When Physical and Social Pain Coexist: Insights Into Opioid Therapy

Neuroplasticity in the transition from acute to chronic pain

Acute pain is a transient sensation that typically serves as part of the body's defense mechanism. However, in certain patients, acute pain can evolve into chronic pain, which persists for months or even longer. Neuroplasticity refers to the capacity for variation and adaptive alterations in the morphology and functionality of neurons and synapses, and it plays a significant role in the transmission and modulation of pain. In this paper, we explore the molecular mechanisms and signaling pathways underlying neuroplasticity during the transition of pain. We also examine the effects of neurotransmitters, inflammatory mediators, and central sensitization on neuroplasticity, as well as the potential of neuroplasticity as a therapeutic strategy for preventing chronic pain. The aims of this article is to clarify the role of neuroplasticity in the transformation from acute pain to chronic pain, with the hope of providing a novel theoretical basis for unraveling the pathogenesis of chronic pain and offering more effective strategies and approaches for its diagnosis and treatment.

Effectiveness of Long-Term Opioid Therapy for Chronic Pain in an Outpatient Palliative Medicine Clinic

Background: Despite widespread use of opioid therapy in outpatient palliative medicine, there is limited evidence supporting its efficacy and safety in the long term. Objectives: We sought to improve overdose risk scores, maintain pain reduction, and preserve patient function in a cohort with severe chronic pain as we managed opioid therapy for a duration of four years in an outpatient palliative care clinic. Design: Over four years, we provided ongoing goal-concordant outpatient palliative care, including opioid therapy, using quarterly clinical encounters for a patient cohort with chronic pain. Setting/Subjects: The project took place in the outpatient palliative medicine clinic of a regional cancer center in Orlando, Florida (United States). The subjects were a cohort group who received palliative care during the time period between July 2018 and October 2022. Measurements: Key metrics included treatment-related reduction in pain intensity, performance scores, and overall overdose risk scores. Secondary metrics included cohort demographics, average daily opioid use in morphine milligram equivalents and categorization of type of pain. Results: In 97 patients, we observed a stable mean treatment-related reduction in pain intensity of 4.9 out of 10 points over four years. The cohort showed a 2-point (out of 100) improvement in performance scores and an 81-point (out of 999) reduction in mean overall overdose risk score. Conclusions: We present evidence that providing outpatient palliative care longitudinally over four years offered lasting treatment-related reductions in pain intensity, preservation of performance status, and reduction in overall overdose risk.

Progress in Pathological and Therapeutic Research of HIV-Related Neuropathic Pain

HIV-related neuropathic pain (HRNP) is a neurodegeneration that gradually develops during the long-term course of acquired immune deficiency syndrome (AIDS) and manifests as abnormal sock/sleeve-like symmetrical pain and nociceptive hyperalgesia in the extremities, which seriously reduces patient quality of life. To date, the pathogenesis of HRNP is not completely clear. There is a lack of effective clinical treatment for HRNP and it is becoming a challenge and hot spot for medical research. In this study, we conducted a systematic review of the progress of HRNP research in recent years including (1) the etiology, classification and clinical symptoms of HRNP, (2) the establishment of HRNP pathological models, (3) the pathological mechanisms underlying HRNP from three aspects: molecules, signaling pathways and cells, (4) the therapeutic strategies for HRNP, and (5) the limitations of recent HRNP research and the future research directions and prospects of HRNP. This detailed review provides new and systematic insight into the pathological mechanism of HRNP, which establishes a theoretical basis for the future exploitation of novel target drugs. HIV infection, antiretroviral therapy and opioid abuse contribute to the etiology of HRNP with symmetrical pain in both hands and feet, allodynia and hyperalgesia. The pathogenesis involves changes in cytokine expression, activation of signaling pathways and neuronal cell states. The therapy for HRNP should be patient-centered, integrating pharmacologic and nonpharmacologic treatments into multimodal intervention.

