A systematic review of sex differences in treatment outcomes among people with opioid use disorder receiving buprenorphine maintenance versus other treatment conditions

Predicting buprenorphine adherence among patients with opioid use disorder in primary care settings

BACKGROUND

Medications for opioid use disorder (MOUD), including buprenorphine, are effective treatments for opioid use disorder (OUD) and reduce risk for overdose and death. Buprenorphine can be prescribed in outpatient primary care settings to treat OUD; however, prior research suggests adherence to buprenorphine in these settings can be low. The purpose of this study was to identify the rates of and factors associated with buprenorphine adherence among patients with OUD in the first six months after a new start of buprenorphine.

METHODS

Data were extracted from the electronic health record (EHR) from a large integrated health system in the upper Midwest. Patients with OUD (N = 345; Mean age = 37.6 years, SD 13.2; 61.7% male; 78% White) with a new start of buprenorphine between March 2019 and July 2021 were included in the analysis. Buprenorphine adherence in the first six months was defined using medication orders; the proportion of days covered (PDC) with a standard cut-point of 80% was used to classify patients as adherent or non-adherent. Demographic (e.g., age, sex, race and ethnicity, geographic location), service (e.g., encounters, buprenorphine formulations and dosage) and clinical (e.g., diagnoses, urine toxicology screens) characteristics were examined as factors that could be related to adherence. Analyses included logistic regression with adherence group as a binary outcome.

RESULTS

Less than half of patients were classified as adherent to buprenorphine (44%). Adjusting for other factors, male sex (OR = 0.34, 95% CI = 0.20, 0.57, p < .001) and having an unexpected positive for opioids on urine toxicology (OR = 0.42, 95% CI = 0.21, 0.83, p < .014) were associated with lower likelihood of adherence to buprenorphine, whereas being a former smoker (compared to a current smoker; OR = 1.82, 95% CI = 1.02, 3.27, p = .014) was associated with greater likelihood of being adherent to buprenorphine.

CONCLUSIONS

These results suggest that buprenorphine adherence in primary care settings may be low, yet male sex and smoking status are associated with adherence rates. Future research is needed to identify the mechanisms through which these factors are associated with adherence.

Predictors of Patient-Initiated Discharge From an Inpatient Withdrawal Management Service: A Sex-Based Study

OBJECTIVES

The purpose of this study was to examine sex-stratified independent predictors of patient-initiated discharge from an inpatient withdrawal management service and to determine whether those predictors differed by sex.

METHODS

This study compared people who had self-initiated versus planned discharges and used sex-stratified generalized estimating equations models to identify independent predictors of patient-initiated discharge. Predictors examined included age, ethnicity, substance of concern, tobacco use, mental health comorbidities, day of discharge, referral source, children, and social assistance funds.

RESULTS

Among females, there were 722 discharges, 116 of which were patient initiated. Among females, increasing age was associated with lower odds of patient-initiated discharge ( OR = 0.97, 95% CI [0.95, 0.98]). Racialized females were nearly 2 times more likely to experience patient-initiated discharge compared with White females ( OR = 1.8, 95% CI [1.09, 3.00]). Compared with weekdays, weekends were associated with over 4 times the odds of patient-initiated discharge ( OR = 4.77, 95% CI [2.66, 8.56]). Having one or more mental health comorbidities was associated with lower odds of patient-initiated discharge compared with having no mental health comorbidities ( OR = 0.51, 95% CI [0.32, 0.82]). Among males, there were 1,244 discharges, 185 of which were patient initiated. Among males, increasing age was associated with decreased odds of patient-initiated discharge ( OR = 0.97, 95% CI [0.95, 0.98]). Compared with weekdays, weekends were associated with nearly 15 times the odds of patient-initiated discharge ( OR = 14.9, 95% CI [9.11, 24.3]).

CONCLUSIONS

Males and females have shared and unique predictors of patient-initiated discharge. Future studies should continue to examine the influence of sex and gender on engagement with addictions care.

PKMζ alters oxycodone-taking in a dose- and sex-dependent manner

Opioid use disorder involves disruptions to glutamate homeostasis and dendritic spine density in the reward system. PKMζ is an atypical isoform of protein kinase C that is expressed exclusively in neurons and plays a role in postsynaptic glutamate signaling and dendritic spine maturation. As opioid use leads to alterations in glutamate transmission and dendritic spine density, we hypothesized that PKMζ deletion would alter opioid-taking behaviors. The current study examined two doses of oxycodone self-administration in male and female mice with constitutive deletion of PKMζ compared to wildtype controls. At a dose of 0.25 mg/kg/infusion, PKMζ deletion significantly potentiated oxycodone self-administration in both male and female mice. However, increases in motivation for oxycodone, as indicated by increased breakpoint on a progressive ratio schedule, were only seen in male PKMζ knockout mice and not females. When we examined a lower dose of oxycodone, 0.125 mg/kg/infusion, PKMζ knockout led to increases in oxycodone self-administration only in female mice. Additionally, female PKMζ knockout mice exhibited higher breakpoints on a progressive ratio schedule at this dose compared to all other groups. In addition to the self-administration studies, we also examined locomotor sensitization in response to experimenter administered oxycodone. PKMζ KO decreased oxycodone induced locomotion in males and potentiated oxycodone sensitization in females. Together, these results suggest that PKMζ acts to dampen oxycodone taking in both sexes, but females may be more sensitive to its effects.

