Functional disability among chronic pain patients receiving long-term opioid treatment

Identifying Predictive Characteristics of Opioid Medication Use among a Nationally Representative Sample of United States Older Adults with Pain and Comorbid Hypertension or Hypercholesterolemia

The prevalence of older adults with pain and comorbid cardiovascular conditions is increasing in the United States (U.S.). This retrospective, cross-sectional database study used 2017 Medical Expenditure Panel Survey data and hierarchical logistic regression models to identify predictive characteristics of opioid use among a nationally representative sample of older U.S. adults (aged ≥50 years) with pain in the past four weeks and comorbid hypertension (pain-hypertension group) or hypercholesterolemia (pain-hypercholesterolemia group). The pain-hypertension group included 2733 subjects (n = 803 opioid users) and the pain-hypercholesterolemia group included 2796 subjects (n = 795 opioid users). In both groups, predictors of opioid use included: White race versus others, Hispanic versus non-Hispanic ethnicity, 1 versus ≥5 chronic conditions, little/moderate versus quite a bit/extreme pain, good versus fair/poor perceived mental health, functional limitation versus no functional limitation, smoker versus non-smoker, and Northeast versus West census region. In addition, Midwest versus West census region was a predictor in the pain-hypertension group, and 4 versus ≥5 chronic conditions was a predictor in the pain-hypercholesterolemia group. In conclusion, several characteristics of older U.S. adults with pain and comorbid hypertension or hypercholesterolemia were predictive of opioid use. These characteristics could be addressed to optimize individuals' pain management and help address the opioid overdose epidemic.

Relationship Between Opioid Analgesic Prescription and Unemployment in Patients Seeking Acupuncture for Chronic Pain in Urban Primary Care

OBJECTIVE

The widespread use of opioid analgesics to treat chronic nonmalignant pain has contributed to the ongoing epidemic of opioid-related morbidity and mortality. Previous studies have also demonstrated a relationship between opioid analgesic use and unemployment due to disability. These studies have been limited to mainly white European and North American populations. The objective of this study is to explore the relationship between opioid analgesic use for chronic nonmalignant pain in an urban, mainly black and Hispanic, low-income population.

DESIGN

This is a cross-sectional observational study.

SETTING

Subjects were recruited from six urban primary care health centers.

SUBJECTS

Adults with chronic neck, back, or osteoarthritis pain participating in an acupuncture trial were included.

METHODS

Survey data were collected as a part of the Acupuncture Approaches to Decrease Disparities in Pain Treatment two-arm (AADDOPT-2) comparative effectiveness trial. Participants completed a baseline survey including employment status, opioid analgesic use, the Brief Pain Inventory, the global Patient Reported Outcomes Measurement Information Systems quality of life measure, the Patient Health Questionnaire-9 (PHQ-9), and demographic information. A multivariable logistic regression model was built to examine the association between opioid analgesic use and unemployment.

RESULTS

Opioid analgesic use was associated with three times the odds of unemployment due to disability while controlling for potential confounders, including depression, pain severity, pain interference, global physical and mental functioning, and demographic characteristics.

CONCLUSIONS

This study adds to the growing body of evidence that opioid analgesics should be used with caution in chronic nonmalignant pain.

A theoretically guided approach to identifying predictors of treatment outcome in Contextual Cognitive Behavioural Therapy for chronic pain

BACKGROUND

Psychological treatments are known to be effective for chronic pain, but little is understood about which patients are most likely to benefit from which ones.

METHODS

The study reported here included 609 people who attended a residential, interdisciplinary, pain management programme based on Acceptance and Commitment Therapy between January 2012 and August 2014. A flexible and theoretically guided approach to model building based on fractional polynomials was used to identify potential predictors of outcome in domains of emotional, physical and social functioning and pain intensity. Variables considered for inclusion were baseline demographic variables along with measures reflecting processes of psychological flexibility, including acceptance, cognitive defusion and committed action.

RESULTS

Employment status, level of distress, decentring (a process like cognitive defusion) and acceptance significantly contributed to the model above and beyond the effects of other baseline variables. The unique effects of these were small but may be clinically relevant.

CONCLUSIONS

Future research should continue to investigate moderators of treatment outcome and to explicitly link these to treatment mechanisms. Taking a flexible, theoretically driven approach to modelling continuous outcomes may be valuable in furthering our understanding of which patients might respond best to which treatments.

SIGNIFICANCE

Further research is needed to better understand who benefits most from psychological treatments for chronic pain. This study suggests that a flexible, multivariate and theoretical approach to identifying predictors of outcome may be valuable in furthering research in this area.