Work-family conflicts and pain interference among midlife adults: a longitudinal serial mediation via family strain and loneliness

OBJECTIVE

Work-family conflict has been shown to adversely affect individuals' health and function, particularly among individuals with chronic pain. The current study's longitudinal serial mediation model examined whether work-to-family conflict predicted greater pain interference through higher levels of family strain and loneliness among midlife adults with chronic pain.

METHODS AND MEASURES

The study consisted of 303 participants from two waves of the national longitudinal study of Midlife in the United States (MIDUS) at wave II from 2004 to 2006 (Mage = 57, SD = 11) and wave 3 from 2013 to 2014 (Mage = 66, SD = 11). Participants were employed at time 1 and had chronic pain at both time points, and 54.5% of participants identified as female.

RESULTS

Family strain at time 1 (T1) and loneliness at time 2 (T2), respectively, significantly mediated the association of work-to-family conflict (T1) on pain interference at T2. Participants with greater work-to-family conflict perceived more family strain, felt lonelier, and, in turn, reported experiencing higher interference from chronic pain.

CONCLUSION

Results suggest that unmanaged work-to-family conflict could be a risk factor that exacerbates chronic pain symptoms through worsening family relationships and loneliness among midlife adults with chronic pain.

Questioning the Right to Pain Relief and Its Role in the Opioid Epidemic

The new discipline of palliative care helped to establish the right to pain relief at the end of life and the necessity of using opioids to achieve that goal. Professional pain organizations followed the United Nations' model for universal human rights in their declaration of a universal right to pain management. Both palliative care and pain medicine specialties worked to establish pain as a legitimate focus of medical treatment separate from its association with disease. Pain intensity became the metric used to determine the need for treatment and the success of that treatment. Opioids were favored as the most reliable and feasible means to reduced pain intensity. The Harrison Act of 1914 restricted legitimate opioid use to that prescribed by medical professionals as analgesics. This legislation helped establish opioids as specific painkillers that had a distinct capacity to induce addiction. This understanding of opioids as having distinct and separable analgesic and addictive potential was challenged by the 1970s discovery of an endogenous opioid system, which integrates pain and reward functions to support survival. Our modern pain neurophysiology places the patient with pain in a passive position from which it makes sense to assert a right to pain relief. To prevent future opioid epidemics we need to abandon clinical outpatient use of pain intensity scores and redefine the medical necessity of pain treatment as less about the reduction of pain intensity and more about the capacity to pursue personally valued activities.

Primary care management of Long-Term opioid therapy

The United States underwent massive expansion in opioid prescribing from 1990-2010, followed by opioid stewardship initiatives and reduced prescribing. Opioids are no longer considered first-line therapy for most chronic pain conditions and clinicians should first seek alternatives in most circumstances. Patients who have been treated with opioids long-term should be managed differently, sometimes even continued on opioids due to physiologic changes wrought by long-term opioid therapy and documented risks of discontinuation. When providing long-term opioid therapy, clinicians should document opioid stewardship measures, including assessments, consents, medication reconciliation, and offering naloxone, along with the rationale to continue opioid therapy. Clinicians should screen regularly for opioid use disorder and arrange for or directly provide treatment. In particular, buprenorphine can be highly useful for co-morbid pain and opioid use disorder. Addressing other substance use disorders, as well as preventive health related to substance use, should be a priority in patients with opioid use disorder. Patient-centered practices, such as shared decision-making and attending to related facets of a patient's life that influence health outcomes, should be implemented at all points of care.Key messagesAlthough opioids are no longer considered first-line therapy for most chronic pain, management of patients already taking long-term opioid therapy must be individualised.Documentation of opioid stewardship measures can help to organise opioid prescribing and protect clinicians from regulatory scrutiny.Management of resultant opioid use disorder should include provision of medications, most often buprenorphine, and several additional screening and preventive measures.

Opioid prescribing practices prior to elective foot and ankle surgery: a population-based evaluation using health administrative data from a tertiary hospital in Canada

Background

Complex elective foot and ankle surgery is known to be painful so most patients are prescribed opioids at the time of surgery; however, the number of patients prescribed opioids while waiting for surgery in Canada is unknown. Our primary objective was to describe the pre and postoperative prescribing practices for patients in Alberta, Canada undergoing complex elective foot and ankle surgery. Secondarily, we evaluated postoperative opioid usage and hospital outcomes.