Building bridges to outpatient treatment services for post-overdose care via paramedic buprenorphine field initiation

INTRODUCTION

Despite sustained efforts to reduce opioid-related overdose fatalities, rates have continued to rise. In many areas, overdose response involves emergency medical service (EMS) personnel administering naloxone and transporting patients to the emergency department (ED). However, a substantial number of patients decline transport, and many EDs do not provide medication for opioid use disorder (MOUD). One approach to filling this gap involves delivering MOUD to overdose patients in the field with trained post-overdose EMS teams who can initiate buprenorphine. In this MOUD field initiation pilot program, a trained EMS Community Paramedicine team initiates buprenorphine in the field and links patients to care. The program includes three pathways to treatment with the first designed for EMS to initiate buprenorphine after overdose reversal when the patient is in withdrawal from naloxone; a second pathway initiates buprenorphine after overdose when the patient is not in withdrawal; and a third enables self-referral via a connection to the community EMS team not necessarily related to a recent overdose.

METHODS

We conducted a retrospective cohort study of the MOUD field initiation pilot program. Data are from 28 patients who entered care immediately post-overdose initiation of buprenorphine, 21 patients who initiated on buprenorphine while not in naloxone withdrawal, and 37 patients who self-referred to treatment following outreach efforts by paramedicine and peer support professionals.

RESULTS

A total of 118 patients initiated buprenorphine during the 12-month study period and 104 (83 %) visited the clinic for their first appointment. Over two thirds (68 %, n = 80) remained engaged in care after 30 days. Retained patients tended to be male, white, uninsured, food insecure, have unstable housing, lack reliable transportation, and report prior involvement with the criminal legal system.

CONCLUSION

The initial 12-month period of the pilot program demonstrated the feasibility of initiating buprenorphine at the site of overdose without requiring transport to the ED and offer self-referral pathways for people experiencing barriers to treatment. Specialized EMS can play a critical role in expanding access to MOUD treatment by bridging the gap between overdose and comprehensive community-based care.

Sex specific effects of buprenorphine on adult hippocampal neurogenesis and behavioral outcomes during the acute phase after pediatric traumatic brain injury in mice

Traumatic brain injury (TBI) in children often causes cognitive and mental dysfunctions, as well as acute and chronic pain. Adult hippocampal neurogenesis plays a key role in cognition, depression, and pain. Adult hippocampal neurogenesis can be modulated by genetic and environmental factors, such as TBI and opioids. Buprenorphine (BPN), a semisynthetic opioid, is commonly used for pain management in children, however, the effects of BPN on adult hippocampal neurogenesis after pediatric TBI are still unclear. This study investigated the sex-specific effects of BPN on adult hippocampal neurogenesis during acute phase after pediatric TBI. Male and female littermates were randomized on postnatal day 20-21(P20-21) into Sham, TBI+saline and TBI+BPN groups. BPN was administered intraperitoneally to the TBI+BPN mice at 30 min after injury, and then every 6-12 h (h) for 2 days (d). Bromodeoxyuridine (BrdU) was administered intraperitoneally to all groups at 2, 4, 6, and 8-h post-injury. All outcomes were evaluated at 3-d post-BrdU administration. We found that TBI induced significant cognitive impairment, depression, and reduced adult hippocampal neurogenesis in both male and female mice, with more prominent effects in females. BPN significantly improved adult hippocampal neurogenesis and depression in males, but not in females. We further demonstrated that differential expressions of opioid receptors, transcription factors and neuroinflammatory markers at the neurogenic niche might be responsible for the differential effects of BPN in males and females. In conclusion, this study elucidates the effects of BPN on adult hippocampal neurogenesis and behavioral outcomes at the acute phase after pediatric TBI.

Clinical and psychosocial outcomes by sex among individuals prescribed buprenorphine-naloxone (BUP-NX) or extended-release naltrexone (XR-NTX) for opioid use disorder

BACKGROUND AND OBJECTIVES

Limited research has explored sex differences in opioid use disorder medication (MOUD) treatment outcomes. The purpose of this study was to examine MOUD initiation onto buprenorphine-naloxone (BUP-NX) versus extended-release naltrexone (XR-NTX) by sex, and sex differences in clinical and psychosocial outcomes.

METHODS

Using data from a 24-week open-label comparative effectiveness trial of BUP-NX or XR-NTX, this study examined MOUD initiation (i.e., receiving a minimum one XR-NTX injection or first BUP-NX dose) and 24-week self-report outcomes. We used regression models to estimate the probability of MOUD initiation failure among the intent-to-treat sample (N = 570), and the main and interaction effects of sex on outcomes of interest among the subsample of participants who successfully initiated MOUD (n = 474).

RESULTS

In the intent-to-treat sample, the odds of treatment initiation failure were not significantly different by sex. In the subsample of successful MOUD initiates, the effect of treatment on employment at week 24 was significantly moderated by sex (p = .003); odds of employment were not significantly different among males by MOUD type; females randomized to XR-NTX versus BUP-NX had 4.63 times greater odds of employment (p < .001). Males had significantly lower odds of past 30-day exchanging sex for drugs versus females (adjusted odds ratios [aOR] = 0.10, p = .004), controlling for treatment and baseline outcomes.

DISCUSSION AND CONCLUSIONS

Further research should explore how to integrate employment support into OUD treatment to improve patient outcomes, particularly among women.

SCIENTIFIC SIGNIFICANCE

The current study addressed gaps in the literature by examining sex differences in MOUD initiation and diverse treatment outcomes in a large, national sample.

