A new study found that "abuse resistant" oxycontin is forcing users to switch to heroin.
Oxycontin was redesigned in 2010 after its users found that they could crush the pill into powder and snort it for a faster, more powerful effect.
The new, abuse resistant drug was made much more difficult to crush, reported the Los Angeles Times.
The reformulation saw Oxycontin go from the primary drug of abuse for 36 percent of people who abuse prescription drugs to just 13 percent nearly two years later said Time.
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The study looked at more than 2500 opiod users from 2009 to 2012 with respondents sending surveys directly to the research team.
The authors expected a drop in oxycontin use but did not expect a rise in more potent opiods.
“But it appears that what they turned to was actually much more potent opioids,” like oxymorphone, hydromorphone, and fentanyl, said study author Theodore Cicero, a professor of psychiatry at Washington University in St. Louis, reported the Christian Science Monitor.
“A number also switched to heroin, which I think was the most unexpected finding."
The study was published in the New England Journal of Medicine.