Ottawa Public Health is warning residents about the dangers of opioid use after a spike in suspected fentanyl overdoses across the city has swamped hospitals this week.

The public health agency said it has seen 15 suspected cases between April 18 and 20.

The Ottawa Hospital alone has seen seven suspected fentanyl cases in the last 48 hours – five at the Civic's trauma centre, and two at the General Campus.

"When you hear [of] near-misses, you know that if it continues, at some point they're not going to be misses," said Peter MacDougall, the hospital's director of pain medicine.

"And I'm very worried that we will see an increase in tragedies around this,"

Task force issues warning

The city-run Overdose Prevention and Response Task Force monitors drug overdoses daily in the event that a sudden spike warrants a public warning.

While the task force couldn't officially confirm the overdoses were caused by opioid use, Ottawa Public Health said the spate of recent hospitalizations does raise that possibility.

Peter MacDougall, the Ottawa Hospital's director of pain medicine, says the recent overdoses could herald a wave of fentanyl on the city's streets — or even potentially more potent carafentanil. (CBC)

"When a sudden increase in the number and severity of suspect drug-related emergency department visits is observed during a short period of time, there is always a possibility of counterfeit drugs being cut with opioids," Ottawa Public Health said in an email to CBC.

The public health agency warns that getting drugs from a non-medical source, like a friend or from a drug dealer, carries significant and potentially life-threatening risks.

"There is no way to know what is actually in them or how toxic they may be. Drugs should only be purchased or obtained from a local pharmacy or a registered medical professional," the agency said.

Hospitals increasing supply of naloxone

The hospital said it has increased its supply of naloxone in emergency departments in recent months, in anticipation of further opioid overdoses.

Some of the recently hospitalized patients required high doses of naloxone, a hospital spokesperson said in an email statement.

"The effects of super opioids can last for hours while naloxone lasts only an hour. Therefore, it is imperative that if a case of opioid overdose is suspected and naloxone is administered to any individual in the community, the patient should be transported to an emergency department for further treatment and possible ongoing naloxone dosing."

MacDougall said the latest spike could suggest an increased supply of fentanyl or even more potent carfentanil has made its way onto Ottawa's streets.

There are spikes in this, and we might be continuing to see that over the coming days. - The Ottawa Hospital's Peter MacDougall

It could also herald a rise in illicit opioid production at Canadian labs, he said, which would "reduce the dependence on foreign trafficking," particularly from southeast Asia, he said.

"There are spikes in this, and we might be continuing to see that over the coming days as this drug — or drugs, I don't really know yet — start to enter the illicit stream of narcotic supply," he said.

Tackling the rise in opioid use, MacDougall said, will require a "multi-pronged" approach involving everything from education and treatment to ensuring access to emergency opioid antidotes.

"We need to be teaching people, not only the dangers of using these medications, but sadly [also] how to respond and how to use things like naloxone kits. We need to develop resources to manage people who have developed addictions to these medications," said MacDougall.

The spike in cases comes a month after hundreds of concerned parents filled a meeting space in Kanata to figure out how to deal with the opioid crisis in Ottawa.

Ottawa Public Health officials at the meeting gave a half-hour information session on fentanyl and counterfeit prescription drugs.

Sean O'Leary, whose 17-year-old daughter Paige is struggling with opioid addiction, has connected with more than 100 families dealing with opioid addiction through a network called We the Parents.

He's frustrated the warning came so late on a Friday afternoon.

""Ottawa [Public] Health should be telling us, so we know," O'Leary said."We've done a blast email to all the people registered on We the Parents that this is going. But it's Friday afternoon. What if people don't look at their emails?"

O'Leary spoke at a news conference earlier Friday with local MPP Lisa MacLeod and Progressive Conservative Leader Patrick Brown to call for more action on the opioid crisis from the provincial government.

Ottawa police have confirmed they are investigating the latest cases.