Male patients' preferences for opioid use treatment programs

BACKGROUND

A patient-centered approach to the treatment of substance use is helpful in achieving positive treatment outcomes. This study aimed to explore male patients' preferences for opioid use treatments.

METHODS

A qualitative study was conducted in Isfahan, a city in the center of Iran. The study sample included 64 male participants who had started treatment for opioid use disorder (OUD). Using a purposive maximum variation sampling procedure, seven treatment centers were selected as interview venues. The semi-structured face-to-face interviews were conducted in a private room in the selected centers. A hybrid inductive/deductive approach was used to thematize the interview transcripts.

RESULTS

A total of three themes and 13 subthemes on opioid treatment preferences were identified: treatment concerns (anonymity, social stigma, fear of treatment distress, and family concerns), treatment attributes (treatment cost, location of the treatment center, treatment period, frequency of attendance, informed treatment, and treatment personnel), and treatment type (maintenance or abstinence and residential and community treatments). The study showed that all treatment programs were perceived to have their own strengths and weaknesses.

CONCLUSIONS

The results showed that patients with OUD carefully compare the positive and negative aspects of existing treatment programs, and they consider a treatment program to be a package of favorable and non-favorable qualities. The identified themes could inform policymakers about the treatment preferences of male patients and provide an opportunity to promote better treatment options for OUD.

Association of receiving opioid medication-assisted treatment with sexual identity and mental health/substance use disorder symptoms in a nationally representative sample of adults

Background

Although the literature suggests that medication-assisted treatment (MAT) is an effective treatment for opioid use disorder, limited studies have assessed the prevalence or the association between MAT use and sexual identity, mental health, or substance use disorder among a nationally representative sample. We assessed the prevalence and association of opioid MAT use between sexual identity, depressive disorder symptoms, alcohol use dependence, and marijuana use dependence in the United States.

Methods

We used the 2019 National Survey on Drug Use and Health public-use data on adults aged 18-64 years (N = 38,841) to conduct a weighted multivariable logistic regression analysis.

Results

A total of 4.80% and 2.32% of the population identified as bisexual and lesbian/gay, respectively. About 0.31% (612,750 people) of the population reported receiving opioid MAT, 3.73% had alcohol use dependence, 1.42% had marijuana use dependence, and 9.13% had major depressive episode (MDE) symptoms. Of those who had received opioid MAT, 0.57% were bisexuals and 1.07% were lesbians/gays, 0.65% were people with alcohol use dependence, 2.32% with marijuana use dependence, and 1.59% with MDE symptoms. Lesbian/gay individuals were more likely to receive opioid MAT (AOR = 3.43, 95% CI = 1.42, 8.25) compared to heterosexual individuals. The odds were higher for people with marijuana use dependence (AOR = 3.44, 95% CI = 1.47, 8.06) and MDE symptoms (AOR = 5.22, 95% CI = 3.46, 7.89) than their counterparts.

Conclusions

In this study, sexual minorities, people with MDE symptoms, and those dependent on marijuana use were more likely to receive opioid MAT, suggesting the need to investigate further opioid use disorder symptoms and their risk factors among these populations.

Sex differences in the medial prefrontal cortical glutamate system

BACKGROUND

Dysregulation in the prefrontal cortex underlies a variety of psychiatric illnesses, including substance use disorder, depression, and anxiety. Despite the established sex differences in prevalence and presentation of these illnesses, the neural mechanisms driving these differences are largely unexplored. Here, we investigate potential sex differences in glutamatergic transmission within the medial prefrontal cortex (mPFC). The goal of these experiments was to determine if there are baseline sex differences in transmission within this region that may underlie sex differences in diseases that involve dysregulation in the prefrontal cortex.

METHODS

Adult male and female C57Bl/6J mice were used for all experiments. Mice were killed and bilateral tissue samples were taken from the medial prefrontal cortex for western blotting. Both synaptosomal and total GluA1 and GluA2 levels were measured. In a second set of experiments, mice were killed and ex vivo slice electrophysiology was performed on prepared tissue from the medial prefrontal cortex. Spontaneous excitatory postsynaptic currents and rectification indices were measured.

RESULTS

Females exhibit higher levels of synaptosomal GluA1 and GluA2 in the mPFC compared to males. Despite similar trends, no statistically significant differences are seen in total levels of GluA1 and GluA2. Females also exhibit both a higher amplitude and higher frequency of spontaneous excitatory postsynaptic currents and greater inward rectification in the mPFC compared to males.

CONCLUSIONS

Overall, we conclude that there are sex differences in glutamatergic transmission in the mPFC. Our data suggest that females have higher levels of glutamatergic transmission in this region. This provides evidence that the development of sex-specific pharmacotherapies for various psychiatric diseases is important to create more effective treatments.

A novel long-acting formulation of oral buprenorphine/naloxone produces prolonged decreases in fentanyl self-administration by rhesus monkeys

BACKGROUND

Due to the poor oral bioavailability of buprenorphine, an oral formulation has not been thought possible. Lyndra Therapeutics is developing a once-weekly long-acting oral product containing buprenorphine. We evaluated the efficacy of this formulation in reducing intravenous (i.v.) fentanyl self-administration by three male and three female rhesus monkeys.

