Common substances & risk contexts

• MDMA/ecstasy: empathogen with hyperthermia, hyponatraemia, serotonin toxicity in polypharmacy contexts.
• Ketamine: dissociative with urinary/urogenital complications in chronic use; acute features include dissociation, nystagmus and risk of airway compromise when sedated.
• Novel psychoactive substances (NPS): unpredictable effects and potency — higher risk of severe toxicity and mixed presentations.

Presentation spectrum

• Psychological: anxiety, panic, paranoid ideation, perceptual distortions, dissociation, flashbacks.
• Physiological: hyperthermia, dehydration, seizures, arrhythmias, hyponatraemia (especially with MDMA), serotonin syndrome with co‑ingestants.
• Behavioural risks: injury, risky sexual behaviour, aggression, impaired judgment leading to trauma.

Initial triage & assessment

1. Scene safety and rapid ABCs — secure airway and breathing, give oxygen if hypoxic.
2. Obtain focused history: substance(s), quantity, route, time of ingestion, co‑ingestants (MAOIs, SSRIs, stimulants), and pre‑existing medical/psychiatric conditions.
3. Perform targeted examination: temperature, HR/BP, pupils, neurology (tremor, rigidity), and mental state.
4. Investigations: ECG, electrolytes (Na⁺ especially), CK, blood glucose, ABG if needed, urine tox screen, and pregnancy test in females of childbearing age.

Immediate management — syndrome‑based

Hyperthermia (MDMA/serotonergic toxicity)

• Active cooling (ice packs, cooled IV fluids), benzodiazepines for agitation, and aggressive fluid management — avoid antipyretics as mechanism is not infection‑mediated.
• Check sodium and treat hyponatraemia cautiously (consult local guidelines for rapid vs gradual correction to avoid osmotic demyelination).

Serotonin syndrome

• Recognise triad: neuromuscular hyperactivity (clonus, hyperreflexia), autonomic dysfunction and altered mental status. Stop serotonergic agents, provide supportive care, benzodiazepines, and consider cyproheptadine in moderate–severe cases under specialist guidance.

Severe agitation, psychosis or risk of harm

• Benzodiazepines first‑line for sedation and calming. Use antipsychotics if benzodiazepines insufficient, with monitoring for QTc and extrapyramidal effects.

Ketamine intoxication

• Support airway and breathing, provide benzodiazepines for agitation; monitor for aspiration and treat injuries. Consider observation for dissociative episodes until resolution.

Disposition & observation

• Admit for observation if there was loss of consciousness, significant hypertension/hyperthermia, hyponatraemia, seizures, or suspected complex NPS exposure.
• Short observation for resolved, mild intoxication with safe social supports and clear discharge advice may be appropriate.

Follow‑up care & harm reduction

• Arrange brief interventions and referral to addiction or mental health services for recurrent or problematic use.
• Provide harm‑reduction advice: testing for adulterants where available, avoid dehydration/overhydration, use in trusted settings, and avoid mixing with other drugs, especially stimulants and antidepressants.
• Educate about warning signs needing urgent care: high fever, seizures, collapse, severe chest pain, severe confusion or persistent visual disturbances.

Key takeaways

• Non‑classic hallucinogen intoxications are heterogenous — manage by the dominant syndrome (hyperthermia, serotonin syndrome, dissociation, severe agitation).
• Benzodiazepines are a safe first‑line agent for agitation across most presentations; treat specific complications (hyponatraemia, hyperthermia) promptly.
• Use intoxication events to provide harm‑reduction education and linkage to support services to reduce future harm.