Acute agitation and toxidrome emergency — assessment and management (MEQ)

(i) Immediate assessment. Scene safety (staff numbers, exit routes, remove weapons/audience), one calm lead communicator, de-escalation. ABCDE already partly reassuring (afebrile, oxygenating) but continue continuous observation. Focused history: substance use, overdose, head injury, seizure, medication timeline (olanzapine restart; possible SSRI exposure). MSE: threat content, command hallucinations, suicidality, attention. Collateral. Targeted medical clearance: ECG QTc, U&E, CK if restraint/exertion, consider toxicology panel if overdose suspected — clearance is risk-based, not ritualistic.[3][1]

(ii) RT plan and the proposed IM lorazepam. Do not give IM lorazepam immediately after IM olanzapine. Parenteral benzodiazepine within an hour of IM olanzapine risks profound respiratory depression and hypotension. Safer plan: continue de-escalation and environmental control; wait at least 1 hour with SpO2 and conscious-level monitoring after olanzapine; if still dangerous, senior review; options thereafter include a non-olanzapine pathway guided by local protocol (for example careful IM lorazepam only after the mandatory interval and monitoring, or alternative agents such as IM aripiprazole, or second-line IM haloperidol 5 mg + promethazine 25–50 mg if cardiac risk allows). Post-sedation monitoring every 15 minutes for at least 1 hour.[1]

(iii) Differential with discriminators. Primary psychotic relapse with agitation after non-adherence then high-dose restart. Stimulant intoxication (mydriasis, tachycardia — less clonus-specific). Early NMS (usually days, lead-pipe rigidity, bradyreflexia, fever — less likely while afebrile but watch). Serotonin toxicity if SSRI was taken with other serotonergics: hours-onset, clonus/hyperreflexia (Hunter criteria) — clonus already noted is a red flag; stop serotonergics and use benzodiazepines once safe relative to olanzapine timing; involve toxicology.[2] Delirium from medical cause if attention fluctuates later. Excited catatonia if purposeless motor signs dominate.

(iv) Capacity and law. Assess capacity for the specific decisions (accepting oral meds, remaining for assessment): understand, retain, use/weigh, communicate. Psychosis may impair capacity but does not automatically erase it for every decision. If incapacitous and serious risk, consider involuntary pathway under local statute, documenting least-restrictive alternatives tried (voluntary stay, oral meds, family support). Do not invent section numbers for other jurisdictions.[4]

(v) Disposition. If medical toxicity suspected → remain under ED/medical with psych liaison. If primary psychosis with high violence risk and incapacity → inpatient psychiatry (voluntary if possible; involuntary if criteria met). If risk falls with supports and means restriction and capacity regained → discharge only with timed follow-up, crisis contacts, and documented safety plan. Handover quality is part of the answer.[1]