A Canadian study shows prescription opioids have become the major form of illicit opioid use, raising questions about the nation's drug control policy.

The study, funded by the Canadian Institutes of Health research, was conducted in seven Canadian cities and led by Dr. Benedikt Fischer of the University of Victoria.

Prescription opioids commonly prescribed as painkillers in Canada include Oxycontin, morphine, Demerol, Percodan and Tylenol 3 or 4.

"Our study suggests that heroin use has become an increasingly marginal form of drug use among illicit opioid users in Canada, especially outside Vancouver and Montreal," said Fischer.

Fischer also noted that in a large number of cases, prescription opioids used by street drug users originate from the medical system and not from illicit production and distribution.

"Our drug control policies ought to be targeting prescription opioid abuse more effectively," said Fischer. "But we also need to ensure we do not compromise legitimate access to and uses of prescription opioids."

The study is detailed in the Canadian Medical Association Journal.

Copyright 2006 by United Press International