Synopsis
Distinguish life-threatening opioid toxicity from withdrawal, restore ventilation with airway support and correctly dosed naloxone, anticipate recurrent respiratory depression, and reduce overdose risk before and after detoxification or treatment transitions.
- Prioritise breathing: the clinically important overdose triad is depressed consciousness, respiratory depression and usually small pupils, but pupils may be atypical in mixed poisoning.
- Naloxone is a competitive opioid antagonist and should be titrated to restore adequate ventilation, not used to force complete alertness at the cost of severe precipitated withdrawal.
- Nyxoid delivers 1.8 mg into one nostril for adults and adolescents aged 14 or over; if there is no response give a second dose after 2–3 minutes, or immediately if respiratory depression returns, using alternate nostrils.
- Prenoxad take-home injection gives 400 micrograms intramuscularly into the outer thigh or upper arm, repeated every 2–3 minutes through resuscitation cycles until breathing recovers, help arrives or the syringe is used.
- In a clinical setting, one injectable naloxone SmPC permits 400–2,000 micrograms intravenously initially, repeated every 2–3 minutes; if 10 mg total gives no response, reconsider the diagnosis, while long-acting opioids may require infusion.
- Every community naloxone dose accompanies a 999 call and airway support; nasal and injectable products have different strengths and instructions, so teach the supplied device.
- Opioid withdrawal causes yawning, lacrimation, rhinorrhoea, piloerection, mydriasis, cramps, diarrhoea, vomiting, insomnia and dysphoria; it is intensely distressing but usually less medically dangerous than alcohol or benzodiazepine withdrawal.
- Detoxification lowers tolerance and increases overdose risk if opioid use resumes; offer continued psychosocial care, opioid substitution treatment where appropriate and take-home naloxone.
Key red flags
A respiratory rate below normal with reduced consciousness, cyanosis, apnoea, snoring or gurgling requires immediate ventilation support and naloxone, not a prolonged history.
Failure to respond after appropriately repeated naloxone requires continued resuscitation and reconsideration of airway obstruction, non-opioid poisoning, hypoglycaemia, stroke, trauma and seizure.
Recurrent drowsiness or slow breathing after initial recovery suggests that naloxone has worn off before the opioid and demands further treatment and monitoring.
Methadone, fentanyl, nitazenes, modified-release products or mixed sedative exposure increases the likelihood of prolonged toxicity and multiple naloxone doses.
Pregnancy, severe dehydration, persistent vomiting or diarrhoea, acute pain, infection, suicidality or a concurrent alcohol or benzodiazepine withdrawal complicates an otherwise usually non-fatal opioid withdrawal.
Investigation priorities
Determine whether immediate ventilation, advanced airway support and naloxone are required.
Management branches
A person is unresponsive or inadequately breathing after known or possible opioid use.
- Call 999, open the airway and provide rescue breathing or CPR according to current life-support guidance.
- Give the supplied intranasal or intramuscular naloxone exactly as trained and repeat after 2–3 minutes if needed while resuscitation continues.
- Stay until emergency services take over, use the recovery position once appropriate and give further dose immediately if respiratory depression returns.