You are provided with clinical findings and investigation results from patients presenting with suspected drug or chemical poisoning. Identify the likely toxidrome or poisoning, interpret the relevant investigations, select an appropriate antidote or supportive treatment, and recognize complications requiring urgent intervention.

Recognition: Pinpoint pupils and respiratory depression suggest opioid poisoning; salivation, bronchorrhea and miosis suggest organophosphate poisoning; dry skin, mydriasis and delirium suggest anticholinergic toxicity.

Investigations: Assess glucose, ECG, electrolytes, renal function and blood gases as indicated. Use specific tests such as timed paracetamol levels, cholinesterase activity or toxic alcohol testing where appropriate.

Antidotes: Select naloxone for opioid toxicity, atropine with pralidoxime for significant organophosphate poisoning, N-acetylcysteine for paracetamol toxicity and fomepizole for methanol poisoning.

Priority: Stabilize airway, breathing and circulation, provide supportive care and urgently treat respiratory failure, seizures, arrhythmias, hyperthermia or severe metabolic acidosis.

1. Assess immediate danger: Review consciousness, respiratory rate, oxygenation, pulse, blood pressure and temperature. Identify patients needing immediate resuscitation.
2. Recognize the toxidrome: Examine pupil size, sweating, secretions, skin temperature, bowel activity, mental status and neuromuscular findings. Differentiate cholinergic, anticholinergic, sympathomimetic, opioid and sedative-hypnotic presentations.
3. Identify the likely toxin: Correlate the clinical pattern with the suspected substance, exposure history, timing and available medication or chemical containers.
4. Interpret investigations: Check bedside glucose, ECG and relevant blood tests. Interpret paracetamol concentration against time since ingestion when eligible for nomogram assessment; recognize high anion-gap metabolic acidosis in toxic alcohol poisoning.
5. Select the antidote: Choose the appropriate agent when indicated, remembering that not all poisonings have specific antidotes and supportive treatment remains essential.
6. Provide supportive treatment: Maintain airway and ventilation, support circulation, correct glucose or electrolyte abnormalities and manage seizures or hyperthermia as clinically indicated.
7. Recognize complications and escalate: Identify respiratory failure, severe arrhythmias, seizures, shock, acute kidney injury, liver injury and severe acidosis. Arrange urgent senior and toxicology consultation where required.

Exam Pearl: Distinguish toxidromes using the combination of pupil findings, skin moisture, secretions, temperature and neurological status rather than relying on a single sign.

Safety Warning: Do not delay airway and ventilatory support while awaiting toxicology investigations or antidotes. Flumazenil is not routinely recommended in undifferentiated benzodiazepine overdose because it can precipitate seizures in susceptible patients.