Commentary: Unregulated drug markets are fast expanding and increasingly mediated through digital technologies. In a context of drug prohibition, the composition, potency and effects of substances are not guaranteed which can expose people to potentially fatal risks. There are pronounced concerns about the harms posed by substances such as synthetic opioids like fentanyl and nitazenes. The coordinated activities of stakeholders who attempt to identify, prepare for and mitigate rapidly emerging drug-related harms are often collectively described as early warning systems (EWSs). EWSs are not exclusive to the drugs field. The conceptual underpinnings and implementation strategies associated with EWSs are thoroughly documented in international guidelines surrounding environmental disaster risk reduction. These guidelines suggest that EWSs incorporate four interconnected subcomponents, [1] risk knowledge, [2] detection monitoring and forecasting, [3] response capability and [4] warning communication. In this commentary we outline the data sources, processes, stakeholders, and outputs involved in the operation of modern drug-related EWSs and consider the extent to which practices align with these four components. In doing so, we consider the ways in which routine drug monitoring and horizon scanning may bolster drug-related EWSs and outline the imperative to meaningfully involve people who use drugs within data collection, interpretation and response processes. Our proposed framework, which outlines the components of drug-related EWSs, is designed to support efforts to devise, describe, evaluate and locally tailor EWSs across diverse jurisdictions.

[See also, short report (2025) Emerging best practices in the design and dissemination of public drug warnings]