METHODS

Buprenorphine HCl and naloxone HCl were co-formulated using an 11:1 ratio of buprenorphine:naloxone in a controlled-release gastric residence formulation administered in an oral capsule (LYN-013). Naloxone was included to determine the feasibility of combining naloxone with buprenorphine in the formulation as an abuse deterrent. Complete fentanyl dose-response functions were determined during each session. The efficacy of single doses of 56/5, 112/10 and 168/15 mg buprenorphine/naloxone in reducing fentanyl self-administration was examined over 13 days.

RESULTS

LYN-013 significantly decreased the rate of responding for fentanyl for 3 days and significantly reduced total intake of fentanyl for 8 days. Time to maximal buprenorphine levels (Tmax) ranged between 56 and 68 h for all 3 doses. The maximal buprenorphine level (Cmax) following 168 mg was 2.3 ng/ml which was significantly greater that those observed for 56 mg (1.22 ng/ml) and 112 mg (1.35 ng/ml). Finally, the area-under-curves (AUCtau) were buprenorphine dose-dependently increased from 88 to 127-265 h*ng/ml. There were no signs of non-specific changes in behavior.

CONCLUSIONS

A once-weekly oral buprenorphine/naloxone formulation produced sustained suppression of fentanyl self-administration in monkeys suggesting that oral delivery of buprenorphine with this formulation could provide a new opportunity to treat opioid use disorders (OUD).

The Impact of Individual Counseling on Treatment for Opioid Use

ABSTRACT

In 2018, more than 67,000 people died because of drug overdoses, and of that number, approximately 69.5% involved an opioid, making it a leading cause of death in the United States. Additionally concerning is that 40 states have reported increased overdose deaths and opioid-related deaths since the start of the COVID-19 global pandemic. Presently, many insurance companies and healthcare providers require patients to receive counseling during medication treatment for opioid use disorder (OUD), despite the lack of evidence that it is necessary for all patients. To inform policy and improve quality of treatment, this nonexperimental, correlational study examined the relationship between individual counseling status and treatment outcomes in patients receiving medication treatment for OUD. Treatment outcome variables (treatment utilization, medication use, and opioid use) were extracted from the electronic health records of 669 adults who received treatment between January 2016 and January 2018. Study findings suggest women in our sample were more likely to test positive for benzodiazepines (t = -4.3, p < .001) and amphetamines (t = -4.4, p < .001), whereas men used alcohol at higher rates than women (t = 2.2, p = .026). In addition, women were more likely to report having experienced Post-Traumatic Stress Disorder/trauma (χ2 = 16.5, p < .001) and anxiety (χ2 = 9.4, p = .002). Regression analyses revealed concurrent counseling was unrelated to medication utilization and ongoing opioid use. Patients who had prior counseling utilized buprenorphine more frequently (β = 0.13, p < .001) and used opioids less often (β = -0.14, p < .001); however, both relationships were weak. These data do not provide evidence that counseling during OUD outpatient has a significant impact on treatment outcomes. These findings provide further evidence that barriers to medication treatment such as mandatory counseling can and should be removed.

Sex specific effects of buprenorphine on behavior, astrocytic opioid receptor expression and neuroinflammation after pediatric traumatic brain injury in mice

Children who suffered traumatic brain injury (TBI) often experience acute and chronic pain, which is linked to a poor quality of life. Buprenorphine (BPN) is commonly used to treat moderate to severe persistent pain in children, however, the efficacy and safety profile of BPN in the pediatric population is still inconclusive. This study investigated the sex-specific effects of BPN on body weight, motor coordination and strength, expression of opioid receptors in the white matter astrocytes, and neuroinflammation in a mouse impact acceleration model of pediatric TBI. Male and female littermates were randomized on postnatal day 20-21(P20-21) into Sham, TBI + saline and TBI + BPN groups. Mice in the TBI + saline and TBI + BPN groups underwent TBI, while the Sham group underwent anesthesia without injury. BPN (0.075 mg/kg) was administered to the TBI + BPN mice at 30 min after injury, and then every 6-12 h for 2 days. Mice in the TBI + saline group received the same amount of saline injections. The impact of BPN on body weight, motor function, opioid receptor expression, and neuroinflammation was evaluated at 1-day (d), 3-d and 7-d post-injury. We found that 1) TBI induced significant weight loss in both males and females. BPN treatment improved weight loss at 3-d post-injury in females. 2) TBI significantly impaired motor coordination and strength. BPN improved motor coordination and strength in both males and females at 1-d and 3-d post-injury. 3) TBI significantly decreased exploration activity at 1-d post-injury in males, and at 7-d post-injury in females, while BPN improved the exploration activity in females. 4) TBI significantly increased mRNA expression of mu-opioid receptors (MOR) at 7-d post-injury in males, but decreased mRNA expression of MOR at 1-d post-injury in females. BPN normalized MOR mRNA expression at 1-d post-injury in females. 5) MOR expression in astrocytes at corpus callosum significantly increased at 7-d post-injury in male TBI group, but significantly decreased at 1-d post-injury in female TBI group. BPN normalized MOR expression in both males and females. 6) TBI significantly increased the mRNA expression of TNF-α, IL-1β, IL-6 and iNOS. BPN decreased mRNA expression of iNOS, and increased mRNA expression of TGF-β1. In conclusion, this study elucidates the sex specific effects of BPN during the acute phase after pediatric TBI, which provides the rationale to assess potential effects of BPN on chronic pathological progressions after pediatric TBI in both males and females.

