British Columbia’s overdose crisis could soon become even worse due to new strains of fentanyl that are resistant to the medication paramedics use to save lives.

The province’s chief medical officer is warning that dozens of new types of illicit street drugs are being manufactured that are resistant to naloxone, also known as Narcan, an antidote used by first responders to block the effects of opioids after an overdose.

Dr. Perry Kendall told CTV News that medical professionals don’t have the technology to keep up with the volume of new designer drugs flooding the market.

“We do see that the chemists are making a whole range of these analogues and tweaking them and we really don't have any experience with them in an illegal drug supply,” said Kendall. “So a new drug comes in and it's a white powder, people really don't know what's in it -- they're lab rats in a way.”

Kendall said he knows of at least 40 different fentanyl analogues created to intensify or prolong a user’s high but are difficult to detect with standard drug tests.

He suspects acryl fentanyl may be one of those analogues. That version of fentanyl promises a longer high and has started emerging in the United States, raising concerns because it’s highly resistant to the Narcan antidote.

“We know already in B.C. we have overdoses with different drugs that require multiple vials of naloxone to bring somebody back,” said Kendall.

Sarah Blyth, who works with the Overdose Prevention Society in Vancouver’s drug-ridden Downtown Eastside, said she knows of several overdoses where naloxone failed to help. They’ve often assumed it’s other illicit drugs like W-18 that are similarly tough to counter with naloxone.

“We normally have oxygen and then Narcan and if that's not working, then we're on the phone to 911 and an ambulance is coming,” said Blyth. "It is a scary time, it's definitely a scary time, and we feel it here."

She pointed out that casual drug users, particularly inexperienced ones, are as much at risk as hardcore addicts.

“Young people, especially teenagers, they're out at a party, there's peer pressure -- you know 'take this pill, I'm going to take this pill' and you end up with dead teenagers.”

The U.S. Drug Enforcement Agency says it has discovered acryl fentanyl in a number of different states.

"It is a constant fight with the drugs that are coming across the border," said DEA spokesperson Michael Bulgrin.

Last Thursday (April 27), BC Emergency Health Services responded to a total 109 suspected overdoses around the province, with 71 reported within the Metro Vancouver area. The day before broke a provincial record with 130 overdose calls.

Roughly half of all fatal overdoses involve people who are using alone.

With files from CTV Vancouver's Penny Daflos