Fibromyalgia

Structured Abstract

Background. Opioid-related harms are increasing among older adults. Until we better understand the factors contributing to this trend, we will be unable to design and implement effective interventions to optimally manage opioid use and its potential harms among older adults. Although considerable research has been done in younger or mixed-age populations, the degree to which it is directly applicable to older adults is uncertain.

Objectives. To provide a framework for understanding how to reduce adverse outcomes of opioid use among older adults, and to describe the evidence available for different factors associated with and interventions to reduce adverse outcomes related to opioid use in this population.

Approach. With input from a diverse panel of content experts and other stakeholders, we developed a conceptual framework and evidence map to characterize empirical studies of factors associated with opioid-related outcomes and interventions to reduce opioid-related harms in older adults. We identified relevant literature among older adults (age ≥60 years) for an evidence map by systematically searching PubMed, PsycINFO, and CINAHL for studies published in English between 2000 and May 6, 2020.

Findings. We identified 5,933 citations, from which we identified 41 studies with multivariable models of factors associated with opioid-related outcomes and 16 studies of interventions in older adults. More than half (22/41) of the multivariable analysis studies evaluated factors associated with long-term opioid use (which, though not a harm per se, may increase the risk of harms if not appropriately managed). Prior or early postoperative opioid use, or greater amounts of prescribed opioids (high number of opioid prescriptions or higher opioid dose), were consistently (100% agreement) and strongly (measure of association ≥2.0) associated with long-term opioid use. Back pain, depression, concomitant use of nonsteroidal anti-inflammatory drugs (NSAIDs), and fibromyalgia also had consistent, but weaker, associations with long-term opioid use. Several factors were mostly associated (>75% agreement) with long-term opioid use, including benzodiazepine use, comorbidity scores, (generally undefined) substance misuse, tobacco use, and low income. However, studies were mostly consistent that alcohol abuse and healthcare utilization were not associated with long-term opioid use. Gender, age among older adults, Black race, dementia, rural/nonurban residence, prescription of long-acting opioids, unmarried status, and use of muscle relaxants were variably associated (<75% agreement) with long-term opioid use.

Six studies examined factors associated with opioid-related disorders, although only one study evaluated factors associated with opioid use disorder. Alcohol misuse and gender were variably associated with opioid misuse (examined by three studies each).

All other evaluations of specific pairs of associated factors and outcomes of interest were evaluated by only one or two studies each. These included analyses of factors associated with multiple opioid prescribers, mental health outcomes, physical health outcomes, all-cause hospitalization, opioid-related hospitalization, nonopioid-specific hospitalization, emergency department visits, opioid overdose, all-cause death, opioid-related death, and nonopioid-related death.

The evidence on interventions directed at older adults is sparse. Of the 16 studies of opioid-related interventions in older adults, six examined screening tools to predict opioid-related harms, but none of these tools was tested in clinical practice to assess real-world results. Two studies found that prescription drug monitoring programs are associated with less opioid use in communities. Other studied interventions include multidisciplinary pain education for patients, an educational pamphlet for patients, implementation of an opioid safety initiative, provision of patient information and pain management training for clinicians, a bundle of educational modalities for clinicians, free prescription acetaminophen, a nationally mandated tamper-resistant opioid formulation, and motivational interview training for nursing students. Few intervention studies evaluated pain or other patient-centered outcomes such as disability and functioning.

Conclusions. The evidence base that is directly applicable to older adults who are prescribed opioids or have opioid-related disorders is limited. Fundamental research is necessary to determine which factors may predict clinically important, patient-centered, opioid-related outcomes. Studies to date have identified numerous possible factors associated with long-term opioid use (whether appropriate or not), but analyses of other opioid-related outcomes in older adults are relatively sparse. Research is also needed to identify interventions to reduce opioid prescribing where harms outweigh benefits (including screening tools), reduce opioid-related harms and disorders, and treat existing misuse or opioid use disorder among older adults.

Objectives. To evaluate the effectiveness and comparative effectiveness of nonopioid pharmacologic agents in patients with specific types of chronic pain, considering effects on pain, function, quality of life, and adverse events.