Persistent inflammatory pain alters sexually-motivated behavior in male rats

Urine from pro-œstrus female rodents evokes increased levels of sexually-motivated behaviors in males, including sniffing and scent marking of the urine spot as well as activation of brain reward regions. Stressors such as social defeat can adversely impact urine scent marking behavior in male rodents, an effect that can be mitigated with anti-depressant drugs. Persistent pain is also known to be a potent stressor, producing elevated levels of plasma corticosterone as well as reduced sucrose preference and reduced social interaction. However, the effect of persistent pain on sexually-motivated behavior is unknown. Here, we compared urine scent marking behavior in male rats for up to 3 weeks following intra-articular injection of Complete Freund’s Adjuvant (CFA) or sham injection. CFA-injected rats exhibited profound and ongoing deficits in static weight bearing capacity. CFA-induced persistent inflammatory pain increased plasma corticosterone levels and reduced urine scent marking behavior in male rats. Moreover, while the vast majority of injured rats showed decreased urine scent marking preference for the pro-œstrus female urine spot, male rats with higher baseline scent marking preference also exhibited higher post-injury scent marking preference, more sniffing behavior and lower levels of plasma corticosterone, compared to those with lower baseline scent marking preference. Overall, scent marking behavior may be an ethologically relevant behavioral predictor of persistent pain-induced stress in rats, representing a novel translational approach to understanding chronic pain comorbidities.

Chronic musculoskeletal pain in European older adults: Cross-national and gender differences

BACKGROUND

In an ageing Europe, chronic pain is a major public health problem, but robust epidemiological data are scarce. This study aimed to analyse the prevalence of and factors associated with chronic musculoskeletal pain by gender in older adults of 14 European countries.

METHODS

A cross-sectional study was performed from wave 5 of the Survey of Health, Ageing and Retirement in Europe (SHARE). The study included people ≥50 years residing in Austria, Belgium, Czech Republic, Denmark, Estonia, France, Germany, Italy, Luxembourg, the Netherlands, Slovenia, Spain, Sweden and Switzerland. Chronic pain was defined as being bothered by joint and/or back pain for the previous 6 months. Multivariable Poisson regression models with robust variance were performed to analyse prevalence ratio by covariates, stratified by sex.

RESULTS

A total of 61,157 participants were included. Overall prevalence of chronic musculoskeletal pain was 35.7% (28.8-31.7), ranging from 18.6% (17.1-20.1) for Switzerland to 45.6% (43.3-47.8) for France. Prevalence was higher in women than in men: 41.3% (40.2-42.4) versus 29.1% (28.0-30.3). Chronic musculoskeletal pain was lower in men aged >75 years (PR = 0.82; 0.72-0.92) than the younger (50-59) group. Separated/divorced status presented opposite effects among men (PR = 0.85; 0.76-0.96) and women (PR = 1.12; 1.03-1.21) compared with married, and unemployment was a significant factor in men (PR = 1.21; 95% CI 1.02-1.43) compared with employed.

CONCLUSIONS

Musculoskeletal pain in older European adults is very frequent, especially in women, with large differences depending on the country of residence. Health policy makers should prioritize strategies aimed at improving the prevention and management of chronic musculoskeletal pain in Europe.

SIGNIFICANCE

This study provides epidemiological data of chronic musculoskeletal pain in older adults. Reported differences contribute to highlight the relevance of considering a gender perspective in chronic musculoskeletal pain research. Cross-national comparison also offers a map of differences that improves the knowledge of this chronic condition in Europe.

Tapering Long-term Opioid Therapy in Chronic Noncancer Pain: Evidence and Recommendations for Everyday Practice

Increasing concern about the risks and limited evidence supporting the therapeutic benefit of long-term opioid therapy for chronic noncancer pain are leading prescribers to consider discontinuing the use of opioids. In addition to overt addiction or diversion, the presence of adverse effects, diminishing analgesia, reduced function and quality of life, or the absence of progress toward functional goals can justify an attempt at weaning patients from long-term opioid therapy. However, discontinuing opioid therapy is often hindered by patients' psychiatric comorbidities and poor coping skills, as well as the lack of formal guidelines for the prescribers. The aim of this article is to review the existing literature and formulate recommendations for practitioners aiming to discontinue long-term opioid therapy. Specifically, this review aims to answer the following questions: What is an optimal opioid tapering regimen? How can the risks involved in a taper be managed? What are the alternatives to an opioid taper? A PubMed literature search was conducted using the keywords chronic pain combined with opioid withdrawal, taper, wean and detoxification. Six hundred ninety-five documents were identified and screened; 117 were deemed directly relevant and are included. On the base of this literature review, this article proposes evidence-based recommendations and expert-based suggestions for clinical practice. Furthermore, areas of lack of evidence are identified, providing opportunities for further research.

