Implementation of preemptive pharmacogenetic testing: progress, puzzles and priorities from an implementation science perspective.

Preemptive pharmacogenetics (PGx) testing, which leverages genetic variation to predict drug response and toxicity, represents a pivotal advancement in precision medicine. By predicting drug-gene interactions and guiding precision dosing, it demonstrates significant potential to enhance drug safety and efficacy. However, its integration into routine clinical practice still faces a substantial translational gap. This review examines preemptive PGx testing implementation through an implementation science lens, moving beyond clinical utility to synthesize the implementation landscape and identify systemic integration challenges. Over the past decade, a growing body of pragmatic implementation studies has systematically cataloged barriers and facilitators across multiple levels. Adoption metrics are now relatively well-documented, however, evidence on fidelity and long-term sustainability remains scarce, and most cost-effectiveness data derive from modeling rather than implementation trials. Successful implementation of preemptive PGx testing requires synergistic strategies across multiple domains, generating robust evidence through large-scale pragmatic trials, building health informatics infrastructure, and establishing multidisciplinary service. Critical to this transformation are standardized clinical workflows, comprehensive education for healthcare providers and patients, and active participation in collaborative networks to accelerate knowledge sharing. A persistent equity gap remains that nearly all published preemptive PGx implementation programs originate from high-income countries, underscoring the urgent need for context-adapted approaches in low- and middle-income settings. Emerging implementation frameworks might offer practical guidance for embedding equity into implementation design. This paradigm shift necessitates coordinated efforts from multi-stakeholders to bridge the translational gap, ultimately enabling equitable and sustainable PGx implementation across diverse healthcare settings.