In a release, the public health agency explained that the strips have several limitations when it comes to detecting fentanyl or other potentially fatal drugs.
“No fentanyl test strips are specifically designed to check street drugs before consumption,” the release read.
Dr. Hance Clarke, a clinical researcher at Toronto General Hospital, told Global News that not all strips work the same way.
Some strips are meant to detect fentanyl in urine samples after drug consumption has already taken place.
Other strips work differently and are used to test drugs themselves, but are used by law enforcement, and not necessarily designed for street drug testing.
The strips then display a plus or minus, or change colour to indicate whether the opioid is present.
“The urine strip tests aren’t going to help you. That just tells you what you’ve consumed after the fact,” Clarke explained.
Another limitation of the strips is that they don’t always detect synthetic forms of fentanyl that may be present, such as carfentanil.
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Clarke says the strips often only offer a “false sense of security,” and it’s hard to know when the results are correct.
This isn’t the first time Health Canada has warned against relying on the strips. In December 2017, a similar warning was issued following a preliminary study that found fentanyl strips may not be accurate.
“A false negative could lead to a false sense of security, which may result in overdose or death,” the warning read. “This is particularly true for people who may choose to use drugs alone or without visiting a supervised consumption site where emergency help is immediately available.”
Strips growing in popularity
Fentanyl strips are growing in popularity as a means of testing drugs easily and at a low cost, according to research published in the Harm Reduction Journal in February.
In the study, young adults who admitted to using drugs were asked about their willingness to use the strips — after some training nearly all of them said they would use the strips and felt confident in how to administer them.
The strips are also available online and can be bought for just a few dollars.
Alternatives to fentanyl testing strips
Clarke suggests those using fentanyl or illicit drugs take a range of precautions.
For starters, those consuming the drugs should never do so alone — a supervised consumption site is best, if available.
“If you’re unsure about the product, you’ve got to consume it not by yourself,” he said. “Obviously don’t take a lot of it.”
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Naloxone, an antidote that can temporarily reverse the effects of fentanyl, should also be carried.
Clarke describes naloxone as a fentanyl “antagonist,” which often comes in the form of a nasal spray or injection, and can help restore breathing in case of an overdose.
— With a file from The Canadian Press