A new study finds that Canadian heroin addicts may be switching to prescription opiates like OxyContin, the National Post reported April 30.

Researchers said that the upside of the trend is that uses may be less likely to inject drugs -- cutting the risk of exposure to HIV and other infectious diseases; however, they also may be more apt to mix prescription opiates with other drugs, raising the risk of accidental overdose.

The research showed that 62 percent of opiate users were only using prescription drugs, not heroin. In some Canadian cities, heroin has virtually disappeared from the streets while prescription-drug abuse has risen. The prescription drugs have several advantages over heroin, experts say: they are cheaper, more available, and more pharmacologically pure.

"This is not a sideshow any more. In many communities, [prescription drugs are] the predominant form of opioid, if not overall street drug, use," said study lead author Benedikt Fischer of the British Columbia Center for Addictions Research. "These things are so abundantly available now, we are looking at multiple supply routes feeding this consumption. And these routes are a lot harder to define and grasp than heroin supply, which is very simple. I don't think our enforcement system has in any way caught up to this or thought about how to cope with it properly."

The study was published in the journal Drug and Alcohol Review.