Consideration of sex and gender differences in addiction medication response

Substance use continues to contribute to significant morbidity and mortality in the United States, for both women and men, more so than another other preventable health condition. To reduce the public health burden attributable to substances, the National Institute on Drug Abuse and the National Institute on Alcohol Abuse and Alcoholism have identified that medication development for substance use disorder is a high priority research area. Furthermore, both Institutes have stated that research on sex and gender differences in substance use medication development is a critical area. The purpose of the current narrative review is to highlight how sex and gender have been considered (or not) in medication trials for substance use disorders to clarify and summarize what is known regarding sex and gender differences in efficacy and to provide direction to the field to advance medication development that is consistent with current NIH 'sex as a biological variable' (SABV) policy. To that end, we reviewed major classes of abused substances (nicotine, alcohol, cocaine, cannabis, opioids) demonstrating that, sex and gender have not been well-considered in addiction medication development research. However, when adequate data on sex and gender differences have been evaluated (i.e., in tobacco cessation), clinically significant differences in response have been identified between women and men. Across the other drugs of abuse reviewed, data also suggest sex and gender may be predictive of outcome for some agents, although the relatively low representation of women in clinical research samples limits making definitive conclusions. We recommend the incorporation of sex and gender into clinical care guidelines and improved access to publicly available sex-stratified data from medication development investigations.

Analysis of female enrollment in clinical trials for alcohol and substance use disorders: Is it time for sex-informed pharmacotherapy?

BACKGROUND

Women represent an increasing number of individuals with alcohol and substance use disorders (ASUDs), and sex-differences might affect results of interventional clinical trials (CTs). We aim at assessing the proportion of women and the reporting of sex-stratified and female-specific data in CTs for ASUDs.

METHODS

We extracted data from ClinicalTrials.gov on Phase 1-3 CTs of investigational drugs for ASUDs conducted from 2000 to 2021 and identified articles related to these trials. We determined the average proportions of women enrolled per trial overall, over time, and by disease area and trial phase. Next, we calculated the proportion of articles reporting sex-stratified and female-specific data.

RESULTS

In the 234 CTs identified, the overall proportion of women was 33.4% [95% CI: 32.7%-33.9%]), with an increasing temporal trend. Women's participation was higher in CTs of investigational drugs for tobacco (43.5% [95% CI: 42.4% -44.5%]) and alcohol use disorder (35.9% [95% CI: 34.54%-37.21%]), and closely mirrored their representation in the disease populations (46% and 37%). Conversely, women were underrepresented in clinical trials of drugs for stimulants and cocaine use disorders (25.8% [95% CI: 24.6%-27.1%]) and opioid use disorders (25.9% [95% CI:24.2%-27.7%]). Nine publications reported sex-stratified data in the method and/or result section, whereas none documented female-specific data.

CONCLUSIONS

Enrollment of women in ASUDs CTs has increased over time but remains low in several disease areas. This, together with the low rates of reporting of sex-stratified data, calls for an adequate inclusion of sex in the design and analysis of CTs for ASUDs.

Gender-specific correlates of nonmedical use of prescription medications in a diverse primary care sample

BACKGROUND

Nonmedical use of prescription medications (NUPM) is a growing problem but little is known about its gender-specific mechanisms despite NIDA's call for gender-stratified research over a decade ago. We explored gender differences in NUPM in a diverse sample of primary care patients.

METHODS

N = 4458 participants participated in an anonymous health survey in urban primary care clinics. The primary outcome was past month NUPM. All analyses were stratified by gender. Bivariate relationships among NUPM and demographic, medical, psychological, and substance use-related variables were analyzed. Stepwise multivariate logistic regression models (LRMs) were estimated by gender.

RESULTS

More men (9.5%) reported NUPM than women (7.4%). The final LRM among men included age (OR=0.98), race (OR=0.49), chronic pain diagnosis (OR=1.73), hepatitis (OR=1.78), depression diagnosis (OR=1.77), positive alcohol misuse screen (OR=1.58), and mood disturbance (OR=1.04). Among women, the model included mood disturbance (OR=1.04), illicit drug use (OR=2.22), family history of drug problems (OR=1.41), and heart disease diagnosis (OR=0.48). Effect sizes ranged from small to moderate.

CONCLUSIONS

Among a sample of primary care patients, gender-stratified analyses indicated differential presentation of NUPM by gender. Demographic factors were more relevant correlates among men, with younger, White men at higher risk. Chronic pain and depression were more notable risk factors for men. Recent illicit drug use and family history of drug problems were uniquely associated among women, while recent distress was a strong correlate among both men and women. A better understanding of gender-specific correlates of NUPM can inform gender-tailored prevention and treatment efforts.

Trends in Mortality From Novel Psychoactive Substances as "Legal Highs": Gender Differences in Manner of Death and Implications for Risk Differences for Women

Introduction

This study aimed to examine drug-related deaths in the UK in which novel psychoactive substances (NPS) are an implicated substance, and to focus on female deaths in comparison with male deaths. While male overdoses dominate epidemiological statistics, there is an increase in female drug-related deaths and a narrowing of the gap between gender mortality rates which is to date unexplained.

Method

This study analyzed data from the National Programme for Substance Abuse Deaths (NPSAD) database that records drug-related deaths in the UK from coronial records. A dataset was constructed using parameters to capture all drug-related cases during the period 2007-2017 when NPS were legal and highly available in the UK, in order to capture deaths recorded among both regular and occasional drug users, and to include all cases recorded during that period regardless of NPS status in order to make comparisons. The final dataset comprised 10,159 cases, with 456 NPS-related deaths. Data for NPS and non-NPS were compared, and comparisons were made between cohorts by gender. The dataset also includes coronial narrative notes which allowed a qualitative analysis of NPS female deaths to add contextual explanation.

