- Naloxone is an opioid receptor antagonist which is used to reverse an opioid overdose, Is also included in selected drug formulations as an abuse deterrent to prevent injection of opioids. Comes as intramuscular injections, nasal spray or intravenous injection
- Naloxone is a competitive inhibitor of the opioid receptor. It antagonises the action of opioids, reversing their effects
- There are little to no side effects of the drug Naloxone itself. The effects come from the withdrawals of the narcotics. These include: vomiting, sweating, runny nose, aches and diarrhoea
- The half-life of opioids is normally longer than Naloxone so further doses may be required
- Withdrawal effects may occur after the administration of Naloxone
- There are no drugs that have severe interactions with Naloxone, however there are a number of drugs that have very mild interactions with Naloxone. There are three medications that have moderate effects including, naloxegol, buprenorphine and buprenorphine buccal
- If a patient has not taken opioids it will have no significant effects on the patient
Pharmacokinetics
- An intranasal dose of Naloxone is 42%-47% bioavailable and reaches its maximum in 25 minutes as well as the same with an IM dose. A 2mg IV dose reaches max if 26.3ng/mL with an AUC of 12.8h*ng/mL
- The volume in distribution is 200L. Naloxone distributes into tissues rapidly and can also pass the placenta and blood brain barrier
- Naloxone is primarily metabolised in the liver. It undergoes glucuronidation to form naloxone-3-glucuronide. Naloxone is also a N-dealkylated to noroxymorphone or undergoes 6-keto reduction to naloxol
- After oral or intravenous administration, Naloxone is 25%-40% eliminated in the urine within 6 hours. 50% in 24 hours and 60%-70% in 72 hours. The metabolites naloxone-3-glucuronide, noroxymorphone and naloxol are all detected in the urine
Pharmacodynamics
- Naloxone is an opioid antagonist medication that blocks the effects of opioid drugs. It has a high affinity for opioid receptors where is acts as an inverse agonist, causing rapid removal of any drugs bound to these receptors. This can reverse the effects of respiratory depression associated with an overdose
- Has a rapid onset of action and half-life and duration are short, approximately 30-60 minutes. This can be concerning, depending on the amount of opioids used, the half life for these is normally a lot longer. Thus, further doses many be needed
- When injected intramuscularly action is within 5 minutes. If injected into a patients not using opioids if will have no effect
Clinical Resources Website
St John Ambulance Western Australia Ltd (ABN 55 028 468 715) (St John WA) operates ambulance and other pre-hospital clinical services. St John WA’s Clinical Resources, including its Clinical Practice Guidelines (Clinical Resources), are intended for use by credentialed St John WA staff and volunteers when providing clinical care to patients for or on behalf of St John WA, within the St John WA Clinical Governance Framework, and only to the extent of the clinician’s authority to practice.
Other users – Terms of Use
The content of the St John WA Clinical Resources is provided for information purposes only and is not intended to serve as health, medical or treatment advice. Any user of this website agrees to be bound by these Terms of Use in their use of the Clinical Resources.
St John WA does not represent or warrant (whether express, implied, statutory, or otherwise) that the content of the Clinical Resources is accurate, reliable, up-to-date, complete or that the information contained is suitable for your needs or for any particular purpose. You are responsible for assessing whether the information is accurate, reliable, up-to-date, authentic, relevant, or complete and where appropriate, seek independent professional advice.
St John WA expressly prohibits use of these Clinical Resources to guide clinical care of patients by organisations external to St John WA, except where these organisations have been directly engaged by St John WA to provide services. Any use of the Clinical Resources, with St John WA approval, must attribute St John WA as the creator of the Clinical Resources and include the copyright notice and (where reasonably practicable) provide a URL/hyperlink to the St John WA Clinical Resources website.
No permission or licence is granted to reproduce, make commercial use of, adapt, modify or create derivative works from these Clinical Resources. For permissions beyond the scope of these Terms of Use, including a commercial licence, please contact medservices@stjohnambulance.com.au
Where links are provided to resources on external websites, St John WA:
- Gives no assurances about the quality, accuracy or relevance of material on any linked site;
- Accepts no legal responsibility regarding the accuracy and reliability of external material; and
- Does not endorse any material, associated organisation, product or service on other sites.
Your use of any external website is governed by the terms of that website, including any authorisation, requirement or licence for use of the material on that website.
To the maximum extent permitted by law, St John WA excludes liability (including liability in negligence) for any direct, special, indirect, incidental, consequential, punitive, exemplary or other loss, cost, damage or expense arising out of, or in connection with, use or reliance on the Clinical Resources (including without limitation any interference with or damage to a user’s computer, device, software or data occurring in connection with such use).
Cookies
Please read this cookie policy carefully before using Clinical Resources from St John WA.
The cookies used on this site are small and completely anonymous pieces of information and are stored on your computer or mobile device. The data that the cookies contain identify your user preferences (such as your preferred text size, scope / skill level preference and Colour Assist mode, among other user settings) so that they can be recalled the next time that you visit a page within Clinical Resources. These cookies are necessary to offer you the best and most efficient possible experience when accessing and navigating through our website and using its features. These cookies do not collect or send analytical information back to St John WA.
Clinical Resources does integrate with Google Analytics and any cookies associated with this service enable us (and third-party services) to collect aggregated data for statistical purposes on how our visitors use this website. These cookies do not contain personal information such as names and email addresses and are used to help us improve your user experience of the website.
If you want to restrict or block the cookies that are set by our website, you can do so through your browser setting. Alternatively, you can visit www.internetcookies.com, which contains comprehensive information on how to do this on a wide variety of browsers and devices. You will find general information about cookies and details on how to delete cookies from your device. If you have any questions about this policy or our use of cookies, please contact us.