Seizures are a recognized and potentially serious complication of recreational drug use. This study examined a large international data set of presentations to Emergency Departments with acute recreational drug toxicity, the European Drug Emergencies Plus (Euro-DEN Plus) Network, to compare presentations with and without seizures and estimate incidence and associated drugs. Amongst 23,947 presentations between January 2014 and December 2017, there were 1013 (4.2%) with reported seizures. Clinical and demographic features were similar between individuals who had a seizure and those who did not, although rates of coma, cardiac arrest, intubation, intensive care admission, and death were significantly higher in those with seizures. There was a significant association between specific drugs and a higher seizure incidence, including fentanyl (odds ratio 2.63, 95% confidence interval 1.20-5.80), and synthetic cannabinoids (OR 2.90, 95% CI 2.19-3,84). Other drugs were associated with a lower seizure incidence, including heroin (OR 0.46, 95% CI 0.35-0.61), clonazepam (OR 0.22, 95% CI 0.06-0.91), and cannabis (OR 0.65, 95% CI 0.50-0.86). This substantiates observations that the synthetic cannabinoids as a group of novel psychoactive substances are clinically different in consequence of intoxication than cannabis, and that individuals who suffer a seizure in the context of recreational drug intoxication are likely to have worse outcomes overall. Utilising this information of what substances have a greater risk of seizures, could provide tailored harm reduction and education strategies to users to reduce the risk of seizures and their associated complications.

Highlights:
Seizures occurred in 4% of recreational drug presentations to emergency departments.
Fentanyl, synthetic cannabinoids, and MDMA associated with increased seizures.
Seizures after recreational drug use associated with worse clinical outcomes.