The association of chronic pain and opioid withdrawal in men and women with opioid use disorder

Sex differences in comorbid pain and opioid use disorder: A scoping review

Opioid use disorder (OUD) and chronic pain are commonly co-occurring disorders which can exacerbate each other. Sex/gender differences have been shown in aspects of the clinical course and biological underpinnings of both OUD and chronic pain. The purpose of this scoping review is to summarize literature which has addressed sex/gender differences in relation to the confluence of OUD and chronic pain. This review focused on peer-reviewed journal articles with human subjects and addressing (a) opioid misuse, chronic opioid use or opioid use disorder (OUD), (b) chronic or persistent pain and (c) sex/gender differences in relation to OUD and/or chronic pain. Of the 146 papers identified by the search strategy, 30 met the criteria for inclusion. Charting focused on a priori themes of chronic pain, opioid misuse/OUD and sex/gender in sample, predictor and outcome variables, and key study findings. The majority of research identified was cross-sectional in nature, and sex/gender differences and treatment effects were largely included as post-hoc analyses. Together, the results of this early work align with higher prevalence for OUD in men/males and chronic pain in women/females, while adding critical information with respect to potential sex/gender differences in the development and treatment of their co-occurrence across a range of biological and psychosocial factors. Findings underline the importance of considering sex and gender in the intersection of the development and treatment of OUD and chronic pain.

Establishing a research agenda for the study and assessment of opioid withdrawal

The opioid crisis is an international public health concern. Treatments for opioid use disorder centre largely on the management of opioid withdrawal, an aversive collection of signs and symptoms that contribute to opioid use disorder. Whereas in the past 50 years more than 90 medications have been developed for depression, only five medications have been developed for opioid use disorder during this period. We posit that underinvestment has occurred in part due to an underdeveloped understanding of opioid withdrawal syndrome. This Personal View summarises substantial gaps in our understanding of opioid withdrawal that are likely to continue to limit major advancements in its treatment. There is no firm consensus in the field as to how withdrawal should be precisely defined; 10-550 symptoms of withdrawal can be measured on 18 scales. The imprecise understanding of withdrawal is likely to result in overestimating or underestimating the severity of an individual's withdrawal syndrome or potential therapeutic effects of different candidate medications. The severity of the opioid crisis is not remitting, and an international research agenda for the study and assessment of opioid withdrawal is necessary to support transformational changes in withdrawal management and treatment of opioid use disorder. Nine actionable targets are delineated here: develop a consensus definition of opioid withdrawal; understand withdrawal symptomatology after exposure to different opioids (particularly fentanyl); understand precipitated opioid withdrawal; understand how co-exposure of other drugs (eg, xylazine and stimulants) influences withdrawal expression; examine individual variation in withdrawal phenotypes; precisely characterise the protracted withdrawal syndrome; identify biomarkers of opioid withdrawal severity; identify predictors of opioid withdrawal severity; and understand which symptoms are most closely associated with treatment attrition or relapse. The US Food and Drug Administration recently established a formal indication for opioid withdrawal that has invigorated interest in drug development for opioid withdrawal management. Action is now needed to support these interests and help industry identify new classes of medications so that real change can be achieved for people with opioid use disorder.

Low-dose ketamine infusion to facilitate opioid tapering in chronic non-cancer pain with opioid-use disorder: a historical cohort study

BACKGROUND

Long-term opioid use is associated with pharmacological tolerance, a risk of misuse and hyperalgesia in patients with chronic pain (CP). Tapering is challenging in this context, particularly with comorbid opioid-use disorder (OUD). The antihyperalgesic effect of ketamine, through N-methyl-D-aspartate (NMDA) antagonism, could be useful. We aimed to describe the changes in the dose of opioids consumed over 1 year after a 5-day hospitalisation with ketamine infusion for CP patients with OUD.

METHODS

We performed a historical cohort study using a medical chart from 1 January 2014 to 31 December 2019. Patients were long-term opioid users with OUD and CP, followed by the Pain Center of the University Hospital of Toulouse, for which outpatient progressive tapering failed. Ketamine was administered at a low dose to initiate tapering during a 5-day hospitalisation.

RESULTS

59 patients were included, with 64% of them female and a mean age of 48±10 years old. The most frequent CP aetiologies were back pain (53%) and fibromyalgia (17%). The baseline opioid daily dose was 207 mg (±128) morphine milligram equivalent (MME). It was lowered to 92±72 mg MME at discharge (p<0.001), 99±77 mg at 3 months (p<0.001) and 103±106 mg at 12 months. More than 50% tapering was achieved immediately for 40 patients (68%), with immediate cessation for seven patients (12%). 17 patients were lost to follow-up.

CONCLUSIONS

A 5-day hospitalisation with a low-dose ketamine infusion appeared useful to facilitate opioid tapering in long-term opioid users with CP and OUD. Ketamine was well tolerated, and patients did not present significant withdrawal symptoms. Prospective and comparative studies are needed to confirm our findings.

