Precision medicine decision-making under pharmacogenomics in nursing: realizing value from limited evidence to scaled clinical pathways.

Background: Inter-individual variability in efficacy and tolerability remains a major challenge in psychiatric prescribing. Pharmacogenomics (PGx) has been proposed as a practical tool to reduce avoidable drug-gene mismatches, particularly for antidepressants and selected antipsychotics metabolized by CYP2D6 and CYP2C19. However, the clinical value of PGx in psychiatry is uneven across drug classes, testing panels, and patient populations. Purpose: To promote the long-term integration of precision medicine and care, transforming digital PGx outcomes into tangible health benefits for patients. Methods: This article was a structured narrative review. PubMed, Embase, and CINAHL were searched for English-language literature published from January 2010 to January 2026, with emphasis on contemporary guidelines, pragmatic trials, randomized controlled studies, meta-analyses, and implementation studies relevant to psychiatric prescribing, nursing practice, and digital decision support. Search terms combined PGx-related keywords with psychiatry, antidepressants, antipsychotics, CYP2D6, CYP2C19, nursing, clinical pathway, electronic health record, and artificial intelligence concepts. We prioritized professional guidelines and primary comparative studies, and excluded preclinical studies, conference abstracts without sufficient methods, non-psychiatric applications, and commercial claims unsupported by peer-reviewed outcome data. Results: Current evidence supports PGx most clearly as an adjunctive prescribing tool for selected antidepressants and antipsychotics with established drug-gene guidance. Across depression trials, pooled estimates suggest modest improvements in remission or response, but the magnitude and durability of benefit vary substantially, and large pragmatic studies have shown smaller and non-persistent effects at endpoint. The patients most likely to benefit are those with prior treatment failure, troublesome adverse effects, concentration-sensitive medications, or complex polypharmacy with potential phenoconversion. By contrast, routine testing for all psychiatric patients is not supported by current evidence. Nurses can contribute meaningfully to medication history-taking, patient education, sample logistics, adherence support and structured monitoring, but implementation in routine care requires realistic attention to workforce capability, genetic literacy, report standardization, electronic health record integration and clinical decision support. Conclusion: PGx should be positioned as part of a broader precision-prescribing framework, which is beneficial in the field of psychiatry that is oriented toward the transformation of clinical practice.