Understanding polydrug use: review of heroin and cocaine co-use

Psychostimulant and opioid abuse: A perspective from Uruguay

The number of people suffering from substance use disorder (SUD) worldwide has increased 45 % compared to the last decade according to the latest United Nations World Drug Report. This staggering increase, partly due to the recent COVID-19 pandemic, further raises the social and economic burden for nations. Prevention and treatment, two of the main strategies employed to curb the increase in SUD, have shown limited success despite our increasing understanding of the underlying processes of SUD. This review will focus on two main drug categories, psychostimulants, especially cocaine, and opioids since these are two of the most prevalent illicit drugs abused by the general public in low, middle, and high-income countries. The use of active adulterants (e.g. caffeine and illegally manufactured fentanyl, IMF) commonly employed in the preparation of illicit drugs will also be covered considering recent data which has shown that these adulterants may increase the health risk of psychostimulant and opioid users. Especially the high risk of the combined use of cocaine and IMF is detailed. An additional section will address drug abuse in women during pregnancy, as it constitutes a major public health concern due to the negative consequences on newborns and infants. Data from Uruguay is presented and compared to illegal drug use in other countries of South and North America. The rapidly changing drug market, together with the current prevalence of SUD, establishes the urgent need for new strategies and innovative treatments to manage this issue.

Explaining the high mortality among opioid-cocaine co-users compared to opioid-only users. A systematic review

RATIONALE

The opioid crisis in North America has recently seen a fourth wave, which is dominated by drug-related deaths due to the combined use of illicitly manufactured fentanyl [IMF] and stimulants such as cocaine and methamphetamine.

OBJECTIVES

A systematic review addressing the question why drug users combine opioids and stimulants and why the combination results in such a high overdose mortality: from specific and dangerous pharmacokinetic or pharmacodynamic interactions or from accidental poisoning?

RESULTS

Motives for the combined use include a more intensive high or rush when used at the same time, and some users have the unfounded and dangerous belief that co-use of stimulants will counteract opioid-induced respiratory depression. Overdose deaths due to combined (intravenous) use of opioids and stimulants are not likely to be caused by specific pharmacokinetic or pharmacodynamic interactions between the two drugs and it is unlikely that the main cause of overdose deaths is due to accidental poisoning.

CONCLUSION

The unexpectedly high overdose rates in this population could not be attributed to accidental overdosing or pharmacokinetic/pharmacodynamic interactions. The most likely explanation for the high rate of drug-related deaths in opioid-cocaine co-users is careless overdosing with either cocaine, opioid(s) or both, probably facilitated by the high level of preexisting impulsivity in these co-users and a further acute increase in impulsivity following cocaine use. The primary corollary is that cocaine users should avoid IMF use in the same time window. In addition, IMF users should refrain from cocaine use to avoid impulsive IMF overdosing.

Patterns of polydrug use among Black Americans who misuse opioids

In the United States, opioid-related deaths involving polydrug use are now more prevalent than those involving only opioids. What often goes unnoticed is that deaths involving more than one substance are increasing more rapidly among Black Americans than Whites. Unfortunately, little research attention is paid to understanding opioid-related polydrug use patterns among Black Americans. As a result, less is known regarding which drug combinations are most common among this population and their reasons for co-using certain drugs. Therefore, the objective of this mixed methods study was to identify which substances were most commonly co-used with opioids among Black Americans, while also capturing their motives for combining opioids with other drugs. This study used data from the Florida Minority Health Study, a mixed-methods project that included online surveys (n = 303) and qualitative in-depth interviews (n = 30) of Black Americans who misuse opioids. Data collection was conducted from August 2021 to February 2022 throughout Southwest Florida. Analyses revealed that opioids were most commonly combined with alcohol, cocaine, and methamphetamine, respectively. Opioids were co-used with alcohol in an attempt to enhance the desired effect (i.e., intoxication), while stimulants and opioids were combined to counteract the undesirable side effects of the other. This study begins to answer the question of which/why substances are combined with opioids among Black Americans and should inform behavioral health interventions targeted at this population. Data on this topic are especially timely as the United States goes through the current fourth wave of the opioid crisis that is characterized by deaths due to polydrug use. These findings invite further study using nationally representative data to determine the extent to which polydrug using patterns differ across racial/ethnic groups.

Disparities in fatal and non-fatal opioid-involved overdoses among middle-aged non-Hispanic Black Men and Women

The gap in fatal opioid overdose rates has been closing between non-Hispanic Black and non-Hispanic White individuals. The rising opioid-involved mortality rates among non-Hispanic Black adults has been identified by SAMHSA as a critical public health issue. However, further research is needed that utilizes comprehensive surveillance data on both fatal and non-fatal opioid-involved overdoses to better assess the changing trends and evaluate factors contributing to changing disparities. We conducted an analysis of medical examiner and hospital data for years 2016-2021 from the largest county in Illinois (Cook) to (1) evaluate disparities in non-fatal and fatal opioid-involved overdoses between middle-aged non-Hispanic Black adults and Black adults of other age groups stratified by sex, (2) to assess if disparities exist across middle-aged adults of different race-ethnicities specifically non-Hispanic White and Hispanic-Latino adults, and (3) evaluate factors contributing to the disparities. Fatal opioid overdose rates among middle-aged Black men 45-64 years old were on average 5.3 times higher than Black men of other age groups, and 6.2 times higher than middle-aged non-Black men. Similarly, fatal opioid overdose rates among middle-aged Black women were on average 5.0 times higher than Black women of other age groups, and 4.9 times higher than middle-aged non-Black women. Hospital utilization rates for opioid-involved overdoses showed similar disparities between age groups and race-ethnicities. Findings indicate that stark disparities in rates of opioid-involved overdoses among middle-aged Black men and women are likely attributed to exposure to more lethal opioids, drug variability in local markets, differences in concurrent drug exposures, and lower access to harm reduction, emergent and preventative health services.

Explaining the causes and motivations for multiple substance use from the perspectives of users and therapists: A qualitative study

Background

The high prevalence of multiple substance use (MSU) is concerning, given the weak awareness about this issue and the potential impact this unawareness has on the severity of substance use disorder (SUD) and treatment outcomes. The aim of this study is to identify and elucidate the causes and motivations for MSU from the viewpoints of users and therapists in this field.

Methods

In this qualitative study, the conventional content analysis approach and purposive sampling were utilized. Deep semi-structured exploratory interviews were conducted with 17 substance users and 8 addiction therapists (including 4 psychiatrists, 3 general practitioners, and 1 psychologist). Field notes were also taken to identify and explain the motivations and reasons for MSU from the perspectives of users and therapists. The data were analyzed comparatively and simultaneously using the method suggested by Graneheim and Lundman (2004).

Results

Based on the findings of this study, the motivations for MSU are reflected in four main categories: 'Pharmacological factors' with subcategories such as achieving desired states and mitigating the undesirable effects of substances through leveraging the balancing, synergistic, and antagonistic effects of substances, substituting the effects of other substances, self-medication of the undesirable effects of other substances, enhancing the overall consumption experience such as heightened peak experience and enhanced pleasure, moderating the come-down, and seeking euphoria experiences in different substances; 'Biological factors' with subcategories including different neurobehavioral systems, individual differences determining substance dependence and the somatic-neural vulnerability of consumers; 'Psychosocial factors' with the subcategories of undesirable norms like the need for acceptance and social interactions, the context of substance use, consumers' experiences and expectations of substance use, and the maladaptive personality traits of consumers; and 'Addiction's inevitability' with the subcategories of coercion and the need to maintain equilibrium, and the difficulties of substance detoxification.

Conclusion

The motivations behind Multiple Substance Use (MSU) behaviors are multifaceted, including pharmacological, biological, psychosocial, and addiction-related factors. Recognizing and comprehending the interplay between these factors and motivations can inform better prevention strategies, assessment of treatment needs, and enhancement of treatment outcomes for individuals dealing with MSU.

Study protocol for a randomized controlled trial to adapt a posttraumatic stress disorder intervention of patients with opioid-stimulant polysubstance use receiving methadone maintenance treatment

BACKGROUND

The purpose of the Treatment for Harnessing Resiliency, Improving emotional regulation, and empowering indiViduals for a brighter future (THRIVE) study is to adapt an evidence-based posttraumatic stress disorder (PTSD) treatment for use among a polysubstance population receiving methadone maintenance treatment (MMT) at an opioid treatment program. Polysubstance use of high-risk combinations, such as illicit opioids and stimulants, is a critical public health issue. Individuals who engage in these high-risk combinations are more likely to have histories of childhood trauma, multiple traumas, PTSD, and greater PTSD severity as compared to mono-substance using individuals. Trauma, co-morbid mental health disorders such as PTSD, and polysubstance use complicate treatment outcomes. This study will use eight study phases to adapt an existing evidence-based PTSD intervention, Skills Training in Affective and Interpersonal Regulation with Narrative Therapy (STAIR-NT), via a massed treatment model (i.e., condensed treatment schedule) for patients in MMT who are engaged in sustained opioid-stimulant polysubstance use.

METHODS AND ANALYSIS

The intervention is an adapted version of the STAIR-NT protocol. The massed version created includes four 60-min sessions of skill building and two weeks of four 60-min sessions of narrative therapy. A preliminary randomized controlled trial (RCT) with 80 participants, randomized 1:1, will be conducted to assess the intervention's implementation and impact on primary short-term outcomes of polysubstance use and PTSD symptoms.

ETHICS AND DISSEMINATION

The results of this study will inform a fully-powered effectiveness trial for individuals with PTSD and polysubstance use receiving MMT. The findings are expected to provide valuable insights into improving both PTSD and substance use outcomes, and real-world implementation insights to integrating trauma-informed care in treatment settings for vulnerable populations.

REGISTRATION

This study is registered at ClinicalTrials.Gov as NCT06307340. Registration date 03/2024.

