Vancouver Coastal Health is worried the city's overdose crisis could become worse after the deadly drug carfentanil was detected in the Downtown Eastside.

The Vancouver Police Department confirmed yesterday it had detected the deadly opioid for the first time in a drug seizure it made on Sept. 20.

According to Dr. Mark Lysyshyn with Vancouver Coastal Health, the opioid works similarly to fentanyl but is 100 times more potent. The drug is typically used to tranquillize large animals like elephants.

"Over the last few weeks, we've really seen an increase in overdoses both at Insite and at our emergency rooms," he told CBC's The Early Edition.

"With this recent seizure by the police it makes us suspicious that carfentanil is circulating on the streets."

Carfentanil resembles table salt but is 100 times more potent than fentanyl. (Canada Border Services)

Carfentanil could require stronger dose of naloxone

Since carfentanil binds to the same brain receptors as fentanyl, naloxone can work as an antidote. However Lysyshyn said it might take a stronger dose.

"Over the years, we've seen that it takes more and more naloxone to reverse their overdoses and that's why we're putting more naloxone in the take-home naloxone kits," he explained.

"But we believe the three doses that are currently in the kits are enough to reverse most overdoses."

Lysyshyn said the health authority will be continuing the same work it has been doing to combat fentanyl.

"We have to keep doing the same things that we're doing. The take-home naloxone program is still an effective intervention, supervised injections services are still effective at preventing overdose morbidity and mortality and we are trying to expand," he said.

Insite will be open 24 hours a day because of the corresponding spike of overdoses expected due to income assistance cheques being issued this week. Mobile overdose response units will be circulating through the Downtown Eastside on foot and bike.

Carfentanil has also been found Manitoba and has been linked to two deaths in Alberta.

With files from The Early Edition

To listen to the interview, click on the link labelled Carfentanil, an opioid more potent than fentanyl, found on Vancouver streets