Status: Ongoing First registered on: 11/07/2023
Last updated on: 28/08/2023
1. Study identification
EU PAS Register NumberEUPAS105644
Official titleDARWIN EU® CC - Use of take-home naloxone for opioid overdose treatment
Study title acronym
Study typeObservational study
Brief description of the studyOpioid overdoses are the primary cause of mortality among problematic drug users globally. Naloxone, an opioid antagonist, can avert such fatalities by rapidly counteracting opioid effects. To address the frequent untreated overdoses due to the lack of recognition, fear of legal consequences, and lack of naloxone access, Take-Home Naloxone (THN) programs have been established, providing naloxone to potential bystanders in 12 European countries. This study will investigate the trend of naloxone use, particularly THN, across Europe, and elucidate user profiles to augment aggregated data from existing THN programs, thereby aiding the monitoring of naloxone use and informing regulatory decisions. The objectives of this study are (i) To investigate the incidence and prevalence of THN use in (1) the general population and (2) among people with a recorded history of opioid use disorder during the study period 2017-2022. Analyses will be stratified by age, sex, calendar year and country/database. (ii) To provide summary baseline characteristics of “new” THN users including demographics, previous medical history, previous medication use and history of opioid use, overdose (iii) To study the use of THN in ”new” users including summary statistics of number of THN packages prescribed at index date for each “new” user (e.g. mean (SD), median, q25 and q75)
Was this study requested by a regulator?Yes: EMA
Is the study required by a Risk Management Plan (RMP)? Not applicable
Regulatory procedure number (RMP Category 1 and 2 studies only)
Other study registration identification numbers and URLs as applicable
2. Research centres and Investigator details
Coordinating study entity
Centre nameDARWIN EU® CC
Centre locationRotterdam, the Netherlands
Details of (Primary) lead investigator
Title Dr
Last name Jodicke
First name Annika
Is this study being carried out with the collaboration of a research network?

Other centres where this study is being conducted
Multiple centres

In total how many centres are involved in this Study?3

University of Oxford, United Kingdom
IDIAP Jordi Gol, Spain
Countries in which this study is being conducted
International study

United Kingdom
3. Study timelines: initial administrative steps, progress reports and final report
Date when funding contract was signed04/05/202304/05/2023
Start date of data collection01/01/201701/01/2017
Start date of data analysis
Date of interim report, if expected
Date of final study report01/11/2023
4. Sources of funding
Please provide estimates of the percentage of funding by source for this study
Names(s)Approximate % funding
Pharmaceutical companies
Government bodyEMA100
Research councils
EU funding scheme
5. Contact details for enquiries
Scientific Enquiries
Title Dr
Last name Jodicke
First name Annika
Address line 1University of Oxford
Address line 2Windmill Road 
Address line 3Headington 
CountryUnited Kingdom
Phone number (incl. country code)31107043050 
Alternative phone number 
Fax number (incl. country code) 
Email address
Public Enquiries
Title Mrs 
Last name Schuemie 
First name Ilse 
Address line 1Dr. Molewaterplein 40 
Address line 2 
Address line 3 
Phone number (incl. country code)31107043050 
Alternative phone number 
Fax number (incl. country code) 
Email address