Chronic exposure to inhaled vaporized cannabis high in Δ9-THC suppresses Adderall-induced brain activity

Background

There are increasing reports of the misuse of prescription psychostimulants for cognitive enhancement together with recreational cannabis. This raises a concern that chronic use of cannabis high in Δ9-THC may alter the sensitivity to amphetamines. In this exploratory study we hypothesized chronic exposure to Δ9-THC through vaporized cannabis would diminish the central nervous system (CNS) activity of Adderall.

Methods

To address this issue we exposed male and female mice to inhaled vaporized cannabis (10.3% Δ9-THC) or placebo for 30 min each day for ten consecutive days. After 24 h, mice were imaged fully awake for changes in BOLD signal following an IP injection of Adderall (60 µg) during the scanning session. After a 2-week washout, without any cannabis or placebo exposure, mice were again imaged and challenged with Adderall during the scanning session. The data were registered to a mouse 3D MRI atlas with 134 brain regions providing site-specific increases and decreases in global brain activity.

Results

Mice exposed to cannabis when compared to placebo showed a decrease in brain activation to Adderall. The blunted Adderall response was characterized by a decrease in positive BOLD signal and increase in negative BOLD. The prefrontal cortex, accumbens, ventral pallidum, caudate/putamen, and thalamus were most affected. After a 2-week wash out there were no significant differences between the cannabis and placebo groups when challenged with Adderall.

Summary

This exploratory study shows that short, daily exposures to inhaled cannabis, something equivalent to recreational use, affects the sensitivity to the psychostimulant Adderall. The reduced Adderall effect on brain activity, particularly circuitry associated with dopaminergic signaling raises concerns about escalation in psychostimulant use.

Substance use and menopausal symptoms among people with and without HIV in the US, 2008-2020

OBJECTIVE

The aim of the study is to assess associations between substance use and menopausal symptoms among US people living with and without HIV in a longitudinal cohort.

METHODS

We analyzed self-reported menopausal symptoms and substance use from biannual Women's Interagency HIV Study (WIHS) visits from 2008-2020. Substance use since the last visit or lifetime cumulative use included tobacco, alcohol, marijuana, crack/cocaine, and opioids. Logistic regression quantified associations between each substance use and menopausal symptom frequency (vasomotor, mood, and musculoskeletal), adjusting for other substance use, HIV status, demographics, comorbidities, and trauma.

RESULTS

A total of 1,949 participants contributed early perimenopausal, late perimenopausal, or postmenopausal study visits. Across reproductive-aging stages, based on menstrual history, and among participants with and without HIV, participants reported frequent vasomotor (range 22-43%), mood (18-28%), and musculoskeletal (25-34%) symptoms. Many reported ever using tobacco (72%), heavy alcohol (75%), marijuana (73%), crack (50%), and opioids (31%). Current heavy alcohol use (odds ratio [OR]: 1.22; 95% confidence interval [CI]: 1.10-1.37), cumulative marijuana use (OR: 1.15, 95% CI: 1.01-1.32), and cumulative tobacco use (OR: 1.06, 95% CI: 1.01-1.12) were associated with a higher frequency of vasomotor symptoms; current heavy alcohol use (OR: 1.20, 95% CI: 1.04-1.39) and current opioid use (OR: 1.13; 95% CI: 1.01-1.25) were associated with mood symptoms; and current opioid use (OR: 1.11, 95% CI: 1.00-1.23) was associated with musculoskeletal symptoms. All other associations were found to be null.

CONCLUSIONS

Current and prior substance use may independently affect symptoms experienced during the menopausal transition and may indicate potential to benefit from additional intervention and referral to menopause specialty care.

Enhancing translation: A need to leverage complex preclinical models of addictive drugs to accelerate substance use treatment options

Preclinical models of addictive drugs have been developed for decades to model aspects of the clinical experience in substance use disorders (SUDs). These include passive exposure as well as volitional intake models across addictive drugs and have been utilized to also measure withdrawal symptomatology and potential neurobehavioral mechanisms underlying relapse to drug seeking or taking. There are a number of Food and Drug Administration (FDA)-approved medications for SUDs, however, many demonstrate low clinical efficacy as well as potential sex differences, and we also note gaps in the continuum of care for certain aspects of clinical experiences in individuals who use drugs. In this review, we provide a comprehensive update on both frequently utilized and novel behavioral models of addiction with a focus on translational value to the clinical experience and highlight the need for preclinical research to follow epidemiological trends in drug use patterns to stay abreast of clinical treatment needs. We then note areas in which models could be improved to enhance the medications development pipeline through efforts to enhance translation of preclinical models. Next, we describe neuroscience efforts that can be leveraged to identify novel biological mechanisms to enhance medications development efforts for SUDs, focusing specifically on advances in brain transcriptomics approaches that can provide comprehensive screening and identification of novel targets. Together, the confluence of this review demonstrates the need for careful selection of behavioral models and methodological parameters that better approximate the clinical experience combined with cutting edge neuroscience techniques to advance the medications development pipeline for SUDs.

Drug Use Patterns in Wastewater and Socioeconomic and Demographic Indicators

Importance

Measuring drug use behaviors in individuals and across large communities presents substantial challenges, often complicated by socioeconomic and demographic variables.

Objectives

To detect spatial and temporal changes in community drug use by analyzing concentrations of analytes in influent wastewater and exploring their associations with area-based socioeconomic and sociodemographic metrics like the area deprivation index (ADI) and rural-urban commuting area (RUCA) codes.

Design, Setting, and Participants

This longitudinal, cross-sectional wastewater study was performed from May 2022 to April 2023 and included biweekly influent wastewater samples of 39 analytes from 8 sampling locations across 6 wastewater treatment plants in southern Nevada. Statistical analyses were conducted in December 2023.

Main Outcomes and Measures

It was hypothesized that wastewater monitoring of pharmaceuticals and personal care products (PPCPs) and high-risk substances (HRSs) could reveal true spatial and temporal drug use patterns in near-real time. Data collection of samples for PPCPs and HRSs was performed using mass spectrometry. Both ADI and RUCA scores were utilized to characterize neighborhood contexts in the analysis. The false discovery rate (FDR) method was utilized to correct for multiple comparisons (PFDR).

Results

Over the 12-month wastewater monitoring period, 208 samples for PPCPs and HRSs were collected, and analysis revealed an increase in the consumption of HRSs and the seasonal variation in PPCP use in southern Nevada. There was a significant increase in levels of stimulant-associated analytes, such as cocaine (β = 9.17 × 10-4; SE = 1.29 × 10-4; PFDR = 1.40 × 10-10), and opioids or their metabolites, notably norfentanyl (β = 1.48 × 10-4; SE = 1.88 × 10-4; PFDR = 1.66 × 10-12). In contrast, DEET, an active ingredient in mosquito and tick repellents, demonstrated a seasonal use pattern (β = -4.85 × 10-4; SE = 2.09 × 10-4; PFDR = 4.87 × 10-2). Wastewater from more disadvantaged or rural neighborhoods, as assessed through ADI and RUCA scores, was more likely to show a significant positive correlation with HRSs, such as cocaine (β = 0.075; SE = 0.038; P = .05) and norfentanyl (β = 0.004; SE = 0.001; P = 1.64 × 10-5).

Conclusions and Relevance

These findings suggest that wastewater monitoring of PPCPs and HRSs offers a complementary method to existing public health tools, providing timely data for tracking substance use behaviors and use of PPCPs at a population level.

"Coke in the Dope": The Underrecognized Complications of a Cocaine-Adulterated Fentanyl Supply

ABSTRACT

The opioid crisis, particularly the "fourth wave" involving fentanyl and stimulants, has been responsible for an alarming increase in overdose deaths in the United States. Although fentanyl contamination in cocaine has gained significant attention, the converse-cocaine-adulterated fentanyl-has been largely overlooked despite its health implications. The rise in concurrent cocaine and fentanyl overdose deaths could be attributed to various factors, from intentional polysubstance use to unintentional adulterations. Cocaine-related health issues may amplify the problem. Four potential pathways for the increased risk of overdose with cocaine-adulterated opioids include enhanced drug reinforcement, potential overdose risk with switching drug samples, altered metabolism of medications used for opioid use disorder, and increased myocardial demand juxtaposed with opioid-induced respiratory depression. With these risks, the importance of drug testing becomes paramount in the unregulated drug market. As polysubstance use overdoses surge, there is an urgent need to understand how drug supplies are changing in order to effectively identify appropriate harm reduction strategies. Specifically, further research is needed evaluating complications of low-level cocaine exposure with chronic/persistent opioid use. The hazards associated with cocaine-adulterated fentanyl emphasize the significance of understanding not only fentanyl's presence in cocaine but also cocaine's role in the fentanyl supply.

Polysubstance Use and Related Risk Behaviors among People Who Inject Drugs in Kenya Preparing for Hepatitis C Virus Treatment

Polysubstance use (PSU), injection drug use (IDU), and equipment sharing are associated with bloodborne infection (BBI) transmission risk, particularly Hepatitis C Virus (HCV), yet data on PSU in low- and middle-income countries (LMICs) is limited. We report on baseline PSU, medication-assisted treatment (MAT) engagement, and motivation to reduce IDU among 95 people who inject drugs (PWID) who accessed needle and syringe programs (NSP) in Nairobi and Coastal Kenya prior to HCV treatment. Bivariate and multivariate logistic regression were used to examine the associations between PSU and behaviors that confer HCV transmission and acquisition risks. Most participants (70.5%) reported PSU in the last 30 days, and one-third (35.8%) reported PSU exclusive to just heroin and cannabis use. Common combinations were heroin and cannabis (49.3%), and heroin, cannabis, and bugizi (flunitrazepam) (29.9%). Participants at baseline were receiving MAT (69.5%), already stopped or reduced IDU (30.5%), and were HIV-positive (40%). PSU was significantly associated with IDU (p = 0.008) and the number of times (p = 0.016) and days (p = 0.007) injected in the last 30 days. Participants reported high PSU and equipment sharing, despite high MAT engagement. While co-locating BBI treatment within existing harm reduction services is necessary to promote uptake and curb re-infection, tailored services may be needed to address PSU, particularly in LMICs.