Inflammation, psychiatric symptoms, and opioid use are associated with pain and disability in patients with cirrhosis

BACKGROUND & AIMS

Cirrhosis is associated with significant pain and disability, the etiologies of which are poorly understood. We investigated whether the pain and disability in patients with cirrhosis are associated with systemic inflammation and psychiatric symptoms.

METHODS

In a prospective study, we recruited 193 patients with cirrhosis caused by hepatitis C virus infection, nonalcoholic steatohepatitis, or alcohol from the hepatology clinic at the University of Pittsburgh. Patients were assessed using the McGill Pain Questionnaire, the Hospital Anxiety and Depression Scale, the Pittsburgh Sleep Quality Index, and the Pain Disability Index. Serum samples were collected and markers of inflammation were measured using standardized Luminex assays (Milipore, St. Charles, MO). We evaluated factors associated with pain, pain-related disability, and chronic opioid use by using multivariable regression models.

RESULTS

Pain was reported by 79% of patients, pain-related disability was reported by 75%, and depression and/or anxiety was reported by 47%; the average Model for End-Stage Liver Disease score was 12 ± 5. Serum samples from 58% percent of patients had increased levels of C-reactive protein. Opioids were prescribed for 30% of patients with pain. In multivariate analysis, factors significantly associated with pain included younger age (odds ratio [OR]/y, 0.93; 95% confidence interval [CI], 0.90-0.99), serum level of interleukin 6 (OR per pg/L, 1.63; 95% CI, 1.09-2.58), Hospital Anxiety and Depression Scale score (OR/point, 1.14; 95% CI, 1.07-1.24), and etiology (hepatitis C virus infection vs alcohol: OR, 3.70; 95% CI, 1.27-11.11). Disability scores were related significantly to psychiatric symptoms (incidence rate ratio [IRR]/point, 1.04; 95% CI, 1.02-1.05), prescription opioid use (IRR, 1.49; 95% CI, 1.14-1.94), Model for End-Stage Liver Disease score (IRR/point, 1.02; 95% CI, 1.0001-1.05), level of C-reactive protein (IRR per mg/dL, 1.13; 95% CI, 1.02-1.24), and pain severity (IRR/point, 1.19; 95% CI, 1.08-1.32).

CONCLUSIONS

Pain and disability are common among patients with cirrhosis, and are associated with inflammation, psychiatric symptoms, and opioid use, which potentially are modifiable. Although opioids are used commonly to treat pain, psychiatric symptoms and inflammation also might be treatment targets in this population.

Novel molecular targets of dezocine and their clinical implications

BACKGROUND

Although dezocine is a partial μ-opioid receptor agonist, it is not a controlled substance. Thus, the characterization of the molecular targets of dezocine is critical for scientific and clinical implications. The goal of this study is to characterize molecular targets for dezocine and determine their implications.

METHODS

A binding screen for dezocine was performed on 44 available receptors and transporter proteins. Functional assays for the novel targets were performed along with computation calculations to locate the binding site. A G protein activation study was performed for the human κ opioid receptor to determine whether dezocine is a κ-antagonist. Data are presented as mean ± standard error.

RESULTS

The affinities for dezocine were 3.7 ± 0.7 nM for the μ receptor, 527 ± 70 nM for the δ-receptor, and 31.9 ± 1.9 nM for the κ-receptor. Dezocine failed to induce G protein activation with κ-opioid receptor and concentration dependently inhibited κ-agonist (salvinorin A and nalbuphine)-induced receptor activation, indicating that dezocine is a κ-antagonist. Two novel molecular targets (norepinephrine transporter and serotonin transporter) were identified. Dezocine concentration-dependently inhibited norepinephrine and serotonin reuptake in vitro. The half maximal inhibitory concentrations (expressed as pIC50) were 5.68 ± 0.11 for norepinephrine transporter and 5.86 ± 0.17 for serotonin transporter. Dezocine occupied the binding site for known norepinephrine transporter and serotonin transporter inhibitors.

CONCLUSIONS

The unique molecular pharmacological profile of dezocine as a partial μ-receptor agonist, a κ-receptor antagonist, and a norepinephrine and serotonin reuptake inhibitor (via norepinephrine transporter and serotonin transporter) was revealed. These discoveries reveal potentially important novel clinical implications and drug interactions of dezocine.