Management of pain with comorbid substance abuse

Characteristics and clinical challenges in patients with substance use disorder in palliative care-experience from a tertiary center in a high-income country

BACKGROUND

Access to palliative care is often limited for challenging and vulnerable groups, including persons with substance use disorders. However, with optimized healthcare options and liberal substitution policies, this patient group is likely to increase over the upcoming years, and comorbidities will also influence the need for palliative support. Here, we aim at analyzing characteristics and specific challenges associated with substance use disorders (SUD) in palliative care.

METHODS

We retrospectively reviewed all patients diagnosed with substance use disorder that were treated at our Competence Center Palliative Care within the University Hospital Zurich, Switzerland between 2015 and 2021. Patient characteristics, including age, gender, duration of hospitalization, as well as specific metrics like body mass index, distinct palliative care assessment scores, and in-hospital opioid consumption were retrieved from the electronic patient files. Demographics and clinical data were analyzed by descriptive statistics, and compared to those of a control group of palliative care patients without SUD. An opioid calculator was used to standardize opioid intake based on morphine equivalents for meaningful comparisons.

RESULTS

The primary characteristics revealed that the majority of individuals were single (56%), had no children (83%), lived alone (39%), and were either unemployed or recipients of a disability pension (in total 50%). Nicotine (89%), opioids (67%), and alcohol (67%) were the most used substances. We identified various comorbidities including psychiatric illnesses alongside SUD (56%), hepatitis A, B, or C (33%), and HIV infection (17%). Patients with SUD were significantly younger (p < 0.5), predominantly male (p < 0.05), and reported a higher prevalence of pain (p < 0.5) compared to the standard cohort of palliative patients. Regarding the challenges most frequently reported by healthcare practitioners, non-compliance, multimorbidity, challenging communication, biographical trauma, lack of social support, and unstable housing situations played a key role.

CONCLUSION

Patients with SUD represent a complex and vulnerable group dealing with multiple comorbidities that profoundly affect both their physical and psychological well-being. Understanding their unique characteristics is pivotal in providing precise and suitable palliative care.

Shared Decision Making in Acute Pain Management in Patients with Opioid Use Disorder: A Scoping Review

The treatment of acute pain over the years has changed with increasing alternative therapies and increased scrutiny of opioid prescriptions. Shared Decision Making (SDM) has become a vital tool in increasing patient engagement and satisfaction in treatment decisions. SDM has been successfully implemented in the management of pain in a variety of settings; however, information regarding the use of SDM for treating acute pain in patients with a history of opioid use disorder (OUD) remains scarce. Following the Preferred Reporting Items for Systematic Reviews and Meta-analysis Extension for Scoping Reviews (PRISMA-ScR), we conducted a review to understand how SDM is used in acute pain management in patients with OUD. We searched Medline, Embase, CINAHL, and PsychInfo databases for relevant articles. Articles were screened and SDM outcomes of eligible articles were charted. The results were grouped by sub-theme based on a 1997 SDM model. There were three original research studies and one quality improvement study. The remaining articles were split evenly between reviews and reviews of clinical guidelines. Four themes emerged from the review: prior judgment and stigma related to OUD, trust and sharing of information, clinical tools, and interprofessional teams. This scoping review consolidated and expounded the current literature on SDM in the management of acute pain in patients with OUD. More work is needed to address prior judgments by both providers and patients and to build greater dialogue. Clinical tools may aid this process as well as the involvement of a multidisciplinary team.

Chronic Pain among Individuals Experiencing Homelessness and Its Interdependence with Opioid and Other Substance Use and Mental Illness

Chronic pain and substance use disorders are serious conditions that are prevalent among homeless populations. The aim of this study was to examine the association between chronic pain and substance use among individuals experiencing homelessness and mental illness. We analyzed cross-sectional data from two sites of the At Home/Chez Soi study (Vancouver and Toronto) using bivariate statistics and multivariate logistic regression. Substance use and chronic pain parameters were assessed with the Maudsley Addiction Profile and purpose-designed short instruments. The sample comprised 828 participants. Mean age was 42.4 years and 54% reported chronic pain. In bivariate analysis, chronic pain was significantly associated with use of opioids and stimulants, daily substance use, polysubstance use and injecting as route of administration. In multivariate analysis, only daily substance use (OR: 1.46, 95% CI: 1.02-2.09) and injecting (OR: 1.81, 95% CI: 1.08-3.05) remained as significant associated factors, whereas neither use of opioids nor use of stimulants specifically were significantly associated with chronic pain. Among participants with chronic pain, daily substance users (50% vs. 22%, p < 0.001) and injectors (66% vs. 24%, p < 0.001) were more likely to use non-prescribed medication for pain. Participants with daily substance use were less likely to receive professional treatment (52% vs. 64%, p = 0.017) and prescribed pain medication (42% vs. 54%, p = 0.023). Our findings suggest an association of chronic pain with patterns related to severity of substance use rather than to specific substance use in homeless persons with mental illness. Interventions aiming at prevention and treatment of chronic pain in this population should consider severity of substance use and associated risk behavior over use of specific substances.

