A narrative review on the environmental impact of medicines: from water analysis and in vivo studies to prescribing appropriateness, based on European and Italian legal frameworks

The environmental impact of medicines has become a growing concern within the One Health framework, which emphasizes the interconnection of human, animal, and environmental health. This narrative review, based on discussions from a 2025 Italian multistakeholder roundtable, explores current strategies for assessing and reducing such impact, including water monitoring, <i>in vivo</i> studies using animal models, prescribing appropriateness, and the relevant European and Italian legal frameworks. The review highlights the crucial role of different stakeholders, including pharmaceutical industries, regulatory agencies, health authorities, researchers, and citizens, in implementing preventive measures to reduce the environmental impact of medicines. It underscores the urgency of integrating environmental sustainability into clinical practice and health policies, encouraging green pharmaceutical innovation, environmentally conscious prescribing, and coordinated governance, in line with the One Health principles. Future research to assess and minimize the environmental footprint of medicines should prioritize the development of standardized metrics for environmental impact, evaluate the long-term efficacy of preventive and mitigation strategies, included those on access to treatments and sustainability of production, and strengthen interdisciplinary collaboration to translate One Health into actionable policies and practices.