Opioid-stimulant trends in overdose toxicology by race, ethnicity, & gender: An analysis in Delaware, 2013-2019

Recent upticks of stimulant presence in overdose deaths suggest the opioid epidemic is morphing, which raises questions about what drugs are involved and who is impacted. We investigate annual and growth rate trends in combined opioid-stimulant overdose toxicology between 2013 and 2019 for White, Black, and Hispanic male and female decedents in Delaware. During these years, toxicology shifted to illegal drugs for all with fentanyl leading the increase and opioid-cocaine combinations rising substantially. While combined opioid-cocaine toxicology grew among Black and Hispanic Delawareans, White males continue to report the highest rates overall. These findings depart from historical patterns and may challenge existing opioid epidemic policies.

Longitudinal patterns of use of stimulants and opioids in the AIDS linked to the IntraVenous experience cohort, 2005-2019

BACKGROUND

Overdoses involving opioids and stimulants are on the rise, yet few studies have examined longitudinal trends in use of both substances. We sought to describe use and co-use of opioids and stimulants, 2005-2019, in the AIDS Linked to the Intravenous Experience (ALIVE) cohort - a community-based cohort of people with a history of injection drug use living in or near Baltimore, MD.

METHODS

We included 2083 ALIVE participants, who had at least two visits during the study period. Our outcome was based on self-reported use of opioids and stimulants in the prior 6 months. We estimated prevalence of 4 categories of use (neither stimulants nor opioids, only stimulants, only opioids, stimulants and opioids), using a non-parametric multi-state model, accounting for the competing event of death and weighting for informative loss to follow-up. All analyses were stratified by enrollment cohort, with the main analysis including participants who enrolled prior to 2015 and a sub-analysis including participants who enrolled 2015-2018.

RESULTS

In the main analysis, prevalence of using stimulants and opioids decreased from 38 % in 2005 to 12 % 2013 but stabilized from 2014 onwards (13-19 %). The prevalence of using only stimulants (7-11 %) and only opioids (5-10 %) was stable across time. Participants who reported using both were more likely to report homelessness, depression, and other substance use (e.g., marijuana and heavy alcohol use) than participants in the other use categories. On average, 65 % of visits with use of both were followed by a subsequent visit with use of both; of participants transitioning out of using both, 13% transitioned to using neither.

CONCLUSIONS

While use of stimulants and opioids declined in the cohort through 2013, a meaningful proportion of participants persistently used both. More research is needed to understand and develop strategies to mitigate harms associated with persistent use of both stimulants and opioids.

Impact of OPRM1 (Mu-opioid Receptor Gene) A112G Polymorphism on Dual Oxycodone and Cocaine Self-administration Behavior in a Mouse Model

The use of mu-opioid receptor (MOP-r) agonists such as oxycodone together with cocaine is prevalent, and deaths attributed to using these combinations have increased.

RATIONALE

It is unknown if functional single nucleotide polymorphisms (SNPs), such as the OPRM1 (MOP-r gene) SNP A118G, can predispose individuals to more dual opioid and psychostimulant intake. The dual self-administration (SA) of MOP-r agonists and cocaine has not been thoroughly examined, especially with regard to neurobiological changes.

OBJECTIVES

We examined oxycodone SA and subsequent dual oxycodone and cocaine SA in male and female A112G (A/G and G/G, heterozygote and homozygote, respectively) mice, models of human A118G carriers, versus wild-type (A/A) mice.

METHODS

Adult male and female A/G, G/G and A/A mice self-administered oxycodone (0.25 mg/kg/infusion, 4hr/session, FR 1.) for 10 consecutive days (sessions 1-10). Mice then self-administered cocaine (2 hr) following oxycodone SA (4 hr, as above) in each session for a further 10 consecutive days (sessions 11-20). Message RNA transcripts of 24 reward-related genes were examined in the dorsal striatum.

RESULTS

Male and female A/G and G/G mice had greater oxycodone SA than A/A mice did in the initial 10 days and in the last 10 sessions. Further, A/G and G/G mice showed greater cocaine intake than A/A mice. Dorsal striatal mRNA levels of Pdyn, Fkbp5, Oprk1, and Oprm1 were altered following oxycodone and cocaine SA.

CONCLUSIONS

These studies demonstrated that this functional genetic variation in Oprm1 affected dual opioid and cocaine SA and altered specific gene expression in the striatum.

Spatial and Temporal Drug Usage Patterns in Wastewater Correlate with Socioeconomic and Demographic Indicators in Southern Nevada

Evaluating drug use within populations in the United States poses significant challenges due to various social, ethical, and legal constraints, often impeding the collection of accurate and timely data. Here, we aimed to overcome these barriers by conducting a comprehensive analysis of drug consumption trends and measuring their association with socioeconomic and demographic factors. From May 2022 to April 2023, we analyzed 208 wastewater samples from eight sampling locations across six wastewater treatment plants in Southern Nevada, covering a population of 2.4 million residents with 50 million annual tourists. Using bi-weekly influent wastewater samples, we employed mass spectrometry to detect 39 analytes, including pharmaceuticals and personal care products (PPCPs) and high risk substances (HRS). Our results revealed a significant increase over time in the level of stimulants such as cocaine (pFDR=1.40×10-10) and opioids, particularly norfentanyl (pFDR =1.66×10-12), while PPCPs exhibited seasonal variation such as peak usage of DEET, an active ingredient in insect repellents, during the summer (pFDR =0.05). Wastewater from socioeconomically disadvantaged or rural areas, as determined by Area Deprivation Index (ADI) and Rural-Urban Commuting Area Codes (RUCA) scores, demonstrated distinct overall usage patterns, such as higher usage/concentration of HRS, including cocaine (p=0.05) and norfentanyl (p=1.64×10-5). Our approach offers a near real-time, comprehensive tool to assess drug consumption and personal care product usage at a community level, linking wastewater patterns to socioeconomic and demographic factors. This approach has the potential to significantly enhance public health monitoring strategies in the United States.

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.

Expert consensus-based guidance on approaches to opioid management in individuals with advanced cancer-related pain and nonmedical stimulant use

BACKGROUND

Clinicians treating cancer-related pain with opioids regularly encounter nonmedical stimulant use (i.e., methamphetamine, cocaine), yet there is little evidence-based management guidance. The aim of the study is to identify expert consensus on opioid management strategies for an individual with advanced cancer and cancer-related pain with nonmedical stimulant use according to prognosis.

METHODS

The authors conducted two modified Delphi panels with palliative care and addiction experts. In Panel A, the patient's prognosis was weeks to months and in Panel B the prognosis was months to years. Experts reviewed, rated, and commented on the case using a 9-point Likert scale from 1 (very inappropriate) to 9 (very appropriate) and explained their responses. The authors applied the three-step analytical approach outlined in the RAND/UCLA to determine consensus and level of clinical appropriateness of management strategies. To better conceptualize the quantitative results, they thematically analyzed and coded participant comments.

RESULTS

Consensus was achieved for all management strategies. The 120 Experts were mostly women (47 [62%]), White (94 [78%]), and physicians (115 [96%]). For a patient with cancer-related and nonmedical stimulant use, regardless of prognosis, it was deemed appropriate to continue opioids, increase monitoring, and avoid opioid tapering. Buprenorphine/naloxone transition was inappropriate for a patient with a short prognosis and of uncertain appropriateness for a patient with a longer prognosis.

CONCLUSION

Study findings provide urgently needed consensus-based guidance for clinicians managing cancer-related pain in the context of stimulant use and highlight a critical need to develop management strategies to address stimulant use disorder in people with cancer.

PLAIN LANGUAGE SUMMARY

Among palliative care and addiction experts, regardless of prognosis, it was deemed appropriate to continue opioids, increase monitoring, and avoid opioid tapering in the context of cancer-related pain and nonmedical stimulant use. Buprenorphine/naloxone transition as a harm reduction measure was inappropriate for a patient with a short prognosis and of uncertain appropriateness for a patient with a longer prognosis.

First drug-checking study at an electronic festival and fentanyl detection in the central region of Mexico

BACKGROUND

Perception of drug adulteration has increased in Mexico, but there is little research on adulterants and toxicity. The aim of this study was to identify drug composition in an electronic music outdoor festival nearby Mexico City.

METHODS

The participants completed a questionnaire with demographic data, harm reduction strategies, drug-use patterns, history, and the drug they expected to find. We took a small sample of each substance and prepared it for drug checking. A two-section drug testing station was placed within the grounds of the festival. Interaction with participants occurred at the front part. Drug checking was conducted at the rear part. The service was free of charge, voluntary and confidential. Forty persons aged 22 to 48 years participated (mode = 28), of which 92.5% were male, most (82.5%) were single. Through the Substance Analysis Program of "ReverdeSer Collective," we conducted the testing with the attendants that provided 51 drug samples, following ethical and biosafety protocols. We used colorimetry, Fourier Transform Infrared Spectroscopy, and fentanyl immunoassay strips for sample analysis.

RESULTS

Substances of choice among attendants were psychostimulants (MDMA and other amphetamine-like drugs) and hallucinogens. Most samples contained what the users expected plus adulterants. Main adulterants were methylene-dioxy-ethyl-amphetamine, methylene-dioxy-propyl-amphetamine, hydroxyamphetamine, and the selective serotonin reuptake inhibitor venlafaxine. Fentanyl was present in 2 out of 4 cocaine samples and in 14 of the 22 confirmed MDMA samples.

