1. New Psychoactive Substance Presentations to the Euro-DEN Plus Network

There has been a significant increase in the availability of NPS in the last 15-20 years with over 800 NPS being monitored by the European Early Warning System. However, there are limited data available on the harms associated with the use of NPS in Europe. The aim of this study is to describe acute NPS toxicity presentations to the Emergency Departments in the Euro-DEN network over the six-year period for 2014 to 2019.

Data were extracted from the European Drug Emergencies Network (Euro-DEN) Plus database for all presentations to the ED (36 EDs in 24 European countries) with acute toxicity between 1 January 2014 and 31 December 2019 (72 months). Patient demographics, agents involved, and clinical outcomes were described and the subgroup of presentations involving NPS was compared with the rest of the cohort.

Out of 43 633 Euro-DEN Plus presentations, 3 304 (7.6%) involved at least one NPS. The proportion of NPS presentations varied by centre, reaching up to 48.8%. Four centres reported no presentations involving NPS over the study period. For the 14 centres where data were available for all 6 years, NPS-related presentations peaked in 2015 (11.9%). In 2014, 78.4% of NPS agents reported were cathinones, while only 3.4% were synthetic cannabinoids (SC); conversely, in 2019 only 11.6% of NPS agents reported were cathinones, while 72.2% were SCs. NPS-related presentations involved younger patients (median 30 (23–37) vs 32 (25–40) years, p < 0.001) and more males (84.8% vs 75.8%, p < 0.001). Patients presenting to ED after using NPS were more likely to self-discharge (22.8% vs 15.1%), less likely to be admitted to critical care (3.6% vs 6.1%) but had a longer length of stay in hospital (median 5.1 (2.7–18.7) vs 4.7 (2.5–9.2) hours, p < 0.001). Death occurred in 0.5% of all presentations involving NPS.

This large multicentre series of NPS presentations to European EDs showed geographical variation and changes over time in the proportion of presentations to ED involving NPS, as well as the proportion of NPS subgroups. Triangulation with data from complementary sources will enable a greater understanding of the public health implications of NPS use in Europe.