By Robert Preidt
WEDNESDAY, April 1, 2015 (HealthDay News) -- Almost a quarter of powerful narcotic painkillers that are prescribed for chronic pain are misused, and the rate of addiction among patients hovers near 10 percent, a new review shows.
The findings raise questions about the benefits of widespread use of these painkillers to treat chronic pain, the researchers said.
"On average, misuse was documented in approximately one out of four or five patients, and addiction [was found] in approximately one out of 10 or 11 patients" prescribed the drugs as part of their treatment for chronic pain, wrote Kevin Vowles, from the University of New Mexico, and colleagues.
In the review, researchers analyzed 38 published studies, 35 of which were conducted in the United States.
The average rates of misuse were 21 percent to 29 percent, while the average rates of addiction were 8 percent to 12 percent, according to the review in the April issue of the journal Pain.
Narcotic painkiller prescriptions have risen sharply in the past 15 years, along with related problems such as dependence, withdrawal and overdose, the researchers said in a journal news release. These medications are also known as "opioids."
"If it is accurate that approximately one in four patients on opioids display patterns of opioid misuse, but not addiction, then perhaps more efficient targeting of treatment resources would be of benefit," the study authors wrote.
For example, education and monitoring could be used for patients at risk of misuse, instead of simply not giving them the medications.
Because of the high rates of misuse and addiction, the study authors added that they "are not certain that the benefits derived from opioids, which are rather unclear . . . compensate for this additional burden to patients and health-care systems."
To combat the misuse of narcotic painkillers, the U.S. Food and Drug Administration announced Wednesday final rules for drug makers seeking to have tamper-resistant, narcotic drugs approved. The FDA guidance outlines the studies manufacturers will have to undertake to prove their narcotic painkillers can't be altered and made into illegal drugs.
"This guidance is one of the many activities being done by the FDA to address opioid-related overdose and death," Dr. Douglas Throckmorton, deputy director of regulatory programs at the FDA's Center for Drug Evaluation and Research, said during a morning news conference.
The guidance specifies not only the kind of studies needed, but how the FDA will evaluate those studies and what labeling claims the agency may approve based on the results of those studies, Throckmorton said.
"The FDA is focused on the development of opioids with abuse-deterrent formulations," he said. "To combat opioid abuse and misuse, FDA is encouraging manufacturers to develop abuse-deterrent drugs that work correctly when taken as prescribed, but are formulated in such a way that someone cannot easily modify them for the purposes of abuse," he said.
In November, the FDA approved a new type of narcotic painkiller that's designed to help thwart abuse.
The painkiller, known as Hysingla ER (hydrocodone bitartrate), has features that should reduce abuse of the drug. According to the FDA, the tablet is difficult to crush, break or dissolve, making it tougher for abusers to snort or inject it.