Methods

In this population-based retrospective analysis, we identified all adult patients who underwent unilateral elective orthopedic foot and ankle surgery at a single tertiary hospital between May 1, 2015 and May 31, 2017. Patient and surgical data were extracted from a retrospective chart review and merged with prospectively collected, individual level drug dispensing administrative data to analyze opioid dispensing patterns, including dose, duration, and prescriber for six months before and after foot and ankle surgery.

Results

Of the 100 patients, 45 had at least one opioid prescription dispensed within six months before surgery, and of these, 19 were long-term opioid users (> 90 days of continuous use). Most opioid users obtained opioid prescriptions from family physicians both before (78%) and after (65%) surgery. No preoperative non-users transitioned to long-term opioid use postoperatively, but 68.4% of the preoperative long-term opioid users remained long-term opioid users postoperatively. During the index hospitalization, preoperative long-term opioid users consumed higher doses of opioids (99.7 ± 120.5 mg/day) compared to opioid naive patients (28.5 ± 36.1 mg/day) (p < 0.001). Long-term opioid users stayed one day longer in hospital than opioid-naive patients (3.9 ± 2.8 days vs 2.7 ± 1.1 days; p = 0.01).

Conclusions

A significant number of patients were dispensed opioids before and after foot and ankle surgery with the majority of prescriptions coming from primary care practitioners. Patients who were prescribed long-term opioids preoperatively were more likely to continue to use opioids at follow-up and required larger in-hospital opioid dosages and stayed longer in hospital. Further research and education for both patients and providers are needed to reduce the community-based prescribing of opioid medication pre-operatively and provide alternative pain management strategies prior to surgery to improve postoperative outcomes and reduce long-term postoperative opioid use.

Diagnosing Prescription Opioid Use Disorder in Patients Using Prescribed Opioids for Chronic Pain

OBJECTIVE

The diagnostic criteria for opioid use disorder, originally developed for heroin, did not anticipate the surge in prescription opioid use and the resulting complexities in diagnosing prescription opioid use disorder (POUD), including differentiation of pain relief (therapeutic intent) from more common drug use motives, such as to get high or to cope with negative affect. The authors examined the validity of the Psychiatric Research Interview for Substance and Mental Disorders, DSM-5 opioid version, an instrument designed to make this differentiation.

METHODS

Patients (N=606) from pain clinics and inpatient substance treatment who ever received a ≥30-day opioid prescription for chronic pain were evaluated for DSM-5 POUD (i.e., withdrawal and tolerance were not considered positive if patients used opioids only as prescribed, per DSM-5 guidelines) and pain-adjusted POUD (behavioral/subjective criteria were not considered positive if pain relief [therapeutic intent] was the sole motive). Bivariate correlated-outcome regression models indicated associations of 10 validators with DSM-5 and pain-adjusted POUD measures, using mean ratios for dimensional measures and odds ratios for binary measures.

RESULTS

The prevalences of DSM-5 and pain-adjusted POUD, respectively, were 44.4% and 30.4% at the ≥2-criteria threshold and 29.5% and 25.3% at the ≥4-criteria threshold. Pain adjustment had little effect on prevalence among substance treatment patients but resulted in substantially lower prevalence among pain treatment patients. All validators had significantly stronger associations with pain-adjusted than with DSM-5 dimensional POUD measures (ratios of mean ratios, 1.22-2.31). For most validators, pain-adjusted binary POUD had larger odds ratios than DSM-5 measures.

CONCLUSIONS

Adapting POUD measures for pain relief (therapeutic intent) improved validity. Studies should investigate the clinical utility of differentiating between therapeutic and nontherapeutic intent in evaluating POUD diagnostic criteria.

