Charting the fourth wave: Geographic, temporal, race/ethnicity and demographic trends in polysubstance fentanyl overdose deaths in the United States, 2010-2021

U.S. trends in methamphetamine-involved psychiatric hospitalizations in the United States, 2015-2019

BACKGROUND

In the U.S., overdose deaths and substance treatment admissions related to methamphetamine are rising. This study aims to measure and compare U.S. temporal trends in methamphetamine-involved psychiatric hospitalizations.

METHODS

We conducted a population-based, trend analysis of U.S. psychiatric hospitalizations and calculated quarterly (Q) rates per 100,000 population of substance-involved psychiatric hospitalizations. We assessed U.S. regional quarterly percentage hospitalization rate changes using Joinpoint regression.

RESULTS

From Q4 2015-Q4 2019, there were 963,202 psychiatric hospitalizations, 50,223 (5.2 %) involved methamphetamine and 102,877 (10.7 %) involved opioids and/or cocaine without methamphetamine. Methamphetamine-involved psychiatric hospitalization rates increased by 68.0 %, psychiatric hospitalizations rates involving opioid and/or cocaine without methamphetamine decreased by 22 %, while nonsubstance-involved psychiatric hospitalizations rates remained unchanged. The largest significant increases in methamphetamine-involved psychiatric hospitalization rates were among people >61 years old, males, and Midwesterners. Methamphetamine-involved psychiatric hospitalization rates doubled among Black patients. The largest average percent increase among methamphetamine-involved psychiatric hospitalizations was 10.2 % from Q4 2015-Q2 2017 in the Midwest.

CONCLUSION AND RELEVANCE

Most psychiatric hospitalizations did not involve substances. Methamphetamine-involved psychiatric hospitalizations greatly increased while opioid-involved psychiatric hospitalizations decreased, but involved more total encounters. Greater access to harm reduction services, contingency management programs, and mental health services is urgently needed.

Racial/ethnic trends in opioid and polysubstance opioid overdose mortality in adolescents and young adults, 1999-2020

OBJECTIVES

Previous reports have described variations in opioid overdose mortalities among different race/ethnicity groups. We have analyzed racial/ethnicity trends in opioid and polysubstance opioid overdose mortalities in adolescents and young adults to further characterize differences and potential sub-epidemics within this specific population.

METHODS

We used mortality data from the U.S. Centers for Disease Control and Prevention Wide-Ranging Online Data for Epidemiologic Research (WONDER) Multiple Cause of Death file from 1999 to 2020. Drug overdose mortalities were identified using International Classification of Diseases, Tenth Revision (ICD-10) codes. Joinpoint regression was used to examine mortality rates for all opioids, opioids with a stimulant, opioids with benzodiazepines, and opioids with alcohol among racial/ethnic groups (non-Hispanic white, non-Hispanic Black, Hispanic, non-Hispanic other) in adolescents and young adults.

RESULTS

The Average Annual Percent Change (AAPC) for mortality due to opioid and polysubstance opioid overdose increased for all racial/ethnic groups where data was available for analysis from 1999 to 2020. For mortality due to any opioid and any opioid with a stimulant, the greatest AAPC was seen among non-Hispanic Blacks.

CONCLUSIONS

Unprecedented increases in mortality due to opioid overdose occurred in the last two decades among adolescents and young adults. Heterogenous trends support the notion that the previously defined opioid overdose epidemic "waves" may not accurately depict the effects of the crisis in all race/ethnicity groups. Additionally, alarming increases in opioid-stimulant overdose mortality starting in 2012 further characterize the interrelated effects of the third and fourth waves.

In vitro structure-activity relationships and forensic case series of emerging 2-benzylbenzimidazole 'nitazene' opioids

