This has occurred after introduction of an abuse-deterrent version.
The rate of OxyContin overdoses dropped 19 percent in the two years after the company that makes the drug introduced an abuse-deterrent formulation in 2010, a new study finds.
Prescriptions of the drug decreased 19 percent after the new version was released.
During the same period, the rate of heroin overdoses increased 23 percent, HealthDay reports.
The findings are published in JAMA Internal Medicine.
"This is the first time in the last two decades that narcotic prescribing had dropped, rather than continued to increase," said lead researcher Dr. Marc Larochelle of Boston University School of Medicine. "Some were skeptical that simply decreasing supply would lead to a decrease in overdoses, but we did find that," he added.
"Reducing supply may have led some people who are abusing these drugs to substitute an illicit narcotic like heroin, and it may partially explain why we have seen an explosion in heroin use across the country," Larochelle said.
The drop in OxyContin prescriptions could be due to fewer people abusing the drug or selling it on the street, he noted.
The original version of OxyContin contained highly concentrated levels of the opioid oxycodone, which was designed so small amounts of the drug were released over a long period. A person who wanted to abuse the drug could crush and then snort it, or dissolve it in liquid and inject it.
The Food and Drug Administration approved an abuse-deterrent version of OxyContin, which is more difficult to crush. It turns into a gooey gel if it is crushed, making it almost impossible to snort or inject.
A study published last month found up to one-fourth of people entering drug rehabilitation programs say they have abused the abuse-deterrent version of OxyContin.