Pharmacological Strategies for Suicide Prevention Based on the Social Pain Model: A Scoping Review

Suicidal behaviour is a public health problem whose magnitude is both substantial and increasing. Since many individuals seek medical treatment following a suicide attempt, strategies aimed at reducing further attempts in this population are a valid and feasible secondary prevention approach. An evaluation of the available evidence suggests that existing treatment approaches have a limited efficacy in this setting, highlighting the need for innovative approaches to suicide prevention. Existing research on the neurobiology of social pain has highlighted the importance of this phenomenon as a risk factor for suicide, and has also yielded several attractive targets for pharmacological strategies that could reduce suicidality in patients with suicidal ideation or a recent attempt. In this paper, the evidence related to these targets is synthesized and critically evaluated. The way in which social pain is related to the “anti-suicidal” properties of recently approved treatments, such as ketamine and psilocybin, is examined. Such strategies may be effective for the short-term reduction in suicidal ideation and behaviour, particularly in cases where social pain is identified as a contributory factor. These pharmacological approaches may be effective regardless of the presence or absence of a specific psychiatric diagnosis, but they require careful evaluation.

Opioid Consumption in Chronic Pain Patients: Role of Perceived Injustice and Other Psychological and Socioeconomic Factors

BACKGROUND

Chronic pain is a complex biopsychosocial phenomenon. Lifestyle, behavioral, socioeconomic, and psychosocial factors such as depression and perceived injustice are often associated with the development of chronic pain and vice versa. We sought to examine the interaction of these factors with opioid intake.

METHODS

At our institution, 164 patients with chronic pain undergoing an interdisciplinary assessment within a three-month period participated in the study and completed the Injustice Experience Questionnaire (IEQ). Data regarding opioid intake, pain levels, pain diagnosis, depression, anxiety, stress, quality of life, pain-related disability, habitual well-being, occupational status, and ongoing workers compensation litigation were extracted from the patients' charts.

RESULTS

Approximately one-fourth of the patients used opioids. The IEQ total was significantly higher in patients using Schedule III opioids. Depression, but not the anxiety and stress scores, were significantly higher in patients using opioids. There were no significant differences regarding pain-related disability, habitual well-being, and the coded psychosocial diagnoses. In the patient group without opioids, the percentage of employed persons was significantly higher but there were no significant differences regarding work leave, pension application, or professional education.

CONCLUSIONS

Opioid use appears to be more closely related to psychological factors and single social determinants of pain than to somatic factors.

Detecting risk level in individuals misusing fentanyl utilizing posts from an online community on Reddit

INTRODUCTION

Opioid misuse is a public health crisis in the US, and misuse of synthetic opioids such as fentanyl have driven the most recent waves of opioid-related deaths. Because those who misuse fentanyl are often a hidden and high-risk group, innovative methods for identifying individuals at risk for fentanyl misuse are needed. Machine learning has been used in the past to investigate discussions surrounding substance use on Reddit, and this study leverages similar techniques to identify risky content from discussions of fentanyl on this platform.

METHODS

A codebook was developed by clinical domain experts with 12 categories indicative of fentanyl misuse risk, and this was used to manually label 391 Reddit posts and comments. Using this data, we built machine learning classification models to identify fentanyl risk.

RESULTS

Our machine learning risk model was able to detect posts or comments labeled as risky by our clinical experts with 76% accuracy and 76% sensitivity. Furthermore, we provide a vocabulary of community-specific, colloquial words for fentanyl and its analogues.

DISCUSSION

This study uses an interdisciplinary approach leveraging machine learning techniques and clinical domain expertise to automatically detect risky discourse, which may elicit and benefit from timely intervention. Moreover, our vocabulary of online terms for fentanyl and its analogues expands our understanding of online "street" nomenclature for opiates. Through an improved understanding of substance misuse risk factors, these findings allow for identification of risk concepts among those misusing fentanyl to inform outreach and intervention strategies tailored to this at-risk group.

The Right to Pain Relief: Its Origins in End-of-life Care and Extension to Chronic Pain Care

OBJECTIVES

The claim of a right to pain relief was made in recent decades by pain professionals, courts, and patient advocacy groups and likely contributed to increased opioid prescribing, overdose deaths, and addictions, but the origins and nature of this right have not been investigated.