2-Benzylbenzimidazole 'nitazene' opioids are presenting a growing threat to public health. Although various nitazenes were previously studied, systematic comparisons of the effects of different structural modifications to the 2-benzylbenzimidazole core structure on μ-opioid receptor (MOR) activity are limited. Here, we assessed in vitro structure-activity relationships of 9 previously uncharacterized nitazenes alongside known structural analogues. Specifically, we focused on MOR activation by 'ring' substituted analogues (i.e., N-pyrrolidino and N-piperidinyl modifications), 'desnitazene' analogues (lacking the 5-nitro group), and N-desethyl analogues. The results from two in vitro MOR activation assays (β-arrestin 2 recruitment and inhibition of cAMP accumulation) showed that 'ring' modifications overall yield highly active drugs. With the exception of 4'-OH analogues (which are metabolites), N-pyrrolidino substitutions were generally more favorable for MOR activation than N-piperidine substitutions. Furthermore, removal of the 5-nitro group on the benzimidazole ring consistently caused a pronounced decrease in potency. The N-desethyl modifications showed important MOR activity, and generally resulted in a slightly lowered potency than comparator nitazenes. Intriguingly, N-desethyl isotonitazene was the exception and was consistently more potent than isotonitazene. Complementing the in vitro findings and demonstrating the high harm potential associated with many of these compounds, we describe 85 forensic cases from North America and the United Kingdom involving etodesnitazene, N-desethyl etonitazene, N-desethyl isotonitazene, N-pyrrolidino metonitazene, and N-pyrrolidino protonitazene. The low-to-sub ng/mL blood concentrations observed in most cases underscore the drugs' high potencies. Taken together, by bridging pharmacology and case data, this study may aid to increase awareness and guide legislative and public health efforts.

Protective or potentially harmful? Altering drug consumption behaviors in response to xylazine adulteration

Background Xylazine is an increasingly common adulterant in the North American unregulated drug supply that is associated with adverse health outcomes (e.g., skin infections, overdose). However, there are significant knowledge gaps regarding how xylazine was initially identified and how syringe services program (SSP) staff and clients (people who use drugs) responded to its emergence. Methods From June-July 2023, we conducted qualitative interviews with medical (e.g., clinicians) and frontline SSP staff (e.g., outreach workers) and adult clients with a history of injection drug use at a Miami-based SSP. Inductive memos identified emergent codes; thematic analysis involving team consensus established final themes. Results From interviews with SSP staff (n = 8) and clients (n = 17), xylazine emergence was identified at different times, in various ways. Initially, during summer 2022, clients identified a "tranquilizer-like substance" that worsened sedation and withdrawal and caused wounds. SSP medical staff later identified this adulterant as xylazine by treating new medical cases and through diverse information-sharing networks that included professional societies and news sources; however, frontline SSP staff and clients needed additional educational resources about xylazine and its side effects. With limited guidance on how to reduce harm from xylazine, SSP clients altered their drug consumption routes, reduced drug use, and relied on peers' experiences with the drug supply to protect themselves. Some individuals also reported preferring xylazine-adulterated opioids and increasing their drug use, including the use of stimulants to avoid over sedation. Conclusions Xylazine's emergence characterizes the current era of unprecedented shifts in the unregulated drug supply. We found that xylazine spurred important behavioral changes among people who use drugs (e.g., transitioning from injecting to smoking). Incorporating these experiences into early drug warning surveillance systems and scaling up drug-checking services and safer smoking supply distribution could help mitigate significant health harms caused by xylazine and other emergent adulterants.

Comparative effectiveness of extended-release naltrexone and sublingual buprenorphine for treatment of opioid use disorder among Medicaid patients

BACKGROUND AND AIMS

Extended-release naltrexone (XR-NTX) and sublingual buprenorphine (SL-BUP) are both approved for opioid use disorder (OUD) treatment in any medical setting. We aimed to compare the real-world effectiveness of XR-NTX and SL-BUP.

DESIGN AND SETTING

This was an observational active comparator, new user cohort study of Medicaid claims records for patients in New Jersey and California, USA, 2016-19.

PARTICIPANTS/CASES

The participants were adult Medicaid patients aged 18-64 years who initiated XR-NTX or SL-BUP for maintenance treatment of OUD and did not use medications for OUD in the 90 days before initiation. Our cohort included 1755 XR-NTX and 9886 SL-BUP patients.

MEASUREMENTS

We examined two outcomes up to 180 days after medication initiation: (1) composite of medication discontinuation and death and (2) composite of overdose and death.

