiplatelets such as clopidogrel [ 2 – 4 , 6 , 7 ].…”

An Integrated Multidisciplinary Circuit Led by Hospital and Community Pharmacists to Implement Clopidogrel Pharmacogenetics in Clinical Practice

“…Community pharmacists' knowledge of pharmacogenetics is lower than that of their hospital pharmacy peers and, to date, their involvement in this field in Spain has been limited, despite the few pilot studies [13]. However, several projects have been implemented in countries such as the UK [14], the USA [15][16][17], Canada [18], and Switzerland [19] and are currently at various stages of development. A systematic review analyzing the implementation of pharmacogenomic testing in community pharmacies in the 2003-2021 period highlighted the barriers to pharmacogenetic implementation.…”