Vancouver Coastal Health says a drug testing study at Insite has shown people are less likely to overdose after testing — and has also shown most of the drugs tested contained some amount of fentanyl.

For the last nine months, VCH has been offering the supervised injection site's clients strips that test for the presence of fentanyl. The strips can be used either before or after consumption, with about 38 per cent of users opting to test their drugs before using them.

Mark Lysyshyn, a medical health officer with VCH, says those who test their drugs before consumption are significantly less likely to overdose.

"They are about 10 times more likely to reduce their dose if they get a positive drug check, and then that makes them about 25 per cent less likely to overdose," he said.

'Heavily contaminated'

Lysyshyn says the study has shown the drugs tested were "heavily contaminated" with fentanyl, with about 80 per cent of samples testing positive.

The synthetic opioid is also being found in non-opioid stimulants like crystal meth and cocaine, VCH says.

Though most Insite clients opt to test their drugs after consumption, Lysyshyn says information is still useful, and may prevent that person from overdosing in future.

Test has limitations

Lysyshyn says the testing strips are relatively inexpensive, costing about a dollar each, but they have a number of limitations. For one, they only test for the presence of fentanyl, not the amount.

The strips are also not able to test for the presence of fentanyl analogues like carfentanil, many of which are more potent.

Lysyshyn says his team's next step is to get more people to test their drugs before consumption — rather than after. His team is also working with the strip vendor to improve the test for fentanyl analogues.

The team also wants to find other settings in which the testing strips could be effective outside of Insite — in concert with the health authority's take-home naloxone program, for example.

"This would be the kind of thing that we could give out like the rest of our harm reduction supplies, [like] clean needles and naloxone kits," Lysyshyn said.

With files from Natasha Frakes.