Animal tranquilizer in street drugs raises alarms

Harm reduction workers in Ottawa say animal tranquilizers in the street drug supply are putting users at even greater risk of severe harm.

Xylazine a big concern because naloxone won't reverse overdoses

A potent tranquilizer is showing up in Ottawa’s drug supply. Here’s how this clinic can test for it

3 months ago
Duration 2:25
Supervised injection sites in Ottawa like the Sandy Hill Community Health Centre are sounding the alarm after finding traces of xylazine, an animal tranquilizer, in the local drug supply. Derrick St John, program manager of the centre’s Oasis program, demonstrates how drugs can be tested in just a few minutes.

Harm reduction workers in Ottawa say animal tranquilizers in the city's street drug supply are putting users at even greater risk of severe harm.

Both Ottawa Inner City Health (OICH) and the Sandy Hill Community Health Centre say they've come across a potent veterinary sedative called xylazine in recent weeks.

Typically used to sedate large farm animals such as cattle and horses, xylazine can have dangerous effects in humans including prolonged blackouts, according to Ottawa Public Health.

As a central nervous system depressant, it dangerously suppresses vital signs such as heart rate and blood pressure. It's not approved for use in humans in Canada and its long-term effects on human health are unknown.

When mixed with fentanyl, it's known as "tranq" or "zombie dope" and can cause painful wounds that lead to amputation.

Its emergence in communities across Canada is also worrying because naloxone, a medication used to reverse overdoses of fentanyl and other opioids, doesn't work on it.

Six fentanyl samples voluntarily submitted for testing at OICH since the beginning of this year have tested positive for xylazine, while Sandy Hill found the tranquilizer for the first time in fentanyl samples brought to the centre by users last week.

"This is kind of new for us — at least that we're finding [it] in the testing," said Derrick St John, a nurse who oversees Sandy Hill's supervised consumption site and other harm reduction services. 

'Atypical overdoses' in past years

Leah Podobnik, a member of the grassroots group Overdose Prevention Ottawa, said xylazine has actually been circulating in Ottawa for two years without this detection.

"We've seen atypical overdoses where we can't revive the person with just naloxone," said Podobnik, who'd previously spent six years working at supervised consumption sites.

The use of new drug-testing machines at Ottawa clinics has helped both drug users and harm reduction workers better navigate a scene where — as St John put it — users unwittingly expose themselves to a "dog's breakfast" of opioids and stimulants with "no quality control."

Both OICH and Sandy Hill are now regularly testing drugs that come in to flag unexpected components such as xylazine. 

St John demonstrated Sandy Hill's testing machine on Friday, when the health centre received three fentanyl samples for testing. 

Wearing gloves, St John took a morsel of crystalline green fentanyl from a baggie, placed it on a chip reader roughly the size of a matchbook and inserted the chip inside a black computer tower with laser scanners. 

The results, displayed on a laptop via Bluetooth about five minutes later, confirmed the presence of xylazine.

A green crystal in a black card reader.
A small piece of fentanyl gets placed inside the testing machine's chip, which is read into a computer tower with scanning lasers. (Guy Quenneville/CBC)

Sandy Hill has done about 400 scans since getting the machine in November. St John said people get their drugs tested for various reasons such as an unusual colour of the drug or an unfamiliar seller.

Other tranquilizers found in drugs elsewhere, including medetomidine and dexmedetomidine, will be added soon to the scanner's database.

People can come to the centre to have their drugs tested seven days a week from 8 a.m. to 8 p.m. 

Drugs given back after testing

Though some people at Sandy Hill ultimately surrender their drugs, they are given the choice of whether to keep them, no matter the test results, St John said. 

Those who keep them are encouraged to also keep naloxone on them and not take the drugs alone.

"Think of harm reduction kind of like a seat belt," St John said. "It doesn't mean that you're not going to get into an accident. It just … won't make it as bad."

A health worker poses for a photo at a desk.
The Sandy Hill Community Health Centre found traces of animal tranquilizer xylazine in samples of fentanyl for the first time last week, according to St John. (Guy Quenneville/CBC)

Ottawa Inner City Health's CEO said the clinic hopes to have improved monitoring now that it's getting "better" surveillance data. 

"Multiple sites are really helpful to understand if there are differences," said Rob Boyd via email. "Ideally, we would establish an intercity or interprovincial system of surveillance."  

Drug dealers are using the testing machines too, Podobnik said, because they don't want to poison their customers.

"It's a lot of different people," she said. "You'd be surprised the amount of people that use this machine."

Xylazine, which is known on the streets as “tranq dope” or “zombie drug”, can cause extended blackouts. Worse still, it’s resistant to naloxone, a fast-acting medication that can reverse opioid overdoses.


Guy Quenneville

Reporter at CBC Ottawa

Guy Quenneville is a reporter at CBC Ottawa born and raised in Cornwall, Ont. He can be reached at

With files from Safiyah Marhnouj, Kristy Nease and Ryan Patrick Jones