CONCLUSIONS

Some of the adulterants found pose serious health risks, especially fentanyl, amphetamine-like substances, and venlafaxine. Therefore, it is urgent to monitor these adulterants at electronic music festivals and to implement prevention, treatment, and harm reduction public policies. Naloxone distribution and drug-assisted therapies should be part of government programs in Mexico.

Effects of fentanyl self-administration on risk-taking behavior in male rats

RATIONALE

Individuals with opioid use disorder (OUD) exhibit impaired decision making and elevated risk-taking behavior. In contrast to the effects of natural and semi-synthetic opioids, however, the impact of synthetic opioids on decision making is still unknown.

OBJECTIVES

The objective of the current study was to determine how chronic exposure to the synthetic opioid fentanyl alters risk-based decision making in adult male rats.

METHODS

Male rats underwent 14 days of intravenous fentanyl or oral sucrose self-administration. After 3 weeks of abstinence, rats were tested in a decision-making task in which they chose between a small, safe food reward and a large food reward accompanied by variable risk of footshock punishment. Following testing in the decision-making task, rats were tested in control assays that assessed willingness to work for food and shock reactivity. Lastly, rats were tested on a probabilistic reversal learning task to evaluate enduring effects of fentanyl on behavioral flexibility.

RESULTS

Relative to rats in the sucrose group, rats in the fentanyl group displayed greater choice of the large, risky reward (risk taking), an effect that was present as long as 7 weeks into abstinence. This increased risk taking was driven by enhanced sensitivity to the large rewards and diminished sensitivity to punishment. The fentanyl-induced elevation in risk taking was not accompanied by alterations in food motivation or shock reactivity or impairments in behavioral flexibility.

CONCLUSIONS

Results from the current study reveal that the synthetic opioid fentanyl leads to long-lasting increases in risk taking in male rats. Future experiments will extend this work to females and identify neural mechanisms that underlie these drug-induced changes in risk taking.

[Bronchial diseases and heroin use. A systematic review]

INTRODUCTION

Heroin use can cause respiratory complications including asthma, chronic obstructive pulmonary disease (COPD) and bronchiectasis (BD).

OBJECTIVES

A general review of the literature presenting the data on the relationships between heroin consumption and bronchial complications, while underlining the difficulties of diagnosis and management.

DOCUMENTARY SOURCES

Medline, 1980-2022, keywords "asthma" or "bronchospasm" or "COPD" or "bronchiectasis" and "heroin" or "opiate" or "opiates", with limits pertaining to "Title/Abstract". Concerning asthma, 26 studies were included, as were 16 for COPD and 5 for BD.

RESULTS

Asthma and COPD are more prevalent among heroin addicts, who are less compliant than other patients with their treatment. The authors found a positive association between frequency of asthma exacerbations, admission to intensive care and heroin inhalation. Late diagnosis of COPD worsens the course of the disease; emphysema and BD are poor prognostic factors.

CONCLUSION

Bronchial diseases in heroin users can be identified by means of respiratory function exploration and chest CT scans. These tests should be performed frequently in view of optimizing their care, which includes their weaning themselves from addictive substances.

Possible Delay in Symptomatology of a Methadone Overdose in a Patient Ingesting an Energy Drink and Dextroamphetamine/Amphetamine

Introduction: Methadone is a mu-opioid agonist with a delayed time to peak concentration that requires an extended period of monitoring following an overdose. Available data suggests that the combination of psychostimulants with methadone may augment antinociception and tolerance to opioids. Case Report: A 26-year-old male (83.9 kg) presented to the ED approximately 1 hour after unintentionally ingesting 200-250 mg of liquid methadone and an energy drink, along with 20 mg of dextroamphetamine/amphetamine prior to the event. Vital signs were: blood pressure (BP), 143/91 mmHg; heart rate (HR), 74; respirations (RR), 16; oxygen saturation 95% on room air. His urine drug screen was positive for amphetamines and methadone. Patient was monitored for 4 hours with no change in status and was discharged home. Approximately 26 hours later patient was found cyanotic and apneic. Patient was given 2 mg of naloxone and awoke with normal mental status. On presentation the patient's vital signs were: BP, 114/70 mmHg; HR, 114; RR 16; oxygen saturation 94% on 3 liters nasal cannula. During his ED stay, he required 2 doses of naloxone secondary to oxygen desaturation and was admitted to the hospital. His repeat urine drug screen was positive for amphetamines and methadone. The patient was discharged the following day. Discussion: This case illustrates an unintentional methadone overdose combined with the intentional ingestion of an energy drink and dextroamphetamine/amphetamine that possibly masked the toxicity for over 24 hrs. Monitoring parameters for methadone overdoses may need re-evaluation in the setting of the co-ingestion of a stimulant.

Transitioning off methadone: A qualitative study exploring why patients discontinue methadone treatment for opioid use disorder

INTRODUCTION

Patients who discontinue methadone for opioid use disorder are at increased risk of overdose and death. We know little about how patients make the decision to stop treatment. This study explored reasons why patients discontinue methadone treatment.

METHODS

We conducted 20 individual semi-structured patient interviews and two staff focus groups, each with five participants, at two opioid treatment programs in Baltimore, MD, in the United States from June 2021 to May 2022. Patient interviews and staff focus groups covered three domains: 1) reasons why patients may want to discontinue methadone; 2) perspectives about the ideal length of methadone treatment; and 3) changes that could improve retention. We used a modified grounded theory approach to code interviews, identify emergent themes, and develop a conceptual model.

RESULTS

We identified three themes related to patients' internal relationships to methadone: patients (1) viewed methadone as a bridge to opioid-free recovery, (2) believed that long-term methadone damages the body, and (3) felt that methadone increases craving for cocaine; and three themes related to their external relationships with opioid treatment programs and society at large: patients (4) viewed daily dosing as burdensome, (5) feared methadone inaccessibility could trigger relapse, and (6) experienced stigma from friends, family, and peers. Patients with internal reasons planned to stop as soon as possible and asked for education about perceived side effects and treatment for cocaine craving to promote retention. Patients with external reasons were willing to continue for longer and asked for adaptive take-home policies and reduced societal stigma around methadone.

CONCLUSIONS

Patients want to discontinue methadone either because of their internal relationship to methadone and its real or perceived side effects, or because of their external experiences with opioid treatment programs and societal stigma of methadone. To improve retention, clinical and policy changes should consider responses to both of these categories of reasons.

Testing the cannabis gateway hypothesis in a national sample of Spanish adolescents

BACKGROUND

The gateway hypothesis holds that the use of legal substances (i.e., tobacco and alcohol) increases the risk of initiating in cannabis use which, in turn, increases the chances of using other illegal substances. The validity of this hypothesis has been the subject of intense debate in recent years, finding sequences with a different order. Moreover, this pattern has been scarcely studied in Spain, where characteristics related to cannabis use are meaningfully different to other countries. This study aims to examine the gateway effects of cannabis towards other legal and illegal substances in Spanish adolescents.

MATERIAL AND METHODS

Data were obtained from the Ministry of Health in Spain, through a representative survey of addictive behaviors of 36,984 Spanish adolescents (M_age = 15.7, SD = 1.2, 51.4% females).

RESULTS

Lifetime cannabis use increased the likelihood of later legal substance use, both tobacco (OR = 2.0; 95%CI 1.81, 2.22) and alcohol (OR = 1.93; 95%CI 1.61, 2.31), as well as illegal substances (OR = 5.36; 95%CI 4.80, 5.98) and polysubstance (OR = 18.24; 95%CI 14.63, 22.73). Early age of cannabis use onset significantly increased the likelihood of subsequent legal and illegal substance use (ORs between 1.82 and 2.65).

CONCLUSIONS

These findings confirm and expand the available evidence on cannabis as a gateway substance. These results can help to drive preventive strategies for substance use in Spanish adolescents.

Characterization of Nonfatal Opioid, Cocaine, Methamphetamine, and Polydrug Exposure and Clinical Presentations Reported to the Toxicology Investigators Consortium Core Registry, January 2010-December 2021

INTRODUCTION

To characterize and compare opioid-only, cocaine-only, methamphetamine-only, opioid-and-cocaine exposure, and opioid-and-methamphetamine exposure and to examine clinical presentations, leading to a better understanding of overdose effects involving these drug exposures.

METHODS

We examined drug exposures in the Toxicology Investigators Consortium (ToxIC) Core Registry from January 2010 to December 2021, a case registry of patients presenting to participating healthcare sites that receive a medical toxicology consultation. Demographic and clinical presentations of opioid-only, cocaine-only, methamphetamine-only, and opioid-and-cocaine exposure, and opioid-and-methamphetamine exposure consultations were described; differences between single and polydrug exposure subgroups were calculated to determine statistical significance. Clinical presentations associated with exposures were evaluated through calculated adjusted relative risk.

RESULTS

A total of 3,883 consultations involved opioids, cocaine, methamphetamine, opioid-and-cocaine exposure, or opioid-and-methamphetamine exposure. Opioid-only (n = 2,268, 58.4%) and methamphetamine-only (n = 712, 18.3%) comprised most consultations. There were significant differences in clinical presentations between exposure subgroups. Opioid-and-cocaine exposure consultations were 8.15 times as likely to present with a sympathomimetic toxidrome than opioid-only. Conversely, opioid-and-cocaine exposure and opioid-and-methamphetamine exposure were 0.32 and 0.42 times as likely to present with a sympathomimetic toxidrome compared to cocaine-only and methamphetamine-only consultations, respectively. Opioid-and-cocaine exposure was 0.67 and opioid-and-methamphetamine exposure was 0.74 times as likely to present with respiratory depression compared to opioid-only consultations. Similarly, opioid-and-cocaine exposure was 0.71 and opioid-and-methamphetamine exposure was 0.78 times as likely to present with CNS depression compared to opioid-only consultations.

CONCLUSIONS

Used in combination, opioids and stimulants may mask typical clinical presentations of one another, misattributing incorrect drugs to overdose in both clinical treatment and public health surveillance.