FINDINGS

In adjusted analyses, treatment with XR-NTX was more likely to result in discontinuation or death by the end of follow-up than treatment with SL-BUP: cumulative risk 75.9% [95% confidence interval (CI) = 73.9%, 77.9%] versus 62.2% (95% CI = 61.2%, 63.2%), respectively (risk difference = 13.7 percentage points, 95% CI = 11.4, 16.0). There was minimal difference in the cumulative risk of overdose or death by the end of follow-up: XR-NTX 3.9% (95% CI = 3.0%, 4.8%) versus SL-BUP 3.3% (95% CI = 2.9%, 3.7%); risk difference = 0.5 percentage points, 95% CI = -0.4, 1.5. Results were consistent across sensitivity analyses.

CONCLUSIONS

Medicaid patients in California and New Jersey, USA, receiving treatment for opioid use disorder stayed in treatment longer on sublingual buprenorphine than on extended-release naltrexone, but the risk of overdose was similar. Most patients in this study discontinued medication within 6 months, regardless of which medication was initiated.

Drug Overdose Death Following Substance Use Disorder Treatment Termination in New York City: A Retrospective Longitudinal Cohort Study

Drug overdose death rates are the highest recorded in New York City (NYC). Substance use disorder (SUD) treatment termination can confer increased risk of drug overdose death. Our objective was to determine the probability of, and factors associated with, drug overdose death following SUD treatment termination. Using a retrospective longitudinal cohort design, we identified those who had NYC-based SUD treatment terminated (01/2016-06/2019) using Chief Medical Examiner and SUD treatment data. Using survival analyses, we examined drug overdose deaths ≤ 14 and ≤ 90 days following SUD treatment termination, respectively. Of 51,171 patients with SUD treatment termination, 140 and 342 had a drug overdose death < 14 and ≤ 90 days, respectively. The crude drug overdose death rate was 26.7 per 1000 person-years at-risk in the ≤ 90-day period and was 71.6 per 1000 person-years at-risk in the ≤ 14-day period. In adjusted Cox proportional hazard model examining death ≤ 14 days, those unemployed (compared to employed) and those terminated from residential treatment (compared to medically supervised withdrawal, opioid treatment programs, and outpatient treatment) were more likely to have had a drug overdose death (all p-values < 0.01). In adjusted Cox proportional hazard model examining death ≤ 90 days, non-Hispanic White people (compared to non-Hispanic Black people), those not stably housed (compared to stably housed), those unemployed and those terminated from residential treatment were more likely to have had a drug overdose death (all p-values < 0.01). Strategies to improve retention including the reassessment of program treatment termination criteria along with strategies to promote ongoing OUD treatment, engagement in harm reduction, and distribution of naloxone are needed.

Transcranial magnetic stimulation for methamphetamine use disorder: A scoping review within the neurocircuitry model of addiction

The use of methamphetamine in the United States is increasing, contributing now to the "fourth wave" in the national opioid epidemic crisis. People who suffer from methamphetamine use disorder (MUD) have a higher risk of death. No pharmacological interventions are approved by the FDA and psychosocial interventions are only moderately effective. Transcranial Magnetic Stimulation (TMS) is a relatively novel FDA-cleared intervention for the treatment of Major Depressive Disorder (MDD) and other neuropsychiatric conditions. Several lines of research suggest that TMS could be useful for the treatment of addictive disorders, including MUD. We will review those published clinical trials that show potential effects on craving reduction of TMS when applied over the dorsolateral prefrontal cortex (DLPFC) also highlighting some limitations that affect their generalizability and applicability. We propose the use of the Koob and Volkow's neurocircuitry model of addiction as a frame to explain the brain effects of TMS in patients with MUD. We will finally discuss new venues that could lead to a more individualized and effective treatment of this complex disorder including the use of neuroimaging, the exploration of different areas of the brain such as the frontopolar cortex or the salience network and the use of biomarkers.

Dependency of fentanyl analogue protomer ratios on solvent conditions as measured by ion mobility-mass spectrometry

