If you (or the person you represent) get any side effects, talk to your doctor, pharmacist or nurse. This includes any possible side effects not listed in the package leaflet. You can also report side effects directly via the Yellow Card Scheme at, yellowcard.mhra.gov.uk.

By reporting side effects you can help provide more information on the safety of this medicine.

About Naloxone in Opioid Overdose

Naloxone is a medication that is used to temporarily reverse the effects of opioid drugs like heroin (diamorphine) and methadone.[1] Naloxone has been used for many years by healthcare professionals in hospitals, and by ambulance crews and paramedics in communities as an 'emergency rescue medicine', administered to people who are suspected of suffering from an opioid (or opioid-related) overdose.[2] When someone accidentally overdoses and opioid drugs are involved, their breathing can be compromised and this can lead to their death.[3] Naloxone can help restore the breathing of the opioid (or opioid-related) overdose casualty,[3] 'buying time' before an ambulance arrives.

Prenoxad Injection (naloxone hydrochloride 1mg/ml solution for injection) is a type of naloxone that can be given to anyone who is at risk of an opioid overdose.[4,5] It can also be supplied to the friends, family or other representative of someone identified to be at risk of opioid or opioid-related overdose, and to anyone likely to witness an overdose.[4] Prenoxad Injection can only be made available once the prescriber has assessed the suitability and competence of a client or representative to administer it in the appropriate circumstances.[4] It is legal to carry Prenoxad Injection and it will not be confiscated by the police as long as the pack has not been opened.

The law allows Prenoxad Injection to be used by members of the public to save a life in an emergency.[6] This could be a friend or family member of someone who is at risk of opioid overdose.[5] It may be used in the home or elsewhere outside of a hospital. Prenoxad Injection is designed as an emergency rescue or first aid treatment so it does not replace the need to get medical attention as soon as possible.[7] It is crucial that an ambulance is still called by dialling 999 and that the casualty is seen by the ambulance crew.[2,7] This is because Prenoxad Injection will wear off after a short time and there is a danger of the casualty going back into an overdose.[2]

In the 'When and how to give Prenoxad Injection' section on this website you will find further information on how to get Prenoxad Injection and when and how to use it.


  1. Prenoxad Patient Information Leaflet. VIEW
  2. Wermeling, DP. Review of naloxone safety for opioid overdose: practical considerations for new technology and expanded public access. Ther Adv Drug Saf 2015;6(1):20–31. VIEW
  3. Sporer, KA and Kral, AH. Prescription naloxone: a novel approach to heroin overdose prevention. Ann Emerg Med 2007;49(2):172-177. VIEW
  4. Prenoxad Injection. Summary of Product Characteristics. VIEW
  5. Department of Health and Social Care, Medicines and Healthcare Products Regulatory Agency and Public Health England. Guidance Widening the availability of naloxone. Updated 18 February 2019. VIEW
  6. Advisory Council on the Misuse of Drugs. Considerations of naloxone. May 2012. VIEW