Everybody Hurts: Researchers find painkillers don’t solve long-term problems
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How likely are you to get hooked if you start taking prescription painkillers?
As I explained last week, there’s limited evidence available in large part because it is so difficult to study addiction. Most studies of painkillers focus on whether they work; whether they are addictive is logged merely as a side effect.
One study that is often cited by those who question using opioids to treat chronic pain was published in the Annals of Internal Medicine in 2007 by Dr. Bridget A. Martell, an associate clinical professor of medicine at Yale, and colleagues.
It was recommended to me by Dr. Andrew Kolodny, chief medical officer at Phoenix House Foundation in New York, a nonprofit chain of treatment centers, who thinks that painkillers are prescribed too frequently for chronic pain.
See Also: What Are the True Addiction Risks of Pain Medicine?
Here’s what Martell and her colleagues did. They looked at Medline, EMBASE, and Psychinfo for studies and information on opioids being used for treating back pain from 1966 through March 2005. They also looked at the Cochrane Central Register of Controlled Clinical Trials, which was current through the end of 2004. They then performed a systematic analysis and review of all the findings to draw conclusions. What were they trying to find out? They narrowed it down to three questions.
- What is the prevalence of opioid treatment in patients with chronic back pain?
- Are opioid medications effective in treating chronic back pain?
- What is the prevalence of substance use disorders among patients receiving opioid medications for chronic back pain?
One key conclusion – not related to addiction but nonetheless important – was that “meta-analysis of the 4 studies assessing the efficacy of opioids compared with placebo or a nonopioid control did not show reduced pain with opioids.”
They explain further:
Our review and meta-analysis has revealed that opioids are commonly prescribed for but may only be efficacious for short-term treatment for chronic back pain (16 weeks). … Our findings are not consistent with previous reviews on the efficacy of opioids for chronic back pain. Opioids, in some instances, have been found to be efficacious for treatment for painful conditions. Our review, however, found that the evidence in favor of opioids is not always consistent, and when supportive, only supports this treatment for short periods (for example, 4 months). Long-term trials of opioid efficacy for chronic back pain are lacking, and there is other evidence that indicates that the long-term efficacy of opioids for chronic pain may be limited.
And here’s what else they found:
The prevalence of lifetime substance use disorders ranged from 36% to 56%, and the estimates of the prevalence of current substance use disorders were as high as 43%. Aberrant medication-taking behaviors ranged from 5% to 24%.
There are some big caveats with both of these findings. First, as the paper points out, the studies on the whole were weak, so weak that very few of them made it into the final analysis. Out of 1,630 studies identified by the researchers, only 38 made the cut. Those that were left behind didn’t meet the researchers criteria, including whether they addressed addiction or substance use disorders or if opioid treatment efficacy was addressed.
Even the final 38 had problems. I noted last week that Cochrane found few studies that covered opioid use longer than one year. In the case of the evidence reviewed by Martell, “No trial evaluating the efficacy of opioids was longer than 16 weeks.”
Here’s another caveat. The researchers only looked at studies where there was “no pre-existing diagnosis of opioid dependence." And, of those 38 studies, just five “reported the prevalence of aberrant medication-taking behaviors.” The researchers were not convinced that these five studies had the numbers right, either: “[O]nly 1 study attempted to use a combination of behaviors that might be consistent with medication abuse.”
Still, the researchers felt that their digging had turned up enough evidence to warrant challenging the idea that opioids are a good treatment for long-term back pain. The researchers ended with a plea for better scientific inquiry into addiction.
Despite the acceptance of opioid treatment as routine care for chronic back pain, this systematic review cannot provide unequivocal evidence that opioids are efficacious for such treatment. In addition, well-designed trials describing the true prevalence of substance use disorders among patients receiving opioids for chronic back pain are lacking. This is a conundrum for the practicing physician. With reports of increased abuse of prescription opioids, especially with long-acting formulations, physicians, policymakers, and regulators are concerned that long-term opioid therapy can result in dependence. … The findings in this review suggest that clinicians should reconsider treating chronic back pain with opioid medications, and consider other treatments with similar benefit yet fewer long-term adverse effects. In addition, because of the state of the science in this field and the limitations we have noted, future research is needed to guide this common and often vexing management issue.
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