Xylazine is an agonist at kappa opioid receptors and exhibits sex-specific responses to opioid antagonism

Xylazine is in the unregulated drug supply at increasing rates, usually combined with fentanyl, necessitating understanding of its pharmacology. Despite commentary from politicians, and public health officials, it is unknown how xylazine impacts naloxone efficacy, and. few studies have examined it alone. Here, we examine the impact of xylazine alone and in combination with fentanyl on several behaviors in mice. Surprisingly, naloxone precipitates withdrawal from xylazine and fentanyl/xylazine coadministration, with enhanced sensitivity in females. Further, xylazine is a full agonist at kappa opioid receptors, a potential mechanism for its naloxone sensitivity. Finally, we demonstrate surprising effects of xylazine to kappa opioid antagonism, which are relevant for public health considerations. These data address an ongoing health crisis and will help inform critical policy and healthcare decisions.

The association of pain impact and sleep disruption with opioid withdrawal during opioid-use disorder treatment

AIMS

Persons with opioid-use disorder (OUD) often experience opioid withdrawal and opioid craving, which can drive continued opioid use and treatment discontinuation. In addition, hyperalgesia is common among persons with OUD, yet few studies have examined the role of pain impact during OUD treatment. The purpose of the present study was to test whether opioid withdrawal and craving were elevated in the context of greater pain impact (i.e. greater pain intensity and interference), and whether these associations changed throughout treatment.

METHODS

Participants in residential OUD treatment (n = 24) wore wrist actigraphy to measure sleep and completed daily measures of pain impact, opioid withdrawal and opioid craving for up to 28 days. Mixed effects models were used to examine whether daily elevations in pain impact and sleep continuity were associated with withdrawal severity and opioid craving.

RESULTS

Elevations in withdrawal, but not craving, occurred on days when individuals reported higher scores on the pain impact scale. Associations between pain impact and withdrawal were present throughout treatment, but stronger during early treatment. In contrast, both withdrawal and opioid craving were elevated following nights of greater wake after sleep onset and awakenings, but these findings were often more pronounced in early treatment.

CONCLUSIONS

Pain impact and sleep disturbance are 2 factors associated with opioid withdrawal and opioid craving. Novel pharmacotherapies and scalable adjunctive interventions targeting sleep and pain impact should be tested in future work to improve OUD treatment outcomes.

Intersectional Risk and the Significant Gap in Care for Persons With Co-occurring Chronic Pain and Opioid Withdrawal

OBJECTIVES

Persons with chronic pain and women tend to enter treatment for opioid use disorder with greater opioid withdrawal severity than persons without chronic pain and men, respectively. This study examined characteristics of facilities with opioid withdrawal treatment, including gender-based services, as a function of whether they reported having a tailored pain management program.

METHODS

The National Survey of Substance Abuse Treatment Services 2020 was used to examine 3942 facilities with opioid withdrawal treatment in the United States. Using a multivariable binary logistic regression model, facilities were examined for the presence of a tailored program for individuals with co-occurring pain. Regional location of the facility, ownership status, and availability of tailored gender programs, nonhospital residential services, and outpatient services served as independent variables in the analysis.

RESULTS

A slight majority of the sample had a program for both adult men and adult women ( n = 2010, 51.0%). Most facilities had outpatient services ( n = 3289, 83.4%) and did not have a tailored program for addressing co-occurring pain ( n = 2756, 69.9%). Binary logistic regression analysis showed that among opioid withdrawal facilities, programs with nonhospital residential services, government or private nonprofit funding, or tailored gender programming had higher odds of reporting having a tailored program for pain and substance use disorder. Facilities in the Western United States were most likely to have tailored programs for pain and substance use disorder.

CONCLUSIONS

Future research should investigate what support patients may receive and how to better scale access to pain management during opioid withdrawal treatment.

Oxycodone withdrawal is associated with increased cocaine self-administration and aberrant accumbens glutamate plasticity in rats

Individuals with opioid use disorder (OUD) frequently use other substances, including cocaine. Opioid withdrawal is associated with increased likelihood of cocaine use, which may represent an attempt to ameliorate opioid withdrawal effects. Clinically, 30% of co-using individuals take opioids and cocaine exclusively in a sequential manner. Preclinical studies evaluating mechanisms of drug use typically study drugs in isolation. However, polysubstance use is a highly prevalent clinical issue and thus, we established a novel preclinical model of sequential oxycodone and cocaine self-administration (SA) whereby rats acquired oxycodone and cocaine SA in an A-B-A-B design. Somatic signs of withdrawal were evaluated at 0, 22, and 24h following oxycodone SA, with the 24h timepoint representing somatic signs immediately following cocaine SA. Preclinically, aberrant glutamate signaling within the nucleus accumbens core (NAcore) occurs following use of cocaine or opioids, whereby medium spiny neurons (MSNs) rest in a potentiated or depotentiated state, respectively. Further, NAcore glial glutamate transport via GLT-1 is downregulated following SA of either drug alone. However, it is not clear if cocaine can exacerbate opioid-induced changes in glutamate signaling. In this study, NAcore GLT-1 protein and glutamate plasticity were measured (via AMPA/NMDA ratio) following SA. Rats acquired SA of both oxycodone and cocaine regardless of sex, and the acute oxycodone-induced increase in somatic signs at 22h was positively correlated with cocaine consumption during the cocaine testing phase. Cocaine use following oxycodone SA downregulated GLT-1 and reduced AMPA/NMDA ratios compared to cocaine use following food SA. Further, oxycodone SA alone was associated with reduced AMPA/NMDA ratio. Together, behavioral signs of oxycodone withdrawal may drive cocaine use and further dysregulate NAcore glutamate signaling.