A prospective, longitudinal study to evaluate the clinical utility of a predictive algorithm that detects risk of opioid use disorder

Purpose

The purpose of this study was to determine the clinical utility of an algorithm-based decision tool designed to assess risk associated with opioid use. Specifically, we sought to assess how physicians were using the profile in patient care and how its use affected patient outcomes.

Patients and methods

A prospective, longitudinal study was conducted to assess the utility of precision medicine testing in 5,397 patients across 100 clinics in the USA. Using a patent-protected, validated algorithm combining specific genetic risk factors with phenotypic traits, patients were categorized into low-, moderate-, and high-risk patients for opioid abuse. Physicians who ordered precision medicine testing were asked to complete patient evaluations and document their actions, decisions, and perceptions regarding the utility of the precision medicine tests. The patient outcomes associated with each treatment action were carefully documented.

Results

Physicians used the profile to guide treatment decisions for over half of the patients. Of those, guided treatment decisions for 24.5% of the patients were opioid related, including changing the opioid prescribed, starting an opioid, or titrating a patient off the opioid. Treatment guidance was strongly influenced by profile-predicted opioid use disorder (OUD) risk. Most importantly, patients whose physicians used the profile to guide opioid-related treatment decisions had improved clinical outcomes, including better pain management by medication adjustments, with an average pain decrease of 3.4 points on a scale of 1–10.

Conclusion

Patients whose physicians used the profile to guide opioid-related treatment decisions had improved clinical outcomes, as measured by decreased pain levels resulting from better pain management with prescribed medications. The clinical utility of the profile is twofold. It provides clinically actionable recommendations that can be used to 1) prevent OUD through limiting initial opioid prescriptions and 2) reduce pain in patients at low risk of developing OUD.

A Predictive Algorithm to Detect Opioid Use Disorder: What Is the Utility in a Primary Care Setting?

PURPOSE

The purpose of this study was to determine the clinical utility of an algorithm-based decision tool designed to assess risk associated with opioid use in the primary care setting.

METHODS

A prospective, longitudinal study was conducted to assess the utility of precision medicine testing in 1822 patients across 18 family medicine/primary care clinics in the United States. Using the profile, patients were categorized into low, moderate, and high risk for opioid use. Physicians who ordered testing were asked to complete patient evaluations and document their actions, decisions, and perceptions regarding the utility of the precision medicine tests.

RESULTS

Approximately 47% of primary care physicians surveyed used the profile to guide clinical decision-making. These physicians rated the benefit of the profile on patient care an average of 3.6 on a 5-point scale (1 indicating no benefit and 5 indicating significant benefit). Eighty-eight percent of all clinicians surveyed felt the test exhibited some benefit to their patient care. The most frequent utilization for the profile was to guide a change in opioid prescribed. Physicians reported greater benefit of profile utilization for minority patients. Patients whose treatment was guided by the profile had pain levels that were reduced, on average, 2.7 levels on the numeric rating scale.

CONCLUSIONS

The profile provided primary care physicians with a useful tool to stratify the risk of opioid use disorder and was rated as beneficial for decision-making and patient improvement by the majority of physicians surveyed. Physicians reported the profile resulted in greater clinical improvement for minorities, highlighting the objective use of this profile to guide judicial use of opioids in high-risk patients. Significantly, when physicians used the profile to guide treatment decisions, patient-reported pain was greatly reduced.

Opioids in Cancer Pain: Right or Privilege?

Opioid analgesia is a mainstay of the treatment of cancer pain. Treatment of pain in patients with cancer with an ongoing substance abuse disorder can be difficult. We report the ethical challenges of treating a patient with cancer with a concomitant substance abuse disorder in an outpatient palliative care setting. We present an analysis of ethical considerations for the palliative care physician and strategies to aid in the successful treatment of such patients. We argue that there are select patients with cancer for whom exclusion from treatment with opioid therapy is warranted if their health is endangered by prescription of these medications.

Preoperative Opioid Use Is Associated with Early Revision After Total Knee Arthroplasty: A Study of Male Patients Treated in the Veterans Affairs System

BACKGROUND

Opioid use is endemic in the U.S. and is associated with morbidity and mortality. The impact of long-term opioid use on joint-replacement outcomes remains unknown. We tested the hypothesis that use of opioids is associated with adverse outcomes after total knee arthroplasty (TKA).