Recently, our group has shown that fentanyl and many of its analogues form prototropic isomers ("protomers") during electrospray ionization. These different protomers can be resolved using ion mobility spectrometry and annotated using mobility-aligned tandem mass spectrometry fragmentation. However, their formation and the extent to which experimental variables contribute to their relative ratio remain poorly understood. In the present study, we systematically investigated the effects of mixtures of common chromatographic solvents (water, methanol, and acetonitrile) and pH on the ratio of previously observed protomers for 23 fentanyl analogues. Interestingly, these ratios (N-piperidine protonation vs. secondary amine/O = protonation) decreased significantly for many analogues (e.g., despropionyl ortho-, meta-, and para-methyl fentanyl), increased significantly for others (e.g., cis-isofentanyl), and remained relatively constant for the others as solvent conditions changed from 100% organic solvent (methanol or acetonitrile) to 100% water. Interestingly, pH also had significant effects on this ratio, causing the change in ratio to switch in many cases. Lastly, increasing conditions to pH ≥ 4.0 also prompted the appearance of new mobility peaks for ortho- and para-methyl acetyl fentanyl, where all previous studies had only showed one single distribution. Because these ratios have promise to be used qualitatively for identification of these (and emerging) fentanyl analogues, understanding how various conditions (i.e., mobile phase selection and/or chromatographic gradient) affect their ratios is critically important to the development of advanced ion mobility and mass spectrometry methodologies to identify fentanyl analogues.

Illicit Fentanyl Use and Hepatitis C Virus Seroconversion Among People Who Inject Drugs in Tijuana and San Diego: Results From a Binational Cohort Study

BACKGROUND

Illicitly manufactured fentanyl (IMF) increases overdose mortality, but its role in infectious disease transmission is unknown. We examined whether IMF use predicts hepatitis C virus (HCV) and human immunodeficiency virus (HIV) incidence among a cohort of people who inject drugs (PWID) in San Diego, California and Tijuana, Mexico.

METHODS

PWID were recruited during 2020-2022, undergoing semi-annual interviewer-administered surveys and HIV and HCV serological rapid tests through 2024. Cox regression was conducted to examine predictors of seroconversion considering self-reported IMF use as a 6-month lagged, time-dependent covariate.

RESULTS

Of 398 PWID at baseline, 67% resided in San Diego, 70% were male, median age was 43 years, 42% reported receptive needle sharing, and 25% reported using IMF. HCV incidence was 14.26 per 100 person-years (95% confidence interval [CI]: 11.49-17.02), and HIV incidence was 1.29 (95% CI: .49-2.10). IMF was associated with HCV seroconversion, with a univariable hazard ratio (HR) of 1.64 (95% CI: 1.09-2.40), and multivariable HR of 1.57 (95% CI: 1.03-2.40). The direction of the relationship with HIV was similar, albeit not significant (HR 2.39; 95% CI: .66-8.64).

CONCLUSIONS

We document a novel association between IMF and HCV seroconversion among PWID in Tijuana-San Diego. Few HIV seroconversions (n = 10) precluded our ability to assess if a similar relationship held for HIV. IMF's short half-life may destabilize PWID-increasing the need for repeat dosing and sharing smoking materials and syringes. New preventive care approaches may reduce HCV transmission in the fentanyl era.

Expanding the opioid use disorder medication treatment workforce in rural communities through the RCORP initiative

PURPOSE

The Rural Communities Opioid Response Program (RCORP) was funded to help rural communities improve prevention, treatment, and recovery services for Opioid Use Disorder (OUD), including increasing the supply of clinicians with a Drug Enforcement Administration (DEA) waiver to prescribe buprenorphine, which was required before 2023. This research investigates the impact of RCORP funding on the supply of DEA-waivered clinicians in rural communities.

METHODS

We used 2017-2022 DEA lists of waivered clinicians to assign clinicians to US counties. Using RCORP service area data, we classified rural counties as either being served by an RCORP grantee or not. We calculated the number of counties in each category with a waivered clinician, clinician-to-population ratios, and treatment slot-to-population ratios.

FINDINGS

In 2017, 3.7% more of RCORP funded counties had a waivered clinician than non-RCORP counties. RCORP counties also had 1.2 more waivered clinicians per 100,000 population and 57.5 more treatment slots per 100,000 population compared to non-RCORP counties. From 2017 to 2022, these differences more than doubled. The supply of waivered clinicians varied across Census Divisions. In most Census Divisions, a greater percentage of RCORP counties had a waivered clinician as well as more waivered clinicians and treatment slots per population, except for the Pacific Census Division, which had more clinicians and treatment slots per population in non-RCORP counties.

CONCLUSIONS

Study findings suggest that federal investments to expand rural OUD patients' access to care may have been successful, but only if increases in clinician supply translate into greater provision of OUD treatment.

