Synopsis
Stabilise toxic physiological effects, identify time-sensitive antidote indications and use exposure-specific evidence to guide observation and discharge.
- Treat dangerous physiology before waiting to identify the exact poison or obtain a screening result.
- Ask what was taken, the amount, formulation, time, route and co-ingestants; retain uncertainty rather than converting an estimate into a fact.
- A normal initial examination does not exclude delayed toxicity from modified-release preparations or hepatotoxic overdose.
Investigation priorities
Identify reversible metabolic threats and follow ventilation, acidaemia and lactate.
Management branches
An adult with suspected illicit opioid use has a pulse, respiratory rate six/min and reduced consciousness. Airway support and bag-mask ventilation are started; IV access is available.
- Call experienced help and provide effective ventilation with oxygen while attaching ECG, oximetry and capnography where available. Check glucose and look for injury or co-ingestion in parallel.
- Titrate small IV naloxone doses to respiratory recovery in this non-arrest setting. After a total 400 micrograms, respiratory rate rises to twelve/min with adequate depth and airway protection, although the patient remains sleepy.
Key medicines
Naloxone for non-arrest opioid respiratory depressionWith airway and ventilation support, give 100–200 micrograms IV every 60 seconds, titrating to adequate breathing and protective reflexes. Larger cumulative doses may be needed; recurrent toxicity requires repeated boluses and a senior infusion plan.Respiratory arrest or peri-arrest needs the separate urgent RCEM escalation regimen alongside resuscitation. Excess reversal may precipitate withdrawal. The opioid may last longer than naloxone, and mixed poisoning can limit response.
Acetylcysteine for paracetamol overdoseThe authorised IV course is 150 mg/kg over 1 hour, then 50 mg/kg over 4 hours, then 100 mg/kg over 16 hours: 300 mg/kg over 21 hours. Use the prescribed product’s dilution chart and a ceiling weight of 110 kg.Alternative local regimens require their own approved protocol. Review tests before stopping; further treatment may be needed. Adapt diluent volume for low weight or fluid restriction and manage reactions promptly with senior or NPIS advice.