OBJECTIVE: New psychoactive substances (NPS), are a range of drugs designed to mimic the effects of established illicit drugs, being legal at the time of their distribution in illicit markets. The review aims to shed a light on the growing threat caused by NPS, and on the dynamics and developments that have led to their spread, including the risk of new adulteration practices which can cause a serious health threat, due to their increased toxicity, e.g., through fentanyl and its analogs.

MATERIALS AND METHODS: An overview of statistical trends relative to NPS use has been provided, in addition to regulatory and legislative approaches in several countries and recommendations and data from International institutions: UN Office on Drugs and Crime, United Nations Commission on Narcotic Drugs, WHO, European Parliament, European Monitoring Centre for Drugs and Drug Addiction, Europol and international collaborative efforts such as the Trans European Drug Information (TEDI) project and the Spanish Energy Control.

RESULTS: Given the elusive nature of NPS, spontaneous pharmacovigilance reporting systems are needed to identify new trends of drug abuse. Broad-ranging legislative initiatives are needed in order to set common international standards (e.g., the European Parliament Regulation 2017/2101, with information exchange, an early warning system and risk assessment procedure for NPS) to tackle a potentially catastrophic and growing threat.

CONCLUSIONS: By virtue of all the complexities and hurdles that have to be overcome in the fight against NPS, and to assist national governments in their identification and reporting, supranational organizations can come to play a key role. Only through international measures, supplementing national legislative initiatives, can this multi-faceted problem be effectively addressed and information about NPS be gathered and disseminated in a timely fashion.