Multilevel Factors Impacting Substance Use Treatment Access, Engagement, and Racial Equity Among Opioid Overdose Survivors in Boston, MA

BACKGROUND

There are well-documented racial/ethnic inequities in drug-related overdoses and access to evidence-based opioid use services nationally and in Boston, MA.

OBJECTIVE

To qualitatively explore the drivers of racial/ethnic inequities in access to opioid use disorder treatment and services in Boston.

DESIGN

Semi-structured qualitative interviews.

PARTICIPANTS

Using purposive sampling, researchers recruited 59 opioid overdose survivors in Boston who self-identified as Black, Hispanic or Latino/a/x, and/or White.

APPROACH

Interviewers administered a socio-demographic and drug use survey, and used a semi-structured interview guide to explore experiences with and perspectives on substance use treatment and services.

KEY RESULTS

Participants' racial/ethnic identities were distributed across three subgroups: non-Hispanic Black (n = 18; 31%), non-Hispanic White (n = 18; 31%), and Latino/a/x (n = 23; 39%). Qualitative analysis identified multiple themes that were organized into four social-ecological levels after analysis. At the individual level, some participants emphasized the importance of personal responsibility and individual motivation in determining access to services. Participants expressed a range of perspectives about using medication for opioid use disorder treatment; Black and Latino/a/x participants were more likely than White participants to have critical perspectives. At the interpersonal level, experiences of bias, stigma, and racism from staff in healthcare and treatment settings were common. At the program/process level, participants described challenges connecting to services following overdose and barriers within specific programs, with Black and Latino/a/x participants experiencing particular gaps. At the systems level, the limited availability of housing, employment, and mental health care negatively impacted treatment access and engagement.

CONCLUSION

A racism lens was used during data interpretation to apply the themes at a broader population level. Through this lens, the identified barriers can be understood to have a disproportionate impact on people of color. Findings call for programmatic and policy solutions that address racism, break down stigma, and ensure equitable access to evidence-based services and social supports.

Water, sanitation and hygiene insecurity predict abscess incidence among people who inject drugs in a binational US-Mexico metropolitan area: A longitudinal cohort study

INTRODUCTION

People who inject drugs (PWID) are at high risk of developing injection-related infections, including abscesses. Access to water, sanitation, and hygiene (WASH) are key human rights and services; yet these services have been underexplored as predictors of abscesses among PWID.

METHODS

Longitudinal analysis was employed among a cohort of PWID to determine if WASH insecurity (lack of access) was associated with abscess incidence in the Tijuana, Mexico and San Diego, United States metropolitan area during 24-months of follow-up survey data from 2020 to 2023. We calculated abscess prevalence at baseline and tracked the incidence of new abscesses among individuals without an abscess during the previous visit. Time dependent Cox regression modeling was employed with variance clustered by participant to characterize the relationship between WASH insecurity and abscess incidence.

RESULTS

At baseline, hand hygiene insecurity, bathing insecurity in the previous six months and open defecation in the last week, were reported by 60 %, 54 % and 38 % of participants, respectively; 21 % reported an abscess in the last six months. The incidence of abscesses was 24.4 (95 %CI: 21.1-27.6) per 100 person-years. After adjusting for covariates, the hazard of developing an abscess remained significantly elevated among individuals using non-improved (with risk of contamination) water sources (e.g., surface water) for preparing drugs (adjusted HR [adjHR]: 1.49 [95 %CI: 1.01-2.21], experiencing bathing insecurity (adjHR: 1.59 [95 %CI: 1.12-2.24]) and open defecation (adjHR: 1.65 [95 %CI: 1.16-2.35]).

CONCLUSIONS

PWID in the Tijuana-San Diego metropolitan area reported facing high rates of insecurity accessing WASH services. Abscess incidence was higher (four to nine times) than observed rate among PWID cohorts in other settings. Access to continuously available toilet facilities, bathing infrastructure, and safe water sources for preparing drugs for injection could prevent abscesses among PWID. Accessible WASH infrastructure should be ensured among PWID communities and promoted as a key component of harm reduction infrastructure.

Considerations when prescribing opioid agonist therapies for people living with HIV

INTRODUCTION

Medications for opioid use disorder (MOUD) include opioid agonist therapies (OAT) (buprenorphine and methadone), and opioid antagonists (extended-release naltrexone). All forms of MOUD improve opioid use disorder (OUD) and HIV outcomes. However, the integration of services for HIV and OUD remains inadequate. Persistent barriers to accessing MOUD underscore the immediate necessity of addressing pharmacoequity in the treatment of OUD in persons with HIV (PWH).

