Preventing injection by modifying existing responses (PRIMER)

This project is part of the Centre on Drug Policy Evaluation.

In Progress

Substance Use and Harm Reduction

More people are dying of opioid overdoses in Canada than ever before. In Ontario, opiate use now accounts for one in six deaths of young adults.

Fentanyl – a hyper-potent and especially deadly form of the drug – is the chief culprit. In Ontario, it was responsible for an astounding 548 per cent rise in deaths from overdose between 2006 and 2015. In Toronto, the number of opioid overdose deaths has more than doubled over the past three years. The problem began with the over-prescribing of opioids in the early 2000s. Now, people who inject opioids are more likely to die of an overdose than anyone else.

Importantly, exposure to injection drug use is the most critical risk factor in determining whether other people begin to inject.

Our work in Mexico, the United States and Canada shows that providing medication-assisted treatment (clinical and social care coupled with medication such as methadone or buprenorphine) halves the risk that a person who injects drugs will initiate others into drug injecting. This type of care means that providing life-saving services for people currently at greatest risk of opioid overdose can simultaneously prevent others – often young people – from starting to inject drugs.

The largest study of injection drug-use initiation, and the first to examine structural solutions to prevent people from injecting for the first time.

This five-year, multi-site study is pooling qualitative and quantitative data from cohorts of people who use drugs across seven different cities in three countries: Vancouver, Canada; San Diego, USA; Tijuana, Mexico; Paris, Marseille, Bordeaux and Strasbourg, France (roughly 3,800 people in total). We’ll examine the data to find out which interventions influence people’s risk of injecting drugs for the first time, and what factors can influence that risk.

We will then compare our results to three other afflicted North American cities where our team is conducting research (Vancouver, San Diego and Tijuana) so that we can evaluate the best way to implement our findings.

This study is funded through the inaugural United States National Institute on Drug Abuse Avenir Award, a USD$1.5 million research grant for creative new investigators proposing highly innovative research at the intersection of HIV and substance use.

Our goal is to prevent new cases of injection drug use and therefore the reduce the risk of subsequent addiction and overdose. This is the first study of its kind.

Learn more about the project.

Substance Use and Harm Reduction

Dr. Dan Werb

A sought-after source of expertise on addictions and drug policy, Dr. Werb has devoted his career to the development of effective solutions to protect health and human rights among communities affected by drug use.



  • National Institute on Drug Abuse
  • Canadian Institutes of Health Research
  • Ontario Ministry of Research, Innovation and Science


  • British Columbia Centre on Substance Use (Vancouver, Canada)
  • Centre hospitalier régional et universitaire (Strasbourg, France)
  • Institut national de la santé et de la recherche médicale (Marseille, France)
  • Université de Bordeaux, (Bordeaux, France)
  • Université René Descartes (Paris, France)
  • University of California (San Diego, USA)
  • University of Xochicalco (Tijuana, Mexico)

Contact Info

Rosalinda Rodriguez

Project Coordinator