Which illicit drugs are injected in Oslo? A study based on analysis of drug residues in used injection equipment and self-reported information

BACKGROUND

People who inject drugs (PWID) have a high risk of premature death due to fatal overdoses. Newly emerged fentanyls, much more potent than heroin and other opioids, may increase this risk further. Therefore, precise information on injected drugs is critical to improving prevention strategies.

AIMS

This study aimed to analyse drug residues in used injection equipment in order to determine drug and drug combinations and compare and complement findings with self-reported information.

METHODS

Used syringes and needles (n=766) were collected at the supervised drug consumption facilities, the needle exchange service and two low-threshold health services for problem drug users in Oslo, Norway. The material was collected every third month from June 2019 to June 2020 and analysed for 64 substances using highly specific analytical methods (ultra-high performance liquid chromatography tandem mass spectrometry). Additionally, a street-recruited sample of PWID was interviewed from 2017 to 2019 regarding their drug injection habits (n=572).

RESULTS

Heroin (65.5%) or amphetamines (59.8%), often in combination (30.5%), were commonly detected in drug residues. Other opioids, stimulants or benzodiazepines were rarely detected (6.1%). Fentanyl was detected in only one syringe. Heroin was the most reported drug (77.6% during the past four weeks, 48.3% daily/almost daily), followed by amphetamines (57.5% during the past four weeks, 23.1% daily or almost daily). Injection of methadone, buprenorphine and dissolved tablets was self-reported more frequently than determined in drug residue findings.

CONCLUSIONS

Analysis of the injection equipment proved useful as a non-invasive, rapid and accurate means to obtain detailed information on injected drugs in Oslo and supplement traditional PWID survey information.

Smoked cannabis reduces peak cocaine plasma levels and subjective effects in a controlled drug administration study of polysubstance use in men

BACKGROUND

Despite the high prevalence of polysubstance use, outcomes and potential risks associated with common drug combinations are not well characterized. Many individuals who use cocaine also use cannabis, yet little is known about how interactions between the two drugs might contribute to continued co-use.

METHODS

The aim of this double-blind, placebo-controlled study was to determine the physiological and subjective effects of smoked cannabis with smoked cocaine, to identify variables that may contribute to the continued use of this drug combination. Healthy, non-treatment seeking volunteers who reported smoking both cocaine and cannabis (N = 9, all males) completed a 13-day inpatient protocol. On session days, cannabis [0.0 or 5.6 % tetrahydrocannabinol (THC)] was administered 28 min prior to cocaine (0, 12, or 25 mg). Dependent measures included pharmacokinetic assessment of THC and cocaine and their respective metabolites, in addition to subjective and cardiovascular effects.

RESULTS

Active cannabis (5.6 % THC) increased plasma levels of THC and the metabolite 11-nor-9-carboxy-Δ9-THC (THCCOOH), as well as subjective ratings of cannabis effects and heart rate relative to inactive cannabis. Cocaine dose-dependently increased plasma cocaine and metabolites and subjective ratings of cocaine effects. Active cannabis pre-treatment decreased plasma levels of cocaine and metabolites. Furthermore, active cannabis attenuated cocaine-related reductions in 'Hunger' and 'Calm.'

CONCLUSIONS

Cannabis pre-treatment altered the subjective experience of smoked cocaine and reduced peak plasma levels of cocaine. Future studies should explore additional doses of each drug and whether these changes also impact cocaine's reinforcing effects.

Toxicological Analysis of Cases of Mixed Poisonings with Synthetic Cathinones and Other Drugs of Abuse

Some of the most commonly used new psychoactive substances (NPSs) are synthetic cathinones (SCs). The literature increasingly indicates that SCs have a significant addictive potential and pose a high risk to human health and life. The vast majority of SC users take a number of substances simultaneously. This article lists the detected concentrations in 26 fatal and 2 non-fatal real cases, in which SCs or an SC along with other substances were determined in blood and other biological materials. The following SCs were found most often: α-pyrrolidinohexiophenone, α-pyrrolidinopentiophenone, N-ethylpentedrone (NEP), 4-methyl-α-ethylaminopentiophenone and N-ethylhexedrone. In addition to detected SCs, the analyzed samples showed the presence of conventional drugs such as methamphetamine, 3,4-methylenedioxymethamphetamine, 3,4-methylenedioxyamphetamine, amphetamine and NPSs from groups other than SCs, such as synthetic cannabinoids (UR-144 and 5F-AMB), synthetic opioids (AH-7921, U-47700 and 4-fluorobutyrfentanyl) and others (desoxypipradrol and etizolam). The quantitative analyses were carried out by liquid chromatography with tandem mass spectrometry (LC-MS-MS). This study presents pioneering data on concentrations and effects of 4-ethylmethcathinone, NEP, N-ethylbuphedrone and mexedrone. Also noteworthy are the data on SCs that until now have rarely been described in the literature together with specified blood concentrations. The analyzed cases of taking SCs were associated with fatal intoxication (n = 26), driving under the influence of drugs (n = 2) and death caused by beating (n = 1). Taking SCs has serious side effects that can lead to multiple organ failure and death. The use of more than one psychoactive substance simultaneously (including at least one SC) contributes to increased SC toxicity. These data could be valuable for further interpretation of other results from toxicological analyses.

Effects of neuromodulation on cognitive and emotional responses to psychosocial stressors in healthy humans

Physiological and psychological stressors can exert wide-ranging effects on the human brain and behavior. Research has improved understanding of how the sympatho-adreno-medullary (SAM) and hypothalamic-pituitary-adrenocortical (HPA) axes respond to stressors and the differential responses that occur depending on stressor type. Although the physiological function of SAM and HPA responses is to promote survival and safety, exaggerated psychobiological reactivity can occur in psychiatric disorders. Exaggerated reactivity may occur more for certain types of stressors, specifically, psychosocial stressors. Understanding stressor effects and how the body regulates these responses can provide insight into ways that psychobiological reactivity can be modulated. Non-invasive neuromodulation is one way that responding to stressors may be altered; research into these interventions may provide further insights into the brain circuits that modulate stress reactivity. This review focuses on the effects of acute psychosocial stressors and how neuromodulation might be effective in altering stress reactivity. Although considerable research into stress interventions focuses on treating pathology, it is imperative to first understand these mechanisms in non-clinical populations; therefore, this review will emphasize populations with no known pathology and consider how these results may translate to those with psychiatric pathologies.

Cessation of self-reported opioid use and impacts on co-occurring health conditions

BACKGROUND

Among veterans in care reporting opioid use, we investigated the association between ceasing opioid use on subsequent reduction in report of other substance use and improvements in pain, anxiety, and depression.

METHODS

Using Veterans Aging Cohort Study survey data collected between 2003 and 2012, we emulated a hypothetical randomized trial (target trial) of ceasing self-reported use of prescription opioids and/or heroin, and outcomes including unhealthy alcohol use, smoking, cannabis use, cocaine use, pain, and anxiety and depressive symptoms. Among those with baseline opioid use, we compared participants who stopped reporting opioid use at the first follow-up (approximately 1 year after baseline) with those who did not. We fit logistic regression models to estimate associations with change in each outcome at the second follow-up (approximately 2 years after baseline) among participants with that condition at baseline. We examined two sets of adjusted models that varied temporality assumptions.

RESULTS

Among 2473 participants reporting opioid use, 872 did not report use, 606 reported use, and 995 were missing data on use at the first follow-up. Ceasing opioid use was associated with no longer reporting cannabis (adjusted odds ratio [AOR]=1.82, 95% confidence interval [CI] 1.10, 3.03) and cocaine use (AOR=1.93, 95% CI 1.16, 3.20), and improvements in pain (AOR=1.53, 95% CI 1.05, 2.24) and anxiety (AOR=1.56, 95% CI 1.01, 2.41) symptoms.

CONCLUSION

Cessation of opioid misuse may be associated with subsequent cessation of other substances and reduction in pain and anxiety symptoms, which supports efforts to screen and provide evidence-based intervention where appropriate.

Polysubstance Use Patterns among Outpatients Undergoing Substance Use Disorder Treatment: A Latent Class Analysis

Substance Use Disorders (SUDs) pose significant challenges to both individuals and society at large. The primary focus of existing research with clinical SUD populations has been on individual substances, but research is required to better understand the profiles of individuals who use different substances simultaneously. The purpose of the current study was, therefore, to identify patterns of use among subjects (n = 1025) who reported using multiple substances by adopting a Latent Class Analysis (LCA) methodology. The Addiction Severity Index (ASI-lite) was included as a measure of substance misuse, we performed LCA to identify patterns of substance use through the administration of the ASI-Lite. Responses were collected from the following substances: alcohol, cannabis/cannabinoids, opioids and heroin, and cocaine. Results identified two latent classes: (1) alcohol use dominant, and (2) poly-abuser use dominants. Class 1 represented 60.0% of the sample and refers to individuals with the dominant use of alcohol, of those a higher proportion (47%) reported low-frequency use (1 to 7 days per month) and 26% reported a frequency of use of 24 to 30 days per month. Furthermore, 18% used alcohol in combination with cocaine. Class 2 represents 40.0% of the sample. This class is characterized by low-frequency and high-frequency users of several substances. The results obtained highlight the importance of deepening the study of the concomitant use of substances in individuals with SUDs to better understand the health risk of the combined use of two or more substances.

Quality of life and its correlated factors among patients with substance use disorders: a systematic review and meta-analysis

Background

Patients with substance use disorder (SUD) usually report lower quality of life (QoL) than other patients and as much as patients with other mental disorders. The present study investigated variables associated with QoL domains among patients with SUD.