METHODS

We performed a retrospective analysis of patients who had had TKA within the U.S. Veterans Affairs (VA) system over a 6-year period and had been followed for 1 year postoperatively. The length of time for which an opioid had been prescribed and the morphine equivalent dose were calculated for each patient. Patients for whom opioids had been prescribed for >3 months in the year prior to the TKA were assigned to the long-term opioid group. A natural language processing-based machine-learning classifier was developed to classify revisions due to infectious and non-infectious causes on the basis of the postoperative note. Survival curves for the time to knee revision or manipulation were used to compare the long-term opioid group with the patients who did not take opioids long-term. Hazard and odds ratios for knee revision and manipulation were obtained as well.

RESULTS

Of 32,636 patients (94.4% male; mean age [and standard deviation], 64.45 ± 9.41 years) who underwent TKA, 12,772 (39.1%) were in the long-term opioid group and 734 (2.2%) had a revision within a year after the TKA. Chronic kidney disease, diabetes, and long-term opioid use were associated with revision within 1 year-with odds ratios (95% confidence intervals [CIs]) of 1.76 (1.37 to 2.22), 1.11 (0.93 to 1.31), and 1.40 (1.19 to 1.64), respectively-and were also the leading factors associated with a revision at any time after the index TKA-with odds ratios (95% CIs) of 1.61 (1.34 to 1.92), 1.21 (1.08 to 1.36), and 1.28 (1.15 to 1.43), respectively. Long-term opioid use had a hazard ratio of 1.19 (95% CI = 1.10 to 0.24) in the analysis of its relationship with knee revision, but the hazard was not significant in the analysis of its association with knee manipulation. The accuracy of the text classifier was 0.94, with the area under the receiver operating characteristic curve being 0.99. There was no association between long-term use of opioids and the specific cause for knee revision.

CONCLUSIONS

Long-term opioid use prior to TKA was associated with an increased risk of knee revision during the first year after TKA among predominantly male patients treated in the VA system.

LEVEL OF EVIDENCE

Therapeutic Level III. See Instructions for Authors for a complete description of levels of evidence.

Psychiatric Disorders Among Patients Seeking Treatment for Co-Occurring Chronic Pain and Opioid Use Disorder

OBJECTIVE

Psychiatric comorbidities complicate treatment of patients with chronic pain and opioid use disorder, but the prevalence of specific comorbid psychiatric disorders in this population has not been systematically investigated.

METHODS

170 consecutive participants entering a treatment research program for co-occurring chronic pain and opioid use disorder between March 2009 and July 2013 were evaluated with the Structured Clinical Interview for DSM-IV-TR Axis I Disorders (SCID-I/P) and the Diagnostic Interview for DSM-IV Personality Disorders (DIPD-IV).

RESULTS

The prevalence of any lifetime (and current) comorbid Axis I disorder was 91% (75%); 52% met criteria for lifetime anxiety disorder (48% current), 57% for lifetime mood disorder (48% current), and 78% for lifetime nonopioid substance use disorder (34% current). Common current anxiety diagnoses were posttraumatic stress disorder (21%), generalized anxiety disorder (16%), and panic disorder without agoraphobia (16%). Common current mood diagnoses were major depressive disorder (40%) and dysthymia (11%). A majority of patients had a personality disorder (52%).

CONCLUSIONS

High rates and persistence of co-occurring psychiatric disorders, including anxiety or mood disorders, may explain in part the difficulty providers have treating patients with co-occurring opioid use disorder and chronic pain and suggest possible targets for improving treatment.

TRIAL REGISTRATION

ClinicalTrials.gov identifiers: buprenorphine/naloxone treatment (NCT00634803), opioid treatment program-based methadone maintenance treatment (NCT00727675).

Examination of the Addictive and Behavioral Properties of Fatty Acid-Binding Protein Inhibitor SBFI26

The therapeutic properties of cannabinoids have been well demonstrated but are overshadowed by such adverse effects as cognitive and motor dysfunction, as well as their potential for addiction. Recent research on the natural lipid ligands of cannabinoid receptors, also known as endocannabinoids, has shed light on the mechanisms of intracellular transport of the endocannabinoid anandamide by fatty acid-binding proteins (FABPs) and subsequent catabolism by fatty acid amide hydrolase. These findings facilitated the recent development of SBFI26, a pharmacological inhibitor of epidermal- and brain-specific FABP5 and FABP7, which effectively increases anandamide signaling. The goal of this study was to examine this compound for any possible rewarding and addictive properties as well as effects on locomotor activity, working/recognition memory, and propensity for sociability and preference for social novelty (SN) given its recently reported anti-inflammatory and analgesic properties. Male C57BL mice were split into four treatment groups and conditioned with 5.0, 20.0, 40.0 mg/kg SBFI26, or vehicle during a conditioned place preference (CPP) paradigm. Following CPP, mice underwent a battery of behavioral tests [open field, novel object recognition (NOR), social interaction (SI), and SN] paired with acute SBFI26 administration. Results showed that SBFI26 did not produce CPP or conditioned place aversion regardless of dose and did not induce any differences in locomotor and exploratory activity during CPP- or SBFI26-paired open field activity. We also observed no differences between treatment groups in NOR, SI, and SN. In conclusion, as SBFI26 was shown previously by our group to have significant analgesic and anti-inflammatory properties, here we show that it does not pose a risk of dependence or motor and cognitive impairment under the conditions tested.

