Seven patients with analytically confirmed MDMB-4en-PINACA toxicity associated with the use of electronic vaping devices.

Introduction: There have been increasing reports of electronic vaping devices (e-cigarettes) being contaminated with synthetic cannabinoid receptor agonists.

Methods: This is an observational case series of patients admitted to two acute hospitals in the United Kingdom between February 2022 and February 2025 who declared use of vaping products and were found on routine toxicological screening of urine to have been exposed to MDMB-4en-PINACA.

Results: Seven patients were exposed to MDMB-4en-PINACA via a vaping device. Six patients (85.7%) were male. The median age was 17 years (range 14-37 years). Five patients (71.4%) presented with unusual changes in behaviour; six patients (85.7%) were agitated on admission; four patients (57.1%) displayed psychotic features, including hallucinations and delusions. In three cases, MDMB-4en-PINACA was the only substance detected.

Discussion: In young patients presenting to hospital with psychiatric symptoms, it is important to ask about the use of vaping products and consider testing for synthetic cannabinoids.

Conclusion: We describe seven patients with analytically confirmed MDMB-4en-PINACA toxicity associated with the use of electronic vaping devices who presented over three years. Most patients were adolescents and presented with a change in behaviour associated with agitation, with or without psychotic features.