Methods

Studies in English published before December 1^st 2021, were searched for on PubMed, Scopus, Cochrane, and Web of Science to identify primary studies on factors associated with QoL domains among patients with SUD. After reviewing for study duplicates, the full-texts of selected papers were assessed for eligibility using PECO (Participants, Exposures, Comparison and Outcome) criteria: (a) participants: patients with SUD; (b) exposures: sociodemographic factors, clinical, and service use variables; (c) comparison: patient groups without SUD; and (d) outcomes: four domains of QoL (physical, mental, social, and environmental domains). Three researchers recorded the data independently using predefined Excel spreadsheets. The Newcastle–Ottawa Scale (NOS) was used for assessing risk of bias and rated each study in terms of exposure, outcome, and comparability. Pooled odds ratios (ORs) and β coefficient were utilized at a 95% confidence level, and because sampling methods differed between studies’ pooled estimates, a random effects model was utilized.

Results

After the assessment of over 10,230 papers, a total of 17 studies met the eligibility criteria. Five studies (1260 participants) found that patients with SUD who were older were less likely to have a good physical Qol (OR = 0.86, 95% CI = 0.78, 0.95). Two studies (1171 participants) indicated that patients with SUD who were homeless were less likely to have a good environmental Qol (β = -0.47, p = 0.003). However, a better mental QoL was observed in four studies (1126 participants) among those receiving support from their family or friends (social networks) (OR = 1.05, 95% CI = 1.04, 1.07). Two studies (588 participants) showed that those using cocaine were less likely to have a good mental QoL (OR = 0.83, 95% CI = 0.75, 0.93). Two studies (22,534 participants) showed that those using alcohol were less likely to have a good physical QoL (β = -2.21, p = 0.001). Two studies (956 participants) showed that those having severe substance use disorders were less likely to have a good mental (β = -5.44, p = 0.002) and environmental (β = -0.59, p = 0.006) QoL respectively. Four studies (3515 participants) showed that those having mental disorders were less likely to have a good physical QoL (β = -1.05, p = 0.001), and another three studies (1211 participants) that those having mental disorders were less likely to have a good mental QoL (β = -0.33, p = 0.001). Finally, two studies (609 and 682 participants) showed that individuals who experienced trauma symptoms or mental disorders were less likely to have good social and environmental QoL, respectively (OR = 0.78, 95% CI = 0.61, 1.00) and (OR = 0.92, 95% CI = 0.9, 0.94).

Conclusions

The findings suggest the need for mental health services to improve the QOL among patients with SUD but further study is needed. Cocaine may cause behavioral changes which can increase the possibility of reckless and suicidal behaviors. Therefore, identifying cocaine user access, adherence, and satisfaction with treatment is recommended as an important component of adaptive functioning. Interventions that help patients with SUD get support from people within their social networks who support their recovery are also essential to their QoL.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13690-022-00940-0.

Associations of Lifetime Nonmedical Opioid, Methamphetamine, and Kratom Use within a Nationally Representative US Sample

Co-use of non-medical opioids (NMO) and methamphetamine is increasing. So too is the use of the psychoactive botanical "kratom," including among people with NMO and methamphetamine use histories. We assessed characteristics associated with respondent groups who reported lifetime methamphetamine and/or kratom use within a nationally representative US sample using 2019 National Survey on Drug Use and Health data from respondents reporting lifetime NMO use (diverted prescription opioids, heroin). Weighted prevalence estimates for demographic, mental health, and substance use outcomes were determined. Logistic regression examined associations between group membership and outcomes. Among this sample of respondents with lifetime NMO use, 67.6% (95% CI = 65.6-69.4%) reported only NMO use; 4.6% (3.9-5.4%) reported NMO+Kratom; 24.7% (22.7-26.7%) reported NMO+Methamphetamine; and 3.2% (2.5-3.9%) reported NMO+Methamphetamine+Kratom. Compared to those in the NMO-only group, the NMO+Kratom group was more likely to report past-year serious mental illness (SMI; OR = 2.27), suicidality (OR = 1.89), and past-month psychological distress (OR = 1.88). The NMO+Methamphetamine+Kratom group was more likely to report past-year SMI (OR = 2.65), past-month psychological distress (OR = 2.06), and unmet mental health needs (OR = 2.03); increased odds for drug injection, opioid withdrawal, and perceived treatment need also emerged. Risk factors were observed for all groups but were greatest among those reporting use of all three substances.

The practice and embodiment of "goofballs": A qualitative study exploring the co-injection of methamphetamines and opioids

BACKGROUND

Polysubstance use is common among people who use drugs, including the co-use of stimulants and opioids. Research suggests the practice of simultaneous co-injection of methamphetamines and opioids, often referred to as "goofballs", is increasing. As a relatively unique drug use practice, little qualitative research currently exists on goofball injecting. This study explores the practice and embodied experiences of goofball injecting.

METHODS

This article draws on in-depth interviews conducted across two qualitative studies undertaken in Vancouver, Canada's Downtown Eastside neighbourhood examining changing dynamics in relation to stimulant use and experiences with an overdose prevention site-based safer supply intervention, respectively. Interviews containing discussions of goofball use (n=29) were extracted from each study and merged into a single qualitative dataset. Data were analysed thematically and focused on the practices and embodied experiences of goofball injection.

RESULTS

Our analysis uncovered how goofball injection represented a complex drug use practice driven by the desire to achieve particular embodied experiences not attainable by using either drug individually. We identified three distinct practices of goofball use: 1) to alter or enhance the effects of opioids; 2) to alter or enhance the effects of methamphetamines; and 3) to balance out the effects of both drugs.

CONCLUSION

Our study fills an important gap in the polysubstance use literature specifically exploring the co-injection of methamphetamines and opioids. Our findings highlight the need to implement and expand interventions and services attentive to polysubstance use and the role of pleasure in drug taking practices, including expanding non-medicalized opioid and stimulant safer supply initiatives across North America.

Role of preexisting inhibitory control deficits vs. drug use history in mediating insensitivity to aversive consequences in a rat model of polysubstance use

RATIONALE

The nature and predictors of insensitivity to aversive consequences of heroin + cocaine polysubstance use are not well characterized.

OBJECTIVES

Translational methods incorporating a tightly controlled animal model of drug self-administration and measures of inhibitory control and avoidance behavior might be helpful for clarifying this issue.

METHODS

The key approach for distinguishing potential contributions of pre-existing inhibitory control deficits vs. drug use history in meditating insensitivity to aversive consequences was comparison of two rat strains: Wistar (WIS/Crl), an outbred strain, and the spontaneously hypertensive rat (SHR/NCrl), an inbred strain shown previously to exhibit heightened cocaine and heroin self-administration and poor inhibitory control relative to WIS/Crl.

RESULTS

In separate tasks, SHR/NCrl displayed greater impulsive action and compulsive-like behavior than WIS/Crl prior to drug exposure. Under two different schedules of drug delivery, SHR/NCrl self-administered more cocaine than WIS/Crl, but self-administered a similar amount of heroin + cocaine as WIS/Crl. When half the session cycles were punished by random foot shock, SHR/NCrl initially were less sensitive to punishment than WIS/Crl when self-administering cocaine, but were similarly insensitive to punishment when self-administering heroin + cocaine. Based on correlation analyses, only trait impulsivity predicted avoidance capacity in rats self-administering cocaine and receiving yoked-saline. In contrast, only amount of drug use predicted avoidance capacity in rats self-administering heroin + cocaine. Additionally, baseline drug seeking and taking predicted punishment insensitivity in rats self-administering cocaine or heroin + cocaine.

CONCLUSIONS

Based on the findings revealed in this animal model, human laboratory research concerning the nature and predictors of insensitivity to aversive consequences in heroin and cocaine polysubstance vs. monosubstance users is warranted.

Cocaine: An Updated Overview on Chemistry, Detection, Biokinetics, and Pharmacotoxicological Aspects including Abuse Pattern

Cocaine is one of the most consumed stimulants throughout the world, as official sources report. It is a naturally occurring sympathomimetic tropane alkaloid derived from the leaves of Erythroxylon coca, which has been used by South American locals for millennia. Cocaine can usually be found in two forms, cocaine hydrochloride, a white powder, or ‘crack’ cocaine, the free base. While the first is commonly administered by insufflation (‘snorting’) or intravenously, the second is adapted for inhalation (smoking). Cocaine can exert local anaesthetic action by inhibiting voltage-gated sodium channels, thus halting electrical impulse propagation; cocaine also impacts neurotransmission by hindering monoamine reuptake, particularly dopamine, from the synaptic cleft. The excess of available dopamine for postsynaptic activation mediates the pleasurable effects reported by users and contributes to the addictive potential and toxic effects of the drug. Cocaine is metabolised (mostly hepatically) into two main metabolites, ecgonine methyl ester and benzoylecgonine. Other metabolites include, for example, norcocaine and cocaethylene, both displaying pharmacological action, and the last one constituting a biomarker for co-consumption of cocaine with alcohol. This review provides a brief overview of cocaine’s prevalence and patterns of use, its physical-chemical properties and methods for analysis, pharmacokinetics, pharmacodynamics, and multi-level toxicity.

