Challenges and lessons learned from clinical pharmacogenetic implementation of multiple gene–drug pairs across ambulatory care settings

Incorporating a patient’s genotype into the clinical decision-making process is one approach to precision medicine. The University of Florida (UF) Health Precision Medicine Program is a pharmacist-led multidisciplinary effort that has led the clinical implementation of six gene–drug(s) pairs to date. This study focuses on the challenges encountered and lessons learned with implementing pharmacogenetic testing for three of these: CYP2D6-opioids, CYP2D6/CYP2C19-selective serotonin reuptake inhibitors, and CYP2C19-proton pump inhibitors within six pragmatic clinical trials at UF Health and partners. We compared common measures collected within each of the pharmacogenetic implementations as well as solicited feedback from stakeholders to identify challenges, successes, and lessons learned. We identified several challenges related to trial design and implementation, and learned valuable lessons. Most notably, case discussions are effective for prescriber education, prescribers need clear concise guidance on genotype-based actions, having genotype results available at the time of the patient–prescriber encounter helps optimize the ability to act on them, children prefer noninvasive sample collection, and study participants are willing to answer patient-reported outcomes questionnaires if they are not overly burdensome, among others. The lessons learned from implementing three gene–drug pairs in ambulatory care settings will help shape future pharmacogenetic clinical trials and clinical implementations.