Evaluation of the availability of clinical pharmacogenomics within the USA and utilization within an academic healthcare system
Year: 2025
Type: article
Study design: Observational Study
Abstract: Background: Pharmacogenomics utilizes molecular testing to identify genetic variants that impact drug metabolism, efficacy, and tolerability. Clinical pharmacogenomics can facilitate optimized drug selection and dosing to reduce adverse events and improve health outcomes. While awareness of pharmacogenomics is growing, significant barriers to clinical implementation remain, including limited access to testing, evolving guidelines, and concern for institutional cost and insurance reimbursement for patients. This study aims to leverage laboratory data to estimate availability and utilization of pharmacogenomics in routine clinical practice. Methods: To estimate the availability of clinical pharmacogenomics testing programs within the USA, we reviewed data from commercially available proficiency testing (PT) reports, which detail the number of enrolled subscribers, participation rate by pharmacogene, and analytical methods employed. Utilization of pharmacogenomics was evaluated across Johns Hopkins Health System from July 2023 through December 2024, representing the first 18 months of in-house testing. Key metrics were collected including order volumes, turnaround time, collection location, and care setting (inpatient vs. outpatient). Chart reviews were performed retrospectively to identify clinical scenarios that prompted testing, the medication class of interest, and the timing of the order relative to medication administration. Results: The number of PT subscribers for pharmacogenomics is low, ranging from 57 to 183 responders, with significant variability in gene-specific reporting rates. UGT1A1, TPMT, and DPYD, which are associated with significant and life-threatening adverse events in poor metabolizers, exhibited the lowest response rates. Evaluation of in-house testing patterns over an 18-month period within our healthcare system indicated that 75% of pharmacogenomic tests were ordered in inpatient settings. General internal medicine was the highest-utilizing department (31.1% of orders), followed by oncology and psychiatry (each 17.8%). Psychiatric medications accounted for 35.6% of orders, closely followed by immunosuppressants (32.2%). Across all departments, 41.3% of tests were ordered for dose optimization, and 43.6% were placed preemptively, with the majority of proactive orders placed for immunosuppressant management in preparation for organ transplant. Conclusions: The availability of pharmacogenomics remains limited, with critical high-impact genes underrepresented among USA-focused PT survey subscribers. Within our healthcare system, usage is increasing, particularly in general internal medicine, but proactive testing remains uncommon outside of transplant care. This underscores the need for targeted education to promote integration of pharmacogenomics into routine practice to advance patient safety and reduce the risk of adverse drug events. Further clinical studies are essential to improve the utilization of pharmacogenomics and deliver personalized medicine to patients.
DOI: 10.21037/jlpm-25-25
Language: English
Subfield: Pharmacology
Domain: Life Sciences
Open Access status: diamond
OpenAlex ID: W4415732220