Many Canadians are prescribed high-dose painkillers such as OxyContin and morphine, among the most dangerous pills, say researchers, who found differences between dispensing between provinces.

Investigators at the Institute for Clinical Evaluative Sciences in Toronto reviewed retail pharmacy dispensing rates for opioids between 2006 and 2011.

In Friday’s issue of Canadian Family Physician, Dr. David Juurlink, a clinical pharmacologist at Sunnybrook Health Sciences Centre and his co-authors said they found "marked inter-provincial variation" in dispensing of high-dose opioids in Canada.

"What this paper looks at is specifically the high-dose products," said Juurlink, who is also a scientist at ICES. "The doses at the upper limit, where if you took them as prescribed, you would be on a watchful or dangerous dose of opioids, and where if a teenager experimented with a single tablet, could easily kill themselves if they took it at a party."

Most of the time, Juurlink said, high-dose opioid drugs are associated with side-effects more than benefits. The risks include:

  • Motor vehicle collisions.
  • Fractures.
  • Confusion.
  • Addiction.
  • Death.

More than 1,000 Canadians die every year from these drugs, Juurlink said, and most start out with a prescription from a doctor.

"It doesn't seem like a very sympathetic comment, but I think it has to be said. We need to expect less of the drugs we have for pain. They just don't work very well for many patients," Juurlink said.

Nav Persaud

Canada's prescribing rates for opioids are among the highest in the world, says family physician Dr. Nav Persaud. (CBC)

"When we get to these doses of opioids, it's very rarely the case that benefits offset the risks, and I think the sooner doctors and patients come to realize that, the fewer prescriptions we'll see and perhaps we'll see fewer people dying as a result."

On average, more than 30 million high-dose opioid tablets or patches are dispensed in Canada each year.

A high-dose prescription would be 80-milligram tablets of oxycodone twice a day.

Painkiller use increasing

In the study, rates of high-dose opioid dispensing across Canada increased from 781 units per 1,000 people in 2006 to 961 units per 1,000 people in 2011.

Ontario showed the highest annual rate of high-dose oxycodone and fentanyl dispensing. Alberta had the highest rate of high-dose morphine dispensing.

Almost half of all the high-dose units dispensed were oxycodone tablets (49 per cent), followed by morphine tablets (24 per cent), hydromorphone tablets (18 per cent) and fentanyl patches (nine per cent).

Nav Persaud is a family doctor at St. Michael’s Hospital in Toronto who has patients with chronic pain and who has prescribed opioids.

Persaud said it’s surprising and disappointing that the rate of prescribing of high-dose opioids remains high in Canada.

"It's definitely bad news that it's plateaued at such a high rate. The rate is very high, maybe among the highest in the world," Persaud said.

'I kept asking for stronger and stronger and stronger ones'

In 2007, executives at Purdue Pharma pleaded guilty to misbranding OxyContin and other long-acting opioids. The agreed statement of facts described claims of lower abuse potential that were part of marketing campaigns.

"You can't put the genie back in the bottle. Once these marketing messages get out, there is no way to counteract them," Persaud said.

Doctors want to help patients in chronic pain to find relief, but there are few medication options beyond acetaminophen, anti-inflammatories like ibuprofen and opioids, Juurlink said.

Pain is one of the most common problems that doctors see, Juurlink said. But even when used as directed, once someone has been on the drugs for three or four weeks, they’re difficult to stop.

Don Pedersen is now learning that. The truck driver from Canmore, Alta., hit a huge hole and jarred his neck last June. Since then, he’s been in chronic pain with pinched nerves.

"I went to a doctor, I tried to get pain medicine, but nothing seemed to be working. I kept asking for stronger and stronger and stronger ones," he said. 

Pedersen said he took a cocktail that included OxyContin and Tylenol 4, and later realized he was hooked.

"I'm addicted to this pain medication," he recalled telling worker’s compensation. "You're going to have to send me to some place to get me off of them."

He is in his second week of treatment at Canmore's Orion Health's pain clinic. "It's been pretty tough because I've been going through some withdrawals, and sweating," he said. 

Dr. Monica O'Gorman is Pedersen's physician at the clinic, where she sees patients come in with 500 high-dose tablets. Patients often say nobody told them the drugs could be a problem.

"I think that's probably something, as family physicians, we're not doing as well at, is going through what are the risks of these medications. These are the things you need to be watching for," O'Gorman said. 

As for the alternatives to medication, some hospitals have mindfulness programs, Persaud suggested, to help patients with chronic pain to cope and function better. In most cases, people with chronic pain learn to manage it, but the pain doesn’t go away completely.

This study was supported by a grant from the Ontario Ministry of Health and Long-Term Care Drug Innovation Fund and ICES.

With files from CBC's Marijka Hurko