Higher perceived stress during admission is associated with shorter retention in short-term residential substance use disorder treatment

Introduction

Over one million people in the U.S. received residential treatment for a substance use disorder (SUD) in 2020. Longer treatment retention is associated with better outcomes (e.g., reduced substance use). Entering treatment with higher stress may be associated with shorter retention. This paper examines the impact of perceived stress at admission on SUD treatment retention in short-term residential treatment.

Methods

A sample of 271 treatment episodes with admissions between October 2019 and February 2020 were collected from de-identified records of an urban mid-Atlantic adult 28-day short-term residential SUD treatment facility. Treatment completion involved finishing 28 days. Sociodemographic, substance use, perceived stress, and treatment discharge variables were analyzed. Bivariate analyses examined differences between treatment completion and early discharge, and Cox regression investigated the effect of perceived stress on treatment retention with covariates.

Results

The sample was primarily male (73.8%) and non-Hispanic Black (71.6%). A majority used heroin as their primary substance (54.6%) and reported polysubstance use (72.3%). About half (51.3%) completed treatment, and completed an average of 18.7 (SD = 10.7) days. Those who prematurely discharged from treatment stayed an average of 8.9 (SD = 7.0) days. The Cox regression model found that higher perceived stress (adjusted hazard ratio (AHR) = 1.028; 95% CI = [1.005, 1.053], p =.019) and a race/ethnicity other than non-Hispanic Black (AHR = 1.546, 95% CI = [1.037, 2.305], p =.033) predicted premature discharge.

Conclusions

Perceived stress at admission is associated with shorter treatment retention. Early stress management interventions may help increase treatment retention.

Association of Urine Fentanyl Concentration With Severity of Opioid Withdrawal Among Patients Presenting to the Emergency Department

BACKGROUND AND AIMS

Fentanyl is involved in most US drug overdose deaths and its use can complicate opioid withdrawal management. Clinical applications of quantitative urine fentanyl testing have not been demonstrated previously. The aim of this study was to determine whether urine fentanyl concentration is associated with severity of opioid withdrawal.

DESIGN

This is a retrospective cross-sectional study.

SETTING

This study was conducted in 3 emergency departments in an urban, academic health system from January 1, 2020, to December 31, 2021.

PARTICIPANTS

This study included patients with opioid use disorder, detectable urine fentanyl or norfentanyl, and Clinical Opiate Withdrawal Scale (COWS) recorded within 6 hours of urine drug testing.

MEASUREMENTS

The primary exposure was urine fentanyl concentration stratified as high (>400 ng/mL), medium (40-399 ng/mL), or low (<40 ng/mL). The primary outcome was opioid withdrawal severity measured with COWS within 6 hours before or after urine specimen collection. We used a generalized linear model with γ distribution and log-link function to estimate the adjusted association between COWS and the exposures.

FINDINGS

For the 1127 patients in our sample, the mean age (SD) was 40.0 (10.7), 384 (34.1%) identified as female, 332 (29.5%) reported their race/ethnicity as non-Hispanic Black, and 658 (58.4%) reported their race/ethnicity as non-Hispanic White. For patients with high urine fentanyl concentrations, the adjusted mean COWS (95% confidence interval) was 4.4 (3.9-4.8) compared with 5.5 (5.1-6.0) among those with medium and 7.7 (6.8-8.7) among those with low fentanyl concentrations.

CONCLUSIONS

Lower urine fentanyl concentration was associated with more severe opioid withdrawal, suggesting potential clinical applications for quantitative urine measurements in evolving approaches to fentanyl withdrawal management.

The importance of translationally evaluating steroid hormone contributions to substance use

Clinically, women appear to be more susceptible to certain aspects of substance use disorders (SUDs). The steroid hormones 17β-estradiol (E2) and progesterone (Pg) have been linked to women-specific drug behaviors. Here, we review clinical and preclinical studies investigating how cycling ovarian hormones affect nicotine-, cocaine-, and opioid-related behaviors. We also highlight gaps in the literature regarding how synthetic steroid hormone use may influence drug-related behaviors. In addition, we explore how E2 and Pg are known to interact in brain reward pathways and provide evidence of how these interactions may influence drug-related behaviors. The synthesis of this review demonstrates the critical need to study women-specific factors that may influence aspects of SUDs, which may play important roles in addiction processes in a sex-specific fashion. It is important to understand factors that impact women's health and may be key to moving the field forward toward more efficacious and individualized treatment strategies.