BioFRAM PGx, an Implementation Proposal for Pharmacogenetics in the Spanish National Health System.

Background/Objectives: Pharmacogenetics (PGx) may improve drug safety and effectiveness, but its integration into routine care remains heterogeneous across the Spanish National Health System (NHS). This article presents BioFRAM PGx, a multicentre implementation framework that defines the methodological and operational basis for subsequent observational validation in cardiovascular and mental-health care settings. Methods: The framework was developed by healthcare centres from eight Spanish Autonomous Communities through a structured review of PharmGKB/ClinPGx clinical annotations, CPIC and DPWG guidelines, and national regulatory resources. Gene-drug pairs were prioritized according to clinical actionability, therapeutic relevance, applicability to the Spanish population, and analytical feasibility. BioFRAM PGx defines a panel of seven pharmacogenes and 35 drugs, standardized genotyping and phenotype-assignment procedures, pharmacovigilance and clinical variables, healthcare-resource measures, and centralized data management. The proposed non-interventional validation phase includes adults receiving at least one selected drug in hospital or primary-care settings, with a minimum six-month follow-up. PGx results are not returned to clinicians and do not modify treatment. Its primary objective is to assess the predictive value of PGx genotyping for adverse drug reactions (ADRs); secondary objectives include ADR incidence and implementation feasibility. Results: The main outputs are the proposed multicentre observational design, the prioritized gene-drug panel, harmonized analytical and pharmacovigilance workflows, standardized data domains, and a centralized data-management strategy. No patient-level clinical, implementation, or economic outcomes are presented. Conclusions: BioFRAM PGx provides a structured multicentre framework for harmonizing pharmacogenetic procedures across the Spanish NHS. Its clinical effectiveness, influence on prescribing, scalability, and economic outcomes remain to be assessed in subsequent studies.