Data sources. Electronic databases (Ovid® MEDLINE®, Embase®, PsycINFO®, CINAHL®, Cochrane Central Register of Controlled Trials, and Cochrane Database of Systematic Reviews) through September 10, 2019, reference lists, data requests, and previous reviews.

Review methods. Randomized controlled trials (RCTs) of nonopioid pharmacologic agents in patients with chronic pain were selected using predefined criteria and dual review. This review focused on seven common chronic pain conditions (neuropathic pain, fibromyalgia, osteoarthritis, inflammatory arthritis, low back pain, chronic headache, sickle cell disease), with effects analyzed at short term (1 to <6 months following treatment completion), intermediate term (≥6 to <12 months), and long term (≥12 months). Magnitude of effects were described as small, moderate, or large using previously defined criteria, and strength of evidence was assessed. Meta-analyses were conducted where data allowed, stratified by duration within each intervention type, using random effects models. We evaluated effect modification through subgroup and sensitivity analyses, including specific drug, dose, study quality, and pain type.

Results. We included 185 RCTs in 221 publications and 5 systematic reviews. In the short term, anticonvulsants (pregabalin, gabapentin, and oxcarbazepine for neuropathic pain, pregabalin/gabapentin for fibromyalgia), serotonin-norepinephrine reuptake inhibitor (SNRI) antidepressants (duloxetine for neuropathic pain, fibromyalgia, osteoarthritis, and low back pain, milnacipran for fibromyalgia), and nonsteroidal anti-inflammatory drugs (NSAIDs) (for osteoarthritis and inflammatory arthritis) were associated with mostly small improvements (e.g., 5 to 20 points on a 0 to 100 scale) in pain and function. Function was not found to be improved with duloxetine for low back pain or pregabalin/gabapentin for neuropathic pain. Moderate improvement in quality of life was seen with duloxetine in patients with neuropathic pain, and small improvements in patients with osteoarthritis, but evidence was insufficient to draw conclusions for other drugs and conditions. While most comparisons of drugs and doses did not identify differences, diclofenac improved pain and function moderately more than celecoxib. In the intermediate term, limited evidence (1 RCT) showed memantine moderately improved pain, function, and quality of life in patients with fibromyalgia; improvements in pain, but not function, were maintained in the intermediate term with duloxetine and milnacipran for fibromyalgia. Other drugs studied, including acetaminophen (osteoarthritis), capsaicin (neuropathic pain), cannabis (neuropathic pain), amitriptyline (fibromyalgia, neuropathic pain), and cyclobenzaprine (fibromyalgia) had no clear effects. Withdrawal from study due to adverse events was significantly increased with nonopioid drugs, with the greatest increase over placebo seen with cannabis. Large increases in risk of adverse events were seen with pregabalin (blurred vision, cognitive effects, dizziness, peripheral edema, sedation, and weight gain), gabapentin (blurred vision, cognitive effects, sedation, weight gain), and cannabis (nausea, dizziness). Dose viii reductions reduced the risk of some adverse events with SNRI antidepressants. In the short term small increases in risk of major coronary events and moderate increases in serious gastrointestinal events (both short and long term) were found with NSAIDs.

Conclusions. In the short term, small improvements in pain and/or function were seen with SNRI antidepressants for neuropathic pain, fibromyalgia, osteoarthritis, and low back pain; pregabalin/gabapentin for neuropathic pain and fibromyalgia; oxcarbazepine for neuropathic pain; and NSAIDs for osteoarthritis and inflammatory arthritis. Improvement in function was not found with duloxetine for low back pain and pregabalin/gabapentin for neuropathic pain. Intermediate- and long-term outcomes were mostly not assessed. Increased incidence of drug class–specific adverse events led to withdrawal from treatment in some patients, suggesting that careful consideration of patient characteristics is needed in selecting nonopioid drug treatments.

Clinical bottom line

There is good evidence that duloxetine at doses of 60 or 120 mg daily helps some people with painful diabetic neuropathy or fibromyalgia. The NNT for one person to have at least 50% pain relief is about 6. Nausea, somnolence constipation and reduced appetite are common adverse events.