The western, southeast and Appalachian regions of the United States lead the nation in the prescribing of opioid painkillers, according to new research published in The Journal of Pain.
In a study of 205 million opioid prescriptions written in 2008, researchers found that the number of physicians in a geographic area – not age, race or socioeconomic conditions – was the strongest predictor of how often opioids are prescribed.
The authors believe the wide variation in opioid prescribing was due in part to aggressive marketing by Purdue Pharma, the maker of OxyContin, an oxycodone formulation that was introduced in 1996.
“To market its extended release oxycodone, the pharmaceutical manufacturer mined prescription data to identify physicians who prescribed opioids with greater than average frequency (especially primary care physicians) and focused its sales efforts on them and the regions where they lived,” said lead author Douglas McDonald, PhD, of Abt Associates in Cambridge, Massachusetts.
Sales of OxyContin alone went from $48 million in 1996 to $1.1 billion in 2000. Several company executives later admitted they misled physicians and the public about the dangers of OxyContin by playing down its addictive and abusive side effects. The drug remains one of the most widely prescribed opioid painkillers.
According to researchers, the explosive growth in opioid prescribing occurred even though there was little evidence that the painkillers are safe and effective long term.
“The analgesic effectiveness of short-term opioid treatment for severe pain has been well established and widely accepted, but the evidence base for long term opioid treatment remains fragmentary to this day,” said McDonald. “Scientific studies have demonstrated that various chronic pain conditions, including neuropathic pain conditions, are opioid responsive, but the extent to which analgesic efficacy is maintained over the long term remains an open question. The evidence basis is also weak for making clinical decisions about other benefits of long-term treatment, such as quality of life and functional improvements.”
Nevada led the nation in opioid prescribing, with 1,150 morphine equivalent milligrams prescribed per resident, more than twice the national average. Midwestern states and Alaska had the lowest rates of prescribing.
The study found that hydrocodone formulations such as Vicodin accounted for over half (53%) of the opioid prescriptions in 2008, followed by oxycodone (21%).
About 85% of the prescriptions were paid for by Medicaid, Medicare or private insurers. The remainder (15%) was paid for in cash.
Many states have adopted prescription drug monitoring programs to prevent the abuse and diversion of painkillers. Contrary to earlier studies, the researchers found that monitoring programs had no impact on levels of opioid prescribing.