Professor Ola Dale of the Norwegian University of Science and Technology (NTNU), Department of Circulation and Medical Imaging (ISB).

The ambulance service in Oslo and Akershus and the ambulance service in Trondheim are the trial locations.

The trial has been approved by the Regional Ethics Committee and the Norwegian Medicines Agency. The trial cooperates with two pharmaceutical companies in Norway named Sanivo Pharma and DnE Pharma.

Naloxone, an antidote for opioids, is primarily administered by syringe at present.

We are researching a new naloxone nasal spray that we feel is simpler and better than the one currently available, and we would like it to be fully approved as a medicine. That is to say that both the efficacy and side effects are well known.

We have been testing the nasal spray on volunteers in Trondheim in 2013 to 2016, and we are now testing the spray on real overdose cases in Oslo and Trondheim.

You have joined a trial in which you have either received the ordinary antidote by syringe or the new naloxone nasal spray. The usual treatment with respiratory facilitation has not changed.

When ambulance personnel find a patient with a suspected overdose, the first thing they do is to help the patient breathe with a mask and breathing bag. This has not changed in the trial.

Patients normally receive the antidote directly into a vein or the shoulder muscle. In this trial, the ambulance has a box of medicines that contains a syringe and nasal spray, both of which are administered to the patient. One of them contains active medicine (naloxone) and the other contains water without medicine. All patients receive the antidote in one way or the other.

The syringe contains 0.4 mg/ml of naloxone. The dose is 2 ml intramuscularly = a dose of 0.8 mg naloxone to the participant. The syringe dose is the same that is usually administered by ambulance personnel today.

The nasal spray has a concentration of 14 mg/ml of naloxone, and the dose is 0.1 ml = a dose of 1.4 mg naloxone to the participant. We expect a little over half of the nasal spray to reach your blood.

It is random whether you receive naloxone as a spray or a syringe, and neither the ambulance personnel nor those who analyse the data will know what has been received until the trial is over. This means that our trial is double-blinded and randomised. This is scientifically the best way to determine how the medicine works.

The safety of the participants has the highest priority in this trial. An overdose is a life-threatening condition, and life-saving first aid and competent ambulance treatment is required.

An opioid overdose is characterised by respiratory problems. Help by the ambulance personnel to free respiratory passages and facilitate breathing has not changed in this trial.

After receiving the medicine, you will be closely monitored and will receive breathing assistance as required for 10 minutes. If you are not awake after 10 minutes, the trial treatment will be discontinued. You will then receive more naloxone of the type the ambulance normally uses, and they will assess whether other medical measures are required.

If your condition worsens before ten minutes have passed, the trial will be discontinued and the ambulance personnel will perform the medical measures that are best for the patient.

To have a suspected opioid overdose, which means to have:

• Reduced respiration
• Small pupils
• Diminished consciousness

And a palpable neck pulse

If one or more of the following conditions are present, you will not be included in the trial:

• Cardiac arrest
• That the ambulance personnel do not manage to breathe for you
• That you have an injury to your face or nosebleed
• That the overdose is caused by health care providers
• That the ambulance personnel know or think you are under 18 years of age
• That the ambulance personnel know or suspect that you may be pregnant
• You have received naloxone before the ambulance personnel arrive
• That the overdose occurs in an individual who is imprisoned or in custody
• The ambulance personnel are not approved as trial workers
• No trial medicine is available
• The trial medicine has been frozen or has expired
• That the location where you suffer an overdose is not suitable for research or any other reason why the ambulance personnel cannot manage to include you in the trial
• If you did not consent to the use of your data.

• Name and national identity number
• Time and place of the treatment and ambulance callout
• Effect of the treatment – your respiration rate before treatment, how much oxygen was in your blood and how long did it took before you breathed normally and were in a normal state of consciousness
• How you were feeling after the treatment
• Whether you were taken to an accident and emergency unit or hospital, or were left where you had the overdose
• Whether you have a new ambulance follow-up for an overdose within 24 hours of the trial
• We do not normally register other contact with the ambulance service, hospital or general practitioner records
• If you are admitted to hospital after the overdose with a side effect of the nasal spray, we will follow up on this together with the hospital, and record the side effect.

• The data on you and your treatment will be anonymised and stored in a secure database. This means that your name and national identity number will be registered in a location other than in the database. This is not available to anyone outside of the trial team. All the data is secured as well as your ordinary medical records in the ambulance service.
• Everything will be deleted 15 years after the end of the trial.
• The data shall not be shared or used for anything other than this trial.
• It will not be possible to recognise you when the results are published.
• The data may be shown to the Norwegian Medicines Agency to verify the trial.
• Anonymised data (so that no one can find your identity) may also be shared with researchers or publishers who want to verify the trial.

• You have the right to withdraw from the trial.
• Even if you said yes on site to the ambulance personnel to join the trial, you may still withdraw afterwards.
• You can contact us to find out what data has been recorded.
• You will receive no benefits from being included in this trial.
• You will be contributing to making it easier to treat and improving the treatment of overdoses in the future.
• You are insured by the Medical Liability Insurance Fund.

Naloxone is a well-known medicine that is considered very safe to use. In many countries, it is available without a prescription. We register side effects such as nausea, vomiting and headaches. If the side effects are serious, you will be hospitalised.

If you were not able to give consent after your overdose, you will be registered in the trial. If you still consent now to be included in the trial, you need not do anything.

If you find that you want to withdraw from the trial, then the trial team must be notified by phone or here on this website that you want to withdraw.