Preventing injection drug use

Dr. Dan Werb wants to prevent potential injection drug users from ever starting, by limiting their exposure to experienced injection drug users. He also wants to increase the opportunities people who inject drugs have to find recovery support when they need it. Luckily, his new research may accomplish both.

Dr. Werb heads a research project called , or Preventing Injecting by Modifying Existing Responses. It was partly inspired by the successful Treatment as Prevention model for reducing HIV prevalence that uses antiretroviral drugs to reduce HIV viral loads to very low or undetectable levels, thereby reducing the risk that HIV-positive people will infect others. Instead of improving access to antiretroviral medication, however, PRIMER will test whether improved access to public health programs such as methadone clinics and supervised injection sites reduces the risk that people who inject drugs initiate others into injecting.

“It seems that first-time drug injectors most often begin injecting because they’ve been exposed to veteran injectors and become desensitized—to the point where the drastic step of sticking a needle in your arm seems normal,” explains Dr. Werb, a scientist with the Li Ka Shing Knowledge Institute of St. Michael’s Hospital.

Dr. Werb—who has a PhD in epidemiology and expertise in HIV and addictions research—said the key to preventing this exposure is expanding existing public health services for the 100,000 Canadians who already inject drugs, typically cocaine, heroin or other opioids such as OxyContin.


“This research will determine whether, by creating more supervised injection sites such as Insite in Vancouver, we can provide safe, private places for injection drug users, while limiting the exposure of those who have never tried injecting drugs,” says Dr. Werb.

Scaling up public health services also improves the likelihood those who are injecting drugs may find recovery support. The more frequently that people who use drugs access public health services, the more frequently they interact with trained support workers.

“Because timing is so important for recovery, increased services will also increase the opportunities people who use drugs are around someone they can ask for help at the moment they are ready,” adds Dr. Werb. “PRIMER will investigate a way to both prevent new cases of and treat the harms experienced by people who have already started.”


In 1993, Switzerland expanded supervised injection sites and methadone maintenance therapy as part of a comprehensive public health approach to reducing drug-related harms. At the time, new injectors comprised 18 per cent of all injection drug users in the country.

“By 2000, new injectors only made up three per cent of all people who injected drugs in Switzerland,” says Dr. Werb. “This suggests that a comprehensive scale up of harm reduction services might actually reduce the socially contagious nature of injecting.”

The U.S. National Institute on Drug Abuse seems convinced by Dr. Werb’s plan. He was recently named one of four inaugural recipients of the institute’s US$1.5 million Avenir research award, a fund set up to support highly innovative research from new scientific investigators.

The PRIMER study will be carried out over the next five years with an international team of researchers across six cities: Vancouver; San Diego, Calif.; Tijuana, Mexico; and Paris, Marseille and Bordeaux, France.