Key recognition features

• Classic triad: reduced consciousness, respiratory depression (respiratory rate <12/min or shallow breaths), and pinpoint pupils — though pupils may be normal with mixed intoxication.
• Other signs: bradycardia, hypotension, cyanosis, poor air entry, hypoxia, and decreased gag reflex.
• Ask for history or bystander report: substance taken, route (injecting increases risk), time since use, and co‑ingestants (benzodiazepines, alcohol, stimulants).

Immediate on‑scene actions

1. Assess responsiveness, call for emergency help, and ensure scene safety.
2. Open airway, perform jaw‑thrust/chin‑lift, and provide rescue breaths if apnoeic (bag‑valve‑mask with oxygen if available).
3. Administer naloxone promptly if opioid overdose suspected — intranasal or intramuscular routes suitable for pre‑hospital use.
4. Place in recovery position if breathing adequately and monitor until EMS arrives.

Naloxone — practical guidance

• Available formulations: intranasal sprays (e.g., 2 mg/2.5 mg) or injectable (0.4 mg/mL). Check local formulations and dosing.
• Adult titration strategy (in hospital): start 0.04 mg IV; if no response, escalate to 0.4 mg IV, then 2 mg IV — titrate to restore adequate spontaneous ventilation rather than full wakefulness to avoid abrupt withdrawal. Repeat doses every 2–3 minutes as needed.
• Pre‑hospital/community use: give 2 mg intranasal (1 mg per nostril if device delivers 1 mg) or 0.4–2 mg IM/SC; repeat every 2–3 minutes if no adequate respiratory response, up to available supply or until EMS takes over.
• Be aware naloxone may precipitate withdrawal (agitation, vomiting, tachycardia); manage symptoms and calming environment. Monitor for re‑sedation since naloxone duration can be shorter than some opioids.

Emergency department management

1. Continue airway support, oxygen, cardiac monitoring and obtain IV access. Check blood glucose, pulse oximetry, ABG if hypoxic, and 12‑lead ECG if arrhythmia suspected.
2. Use naloxone IV titration as above; consider continuous infusion if frequent boluses required (infusion rate = total effective bolus over 4 hours, adjusted to clinical response).
3. Treat complications: aspiration pneumonitis, non‑cardiogenic pulmonary edema, infections; provide antiemetics and manage agitation with benzodiazepines if needed.
4. Consider admission for observation (recommended ≥4–6 hours after the last naloxone dose for short‑acting opioids; longer for long‑acting opioids or if co‑ingestants present).

Post‑overdose care & pathways

• Offer brief motivational intervention and immediate linkage to treatment (OAT) where available; evidence supports offering treatment from the ED itself when possible.
• Provide naloxone kit and train patient and carers before discharge; discuss overdose prevention (avoid using alone, test dose, not mixing with benzodiazepines/alcohol).
• Arrange follow‑up within a few days with addiction services, primary care or community outreach teams. Screen for blood‑borne viruses and offer vaccinations (HBV) as indicated.

Special considerations

• Polysubstance overdose: respiratory depression may be due to combination of depressants — naloxone will reverse opioid effects but other agents may still cause CNS depression.
• Pregnancy: naloxone should be given in maternal overdose; maternal stabilization takes priority. Neonatal withdrawal may occur if given near delivery — involve obstetrics and neonatology.
• Children: use weight‑based naloxone dosing (0.01 mg/kg IV/IM/IN up to standard adult preparations) and paediatric airway considerations.

Key takeaways

• Recognise opioid overdose early (respiratory depression + reduced consciousness) and prioritise airway and breathing.
• Administer naloxone promptly and titrate to restore adequate ventilation; monitor for re‑sedation.
• Use the overdose as a moment to offer treatment and harm reduction (naloxone kit, OAT referral) to reduce future mortality.