Opiate prescriptions and overdoses in the U.S. have declined since the debut of an abuse-resistant version of the painkiller OxyContin and the market withdrawal of the narcotic Darvon, a study finds. 

Researchers reviewed insurance claims records with data on prescriptions and hospitalizations for more than 30 million adults covered by UnitedHealthCare from 2003 to 2012. In the two years after OxyContin was reformulated and Darvon was withdrawn in 2010, prescriptions and overdoses both decreased about 20 percent.

"The weight of evidence to date suggests that abuse of OxyContin decreased after the formulation change," said lead researcher Marc Larochelle of Boston University School of Medicine and Boston Medical Center, in an email.

Larochelle and colleagues write in JAMA Internal Medicine that the abuse-deterrent OxyContin formulation (extended-release oxycodone hydrochloride) is resistant to crushing and dissolving, actions that have been used to bypass the extended-release action for a faster, more intense high. And before coming off the market, Darvon (propoxyphene) was linked to cardiac side effects and was the second-leading cause of prescription drug-related deaths.

The research team analyzed prescriptions filled for all opioid painkillers by adults with Optum insurance and found that the average dose declined after 2010.

Opioid overdoses also fell, based on hospital records. But heroin overdoses, while rare, increased after 2010, the study found.

"Abuse-deterrent formulations can represent only a portion of a comprehensive strategy to tackle the opioid epidemic we are facing," Larochelle said.

Public health outreach is a critical component, said Dr. Hillary Kunins of the New York City Department of Health and Mental Hygiene's division devoted to substance abuse prevention and treatment. In New York, campaigns to educate patients about the dangers of opioids and to get doctors to prescribe the smallest doses possible for the shortest periods of time have both helped to address abuse, as have treatment programs for addicts, she told Reuters Health.

"Making tamper-resistant forms of the long-acting opioids available is one part of a larger strategy," said Kunins, who wrote an editorial accompanying the study. "They help reduce the risk of overdose among people who may be misusing the medication because they have already developed an addiction, but this does not prevent the development of addiction."

Still, the study findings add to a growing body of evidence linking the tamper-resistant version of OxyContin to a decline in misuse, said Dr. Andrew Rosenblum, director of the Institute for Treatment and Services Research at the National Development and Research Institutes in New York.

Some of the uptick in heroin overdoses might be due to heroin’s cheaper cost and easier availability than prescription opioids in many parts of the U.S., Rosenblum, who wasn't involved in the current study, said by email.

Reducing prescriptions is key to curbing addiction and overdoses, he said. "Misuse of prescription opioids can lead to opioid addiction. We are likely to see fewer people misusing and becoming addicted to prescription opioids due to systemic interventions such as prescribing monitoring plans and abuse-deterrent medications."