By Pat Anson, Editor

Overdoses from opioid painkillers occur frequently in people who are taking relatively small doses over a short period of time, according to a new study that has some experts calling for more restrictions on opioid prescribing.

Researchers at the University of Washington School of Public Health analyzed Medicaid data on over 2,200 opioid overdoses in Washington State between 2006 and 2010 – and found that many patients didn’t fit the usual profile of a long term opioid user taking high doses of pain medication.

The study, published in the journal Medical Care, found that less than half of the patients were “chronic users” who had been prescribed opioids for more than 90 days.

Only 17% percent of the overdoses involved patients taking a high morphine-equivalent dose of over 120 mg per day -- what is considered a "yellow flag" in Washington State for possible opioid abuse.

Surprisingly, nearly three out of ten (28%) patients who overdosed were taking a relatively low opioid dose of just 50 mg per day.

Sedatives were involved in nearly half of the overdoses and methadone in about a third of them.

In 2007, Washington State adopted some of the toughest regulations in the country on opioid prescribing -- guidelines that the researchers believe should be even more restrictive.

"It may be prudent to revise guidelines to also address opioid poisonings occurring at relatively low prescribed doses and with acute and intermittent opioid use, in addition to chronic, high-dose use," said lead author Deborah Fulton-Kehoe, PhD, a research scientist in the Department of Environmental and Occupational Health Sciences at the University of Washington School of Public Health in Seattle.

Based on the recommendations of this and other studies, Washington State’s Interagency Guideline on Prescribing Opioids for Pain was recently revised to caution doctors about prescribing opioids at any dose. The new guidelines extend to the treatment of acute pain, not just chronic pain. Physicians are also advised not to continue prescribing opioids to a patient if they don't show “clinically meaningful improvement” in physical function, in addition to pain relief.

While the overdose study focused on only one state, one expert says it has national and even global implications.

“The article notes that many overdoses occur when patients are prescribed medications at low doses. This has important implications for national policy and debate,” said  Dr. Jeroan Allison of University of Massachusetts Medical School, who is co-editor-in-chief of Medical Care. "The statistics are quite overwhelming and dramatic, and this problem affects every state in our nation."

According to the Centers for Disease Control, over 16,500 deaths in the U.S. were linked to opioid overdoses in 2010.

More recent data suggest that the “epidemic” of painkiller abuse is abating.

Hydrocodone prescriptions fell by 8% last year and it is no longer the most widely prescribed medication in the U.S.

A recent report by a large national health insurer found that total opioid dispensing declined by 19% from 2010 to 2012 and the overdose rate dropped by 20 percent.

According to the National Institutes of Health, only about 5% of patients taking opioids as directed for a year end up with an addiction problem.