Evaluation of pharmacogenomic information in package leaflets and summaries of product characteristics for CNS-acting drugs in Portugal

Pharmacogenomics (PGx), the field that studies the influence of genetic variation on drug response, has emerged as a cornerstone of precision medicine (1). In the context of central nervous system (CNS) disorders, where therapeutic efficacy and tolerability often vary significantly between individuals, the integration of PGx into clinical practice is particularly relevant. By identifying genetic biomarkers associated with drug metabolism, efficacy, or toxicity, pharmacogenomic approaches enable tailored treatment strategies that improve outcomes and minimize adverse drug reactions (1,2). However, the implementation of PGx in routine care depends heavily on the availability and accessibility of relevant information (2), especially in regulatory documents such as Package Leaflets (PLs) and Summaries of Product Characteristics (SmPCs). These documents serve as primary sources of drug-related information for healthcare professionals and patients alike. Despite their importance, the degree to which PGx information is included, standardized, and aligned with clinical guidelines in these materials remains underexplored, particularly within the Portuguese pharmaceutical context.