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Novel Psychoactive Substances — MRCPsych Paper B MCQ

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ModerateSubstance MisuseNovel Psychoactive SubstancesMRCPsych Paper B

A 22-year-old man presents to the emergency department after smoking ‘spice’, a synthetic cannabinoid receptor agonist. He is pacing, shouting and verbally aggressive, with a pulse of 118 beats/min and blood pressure of 168/96 mmHg. His temperature and blood glucose are normal, and he has no seizures, chest pain, delirium or persistent psychotic symptoms. He can follow instructions and agrees to take oral medication. What is the most appropriate initial management?

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Correct answer: B — Give oral diazepam, reduce environmental stimulation and monitor closely

The correct answer is B. Acute synthetic cannabinoid intoxication is managed primarily with supportive care, reduced stimulation, close physical observation and symptomatic treatment. A benzodiazepine such as diazepam is appropriate for agitation and autonomic arousal when the patient can safely accept oral medication. Haloperidol may be considered for prominent or persistent psychosis, but intramuscular haloperidol alone is not the preferred rapid-tranquillisation regimen and this patient has no persistent psychotic symptoms. If oral medication were impossible and urgent sedation were necessary, NICE recommends intramuscular lorazepam or intramuscular haloperidol combined with promethazine. Naltrexone has no role in reversing cannabinoid intoxication. Activated charcoal is inappropriate after a smoked exposure. Fluoxetine has no immediate anti-agitation effect.

Reference: Tees, Esk and Wear Valleys NHS Foundation Trust. Protocol for Management of Substance Misuse in Inpatient Settings, synthetic cannabinoids and intoxication management section, 2019. https://www.tewv.nhs.uk/wp-content/uploads/2021/11/Management-of-substance-misuse-in-inpatient-settings-protocol.pdf