Modeling Stimulant and Opioid Co-use in Rats Provided Concurrent Access to Methamphetamine and Fentanyl

Concurrent use of stimulants (e.g., methamphetamine) and opioids (e.g., fentanyl) has become increasingly common in recent years and continues to pose an enormous health burden, worldwide. Despite the prevalence, relatively little is known about interactions between the reinforcing effects of stimulants and opioids in this pattern of polysubstance use. The goals of the current study were to evaluate the relative reinforcing and relapse-related effects of methamphetamine and fentanyl using a concurrent access, drug-vs.-drug choice procedure. Male Sprague-Dawley rats were first allowed to acquire self-administration for either 0.1 mg/kg/infusion methamphetamine or 0.0032 mg/kg/infusion fentanyl, independently, after which concurrent access to both drugs was provided. When training doses of methamphetamine and fentanyl were concurrently available, a subset of rats self-administered both drugs, either within a session or alternating across sessions, whereas the remaining rats responded exclusively for one drug. When the cost of the preferred drug was increased (i.e., unit dose reduced), or the cost of the non-preferred drug was decreased (i.e., unit dose increased), choice was largely allocated toward the cheaper alternative. Following extinction of responding, methamphetamine- and fentanyl-paired cues reinstated responding on both levers. Responding reinstated by a priming injection of methamphetamine or fentanyl allocated more responding to the lever previously reinforced by the priming drug. The current studies suggest that choice of methamphetamine and fentanyl is largely allocated to the cheaper alternative, although more co-use was observed than would be expected for economic substitutes. Moreover, they lay the groundwork for more fully evaluating interactions between commonly co-abused drugs (e.g., stimulants and opioids) in order to better understand the determinants of polysubstance use and develop effective treatment strategies for individuals suffering from a polysubstance use disorder.

Effects of the psychoactive compounds in green tea on risky decision-making

Epigallocatechin-3-gallate (EGCG) and caffeine are the two primary compounds found in green tea. While EGCG has anxiolytic and anti-inflammatory effects, its acute effects on cognition are not well understood. Furthermore, despite widespread green tea consumption, little is known about how EGCG and caffeine co-administration impacts behavior. Here, we investigated the effects of multiple doses of either EGCG or caffeine on a rat model of risk-taking. This was assessed using the risky decision-making task (RDT), in which rats choose between a small, well-tolerated reward and a large reward with escalating risk of mild footshock. Rats were tested in RDT after acute systemic administration of EGCG, caffeine or joint EGCG and caffeine. EGCG caused a dose-dependent reduction in risk-taking without affecting reward discrimination or task engagement. Caffeine did not impact risk-taking, but elevated locomotor activity and reduced task engagement at high doses. Finally, exposure to both EGCG and caffeine had no effect on risk-taking, suggesting that low-dose caffeine is sufficient to mask the risk-aversion caused by EGCG. These data suggest EGCG as a potential therapeutic treatment for psychological disorders that induce compulsive risky decision-making.

Dopamine Supersensitivity: A Novel Hypothesis of Opioid-Induced Neurobiological Mechanisms Underlying Opioid-Stimulant Co-use and Opioid Relapse

Emergent harms presented by the co-use of opioids and methamphetamine highlight the broader public health challenge of preventing and treating opioid and stimulant co-use. Development of effective therapeutics requires an understanding of the physiological mechanisms that may be driving co-use patterns, specifically the underlying neurobiology of co-use and how they may facilitate (or be leveraged to prevent) continued use patterns. This narrative review summarizes largely preclinical data that demonstrate clinically-meaningful relationships between the dopamine and opioid systems with direct implications for opioid and stimulant co-use. Synthesized conclusions of this body of research include evidence that changes in the dopamine system occur only once physical dependence to opioids develops, that the chronicity of opioid exposure is associated with the severity of changes, and that withdrawal leaves the organism in a state of substantive dopamine deficit that persists long after the somatic or observed signs of opioid withdrawal appear to have resolved. Evidence also suggests that dopamine supersensitivity develops soon after opioid abstinence and results in increased response to dopamine agonists that increases in magnitude as the abstinence period continues and is evident several weeks into protracted withdrawal. Mechanistically, this supersensitivity appears to be mediated by changes in the sensitivity, not quantity, of dopamine D2 receptors. Here we propose a neural circuit mechanism unique to withdrawal from opioid use with implications for increased stimulant sensitivity in previously stimulant-naïve or inexperienced populations. These hypothesized effects collectively delineate a mechanism by which stimulants would be uniquely reinforcing to persons with opioid physical dependence, would contribute to the acute opioid withdrawal syndrome, and could manifest subjectively as craving and/or motivation to use that could prompt opioid relapse during acute and protracted withdrawal. Preclinical research is needed to directly test these hypothesized mechanisms. Human laboratory and clinical trial research is needed to explore these clinical predictions and to advance the goal of developing treatments for opioid-stimulant co-use and/or opioid relapse prevention and withdrawal remediation.

Effects of cocaine and/or heroin use on resting cardiovascular function

Background

Regular cocaine and/or heroin use is associated with major health risks, especially cardiovascular disease, but confounded by other factors. We examined effects of chronic (years regular use) and recent (past-month) cocaine and heroin use, controlling for other factors, on resting cardiovascular function.

Methods

In a sample of 292 cocaine and/or heroin users, we assessed demographics, body mass index (BMI), substance use history, electrocardiogram, heart rate (HR) and blood pressure (BP). Three-block (1: demographics, BMI; 2: tobacco, alcohol, cannabis; 3: cocaine, heroin) regression analyses were conducted to predict cardiovascular measures.

Results

Higher BMI predicted increased systolic and diastolic BP (as did older age), increased supine HR, and longer QRS duration, QTc interval, PR interval, and P-wave duration. Past-month cannabis-use days predicted higher systolic BP, lower supine HR, and greater likelihood of early repolarization and ST elevation; average daily cannabis use predicted shorter QTc interval. Average daily alcohol use predicted higher diastolic BP, higher supine HR and lower likelihood of sinus bradycardia (HR < 60 bpm). Past-month tobacco-use days predicted shorter QTc interval and lower lower likelihood of profound bradycardia (HR < 50 bpm). Past-month heroin-use days predicted lower seated HR, greater likelihood of sinus bradycardia and lower likelihood of left ventricular hypertrophy. More years of regular cocaine use and past-month cocaine-use days predicted longer QTc interval.

Conclusions

Cocaine and heroin use incrementally predicted modest variance in resting bradycardia and QTc interval. Clinicians should first consider demographics and recent use of tobacco, alcohol and cannabis before assuming cocaine and heroin affect these measures.

The association between depression and oral health related quality of life in people who inject drugs

BACKGROUND AND AIMS

Oral health related quality of life (OHRQoL) is known to be reduced in disadvantaged populations, including people who inject drugs. Mental health issues, such as depression are also commonly reported. In this study we examined the association between depression and OHRQoL.

METHODS

Cross-sectional analysis survey data was collected from the Melbourne Injecting Drug User Cohort Study (SuperMIX) of people who inject drugs (N = 982). Three measures derived from the Oral Health Impact Profile (OHIP-14) were used to assess OHRQoL: Prevalence (reporting one or more dental issue "Very often" or "Fairly often" in the previous year), Extent (number of items reported either "Very often" or "Fairly often") and Severity (summary score of all ordinal responses). Regression analyses assessed the association between depression, indexed as scoring above 10 on the Patient Health Questionnaire (PHQ-9), and OHIP-14 measures, adjusted for sociodemographic, drug use and dental service utilisation variables.

RESULTS

Overall, participants had low levels of OHRQoL, indexed through OHIP-14 scores (46% exhibiting prevalence, mean extent of 2.35 and mean severity of 12.72). Depression was associated with increases in all OHIP-14 measures, after adjustment for potential confounders.

CONCLUSIONS

We found a significant association between depression and poor OHRQoL in this sample of people who inject drugs. Further research using a longitudinal frame is needed to determine the direction of this relationship. Interventions to improve oral health of people who inject drugs are urgently needed, and these may benefit mental health outcomes for people who inject drugs.

Dopamine Circuit Mechanisms of Addiction-Like Behaviors

Addiction is a complex disease that impacts millions of people around the world. Clinically, addiction is formalized as substance use disorder (SUD), with three primary symptom categories: exaggerated substance use, social or lifestyle impairment, and risky substance use. Considerable efforts have been made to model features of these criteria in non-human animal research subjects, for insight into the underlying neurobiological mechanisms. Here we review evidence from rodent models of SUD-inspired criteria, focusing on the role of the striatal dopamine system. We identify distinct mesostriatal and nigrostriatal dopamine circuit functions in behavioral outcomes that are relevant to addictions and SUDs. This work suggests that striatal dopamine is essential for not only positive symptom features of SUDs, such as elevated intake and craving, but also for impairments in decision making that underlie compulsive behavior, reduced sociality, and risk taking. Understanding the functional heterogeneity of the dopamine system and related networks can offer insight into this complex symptomatology and may lead to more targeted treatments.

Interactions between opioids and stimulants: Behavioral pharmacology of abuse-related effects

Opioid abuse continues to be a significant public health challenge, with rates of opioid-related overdose deaths increasing continuously over the last two decades. There also has been a sharp increase in overdose deaths involving stimulant drugs, primarily cocaine and methamphetamine. Recent estimates indicate a high prevalence of co-use of opioids and stimulants, which is a particularly complex problem. Behavioral pharmacology research over the last few decades has characterized interactions between opioids and stimulants as well as evaluated potential treatments. This chapter describes interactions between opioids and stimulants, with a focus on pre-clinical studies of abuse-related behavioral effects using self-administration, reinstatement, drug discrimination, place conditioning, and intracranial self-stimulation paradigms in laboratory animals. In general, the literature provides substantial evidence of mutual enhancement between opioids and stimulants for abuse-related effects, although such results are not ubiquitous. Enhanced abuse-related effects could manifest in many ways including engaging in drug seeking and taking behaviors with greater persistence, effort, and motivation and/or increased likelihood of relapse. Moreover, studies on opioid/stimulant combinations set the stage for evaluating potential treatments for polysubstance use. Behavioral pharmacology research has proven invaluable for elucidating these relationships using rigorous experimental designs and quantitative analyses of pharmacological and behavioral data.

Ethanol pre-exposure differentially impacts the rewarding and aversive effects of α-pyrrolidinopentiophenone (α-PVP): Implications for drug use and abuse

RATIONALE

Exposure to a drug can subsequently impact its own reactivity as well as that of other drugs. Given that users of synthetic cathinones, i.e., "bath salts", typically have extensive and varied drug histories, an understanding of the effects of drug history on the behavioral and physiological consequences of synthetic cathiones may be important to their abuse liability.

