Toxidrome approach — two patients and antidote selection

Shared principles. Resuscitation before diagnosis: ABCDE, bedside glucose, oxygen/airway, monitoring. Six-compartment toxidrome exam (vitals, pupils, secretions, skin, bowel, neuromuscular). Send paracetamol (± salicylate) on deliberate OD; ECG for QRS/QT; VBG with anion ± osmolar gap as indicated.^[1][2]

Patient A — opioid toxidrome. Triad: CNS depression + miosis + respiratory depression (rate and depth). Protect airway (lateral, suction); high-flow O₂. Naloxone 400 micrograms IV every 2–3 minutes, titrated to adequate ventilation (RR ~12–14) not full wakefulness. If no IV: 800 micrograms IM. If re-narcotisation or long-acting agent suspected → infusion at two-thirds of effective bolus per hour. Charcoal only if awake/protected and early oral ingestion.^[1]

Patient B — serotonin syndrome (not pure sympathomimetic): hyperthermia + agitation + inducible clonus/hyperreflexia after serotonergic agents. Stop offending drugs; benzodiazepines (e.g. midazolam/diazepam IV titrated); active cooling; cyproheptadine 12 mg oral/NG then 2 mg every 2 hours to a maximum of 32 mg in 24 hours if available and airway allows. Support BP/HR; ICU if severe rigidity/hyperthermia. Distinguish from NMS (lead-pipe, hyporeflexia, slower onset on antipsychotics) and anticholinergic (dry skin, no clonus). ^[1]

Decontamination general rule. Activated charcoal 50 g (1 g/kg child) if protected airway and ideally ≤1 h for many agents; never unprotected airway; not for iron/lithium/alcohols/acids/alkalis/hydrocarbons.^[3]