By Pat Anson, Editor
Dispensing of opioid pain relievers and painkiller overdoses both declined substantially after an abuse-deterrent formula of OxyContin was introduced and the painkiller propoxyphene was withdrawn from the U.S. market in 2010, according to a new study published online in JAMA Internal Medicine.
The study is another indication there has been a reversal in the growth of opioid prescribing – which has long been blamed for the so-called “epidemic” of prescription drug abuse. Last week another study was released showing that the painkiller hydrocodone was no longer the most-widely prescribed drug in the U.S.
Researchers analyzed claims from over 31 million members of a large national health insurer, and estimated that by 2012 total opioid dispensing declined by 19% and the overdose rate dropped by 20 percent. The drop in prescription opioid overdoses was partially offset by a 23% increase in overdoses due to heroin.
“Our results have significant implications for policymakers and health care professions grappling with the epidemic of opioid abuse and overdose,” said lead author Marc Larochelle, MD, of the Harvard Medical School and Boston University School of Medicine.
"Changes imposed through regulatory mandates or voluntary company actions may be a viable approach to stemming prescription abuse. However, identifying interventions that reduce opioid supply without affecting access to individuals who benefit from opioid therapy remains a challenge.”
Propoxyphene (also known as Darvon) was voluntarily withdrawn from the U.S. market after data emerged about its cardiac toxic effects.
The abuse-deterrent formula of OxyContin introduced by Purdue Pharma in 2010 is harder for drug abusers to crush or dissolve for snorting or injecting. Researchers said the prescribing of OxyContin and other extended released oxycodone products dropped by 39% in the two years after the formulation change.
They noted there was “minimal” evidence that people switched to other pain medications because of the formulation change – an indication they weren’t taking OxyContin for pain relief.
"These results suggest that many people who were prescribed OxyContin before it was reformulated may have been diverting or misusing the drug," said Larochelle. "Given the decreased supply of prescription opioids, those seeking out an opioid could be turning to heroin, which may partially explain the tremendous increase in heroin overdose deaths over the past few years both locally and nationally."
“This study parallels other independent and internal research that shows reformulated OxyContin is associated with a reduction in abuse,” Purdue Pharma said in a statement.
“We agree with the FDA, the U.S. Drug Enforcement Administration, The White House Office of National Drug Control Policy and many federal and state policymakers that abuse-deterrent formulations are a valuable public health tool that must be part of any comprehensive approach to combatting prescription drug abuse.”
The study also suggests that legitimate pain patients were not the ones abusing opioids.
“Most overdoses do not occur among patients who are receiving daily prescribed opioids or among those receiving the highest doses,” said Hillary Kunins, MD, of the New York City Department of Health and Mental Hygiene in an editorial also published in JAMA Internal Medicine.
"Recasting the often-maligned 'doctor-shopper' instead as a patient with a substance use disorder reminds us that using public health strategies to promote judicious opioid prescribing, including via pharmaceutical market change to reduce overdose risk, needs to be accompanied by similar policy approaches to provide accessible and effective services for people who use drugs.”