Growing misuse of opioids like OxyContin has resulted in overdose deaths but new Canadian guidelines for prescribing the drugs aim to curtail the problem.

A committee of medical specialists struck by colleges of physicians and surgeons issued guidelines Monday for family doctors prescribing opioids in an effort to prevent overdoses and address under-treatment of some types of pain.

Canada is the world's third-largest per capita consumer of opioid painkillers, researchers noted in a summary on the guidelines, published in Monday's issue of the Canadian Medical Association Journal.

The guidelines, which have been in development since 2007, aim to provide physicians with information to prescribe opioids such as Percocet effectively to patients with chronic, non-cancer pain — pain that lasts more than six months and comes from a non-cancer source such as osteoarthritis or chronic low back pain.

"Certainly we've been hearing from physicians that they're seeking advice and guidance in this particular area. It is, or can be a difficult area of treatment," said Clarence Weppler of the Alberta College of Physicians and Surgeons in Edmonton.

Weppler is co-chair of the National Opioid Use Guideline Group, which wrote the guidelines.

"Chronic pain … may be seen to be over-treated for some people, but in fact as our article in the CMAJ indicates under-treatment of pain is also a problem. So we're trying to balance the information available to cover both ends of that spectrum."

Comparison gaps

The guidelines are meant to help primary-care physicians and medical and surgical specialists whose patients suffer chronic, non-cancer pain by offering a step-by-step approach, including:

  • Doing a thorough assessment.
  • Determine whether opioids are the best choice for a particular patient.
  • How to detect and respond to opioid misuse, including addiction, and minimize side-effects.
  • How to monitor whether the dose is effective over time.
  • Reducing or stopping treatment.

The guidelines are not designed as a training manual, said Weppler.

Pharmacists, nurses and dentists may also find the guidelines useful, the group said.

The guidelines are useful, but more research is needed to guide treatment decisions, said Dr. Roger Chou of the departments of medicine and medical informatics and clinical epidemiology at Oregon Health and Science University in Portland.

Chou said in a journal commentary there are gaps in understanding the comparative benefits of different opioids, particularly with regards to rates of addiction or abuse, methods of prescribing short-acting versus long-acting forms of opioids, and what are the appropriate methods of monitoring patients, such as urine screening for drugs.

"While waiting for the research that is still needed, clinicians can use the new Canadian guideline as a clinically sensible framework for decisions that need to be made now," Chou concluded.

Risks of high doses

As opioids have become more widely used and abused, the number of people who've died as a result of taking opioids has doubled since 1991 to about 300 people a year in Ontario alone, according to a study published in December 2009.

The lead author of that study, pharmaceutical policy researcher Irfan Dhalla of St. Michael's Hospital in Toronto, also called the new guidelines a good start. But Dhalla would have preferred that the guidelines had recommended lower maximum doses, as some U.S. guidelines have done.

"We do know that these drugs are much more likely to cause harm when prescribed in very high doses," Dhalla said, since the risk-benefit trade-off becomes less favourable at higher doses.

Drug ads for OxyContin still promote high doses, and family doctors may not realize the risk, Dhalla said. But producing the new guidelines has raised awareness and could save lives, he added.