Prevalence of pain-related single nucleotide polymorphisms in patients of African origin with sickle cell disease

BACKGROUND

Prospective pain genetics research is hindered by a lack of data on the prevalence of polymorphisms in pain-relevant genes for patients with sickle cell disease (SCD). For African-Americans in general, limited information is available in public databases.

METHODS

We prioritized and examined the genotype and allele frequencies of 115 SNPs from 49 candidate pain genes in 199 adult African-Americans and pediatric patients of African origin with SCD. Analyses were performed and compared with available data from public databases.

RESULTS

Genotype and allele frequencies of a number of SNPs were found to be different between our cohort and those from the databases and between adult and pediatric subjects.

CONCLUSION

As pain therapy is inadequate in a significant percentage of patients with SCD, candidate pain genetic studies may aid in designing precision pain medicine. We provide prevalence data as a reference for prospective genetic studies in this population.

Prevalence and experience of chronic pain in suburban drug injectors

AIMS

To explore the relationship between chronic pain and characteristics, behaviors, and psychological status of suburban Connecticut injection drug users.

METHODS

Cross-sectional study with quantitative interview and serological testing for HIV and hepatitis B and C in 456 individuals who injected drugs in the past month. Participants were dichotomized into those reporting current chronic pain of at least six months duration and all others. The interview covered (i) sociodemographics, (ii) injection drug use, (iii) interactions with drug treatment, criminal justice, and harm reduction, (iv) screening for alcohol use, chronic pain, anxiety, and depression, and (v) knowledge regarding HIV, hepatitis B (HBV) and C (HCV), and opioid overdose. Serological testing for HIV, HBV, and HCV was conducted.

RESULTS

One-third (n = 143) reported chronic pain. These individuals differed significantly from those not reporting chronic pain on characteristics that included older age, lower educational achievement, and injection of pharmaceutical opioids. They also reported experiencing more psychological and family problems on the ASI and higher levels of depression and anxiety. Four of five individuals with chronic pain (n = 117) reported non-medical opioid use prior to the onset of chronic pain.

CONCLUSIONS

Chronic pain is common among drug injectors in our study population although it was unusual for chronic pain to have preceded non-medical opioid use. Psychological problems in injectors with co-occurring chronic pain are likely pose significant complications to successful treatment for substance abuse, pain, or infectious disease treatment.

Self-management of pain among people who inject drugs in Vancouver

AIMS

To evaluate factors and methods associated with self-management of pain among people who inject drugs (IDUs) in Vancouver (Canada).

PATIENTS & METHODS

This cross-sectional study used bivariate statistics and multivariate logistic regression to analyze self-reported responses among 483 IDUs reporting moderate-to-extreme pain in two prospective cohort studies from 1 December 2012 to 31 May 2013.

RESULTS

Median age was 49.6 years (interquartile range: 43.9-54.6 years), 33.1% of IDUs were female and 97.5% reported self-management of pain. Variables independently and positively associated with self-managed pain included having been refused a prescription for pain medication (adjusted odds ratio: 7.83; 95% CI: 1.64-37.3) and having ever been homeless (adjusted odds ratio: 3.70; 95% CI: 1.00-13.7). Common methods of self-management of pain included injecting heroin (52.7%) and obtaining diverted prescription pain medication from the street (65.0%).

CONCLUSION

Self-management of pain was common among IDUs who reported moderate-to-extreme pain in this setting, particularly among those who had been refused a prescription for pain medication and those who had ever been homeless. These data highlight the challenges of adequate pain management among IDUs.

Calcium-permeable ion channels in pain signaling

The detection and processing of painful stimuli in afferent sensory neurons is critically dependent on a wide range of different types of voltage- and ligand-gated ion channels, including sodium, calcium, and TRP channels, to name a few. The functions of these channels include the detection of mechanical and chemical insults, the generation of action potentials and regulation of neuronal firing patterns, the initiation of neurotransmitter release at dorsal horn synapses, and the ensuing activation of spinal cord neurons that project to pain centers in the brain. Long-term changes in ion channel expression and function are thought to contribute to chronic pain states. Many of the channels involved in the afferent pain pathway are permeable to calcium ions, suggesting a role in cell signaling beyond the mere generation of electrical activity. In this article, we provide a broad overview of different calcium-permeable ion channels in the afferent pain pathway and their role in pain pathophysiology.