It seems like a relatively straightforward question: How many Canadians die each year as a result of prescription drug overdoses?

But there is no simple answer, and the fact that no number is readily available is one indication of the many challenges scientists, medical professionals and others face in the fight to overcome what some have labelled a public health crisis: prescription drug misuse and abuse in Canada.

While there is a sense the number of deaths from overdoses of prescription painkillers and other drugs has been growing, there is no central clearing house that can provide definitive statistics.

"We don't have national data to be able to give that answer," says Deborah Cumming, national priority adviser at the Canadian Centre on Substance Abuse in Ottawa. "The tracking is done differently in different provinces."

And that creates a big problem: "We don't have a comprehensive national view of this issue," Cumming said.

Still, Cumming and others are searching for ways to develop strategies to address the issue.

"There's quite a few streams and ways of tackling this," she says. "It's not going to happen overnight, and there is no magic bullet."

When scientists start looking at the provincial numbers, they go back a few years.

Accidental deaths

For example, statistics from the Coroners Service of British Columbia show that from 2000 to 2010, overdoses of prescription medication resulted in 140 to 180 deaths annually.

In Ontario, there were about 423 deaths related to opioids such as oxycodone and hydrocodone in 2006, says Tara Gomes, a scientist at the Institute for Clinical Evaluative Sciences in Toronto.

'This is particularly concerning because these are deaths in a younger population of men and they're largely avoidable deaths.' —Tara Gomes

"Typically these deaths are in younger people between the ages of 40 and 45 years and the majority are men," she said.

"When we look at the cause of death, we find that these deaths are typically accidental deaths. In my opinion, from a public health perspective, this is particularly concerning because these are deaths in a younger population of men and they're largely avoidable deaths so if we could do something to address the problem, it could lead to reductions in these deaths in Ontario."

Statistics from the office of Ontario's chief coroner indicate deaths related to opioids increased by 49 per cent between 2002 and 2006. Deaths due to oxycodone itself — sold under the brand name OxyContin — rose 240 per cent in that same period.

In 2002, a new, long-release formulation of oxycodone was released.

"It was a more potent drug and people didn't adjust their usage of it so we saw more deaths," Cumming said. "We saw more crushing, snorting, injecting of a more potent formulation so it increased the toxicity level. And it was often combined with another [central nervous system] depressant. So there was poly-substance abuse. It wasn't explicitly and solely oxycodone."

Less heroin

As the use of oxycodone rose, Cumming says, the use of heroin and other illicit drugs fell.

"People are going to their doctors and getting prescriptions versus going on the streets and scoring heroin or crack or something like that," she said. "The view of individuals who are using prescription medications is in fact they know what's in this medication versus going on the street and you're not quite sure what the mix of your heroin is."

Sometimes the prescription drug misuse isn't the result of an addiction or someone looking for a high.

"People are also sharing these drugs with their friends and their family members, not necessarily to be abused, but because they know somebody who has a backache and they say, 'Well, this pill worked for me,'" Gomes said. "To me that highlights an issue of a lack of education of people around the risks of these drugs and the fact that they shouldn't be shared and that the wrong drug taken by the wrong person at the wrong dose could lead to fatal consequences."

In Ontario, the provincial government is removing OxyContin and its successor — OxyNeo — from the list of drugs it routinely funds. Other provinces are weighing whether to include OxyNeo in their formularies.

OxyNeo is being introduced as maker Purdue Pharma Canada phases out OxyContin at the end of the month. The new drug includes oxycodone, but is made in a way that is intended to make it harder to crush and abuse.

Unknown implications

Because OxyNeo is more difficult to crush than OxyContin, it is less likely to be inhaled or injected, Gomes says.

"What I don't know is what the implications of that will be — whether it will mean that people who have developed an addiction are seeking other drugs such as heroin; whether they're switching to other opioids, which they can abuse; or whether people will find a way to abuse OxyNeo."

As OxyContin is pulled from the market, Gomes says, there is also a need to ensure "adequate accessibility to addiction and detox services in Ontario, particularly in remote communities."

While there is no data available to indicate whether the number of deaths related to prescription drugs has increased, decreased or remained the same in the past five years, Gomes notes that prescribing of the opioids has gone up and she thinks the risk of dying from an overdose is unlikely to have gone down.

Gomes says he welcomes efforts by the Ontario Ministry of Health and Long Term Care to address the issue, such as the adoption of a narcotics strategy late last year.

"That was an attempt by the government to really develop some policies around the prescribing of these drugs and the safety of prescribing of these drugs," she said. "That's been a really good step in the right direction."

But more needs to be done, she added, suggesting for example an electronic record system that would allow doctors to know in real time every drug that a patient is receiving.

'Everybody is accountable'

The Canadian Centre for Substance Abuse organized a "national dialogue" earlier this month looking at legislation and regulations. More than 60 people from backgrounds ranging from treatment to education and law enforcement were involved.

"We're pulling together a comprehensive, pan-Canadian strategy to address the prescription drug misuse that we're seeing," Cumming said. "It will be multi-faceted. Everybody is accountable. We cannot simply enforce our way out of this. We cannot simply point fingers at prescribers and physicians. We all have a role to play, including the patient.

"When we get our medications and we just take them home and put them in the cabinet, we need to be mindful that the main route of diversion is people stealing it from homes, sharing it amongst themselves."

Cumming also points to the need for safe disposal practices and education.

"We need to have a balanced approach to this," she said. "We need to recognize that these are important drugs for treating chronic and acute pain, and those people requiring that type of treatment should not be denied access. But we have to manage these medications and how we prescribe them a lot better than we are currently."