Change in the new psychoactive substances associated with Emergency Department acute toxicity presentations associated with the introduction of the UK 2016 Psychoactive Substances Act

Objectives: In May 2016, the Psychoactive Substances Act (PSA) came into effect in UK making it an offence to produce or supply new psychoactive substances (NPS). The aim of this study was to determine whether this was associated with a change in Emergency Department (ED) presentations with acute NPS toxicity. Method: ED presentations to our inner-city hospital in London, UK, with acute NPS toxicity in the 12 months before and after the PSA introduction [June 2015-May 2016 (2015/2016) and June 2016-May 2017 (2016/2017)] were obtained from our database. The following data were extracted: (i) demographics; (ii) NPS(s) self-reported [categorized as synthetic cannabinoids (SC), cathinones, and "other NPS")]; and (iii) month of presentation. Results: There were 1884 presentations with recreational drug toxicity, 447 (23.7%) involved NPS. There was no difference in the overall proportion of presentations involving an NPS in 2015/2016 [n = 196 (22.3%)] and 2016/2017 [251 (24.9%); (p = .48)]. There were a mean +/- SD of 16.3 +/- 3.7 NPS-related presentations per month in 2015/2016 and 20.9 +/- 9.2 in 2016/2017; there was no significant change in overall monthly NPS-related presentations between these periods (p = .15). However, mean +/- SD monthly SC-related presentations increased from 2015/2016 (5.9 +/- 2.5) to 2016/2017 (17 +/- 9.8); p = .004. Mean monthly cathinone-related presentations decreased from 2015/2016 (8.8 +/- 4.2) to 2016/2017 (3.8 +/- 2.7); p = .001. There was no significant change in monthly mean "other NPS" presentations from 2015/2016 (1.8 +/- 2.2) to 2016/2017 (0.5 +/- 0.8); p = .062. Between 2015/2016 and 2016/2017, SCs as a proportion of NPS-related presentations increased (r = .90) whilst cathinones decreased (r = -0.82). Conclusion: NPS present front-line health services with unique challenges, and the PSA 2016 represents a major legislative effort in UK to limit their availability and supply. The burden of NPS use on this inner-city ED remains large 12 months after this legislation has come into force, with evolving patterns of NPS use.