Results

The proportion of male NPS deaths is significantly higher than that for female NPS deaths but does not reflect the generalized difference between male and female drug-related mortality of this period studied. Demographic and outcome data by gender difference were significant for all drug-related deaths, but not for NPS-only deaths, indicating a greater homogeneity among NPS deaths by gender. Older women using NPS were more likely to have methadone or diazepam as another drug implicated and have established histories of drug misuse.

Conclusion

Where NPS have been used, differences in drug death profiles are less likely to be accounted for by gender than other demographic or behavioral differences more typically found in opiate deaths. The social and health problems of older women may be key characteristics that differentiate female deaths from male deaths. These findings also support evidence of increasing uptake of NPS among older established drug users that adds further risk to polydrug use.

Systematic review and meta-analysis of retention in treatment using medications for opioid use disorder by medication, race/ethnicity, and gender in the United States

BACKGROUND AND AIMS

There is mounting evidence that opioid use disorder is experienced differently by people of different genders and race/ethnicity groups. Similarly, in the US access to specific medications for opioid use is limited by gender and race/ethnicity. This study aims to evaluate if gender or race/ethnicity is associated with different rates of treatment retention in the US, for each of three medications used to treat opioid use disorder.

METHODS

A systematic search was conducted using PubMed, CINHAL, and PsychINFO, databases. All studies that provided a ratio of those retained in treatment at a specified time in terms of gender and/or race/ethnicity and medication were included. Variables were created to assess the effects of time in treatment, recruited sample, required attendance at concurrent psychosocial treatment, and adherence to strict rules of conduct for continuation in treatment on retention. Meta-analytical and meta-regression methods were used to compare studies on the ratio of those who completed a specific time in treatment by race/ethnicity group and by gender.

RESULTS

Nineteen articles that provided the outcome variable of interest were found (11 buprenorphine, six methadone, and two naltrexone). Meta-analyses found that treatment retention was similar for all gender and racial/ethnic groups for all three medications. Meta-regression found that those of the African American group who were recruited into buprenorphine treatment were retained significantly longer than African Americans in buprenorphine treatment who were studied retrospectively. Also, both genders had significantly lower retention in methadone treatment when there was the additional requirement of psychosocial therapy.

Diversity inclusion in United States opioid pharmacological treatment trials: A systematic review

Pharmacological treatments for opioid use disorders (OUDs) may have mixed efficacy across diverse groups, i.e., sex/gender, race/ethnicity, and socioeconomic status (SES). The present systematic review aims to examine how diverse groups have been included in U.S. randomized clinical trials examining pharmacological treatments (i.e., methadone, buprenorphine, or naltrexone) for OUDs. PubMed was systematically searched according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. The initial search yielded 567 articles. After exclusion of ineligible articles, 50 remained for the present review. Of the included articles, 14.0% (n = 7) reported both full (i.e., accounting for all participants) sex/gender and race/ethnicity information; only two of those articles also included information about any SES indicators. Moreover, only 22.0% (n = 11) reported full sex/gender information, and 42.0% (n = 21) reported full racial/ethnic information. Furthermore, only 10.0% (n = 5) reported that their lack of subgroup analyses or diverse samples was a limitation to their studies. Particularly underrepresented were American Indian/Alaska Native (AI/AN), Asian, Native Hawaiian/Other Pacific Islander (NH/OPI), and multiracial individuals. These results also varied by medication type; Black individuals were underrepresented in buprenorphine randomized controlled trials (RCTs) but were well represented in RCTs for methadone and/or naltrexone. In conclusion, it is critical that all people receive efficacious pharmacological care for OUDs given the ongoing opioid epidemic. Findings from the present review, however, support that participants from diverse or marginalized backgrounds are underrepresented in treatment trials, despite being at increased risk for disparities related to OUDs. Suggestions for future research are advanced. (PsycInfo Database Record (c) 2021 APA, all rights reserved).

Gender disparities in opioid treatment progress in methadone versus counseling

BACKGROUND

In the United States, the high dropout rate (75%) in opioid use disorder (OUD) treatment among women and racial/ethnic minorities calls for understanding factors that contribute to making progress in treatment. Whereas counseling and medication for OUD (MOUD, e.g. methadone, buprenorphine, naltrexone) is considered the gold standard of care in substance use disorder (SUD) treatment, many individuals with OUD receive either counseling or methadone-only services. This study evaluates gender disparities in treatment plan progress in methadone- compared to counseling-based programs in one of the largest SUD treatment systems in the United States.

METHODS

Multi-year and multi-level (treatment program and client-level) data were analyzed using the Integrated Substance Abuse Treatment to Eliminate Disparities (iSATed) dataset collected in Los Angeles County, California. The sample consisted of 4 waves: 2011 (66 SUD programs, 1035 clients), 2013 (77 SUD programs, 3686 clients), 2015 (75 SUD programs, 4626 clients), and 2017 (69 SUD programs, 4106 clients). We conducted two multi-level negative binomial regressions, one per each outcome (1) making progress towards completing treatment plan, and (2) completing treatment plan. We included outpatient clients discharged on each of the years of the study (over 95% of all clients) and accounted for demographics, wave, homelessness and prior treatment episodes, as well as clients clustered within programs.

