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Contact Information:

Dr James Dear
+44 (0)131 242 9214
James.dear@ed.ac.uk


Ms Kat Oatey
+44 (0)131 651 9913
Hisnap.trial@ed.ac.uk


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Be Part of Research - Trial Details - A trial of normal versus higher dose acetylcysteine in patients with paracetamol overdose
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A trial of normal versus higher dose acetylcysteine in patients with paracetamol overdose

Recruiting

Open to: All Genders

Age: Mixed

Kirkcaldy Lothian Lothian

Medical Conditions

Paracetamol overdose

This information is provided directly by researchers, and we recognise that it isn't always easy to understand. We are working with researchers to improve the accessibility of this information. In some summaries, you may come across links to external websites. These websites will have more information to help you better understand the study.


Paracetamol overdose is very common. Someone presents to the hospital following an overdose every 5 minutes across the UK. This rate is the same as the rate for heart attacks. Despite having an effective antidote called acetylcysteine (NAC), 1 in 10 patients go on to develop liver damage. NAC causes side effects such as allergic reactions that are unpleasant for the patient and may result in this essential treatment being stopped. It is unknown whether increasing the dose of NAC is more effective at preventing liver damage partly because, until recently, dose increases have not been possible due to the side effects. To address this, we designed a new protocol for giving NAC (the SNAP regimen) that is now used across the UK and has dramatically reduced the risk of patients experiencing side effects. The improved safety of the SNAP regimen allows us to look at the potential benefits of treating patients with higher NAC doses. This trial will determine whether increasing the NAC dose results in an increase in the breakdown of paracetamol, without causing an unacceptable rate of side-effects.

Start dates may differ between countries and research sites. The research team are responsible for keeping the information up-to-date.  

The recruitment start and end dates are as follows:

19 Feb 2024 31 Jan 2026

Publications

2025 Protocol article in https://pubmed.ncbi.nlm.nih.gov/40122550/ (added 24/03/2025)

The trial will compare the effects of NAC given for 12 hours at 1.5 times and double the standard dose with standard treatment (dose groups: standard = 300 mg/kg; 1.5 = 450 mg/kg and double=600 mg/kg). Paracetamol breakdown will be assessed by measurement of the breakdown products (metabolites) in the blood. Side effects will be assessed using a patient questionnaire. Participants will be followed up for 7 days using their medical notes to review their recovery. The results of this trial are essential information for the next step, a UK-wide trial to determine whether a higher dose of NAC improves the outcome for patients.


Patients who have had a paracetamol overdose from the Emergency Department at participating sites in Scotland.

You can take part if:



You may not be able to take part if:


Current participant exclusion criteria as of 25/10/2024:1. Patients that do not have the capacity to consent2. Patients who are pregnant or breastfeeding3. Patients who have previously participated in the study4. Patients who, in the opinion of the responsible clinician/nurse, are unlikely to complete the full course of NAC e.g. expressing wish to self-discharge5. Patients detained under the Mental Health Act6. Patients already started on NAC treatment7. Patients with known viral hepatitis or HIV8. Prisoners





Previous participant exclusion criteria:1. Patients that do not have the capacity to consent2. Patients who are pregnant or breastfeeding3. Patients who have previously participated in the study4. Patients who, in the opinion of the responsible clinician/nurse, are unlikely to complete the full course of NAC e.g. expressing wish to self-discharge5. Patients detained under the Mental Health Act6. Patients already started on NAC treatment7. Known overdose of a modified/extended-release preparation of paracetamol8. Patients with known viral hepatitis or HIV


Below are the locations for where you can take part in the trial. Please note that not all sites may be open.

  • Victoria Hospital
    Hayfield Road
    Kirkcaldy
    KY2 5AH
  • Royal Infirmary of Edinburgh at Little France
    51 Little France Crescent Old Dalkeith Road Edinburgh
    Lothian
    EH16 4SA
  • St Johns Hospital
    Howden W Road Howden, Livingston
    Lothian
    EH54 6PP

This information has not yet been provided by the study team. You'll have an opportunity to discuss any risks and benefits that may be associated with this study prior to consenting to taking part.

Ms Kat Oatey
+44 (0)131 651 9913
Hisnap.trial@ed.ac.uk


Dr James Dear
+44 (0)131 242 9214
James.dear@ed.ac.uk



The study is sponsored by Accord (United Kingdom) and funded by Chief Scientist Office, Scottish Government Health and Social Care Directorate.



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Read full details for Trial ID: ISRCTN17516192

Or CPMS 59286

Last updated 24 March 2025

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