MATERIALS AND METHODS

Relevant clinical, ethical, and legal literature concerning patient rights to pain care was reviewed.

RESULTS

The record describes the effort to improve end-of-life and cancer pain care in the 1980s and 1990s, which simultaneously legitimated pain relief as an independent goal of medical care and opioids as a safe and effective means to achieve this relief. In 1997, the US Supreme Court denied the right to assisted suicide but affirmed a right to palliative care to prevent dying in overwhelming pain. Other guidelines and regulations extended this right to pain relief from end-of-life care to chronic pain care, along with the titrate-to-effect principle, which specified that the correct opioid dose was the dose that relieved pain.

DISCUSSION

The most important consequence of combining the right to pain relief with the titrate-to-effect principle was the idea that a high pain score must not be ignored. This extension of the right to pain relief neglected important differences between end-of-life care and chronic pain care including: time frame, clinical setting and context, target of titration, and nature of iatrogenic harms. To help end our current opioid epidemic and prevent a future epidemic, we need to demedicalize pain and reintegrate it with the rest of human suffering as an experience connected to other personal behaviors and meanings.

The Aversion Function of the Limbic Dopaminergic Neurons and Their Roles in Functional Neurological Disorders

The Freudian theory of conversion suggested that the major symptoms of functional neurological disorders (FNDs) are due to internal conflicts at motivation, especially at the sex drive or libido. FND patients might behave properly at rewarding situations, but they do not know how to behave at aversive situations. Sex drive is the major source of dopamine (DA) release in the limbic area; however, the neural mechanism involved in FND is not clear. Dopaminergic (DAergic) neurons have been shown to play a key role in processing motivation-related information. Recently, DAergic neurons are found to be involved in reward-related prediction error, as well as the prediction of aversive information. Therefore, it is suggested that DA might change the rewarding reactions to aversive reactions at internal conflicts of FND. So DAergic neurons in the limbic areas might induce two major motivational functions: reward and aversion at internal conflicts. This article reviewed the recent advances on studies about DAergic neurons involved in aversive stimulus processing at internal conflicts and summarizes several neural pathways, including four limbic system brain regions, which are involved in the processing of aversion. Then the article discussed the vital function of these neural circuits in addictive behavior, depression treatment, and FNDs. In all, this review provided a prospect for future research on the aversion function of limbic system DA neurons and the therapy of FNDs.

Clinical and psychological factors associated with interdose opioid withdrawal in chronic pain population

BACKGROUND

The DSM-5 diagnostic criteria for Prescription Opioid-Use Disorder (POUD) have undergone some significant changes. One of the most controversial changes has been the elimination of the withdrawal symptoms criterion when opioid use is under appropriate medical supervision. For this reason, the goal of this study was to analyze factors associated with opioid withdrawal in patients with chronic non-cancer pain (CNCP).

METHODS

This cross-sectional descriptive study involved 404 patients who use prescription opioids for long-term treatment (≥90 days) of CNCP. Measures included sociodemographic and clinical characteristics, POUD, withdrawal symptoms, craving, anxiety-depressive symptoms, and pain intensity and interference.

RESULTS

Forty-seven percent (n = 193) of the sample reported moderate-severe withdrawal symptoms, which were associated with lower age, higher daily morphine dose and duration of treatment with opioids, moderate-severe POUD, use of psychotropic drugs, higher anxiety-depressive symptoms, and greater pain intensity and interference (p < .05). Binary logistic regression analysis showed that moderate-severe POUD (OR = 2.82), anxiety (OR = 2.21), depression (OR = 1.81), higher pain interference (OR = 1.05), and longer duration of treatment with opioids were the strongest factors associated with moderate-severe withdrawal symptoms (p < .05).

CONCLUSION

Psychological factors seem to play a key role in the severity of withdrawal symptoms. Since greater intensity of these symptoms increases the risk of developing POUD, knowing the factors associated with withdrawal may be useful in developing preventive psychological interventions.