Opioid toxicity

Last Updated on by frcemuser

Clinical Features

  • miosis
  • CNS depression
  • respiratory depression
  • complications of hypoxia: seizures, dysrrhythmia, brain injury


  • 12 lead ECG,
  • BSL,


  • Respiratory Rate (RR)
  • Oxygen Saturations (SpO2)
  • Heart Rate (HR)
  • Non-Invasive Blood Pressure (NIBP)
  • Sedation Score (AVPU)

should be documented with a minimum interval of 15 minutes



  • appropriate use of naloxone can prevent intubation

Electrolytes and Acid-base

  • respiratory acidosis

Specific Therapy

  • Commence high-flow oxygen (15l/min) via non-rebreathe mask
  • Carefully record Respiratory Rate and Sedation Score (AVPU) – continually reassess
  • Commence continuous SpO2 monitoring


  • Respiratory arrest due to opioid toxicity or recreational/intentional opioid overdose
  • Severe opioid-induced respiratory depression (RR 5 or less)
  • Reduced consciousness (P on AVPU) due to opioid toxicity


  • Initially give 400 micrograms intravenously. If no response after 1 minute, give 800 micrograms for up to 2 doses at 1-minute intervals. If there is still no response give 2 mg for 1 dose (a 4 mg dose may be required in seriously poisoned people), then review the diagnosis.
  • Good Response’: Implies improvement of both respiratory rate to >8 breaths/minute AND improvement of the level of consciousness to at least V on the AVPU scale
  • Note: The primary aim of treatment is to reverse the toxic effects of opioids such that patients are no longer at risk of respiratory arrest, airway loss, or other opioid-related complications, it is not to restore a normal level of consciousness.
  • Beware of re-sedation and need for naloxone infusion- Naloxone Infusion,may be required if the patient becomes resedated as effect of naloxone bolus wears off
  • If IV is not Available,IM /SC with 3 minute intervals between doses

Infusion regime

  • Naloxone infusion 10mg in 50mls of 0.9% saline (200mcg/ml) given at 60% (-2/3rd) of initial dose/hr

Underlying Cause

  • addiction counselling/ psychiatric review

Adverse Effects / Symptoms of Withdrawal

Abrupt reversal of opioid drugs in the context of chronic use has been reported to precipitate an acute withdrawal syndrome with symptoms

  • restlessness,
  • severe agitation,
  • delirium,
  • nausea and vomiting,
  • sweating,
  • shivering,
  • abdominal pain,
  • tachycardia,
  • hypertension
  • tachypnoea.




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