Synopsis
Recognise common poisoning patterns, stabilise threatened physiology and use selected antidotes with correct dosing, exposure assessment and toxicology support.
- Toxidromes are patterns that narrow a differential; mixed ingestion, delayed absorption and coexisting illness can prevent a textbook pattern from appearing.
- Opioid toxicity is suggested by reduced consciousness and inadequate breathing, often with small pupils. Support ventilation immediately and use naloxone for clinically important opioid-induced respiratory depression.
- The selected naloxone injection SmPC allows an adult overdose dose of 400–2,000 micrograms intravenously, repeated every 2–3 minutes according to response; titrate to effective breathing and use an appropriate lower-dose strategy when reversal could precipitate severe withdrawal.
Investigation priorities
Identify reversible metabolic disturbance and track evolving physiology.
Management branches
An adult is poorly responsive with slow shallow breathing and a plausible opioid exposure.
- Call for help, open and protect the airway, provide oxygen and support ventilation as required. Check glucose and assess for injury or another cause of reduced consciousness while obtaining intravenous access and monitoring.
- Give naloxone according to the emergency protocol and the patient’s dependence risk. The selected adult overdose SmPC range is 400–2,000 micrograms intravenously, with reassessment and repeat doses at 2–3-minute intervals when needed; lower titrated regimens may suit dependence or iatrogenic toxicity.
Key medicines
Naloxone for adult opioid overdoseSelected injection SmPC: 400–2,000 micrograms IV initially, with further doses every 2–3 minutes if required by the response. Reconsider the diagnosis if there is no response after a cumulative 10 mg.Titrate to adequate breathing; opioid dependence or iatrogenic toxicity may need a lower-dose local strategy to avoid abrupt withdrawal. Long-acting exposure can require repeated doses or specialist infusion. Pregnancy does not remove the need to treat life-threatening toxicity.
Acetylcysteine: licensed adult three-infusion regimenIV: 150 mg/kg over 1 hour in 200 mL diluent, then 50 mg/kg over 4 hours in 500 mL, then 100 mg/kg over 16 hours in 1,000 mL; total 300 mg/kg over 21 hours, with a 110 kg dose-weight ceiling.Use actual weight up to the ceiling and the product-approved diluent and preparation chart; final pump volume depends on preparation. Lower body weight or fluid restriction needs an appropriate protocol. Monitor infusion reactions and use laboratory stopping criteria; do not combine parts of alternative regimens.