Theranostics in primary care: pharmacogenomics tests and beyond.

Theranostics represents a broadening in the scope of personalized medicine to include companion diagnostics for health interventions ranging from drugs to vaccines, as well as individual susceptibility to disease. Surprisingly, in the course of this broadening of personalized medicine discourse, relatively little attention has been paid to primary care (as compared with tertiary healthcare settings) despite its vast patient population and being a crucial entry point to health services. Recent advances in pharmacogenomics (PGx), a classical theranostics application whereby genotyping and/or gene expression-based tests are used for targeted or optimal therapy, revealed new opportunities to characterize more precisely human genomic variation and the ways in which it contributes to person-to-person and population variations in drug response. In the immediate foreseeable future, the primary-care physicians are expected to play an ever increasing crucial role in PGx-based prescribing in order to reduce the rates of adverse drug events and improve drug efficacy, yet PGx testing in primary care remains limited. In this article, the authors review the advances in PGx applications, the barriers for their adoption in the clinic from a primary care point of view and the efforts that are being undertaken to move PGx forward in this hitherto neglected application context of theranostic medicine. Finally, the authors propose several salient recommendations, including a 5-year forecast, to accelerate the current convergence between PGx and primary care.