Canada's highly toxic illicit drug supply is worsening with the emergence of xylazine, a dangerous and unpredictable animal tranquillizer that's putting drug users' lives at risk in alarming new ways, and advocates are calling for more to be done to address the issue.
The severely potent veterinary sedative, known on the street as "tranq dope" or "zombie drug," is being cut with opioids like fentanyl to prolong their effects, but can also cause hours-long blackouts and horrific, painful wounds that can lead to amputation.
"It puts people in sort of blackout states, people are at really high risk of walking into traffic because they don't really know what's going on," said Matt Johnson, a drug user and harm reduction worker at the Parkdale Queen West Community Health Centre in Toronto.
"We have definitely seen people get brain injuries from having these mild overdoses again and again and again. We've had people who have died from a mix of fentanyl and xylazine."
Xylazine is typically used as a sedative in large farm animals such as horses, but the tranquillizer is not approved for use in humans in Canada and its long-term effects on human health are unknown.
"It can cause respiratory depression, it can lower your blood pressure, it can actually lower your heart rate," said Dr. Shovita Padhi, Toronto's associate medical officer of health.
"And when you have xylazine present with opioids such as fentanyl, this actually greatly increases the risk for fatal overdoses."
A new report from Health Canada shows the rapid spread of xylazine across the country during the past few years, with a growing number of street drug samples seized by law enforcement agencies testing positive for the tranquillizer — overwhelmingly in Ontario.
In 2018, there were just five samples of xylazine analyzed by Health Canada's Drug Analysis Service, which tests tens of thousands of drugs apprehended by the Canada Border Services Agency, the Correctional Service of Canada and police forces each year.
By 2019, that number grew to 205. Last year alone there were 1,350.
"This is a changing and ongoing dynamic emergency here, not the same thing that it was five years ago, not the same thing that was even two years ago," said Karen Ward, a harm reduction advocate for drug users in Vancouver's Downtown Eastside.
"The supply is changing so quickly and it can only get worse, it's only going to get more chaotic."
To make a bad situation worse, one of the best overdose prevention tools available — the life-saving overdose-reversal medication naloxone — is rendered completely ineffective against xylazine, meaning attempts to revive people can be futile.
"There's a significant amount about xylazine that we don't know because it is a veterinary drug, so it hasn't been used or tested in humans. We don't really know what it does to people long-term necessarily," said Johnson.
"Xylazine also doesn't respond to naloxone because it's not an opioid."
The short-term effects of the drug are devastating: knocking users out for hours on end, leaving them vulnerable to robbery, physical harm and sexual abuse, and worsening the effects of opioid withdrawal due to long stretches of time spent unconscious.
"People are waking up with no idea where they are, they're disoriented and they don't know what they've used," said Ward. "People are being robbed, people are passing out here and there, and it's putting them at risk in many, many ways."
Nicole Luongo, the systems change co-ordinator for the Canadian Drug Policy Coalition, a policy advocacy group made up of about 50 organizations, said xylazine is being added to the illicit supply as a way to make drugs such as fentanyl even more potent.