RESULTS

We detected gender differences in two treatment outcomes (progress and completion) considering two outpatient program service types (MOUD-methadone vs. counseling). Clients who received methadone vs. counseling had lower odds of completing their treatment plan (OR = 0.366; 95% CI = 0.163, 0.821). Female clients receiving methadone had lower odds of both making progress (OR = 0.668; 95% CI = 0.481, 0.929) and completing their treatment plan (OR = 0.666; 95% CI = 0.485, 0.916) compared to male clients and receiving counseling. Latina clients had lower odds of completing their treatment plan (OR = 0.617; 95% CI = 0.408, 0.934) compared with non-Latina clients.

CONCLUSIONS

Clients receiving methadone, the most common and highly effective MOUD in reducing opioid use, were less likely to make progress towards or complete their treatment plan than those receiving counseling. Women, and in particular those identified as Latinas, were least likely to benefit from methadone-based programs. These findings have implications for health policy and program design that consider the need for comprehensive and culturally responsive services in methadone-based programs to improve outpatient treatment outcomes among women.

An Exploratory Study of Sex and Gender Differences in Demographic, Psychosocial, Clinical, and Substance Use Treatment Characteristics of Patients in Outpatient Opioid Use Disorder Treatment with Buprenorphine

As treatment expansion in the opioid epidemic continues, it is important to examine how the makeup of individuals with opioid use disorder (OUD) is evolving. Treatment programs are increasingly utilizing buprenorphine, an effective OUD medication. This exploratory study examines sex and gender differences in psychosocial, clinical and substance use treatment characteristics of a clinical population in outpatient medication treatment for OUD with buprenorphine. This is a secondary data analysis from a cross-sectional survey study with retrospective medical record review conducted with patients recruited from an office-based opioid treatment clinic between July-September 2019. Participants on buprenorphine for at least 28 days at time of survey completion were included (n=133). Differences between men and women were explored with Pearson χ2 and Fisher's Exact Tests for categorical variables and T-Tests for continuous variables. The sample was 55.6% women and nearly three-fourths Black (70.7%). Mean days in current treatment episode was 431.6 (SD=244.82). Women were younger and more likely to be unemployed, identify as a sexual minority, and live alone with children than men. More women than men had a psychiatric comorbidity. Women reported more prescription opioid misuse while men had more heroin only opioid use. More men reported comorbid alcohol use and a history of drug overdose. One-third of participants reported recent discrimination in a healthcare setting due to substance use. As buprenorphine-based outpatient treatment programs continue to expand, present study findings support evaluation of the unique needs of men and women in order to better tailor OUD-related services and improve treatment outcomes.

Gender disparities in access and retention in outpatient methadone treatment for opioid use disorder in low-income urban communities

The purpose of this study was to detect and understand gender disparities in access and retention among outpatient methadone treatment programs located in low-income urban communities in Los Angeles, California. The study collected client- and program-level data in 4 waves in 2011, 2013, 2015, and 2017 from 34 publicly funded methadone treatment programs serving 11,169 clients with opioid use disorder (OUD). The sample included 29.8% female and 70.2% male clients, where 10.6% identified as Black or African American, 41.5% as Latino, 44.2% as non-Latino white, and 3.8% as Other. We conducted two multilevel negative binomial regression models to examine direct and moderated relationships related to both access (days on the waitlist) and retention (days in treatment) while accounting for clients clustered within programs. Gender disparities existed in both access and retention where women spent more time than men waiting to enter treatment but then remained in treatment longer. Further, female clients identifying as African American, Latino, and Other were at greater risk for shorter treatment duration than those who identified as non-Latino white and men. Overall, OUD clients receiving methadone treatment in low-income neighborhoods experienced barriers to access and retention in treatment associated with mental illness, family responsibilities, and use severity. OUD clients with MediCal insurance eligibility were consistently more likely to gain access to and remain in methadone treatment. Overall, findings call for improving treatment access and retention for women with OUD who receive methadone in outpatient methadone treatment programs through comprehensive, gender-specific, and evidence-based programming.

Sex-specific risk profiles for substance use among college students

INTRODUCTION

Growing evidence indicates sex and gender differences exist in substance use. Framed by a lifecourse perspective, we explored prospectively by sex the effects of distal and proximal factors on the initiation of drug use in college.

METHODS

College students without prior drug use (n = 5,120 females; n = 2,951 males) were followed longitudinally across 4 years. Analyses were estimated as a multigroup survival analysis separately by sex within a latent variable SEM framework with illicit drug use (6 or more times in past year) as the latent factor.

RESULTS

More males initiated drug use (8.5%) than females (6.4%, χ2 (1) = 10.351, p = .001), but less so for Black males (AOR 0.33, 95% CI [0.18, 0.60]) and females (0.35 [0.23, 0.54]). Students initiating drug use more likely included students smoking cigarettes at baseline (males 1.40 [1.23, 1.59]; females 1.43 [1.24, 1.64]), using alcohol (males 1.04 [1.02, 1.06]; females 1.04 [1.02, 1.06]), or having cannabis using peers (males 1.79 [1.52, 2.11]; females 1.70 [1.49, 1.93]). Impulsivity domain associations differed by sex [negative urgency: females (1.23 [1.02, 1.49) and sensation seeking: males (1.33 [1.01, 1.75])]. History of unwanted/uncomfortable sexual experience predicted drug use for males (1.60 [1.09, 2.35]) and females (1.95 [1.45, 2.62]) but physical assault only for females (1.45 [1.08, 1.94]). Mood symptoms predicted drug use only for males [depression (0.73 [0.56, 0.95]); anxiety (1.40 [1.04, 1.89])].

