Fewer than 5% of patients prescribed narcotics to treat chronic pain become addicted to the drugs, according to a new systematic review.
The finding suggests that concerns about the risk of becoming addicted to prescription painkillers might be "overblown," said addiction specialist Dr Michael Fleming at Northwestern University's Feinberg School of Medicine.
"If you're a person that doesn't have a history of addiction and doesn't have any major psychiatric problems, narcotics are relatively safe as long as your doctor doesn't give you too much and uses the right medication," Dr Fleming, who was not involved in the new study.
Some recent research has concluded the same thing, but another expert remained sceptical about the new report because many of the studies it included were not considered the best quality research, and they varied widely in their results.
"I think the jury's still out" on how worrisome prescription opioid addiction is, said Dr Joseph Boscarino of the Geisinger Clinic in Danville, Pennsylvania, who studies pain and addiction.
Dependent on painkillers
One recent study found that the number of people diagnosed with a substance abuse problem increased by 70% from 2001 to 2009, and doctors suspect the increased popularity of prescription painkillers is a primary driver.
Researchers from The Cochrane Collaboration collected results from 17 studies covering more than 88 000 people. All of the patients had been prescribed opioids to treat chronic pain, and nearly all of them had pain unrelated to cancer.
In 10 of the studies, patients used the painkillers for anywhere from three months to several years, while one study included just short-term use of several days and the others did not report the length of time patients were on the drugs.
Taken together, the studies found that 4.5% of people developed a dependency on the painkillers.
"It's a low percentage," said Dr Silvia Minozzi, lead author of the study and a member of the Cochrane Drugs and Alcohol Group in Rome.
Although 4.5% was the most common rate of addiction among the studies, Dr Minozzi pointed out there were large differences in the rates each study found - ranging from zero to 31%.
For instance, a study by Dr Boscarino and his colleagues that was included in Dr Minozzi's review found that 25% of patients became addicted.
The group of patients Dr Boscarino surveyed had a high rate of alcoholism and illegal drug use, though.
He said the disparities among the various studies could also be a result of how people were surveyed about their behaviours.
"We surveyed the patients about their pain in their homes (where) they were relaxed," he said. "I think they were more inclined not to try to hide their symptoms."
People with history at risk
Dr Minozzi's review found that, among the three studies with information on substance abuse, people with a history of drug use were more likely than other patients to develop an addiction to their prescription pain pills.
Addiction "does happen, but it's not very common," said Dr Fleming. "But if you give a big bottle of Percocets to someone who has an addiction history, who may or may not be using cocaine and marijuana at the same time, they have pain and maybe they should be treated, but they're much more likely to get into trouble with that."
Knowing this can help physicians screen patients to judge who might be the most vulnerable to becoming addicted and get them into the appropriate interventions, he said.
Dr Minozzi noted the fact that her review found a "deficiency of good-quality" studies on this subject, "seems to stand in contrast to the widespread concern of doctors and authorities relating to the prescription of opioids for pain."
(Reuters Health, November 2012)