Influential Minnesota study finds that opioids are no better for long-term pain

An influential study on opioid painkillers by the Minneapolis VA has gained a national platform, where its findings on the effectiveness of the potentially addictive drugs vs. alternatives are likely to shape federal and state policy governing use and abuse of prescription medications.

The study's headline finding remains the same as when Dr. Erin Krebs presented it last spring at the Minneapolis VA Medical Center: Setting aside their potential side effects and risks, opioid painkillers are no more effective than safer alternatives in long-term treatment of patients with chronic pain in their backs, hips or knees.

But Tuesday's publication of the full results in the Journal of the American Medical Association could have additional impact, Krebs said, because policymakers nationally have had little comparative data on whether opioids work well enough to justify their risks.

"People have been making recommendations mostly based on the harms, just knowing these medications were much more risky than other treatment options," Krebs said. "This [study] is really what a lot of people were waiting for."

The study was one of the first comparative trials of opioid painkillers in the United States — assigning 120 military veterans to take opioids for chronic joint pain for one year, and another 120 to manage their pain with alternatives such as acetaminophen and nonsteroidal anti-inflammatory drugs. Participants were free to pursue physical therapy and other nonsurgical options to address their pain.

According to the results published Tuesday, veterans in both groups had similar success, on average, in managing pain and maintaining daily activities for the first six months. But after nine months, patients in the opioid group reported no further progress in reducing the intensity of their pain, while patients in the comparison group showed continued improvement.

One possibility is that patients in the opioid group developed tolerance to the drugs, Krebs said. "That happens with opioids and not with other pain medications."

Patients taking opioids reported a greater reduction in anxiety over 12 months, though the difference was small, Krebs said.

"It might be why some people say they feel a little bit better on opioids, because they take the edge off that feeling" of anxiety.

Prescription opioid abuse has triggered national alarm, in part because the drugs have been linked to a rapid increase in drug overdose deaths — either because people misused the prescription drugs themselves, or because the painkillers served as gateway drugs that led people to try illicit drugs such as heroin.

Minnesota recorded 402 deaths in 2016 linked to opioids — more than twice the total in 2006, according to a Star Tribune review of death certificate records.

Late last year, a state opioid task force adopted recommendations advising Minnesota prescribers to refrain from starting patients on opioids for long-term chronic pain, due to the lack of evidence that they work for this purpose.

Most states have taken steps to address opioid misuse, such as identifying patients with excessive prescriptions or doctors with liberal prescribing practices. Many are still weighing whether to restrict dosages that prescribers can issue, and what to do for patients already dependent on opioids.

The VA trial addressed only long-term use, not opioid prescriptions for acute pain or immediately following medical procedures.

Participants taking opioids were much more likely to report side effects caused by their drugs, the study showed, but there were no substantial differences in other complications or drug-related ER visits or hospital admissions.

Despite the potential addictiveness of the opioids, the study reported no incidents of patients in the opioid group developing addictions or trying to "doctor shop" to gain additional medications.

Krebs said that could reflect the fact that the study did not enroll patients with addiction histories, and because the VA provided close supervision to all participants during the yearlong study.

"We were keeping pretty close tabs on people," she said. "Which is actually how you should do it [when prescribing opioids to a patient], but it's not how it is done."

A key finding is that people with chronic pain need patience as their medications are fine-tuned, Krebs said. Participants in the non-opioid group tried four different medications during the year.

"You have to do some careful trial and error to find what's going to work," she said. "Moving to opioids isn't likely to be the answer."

Jeremy Olson • 612-673-7744