OBJECTIVES

The goal of the current work was to assess the effects of an ethanol pre-exposure on the rewarding and aversive effects of α-PVP.

METHODS

Adult male Sprague Dawley rats were exposed to ethanol prior to combined conditioned taste avoidance/conditioned place preference training in which rats were injected with 1.5, 3 or 5 mg/kg of racemic α-PVP or vehicle. Following a 7-day washout period, rats were then tested for thermoregulatory effects of α-PVP using subcutaneous probes to measure body temperature changes over the course of 8 h. This was followed 10 days later by assessments for α-PVP-induced locomotor activity and stereotypies over a 1-h session.

RESULTS

α-PVP induced significant dose- and trial-dependent taste avoidance that was significantly attenuated by ethanol history and dose- and time-dependent increases in locomotor activity that were significantly increased by ethanol. α-PVP also induced place preferences and dose- and time-dependent increases in body temperature, but these measures were unaffected by ethanol history.

CONCLUSIONS

α-PVP's aversive effects (as measured by taste avoidance) were attenuated, while its rewarding effects (as indexed by place preference conditioning) were unaffected, by ethanol pre-exposure. Such a pattern may indicate increased α-PVP abuse liability, as changes in the balance of aversion and reward may impact overall drug effects and likelihood of drug intake. Future self-administration studies will be necessary to explore this possibility.

Co-exposure of cocaine and cannabinoids and its association with select biological, behavioural and health outcomes: A systematic scoping review of multi-disciplinary studies

Cocaine use entails severe health- and social-related harms globally. Treatment options for cocaine dependence are highly limited. Benefits of cannabinoids for addiction have been documented, making it opportune to examine existing data on the possible outcomes associated with cannabinoids and cocaine co-use. We conducted a systematic scoping review following the PRISMA guidelines of peer-reviewed, English-language studies published from 2000 to 2021 in four databases (Medline, Web-of-Science, CINAHL Plus, and PsycInfo), assessing the co-exposure of cannabis/cannabinoids with cocaine on behavioural, biological or health outcomes. Both quantitative and qualitative, as well as humans and pre-clinical animals' studies (n=46) were included. Pre-clinical studies (n=19) showed mostly protective effects of cannabidiol (CBD) administration on animal models of addiction (e.g., cocaine-craving, -relapse, and -withdrawal) and cocaine-toxicity. Tetrahydrocannabinol (THC) had more inconsistent results, with both protective and counter-protective effects. Human studies (n=27) were more heterogeneous and assessed natural ongoing cannabis and cocaine use or dependence. Quantitative-based studies showed mostly enhanced harms in several outcomes (e.g., cocaine use, mental health); two available clinical trials found no effect upon CBD administration on cocaine-related treatment outcomes. Qualitative data-based studies reported cannabis use as a substitute for or to alleviate harms of crack-cocaine use. While pre-clinical studies suggest a potential of cannabinoids, especially CBD, to treat cocaine addiction, the few trials conducted in humans found no benefits. Cannabis co-use by cocaine users commonly presents a risk factor, entailing enhanced harms for users. More rigorous, controlled trials are still necessary to investigate cannabinoids' potential considering pre-clinical findings and reported benefits from specific drug users.

Use of methamphetamine and alcohol among people with opioid use disorder and HIV in Vietnam: a qualitative study

BACKGROUND

Heroin use continues to drive HIV transmission in Vietnam, but methamphetamine and alcohol use are growing rapidly and, as in other countries, polysubstance use is widespread. The objective of this study was to understand the interplay between heroin, methamphetamine, and alcohol use among people with opioid use disorder (OUD) and HIV in Vietnam.

METHODS

We conducted 44 in-depth, face-to-face qualitative interviews with people with OUD and HIV who participated in the BRAVO trial of buprenorphine versus methadone in five Vietnam HIV clinics. Interviews probed participants' experiences of heroin, methamphetamine, and alcohol use and their interplay with HIV/OUD treatment. Interviews were professionally transcribed and analyzed using a thematic analysis approach.

RESULTS

Of 44 participants interviewed 42 were male, on average 38.8 years of age, with 30 reporting a history of methamphetamine use and 33 reporting a history of alcohol use. Several themes emerged: 1) Methamphetamine and alcohol were perceived to have lower addiction potential than heroin 2) Social settings were key facilitators of alcohol and methamphetamine use 3) Some participants, but not all, used methamphetamine to help quit heroin 4) Consuming alcohol blunted the effects of heroin, while paradoxically serving as a catalyst for heroin use 5) Use of methamphetamine was perceived by many participants to be incompatible with treatment for HIV.

CONCLUSIONS

Participant experiences reflected a significant impact of polysubstance use on treatment of HIV and OUD. Patterns of polysubstance use are subject to common preconceptions of alcohol and methamphetamine as having a low addictive potential, and these substances are deeply enmeshed in the social life of many people with OUD in Vietnam. Interventions to address complex social norms and potential harms of polysubstance use are urgently needed as the population of people receiving medication for OUD (MOUD) increases in Vietnam and globally.

TRIAL REGISTRATION

BRAVO - NCT01936857 , September 2013.

Drugs of Abuse: Sympathomimetics

Sympathomimetic drugs comprise a broad category of substances including both illicit and prescribed drugs that have deleterious effects when ingested or abused. The clinical syndromes that result from overstimulation of the sympathetic nervous system by reuptake inhibition of biogenic amines, such as norepinephrine and dopamine, carry significant morbidity. Recognition and awareness of the appropriate supportive measures are required to mitigate life-threatening complications of multiple organ systems. The sympathomimetic toxidrome is recognized by a constellation of symptoms including agitation, hyperthermia, tachycardia, and hypertension, and the primary treatment involves supportive care, including the liberal use of benzodiazepines.

Dissociable neural substrates of opioid and cocaine use identified via connectome-based modelling

Opioid use disorder is a major public health crisis. While effective treatments are available, outcomes vary widely across individuals and relapse rates remain high. Understanding neural mechanisms of treatment response may facilitate the development of personalized and/or novel treatment approaches. Methadone-maintained, polysubstance-using individuals (n = 53) participated in fMRI scanning before and after substance-use treatment. Connectome-based predictive modeling (CPM)-a recently developed, whole-brain approach-was used to identify pretreatment connections associated with abstinence during the 3-month treatment. Follow-up analyses were conducted to determine the specificity of the identified opioid abstinence network across different brain states (cognitive vs. reward task vs. resting-state) and different substance use outcomes (opioid vs. cocaine abstinence). Posttreatment fMRI data were used to assess network changes over time and within-subject replication. To determine further clinical relevance, opioid abstinence network strength was compared with healthy subjects (n = 38). CPM identified an opioid abstinence network (p = 0.018), characterized by stronger within-network motor/sensory connectivity, and reduced connectivity between the motor/sensory network and medial frontal, default mode, and frontoparietal networks. This opioid abstinence network was anatomically distinct from a previously identified cocaine abstinence network. Relationships between abstinence and opioid and cocaine abstinence networks replicated across multiple brain states but did not generalize across substances. Network connectivity measured at posttreatment related to abstinence at 6-month follow-up (p < 0.009). Healthy comparison subjects displayed intermediate network strengths relative to treatment responders and nonresponders. These data indicate dissociable anatomical substrates of opioid vs. cocaine abstinence. Results may inform the development of novel opioid-specific treatment approaches to combat the opioid epidemic.

Hair Analysis to Evaluate Polydrug Use

Polydrug use is a frequent pattern of consumption in Europe. This behavior has mainly been analyzed within restricted groups; more rarely in large populations. Current polydrug use is less studied than simultaneous use. This study focused on the concurrent assumption of polydrug among drivers using hair matrix. Hair matrix, for its biological characteristics, allows to identify illicit drug use more often than other matrices, i.e., urine, and it provides information on the long-term use of them. Hair samples of subjects positive for opiates, cocaine and delta-9-tetrahydrocannabinol (Δ⁹-THC) collected by the forensic toxicology laboratory of the University of Macerata in the period 2010–2020, were analyzed using a gas chromatography-mass spectrometry method. Our results evidenced that a significant part of the examined population (12.15%) used polydrug. A strong predominance of males over females was evident. Polydrug users were more frequently young people. The abuse of two substances was predominant. Cocaine and Δ⁹-THC was the most common combination, followed by cocaine and morphine, and morphine and Δ⁹-THC. The timeframe of polydrug use was also analyzed. Our study shows that polydrug use is a very frequent behavior, and that hair analysis may be a powerful tool to obtain objective biological information of this complex phenomenon.

Understanding opioid overdose risk and response preparedness among people who use cocaine and other drugs: Mixed-methods findings from a large, multi-city study

BACKGROUND

Fatal overdoses involving cocaine (powdered or crack) and fentanyl have increased nationally and in Massachusetts. It is unclear how overdose risk and preparedness to respond to an overdose differs by patterns of cocaine and opioid use. Methods: From 2017 to 2019, we conducted a nine-community mixed-methods study of Massachusetts residents who use drugs. Using survey data from 465 participants with past-month cocaine and/or opioid use, we examined global differences (p < 0.05) in overdose risk and response preparedness by patterns of cocaine and opioid use. Qualitative interviews (n = 172) contextualized survey findings. Results: The majority of the sample (66%) used cocaine and opioids in the past month; 18.9% used opioids alone; 9.2% used cocaine and had no opioid use history; and 6.2% used cocaine and had an opioid use history. Relative to those with a current/past history of opioid use, significantly fewer of those with no opioid use history were aware of fentanyl in the drug supply, carried naloxone, and had received naloxone training. Qualitative interviews documented how people who use cocaine and have no history of opioid use are largely unprepared to recognize and respond to an overdose. Conclusions: Public health efforts are needed to increase fentanyl awareness and overdose prevention preparedness among people primarily using cocaine.