Fibromyalgia May Predict Pain-related Worsening of Opioid Use Disorder, Say Authors of New Study

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A new study provides the first evidence of fibromyalgia as a potential risk factor for pain-related exacerbation of opioid use disorder (OUD) and introduces a new scale that may help clinicians identify patients with pain and OUD at high risk for the dangerous exacerbations.

"Fibromyalgia and opioid use disorder are highly burdensome chronic diseases with substantially overlapping psychosocial, neurobiological and clinical features,” wrote first author Orman Trent Hall, DO, clinical assistant professor of psychiatry and behavioral health at Wexner Medical Center at The Ohio State University, and colleagues in the journal Pain.

“Recently, our group discovered differences in self-report of pain-motivated maintenance, escalation, treatment delay, and fear of relapse based on an established measure of fibromyalgia in a clinical sample of patients with OUD,” continued authors. That research, they say, studied only group differences and not how fibromyalgia affects the odds of acknowledging pain-related OUD exacerbation among individuals with pain and OUD. Hall and colleagues designed the current study with that objective.

The researchers recruited 125 adults aged 18-88 years between July 2021 and December 2021 from an academic substance use treatment facility. Participants completed the 2011 American College of Rheumatology Fibromyalgia Survey (ACR-FMS), a validated self-report questionnaire that assesses bodily pain and related symptoms, as well as a novel scale created by the investigators specifically for this study. The 4-item Pain-related OUD Exacerbation Scale (PrOUD ES) measures pain-related maintenance of OUD, escalation of OUD, treatment delay, and fear of pain-precipitated relapse. Participants indicate agreement or disagreement with statements corresponding to each item.

Mental health and body pain status were measured via the Research and Development 36-item health survey (RAND-36).

Among the 117 participants that provided demographic information, 49 were women, 68 were men, and 113 indicated non-Hispanic ethnicity.

Findings

Results showed all participants reported pain in at least 1 body region, with lower back pain the most frequently reported (n=99, 79.2%), followed by neck (n=45, 36%), and upper back pain (n=43, 34.4%). The mean number of body regions with pain was 3.69.

Moderate to severe cognitive symptoms, fatigue, or feeling unrefreshed upon waking were reported in 46.4%, 65.6%, and 69.6% of participants, respectively. Nearly one-third of participants (31.2%) had an ACR-FMS score of at least 13, which indicated that they met survey criteria for fibromyalgia, according to investigators.

Although all participants had some type of pain, those with fibromyalgia had significantly greater odds of strongly agreeing with the following statements from the PrOUD ES, in effect acknowledging pain-related OUD exacerbations:

• “Pain is a major reason why I have kept using opioids.” (Maintenance)
• “I find myself needing more and more opioids to control my pain.” (Escalation)
• “I have put off getting treatment for opioid use disorder because I am afraid my pain will be worse when I stop using opioids.” (Treatment delay)
• “I am worried pain will cause me to relapse in the future.” (Fear of pain-precipitated relapse)

For example, Hall et al report that the odds of strongly agreeing with the statement “I find myself needing more and more opioids to control my pain” was 4.43 (95% CI, 1.98-9.92) times higher among participants identified as having fibromyalgia.

Fibromyalgia was also associated with significantly increased odds of pain-related OUD maintenance (2.31, 95% CI, 1.08-4.92).

“We have demonstrated a promising new scale for measuring pain-related OUD exacerbations (PrOUD ES), as well as a novel methodology for studying fibromyalgia in OUD treatment settings where practitioners may lack specialized knowledge of musculoskeletal pain conditions,” concluded Hall et al. “American College of Rheumatology Fibromyalgia Survey and PrOUD ES may be considered for use as patient-reported outcome measures in OUD research. Additional studies are needed to further assess the psychometric properties of PrOUD ES and its relationship to pain catastrophizing.”

“The American College of Rheumatology Fibromyalgia Survey might be useful in epidemiological and community-based studies of OUD, including among non–treatment-seeking populations, to establish the role of fibromyalgia in OUD,” continued authors. “Although additional research is needed, these instruments might be useful for identifying patients at risk of pain-related OUD exacerbations.”

Reference: Hall OT, Teater J, Entrup P, et al. Fibromyalgia predicts increased odds of pain-related addiction exacerbation among individuals with pain and opioid use disorder. Pain. Published online March 14, 2023. doi:10.1097/j.pain.0000000000002878.