CONCLUSIONS

Risk factors for initiating drug use during college differ by sex. As substance use during early age predisposes one for addiction, sex- and gender-informed interventions for young adults are needed.

Women, opioid use and addiction

In the midst of the current coronavirus pandemic, the United States continues to struggle with an ongoing opioid epidemic, initially fueled by widespread prescribing of opioid medications during the 1990s. The primary reason for prescribing opioids is to treat pain. Women have more acute and chronic pain and have been prescribed these drugs in significantly greater numbers than men. Comparison of women and men with chronic pain also shows that women receive the majority of prescription opioids, and the use of these prescribed medications became the major pathway to misuse and addiction for women. Yet, recognition of the extent of women's exposure to opioids and the attendant consequences has been limited. Attempts to stem the overall tide of the epidemic focused on reducing the availability of prescription opioids. However, as these medications became more difficult to obtain and treatment opportunities were limited, many turned to other synthetic opioids, such as heroin and fentanyl. Thus, the public health crisis of opioid addiction has endured. This paper highlights the importance of understanding differences among women and men in opioid use and its biological and psychosocial effects to advance the gender-based treatment approaches and effective public health policy.

Challenges for Women Entering Treatment for Opioid Use Disorder

PURPOSE OF REVIEW

Women with opioid use disorder (OUD) face unique challenges the moment they enter treatment. This narrative review focused on recent literature regarding sex- and gender-based issues that could affect treatment outcomes in women with OUD.

RECENT FINDINGS

Women respond differently to opioids based on hormonal factors, are more likely to present to treatment with mental health conditions, especially depression, and are more likely to have experienced trauma via intimate partner violence compared with men. Women also face stigma when entering OUD treatment, particularly if they have children. Future research to improve OUD treatment outcomes in women should account for sex as a biological variable and gender as a social construct. Women have a fundamentally different experience than men during the course of OUD and upon treatment entry. Programs that address childcare/family support, mental health, and trauma are warranted for women with OUD.

The Influence of Co-Occurring Substance Use on the Effectiveness of Opiate Treatment Programs According to Intervention Type

This systematic review describes the influence of co-occurring substance use on the effectiveness of opiate treatment programs. MEDLINE/PubMed, Embase, PsychINFO, and the Cumulative Index to Nursing and Allied Health Literature were searched from database inception to November 28, 2018, to identify eligible opioid treatment studies in the United States that assessed the relationship between co-occurring substance use and treatment outcome (i.e., opioid abstinence and treatment retention). A total of 34 eligible studies were included. Overall, co-occurring substance use was associated with negative treatment outcomes regardless of intervention type. However, patterns varied by substance and intervention type. In particular, co-occurring use of cocaine or marijuana with opioids was associated with reduced treatment retention and opioid abstinence regardless of intervention type. Co-occurring use of amphetamines, compared with no use or reduced use of amphetamines, decreased treatment retention. Co-occurring use of alcohol was both positively and negatively associated with treatment outcomes. One study reported a significant positive association between sedative use and opioid abstinence. Generally, findings suggest that combined interventions reported better health outcomes compared with pharmacological or behavioral intervention studies alone. The findings of this review emphasize the need to comprehensively study and address co-occurring substance use to improve opiate treatment programs.

Social functioning outcomes in men and women receiving medication-assisted treatment for opioid use disorder

Background

Social functioning (SF), the ability to engage with life and fulfill roles may be a salient “patient important outcome” in addiction treatment. It is not known if medication-assisted treatment (MAT) impacts SF in opioid use disorder (OUD). There is a growing evidence to suggest that men and women are impacted differently by OUD. This study is the largest to date to study sex differences in OUD and explore associations between MAT and SF.

Methods

Data were collected from 2736 participants with OUD, enrolled in MAT for varying lengths of time, in outpatient clinics across Ontario. SF was defined according to the Maudsley Addiction Profile’s domains of (1) employment, (2) criminal activity, and (3) interpersonal conflict. Using logistic regression analysis, we examined sociodemographic and clinical factors associated with domains of SF.

Results

There were 1544 men (56%) and 1192 women (44%) in this study, and ages varied from 17 to 76 years for men and 18 to 69 years for women. At study entry, participants had been on MAT for a median of 2 years. Compared to men, women reported more psychological (mean MAP score 14/40, SD = 9.55, versus 11/40, SD = 8.64; p < 0.001) and physical symptoms (mean MAP score 17/40, SD = 7.70 versus 14/40, SD = 7.74; p < 0.001). More women reported unemployment(74% versus 58%; p < 0.0001) and interpersonal conflict (46% versus 35%; p < 0.0001). Men were more likely than women to report criminal activity (11%, versus 8%; p = 0.001). Psychological symptoms increased the risk of worse SF, across domains, for men and for women. Every year on MAT was associated with a 7% increase in the odds of women engaging with criminal activity (OR = 1.07, 95% CI 1.02, 1.12, p = 0.006).

Conclusions

Men and women had different SF profiles and psychological symptoms scores while on MAT. The length of time on MAT increased the risk of criminal activity in women, and overall, duration of MAT was not associated with improvement in SF. This may suggest that MAT alone may not support continual improvements in SF in OUD.