SYDNEY, May 26 (UPI) -- Although the drugs can have some short-term effects, opioid-based painkillers such as oxycodone and Percocet have largely minimal effects on chronic lower back pain unrelated to other injuries, according to researchers in Australia.
Opioid painkillers are often prescribed for chronic back pain but researchers at The George Institute found in a review of studies that the drugs do not always work for patients, and many participants in studies drop out because any benefits are outweighed by side effects.
The causes for lower back pain not linked to an injury or other condition can be difficult to determine, according to doctors, and the evidence that opioid drugs, or any others, alleviate symptoms of the condition is weak at best.
The U.S. Centers for Disease Control changed its recommendations for opioid drugs earlier this year, suggesting chronic pain patients are at higher risk to develop a dependence on the drugs while their conditions are unaffected.
The agency also cited a lack of long-term studies on the drugs examining their positive or negative effects, posing a potential concern for patients with chronic conditions.
Researchers in the new study, as well as CDC scientists, suggest pairing opioid drugs on a short-term basis with other forms of pain management, including non-pharmaceutical therapies, if opioids are to be used at all.
"We do not yet understand the effects of the long term use of opioid analgesics, as no trials have followed up patients beyond 3 months," Dr. Andrew McLachlan, a professor at the University of Sydney, said in a press release."Importantly, we do know that these medicines can have significant harmful effects when used inappropriately or for longer periods of time. The recent CDC guideline for prescribing opioids for chronic pain provides some excellent advice for clinicians considering use of opioid analgesics for their patients."
For the study, published in JAMA Internal Medicine, researchers reviewed the results of 20 randomized, controlled trials with a total of 7,925 participants.
Of these, 13 trials looked at the short-term effects of opioids on chronic low back pain, and none of the placebo-controlled trials included patients with acute low back pain. At least half of participants in these trials withdrew because the drugs did not work or they experience adverse health events.
Overall, the studies showed opioids can benefit chronic low back pain patients on a short-term basis, but that even at doses much higher than recommended the benefits are moderate.
With eight of 10 people who abuse painkillers saying they do so for pain management, and a strong link already established between chronic pain treatment and prescription drug abuse, Australian researchers say finding other, more effective methods of treatment is warranted.
"People have the mistaken belief that opioids are strong pain killers," said Dr. Chris Maher, a professor at Sydney Medical School and director of the musculoskeletal division at The George Institute. "When you look closely at the evidence from the low back pain trials, a completely different picture emerges."