Chronic Pain Is Poorly Managed in People with Opioid Use Disorder

A recent study shows that undertreatment of pain is common in those being treated at opioid use disorder treatment centers. Image credit: blojfo/123RF Stock Photo.

You might think that treating pain in people with an opioid use disorder (OUD) is a no-brainer, especially since pain is sometimes the reason why some people turn to opioids in the first place. But for many people in the United States living with chronic pain and OUD, treating pain is not a priority among healthcare providers working in substance use treatment programs, and is often given no attention at all – this according to a new study from researchers at Washington University School of Medicine in St. Louis, US.

Investigators led by Matthew Ellis, an epidemiologist and addiction researcher, show in survey research that while a third of people with OUD experienced chronic pain (pain persisting for three or more months), two-thirds of those with OUD and chronic pain reported inadequate management of their pain while enrolled in an OUD treatment program. Even more concerning, nearly 50% of those with pain said that their pain had actually worsened since they first started using opioids.

The results highlight an important gap in chronic pain treatment, in the context of OUD. They also point the way towards solutions to this urgent problem, including more teamwork in healthcare and improved education for treatment providers.

“This is an important study pointing to a need for coordinated care and improvement in the assessment and management of pain in substance use treatment programs to support people who have both chronic pain and opioid use disorder,” said Laura Murphy, an assistant professor at the University of Toronto, Canada, and a pharmacist.

The study was published in the April 2021 issue of the Journal of Pain.

Are people who use opioids and have chronic pain different from those who use opioids but have no history of pain?
Ellis said that the impetus for the new study was to raise awareness of the need to treat the accompanying pain and mental health problems that people with OUD often face (these accompanying conditions are known as co-morbidities).

The motivation for the research “was really to understand not only the extent to which there are gaps in co-morbid management in opioid addiction that lead to poor treatment outcomes – so as to bring more attention to this particular need among both pain and addiction medicine providers – but also to provide an understanding of the patient experience,” according to Ellis. “If patients say they are relapsing because of chronic pain, that their pain is worsening, that their medication-assisted treatment is benefiting their chronic pain, that they hope to use prescription opioids again – these are voices we need to be listening to.” (Medication-assisted treatment refers to the use of medications, along with counseling and behavioral therapies, to treat substance use disorders).

So, Ellis and his colleagues conducted two studies. The first used data from the Survey of Key Informants’ Patients (SKIP) program, which collects survey data from people newly entering a substance use treatment program for OUD across the United States. The new research ultimately included over 13,000 people from SKIP, who were asked to report their pain, demographic information, and their reasons for using opioids.

For their second study, the investigators conducted a smaller online survey of a subset of SKIP participants, including over 300 people who answered questions about the relationship between their chronic pain and opioid use.

Of the SKIP participants, more than one third-reported a history of chronic pain. Compared to opioid users without a history of chronic pain, opioid users with a history of chronic pain included a higher number of individuals who were women, older (35 and over), white, had completed education beyond high school, were on Medicare/Medicaid, and were less likely to be employed.

People with chronic pain and OUD were also more likely than those without pain to have first been exposed to opioids through a medical prescription (66% vs. 32%) and to have a psychiatric disorder. There were also differences in what drove people to use opioids. For those with chronic pain, self-medication for treatment of physical pain was the most common motivation; these individuals were also more likely to be motivated by alleviating/avoiding withdrawal pain, and to be self-medicating for psychological issues, among other factors. Getting a “high” was also a widely endorsed motivation to use opioids among those with pain but those without pain were more likely to be driven to use opioids for this reason.

Next, looking further at the perceptions and behaviors of opioid users with chronic pain, the investigators were able to validate their initial findings. Indeed, they saw that about two-thirds of those with chronic pain said they started using opioids because of their pain, with roughly half saying they used substances like marijuana and heroin for pain. Strikingly, about half said their pain was worse than when they began using opioids, and only a third said the pain was adequately managed by their treatment program. About 60% said they would stop taking opioids if the pain disappeared, while a fifth said they would still use opioids for pain after their current treatment program.

The barren landscape of pain management during OUD treatment
Drilling down into the management of pain in the OUD treatment center setting, the researchers saw that two-thirds of survey respondents didn’t receive treatment for their chronic pain.

Of those who did receive pain treatment, 75% received medications, with about one-third receiving opioids such as buprenorphine and methadone with the primary purpose of managing OUD. The current study revealed that those two drugs also relieved pain. Detailed guidelines on the use of buprenorphine and methadone for chronic pain management are scant.

Importantly, only one in five survey participants were offered non-drug approaches like talk therapy and exercise, exposing an important gap in the treatment of those with pain and OUD. This is particularly problematic considering that pain, OUD, and psychiatric conditions often occur together; in the current study, the researchers found that participants with OUD and chronic pain were more likely to have had a history of psychiatric treatment.

“To address the comorbid pain, psychiatric conditions and OUD, a coordinated, patient-centered, biopsychosocial approach is best,” said Murphy,  who was referring to the perspective that biological, psychological and social factors all contribute to pain. “Rather than treating OUD in a silo, including people’s pharmacist and general practitioner in a collaborative team offers care that can address their pain, OUD, and psychiatric condition together,” according to Murphy.

Finally, nearly 75% of those who took part in the smaller follow-up study had at least one relapse, with nearly half attributing their relapse to pain.

“When individuals leave their OUD program, they aren’t prepared to manage their pain. In some cases, people may actually be re-prescribed opioids to manage their symptoms,” said Ellis.

Seeking explanations
So what explains the poor management of pain in the setting of OUD? “My job is to treat addiction, not pain,” Ellis recalls a health-care provider saying during some of his other research.

Indeed, pain and addiction are often viewed as independent issues requiring separate treatment, rather than being handled simultaneously. Both Ellis and Murphy pointed to a lack of education as one underlying issue.

“Pain management and addiction are currently not taught together in medical school although I think it should be integrated at the beginning of training,” Ellis said. Without this training, doctors are ill-equipped to recognize and treat pain in the context of OUD.

Another obstacle to adequate pain management in OUD treatment is poor communication between different health care providers. Murphy highlighted the “need for interprofessional care at the forefront of OUD treatment to address this. Healthcare workers should work together, rather than in parallel, to achieve the common goal of treating the patient.”

Having patients be partners on the healthcare team is also crucial, particularly in light of the negative experience many of them have in the healthcare system. “Those with OUD and chronic pain are a vulnerable population of individuals who are highly stigmatized,” Murphy said. Including patients as true partners, and empowering them to make decisions about their own healthcare, are ways to overcome this problem.

In the end, Ellis suggested that “a continuum of care be provided to support those individuals with OUD and chronic pain after OUD treatment, in order to ensure that they have the toolkit and support to manage both.”

Danielle Perro is a DPhil candidate at the University of Oxford, UK.