Cognitive Function During Opioid Tapering in Patients with Chronic Pain: A Prospective Cohort Study

Opioid Use Behaviors Among People With Disability in the United States: An Analysis of the National Survey on Drug Use and Health

OBJECTIVE

People with disability (PWD) often experience chronic pain, and opioid is widely used prescription medication. However, population-based evidence of opioid use behaviors among PWD is lacking. This study examined the prevalence of opioid use behaviors by sociodemographic and health-related characteristics among PWD compared with people without disability (PWoD).

METHODS

This cross-sectional study used data from 2015-2019 National Survey on Drug Use and Health. Three types of opioid use behaviors (any use, misuse, and use disorder) were defined and compared by disability status. Five self-reported disability types were measured, including hearing, vision, cognitive, mobility, and complex activity limitations. Complex survey design-adjusted descriptive and logistic regression models were used for statistical analysis.

RESULTS

Of 201,376 respondents aged 18 years or older, 34.6% reported any opioid use, 4.2% opioid misuse, and 0.8% opioid use disorder. Compared with PWoD, PWD had higher prevalence of any opioid use (49.7% vs 30.7%), misuse (6.2% vs 3.7%), and use disorder (1.7% vs 0.8%). In adjusted analysis, PWD with mobility limitation (odds ratio [OR], 1.95; 95% confidence interval, 1.81-2.11) or multiple limitations (OR, 1.92; 95% CI, 1.83-2.02) were almost 2 times more likely to report any opioid use than PWoD. The likelihood of reporting any opioid use (ORs, 1.42-2.50), misuse (ORs, 1.24-2.41), and disorder (ORs, 1.38-2.54) increased as the number of limitations increased.

CONCLUSIONS

People with vision, cognitive, or multiple limitations had higher rates of opioid misuse and disorder than PWoD. Development of more inclusive opioid abuse prevention strategies for PWD is warranted.

Endogenous opiates and behavior: 2020

This paper is the forty-third consecutive installment of the annual anthological review of research concerning the endogenous opioid system, summarizing articles published during 2020 that studied the behavioral effects of molecular, pharmacological and genetic manipulation of opioid peptides and receptors as well as effects of opioid/opiate agonists and antagonists. The review is subdivided into the following specific topics: molecular-biochemical effects and neurochemical localization studies of endogenous opioids and their receptors (1), the roles of these opioid peptides and receptors in pain and analgesia in animals (2) and humans (3), opioid-sensitive and opioid-insensitive effects of nonopioid analgesics (4), opioid peptide and receptor involvement in tolerance and dependence (5), stress and social status (6), learning and memory (7), eating and drinking (8), drug abuse and alcohol (9), sexual activity and hormones, pregnancy, development and endocrinology (10), mental illness and mood (11), seizures and neurologic disorders (12), electrical-related activity and neurophysiology (13), general activity and locomotion (14), gastrointestinal, renal and hepatic functions (15), cardiovascular responses (16), respiration and thermoregulation (17), and immunological responses (18).

Efficacy of interventions to reduce long term opioid treatment for chronic non-cancer pain: systematic review and meta-analysis

OBJECTIVE

To review interventions to reduce long term opioid treatment in people with chronic non-cancer pain, considering efficacy on dose reduction and discontinuation, pain, function, quality of life, withdrawal symptoms, substance use, and adverse events.

DESIGN

Systematic review and meta-analysis of randomised controlled trials and non-randomised studies of interventions.

DATA SOURCES

Medline, Embase, PsycINFO, CINAHL, and the Cochrane Library searched from inception to July 2021. Reference lists and previous reviews were also searched and experts were contacted.

ELIGIBILITY CRITERIA FOR STUDY SELECTION

Original research in English. Case reports and cross sectional studies were excluded.

DATA EXTRACTION AND SYNTHESIS

Two authors independently selected studies, extracted data, and used the Cochrane risk-of-bias tools for randomised and non-randomised studies (RoB 2 and ROBINS-I). Authors grouped interventions into five categories (pain self-management, complementary and alternative medicine, pharmacological and biomedical devices and interventions, opioid replacement treatment, and deprescription methods), estimated pooled effects using random effects meta-analytical models, and appraised the certainty of evidence using GRADE (grading of recommendations, assessment, development, and evaluation).

RESULTS

Of 166 studies meeting inclusion criteria, 130 (78%) were considered at critical risk of bias and were excluded from the evidence synthesis. Of the 36 included studies, few had comparable treatment arms and sample sizes were generally small. Consequently, the certainty of the evidence was low or very low for more than 90% (41/44) of GRADE outcomes, including for all non-opioid patient outcomes. Despite these limitations, evidence of moderate certainty indicated that interventions to support prescribers' adherence to guidelines increased the likelihood of patients discontinuing opioid treatment (adjusted odds ratio 1.5, 95% confidence interval 1.0 to 2.1), and that these prescriber interventions as well as pain self-management programmes reduced opioid dose more than controls (intervention v control, mean difference -6.8 mg (standard error 1.6) daily oral morphine equivalent, P<0.001; pain programme v control, -14.31 mg daily oral morphine equivalent, 95% confidence interval -21.57 to -7.05).

CONCLUSIONS

Evidence on the reduction of long term opioid treatment for chronic pain continues to be constrained by poor study methodology. Of particular concern is the lack of evidence relating to possible harms. Agreed standards for designing and reporting studies on the reduction of opioid treatment are urgently needed.

REVIEW REGISTRATION

PROSPERO CRD42020140943.

Opioid Taper is Associated with Improved Experimental Pain Tolerance in Patients with Chronic Pain: An Observational Study

Introduction

The degree to which opioid-induced hyperalgesia contributes to the pain experience of patients with chronic pain remains relatively undescribed. The objective of this pilot study was to determine if experimental pain responses improve in patients with chronic pain as they undergo a planned opioid taper.

Methods

This was a prospective observational study. Seven patients with chronic neuropathic pain on at least 120 mg morphine equivalents/day were enrolled. The participants were followed over the course of an individualized opioid taper to a lower dose. Measures of experimental pain sensitivity, including indicators of central pain modulation, were collected on a biweekly basis; in addition, measures of function and quality of life were collected monthly. The effect of opioid taper on pain responses and functional outcomes over time were examined using longitudinal mixed-effects regression modeling and general linear regression modeling with regularization as a function of baseline dose, end dose, and taper rate.

Results

In this small sample of patients undergoing highly individualized and variable opioid taper, the opioid taper was significantly associated with improved pain responses to the cold-pressor test, with the pain threshold on average increasing by 1.14 s every 6 weeks (p = 0.0084, 95% confidence interval [CI] for 6-week change 0.3039–2.0178) and pain tolerance on average increasing by 2.87 s every 6 weeks (p = 0.0026, 95% CI for 6-week change 1.02–4.7277). Taper-related changes in central pain modulation were not observed, although conditioned modulation trended toward improvement by the completion of opioid taper. Similarly, no declines in function and quality of life were observed with the opioid taper, suggesting stability despite decreased opioid dose.

Conclusions

Opioid taper was associated with improvements in experimental pain responses without a decline in function and quality of life, suggestive of diminished opioid-induced hyperalgesia in this clinical sample.

Trial Registration

ClinicalTrials.gov identifier, NCT03912298.

Supplementary Information

The online version contains supplementary material available at 10.1007/s40122-021-00348-8.