Reversal of Opioid-induced Respiratory Depression

This guideline relates to the use of naloxone in the urgent reversal of opioids and opiates in non-palliative adult patients. For naloxone guidance in palliative care patients see the Scottish Palliative Care Guideline and for further information regarding the management of opioid overdose, contact the National Poisons Information Service (telephone 0344 892 0111) or consult TOXBASE – www.toxbase.org (password required).

Management

Naloxone should be considered when there is an immediate threat to life, impaired consciousness or a diagnosis of respiratory depression. The primary aim of treatment is to reverse the toxic effects of opiates so that patients are no longer at risk of respiratory arrest, airways loss or other complications. Give:

  1. Oxygen therapy (see guidelines on Blood Gas Analysis and Oxygen and Oximetry).
  2. Naloxone - read the caution notes and dosing regimens below before prescribing.
  3. Observe patients for at least 6 hours after the last dose of naloxone. Monitor BP, pulse, respiratory rate, oxygen saturation and conscious level at least every 15 minutes initially. 
  4. If no response to naloxone, do not delay establishing a clear airway, adequate ventilation and oxygenation. 
  5. Assistance from Intensive Care, Anaesthesia or Acute Pain Team may be required. 

Caution with naloxone

  • Patients who have received longer term opioids / opiates treatment for pain control may have possible physical dependence.
  • The use of inappropriate doses of naloxone may cause rapid reversal of the physiological effects of long-term opioids / opiates used to control pain leading to intense pain, distress and possibly acute withdrawal syndrome. 
  • Too much naloxone may lead to hypertension, cardiac arrhythmia, pulmonary oedema and cardiac arrest.

Naloxone regimens

Two dosing regimens exist for naloxone:

  • Higher initial dose regimen (for severe opioid-induced respiratory depression / arrest following acute toxicity / overdose). Associated with drug misuse and dependence. See below for dosing information. 
  • Lower initial dose regimen (for acute toxicity with respiratory depression, in patients at risk of severe pain or acute withdrawal). For e.g. post-operative patients or patients on long-term opioid therapy requiring tailored reversal of accidental opioid induced respiratory depression. See below for dosing information. 

If response remains inadequate despite dosing guidance below, then review diagnosis and seek senior advice.

Once an adequate response has been achieved, monitor blood gases, oxygen saturations and respiratory rate. The duration of action of naloxone is shorter than that of all opioid analgesics. Repeat doses of naloxone may be needed.

Naloxone IV infusion - administration information

A continuous infusion of naloxone may be required:

  • Especially in cases of opiates with a long half-life or if particularly large doses have been given or where repeated doses are required.
  • To prevent lapse back into sedation and respiratory depression following the initial treatment. Naloxone has a shorter plasma half-life than that of all opioid analgesics. 

The following administration advice is from TOXBASE – www.toxbase.org (password required) and RCEM / NPIS 2024 guidance. The RCEM / NPIS guidance - Acute Opioid Toxicity - Best Practice Guidance - can be found under the Clinical Guidance section here.  

 

Guideline reviewed May 2025
Page updated September 2025



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