AREAS COVERED

In this review article, we specifically focus on OAT among PWH, as it is the most commonly utilized form of MOUD. Specifically, we delineate the intersection of HIV and OUD services, emphasizing their integration into the United States Ending the HIV Epidemic (EHE) plan by offering comprehensive screening, testing, and treatment for both HIV and OUD. We identify potential drug interactions of OAT with antiretroviral therapy (ART), address disparities in OAT access, and present the practical benefits of long-acting formulations of buprenorphine, ART, and pre-exposure prophylaxis for improving HIV prevention and treatment and OUD management.

EXPERT OPINION

Optimizing OUD outcomes in PWH necessitates careful attention to diagnosing OUD, initiating OUD treatment, and ensuring medication retention. Innovative approaches to healthcare delivery, such as mobile pharmacies, can integrate both OUD and HIV and reach underserved populations.

Sexually transmitted and blood-borne infection risk reduction with methadone and buprenorphine/naloxone among people with prescription-type opioid use disorder: Findings from a Canadian pragmatic randomized trial

INTRODUCTION

People who use drugs are disproportionally affected by sexually transmitted and blood-borne infections (STBBIs). While the benefits of methadone in reducing injecting-risk behaviours are well documented, less is known on its impacts on sexual-related risks, as well as its comparative effectiveness to buprenorphine/naloxone, particularly in the context of highly potent opioids. The aim of this study was to estimate the relative effects of buprenorphine/naloxone and methadone on injecting and STBBI risks among people with prescription-type opioid use disorder (POUD).

METHODS

Secondary analysis of a pan-Canadian pragmatic 24-week randomized clinical trial comparing methadone and buprenorphine/naloxone models of care among 272 people with POUD (including licit or illicit opioid analgesics, fentanyl). The Risk Behaviour Survey was used to collect injecting and sexual risks at baseline, and weeks 12 and 24.

RESULTS

In total, 210 participants initiated treatment (103 buprenorphine/naloxone and 107 methadone). At baseline, 113/205 (55.1%) participants reported recently injecting drugs, 37/209 (17.7%) unsafe injection practices and 67/162 (41.4%) high-risk sex. Both methadone and buprenorphine/naloxone were associated with reductions in the prevalence of injection drug use and high-risk sex at weeks 12 and 24 with no interactions between treatment arm and time.

CONCLUSION

Methadone and buprenorphine/naloxone were similarly effective in reducing injecting and sexual risk behaviours among people with POUD.

CLINICAL TRIALS REGISTRATION

clinicaltrials.gov NCT03033732.

Unmet needs and harm reduction preferences of syringe services program participants: differences by co-use of illicit opioids and methamphetamine

BACKGROUND

The current fourth wave of the United States opioid overdose epidemic is characterized by the co-use of opioids and stimulants, including illicit opioids and methamphetamine. The co-use of these two drugs, known as "goofballing," is associated with higher risk for several adverse outcomes, including more frequent injections, greater health risks, and higher morbidity. Considering these differences, this unique subpopulation of people who inject drugs (PWID) may also have unique unmet needs and harm reduction preferences.

METHODS

We collected self-reported data from participants (N = 50) of a syringe services program (SSP), including basic needs and harm reduction preferences. Using bivariate analyses, we examined differences between SSP participants who do and do not co-use illicit opioids and methamphetamine. Co-use was defined as reporting the use of both drugs, which may or may not have been used simultaneously.

RESULTS

In the overall sample, the mean level of need was highest for bus passes or other transportation, a person who can help you get the services you need, medication for opioid use disorder, and a job or job training. Additionally, all participants reported being either interested or very interested in fentanyl test strips, safe consumption sites, delivery of syringe service supplies, and delivery of naloxone. Those who endorsed co-use had a greater need for food, healthcare, substance use disorder treatment, a support person to help them access needed services, and bus passes or transportation.

CONCLUSIONS

Unmet needs were prevalent, and the desire for more harm reduction services was high among these PWID. Results also suggest people who co-use illicit opioids and methamphetamine may have the greatest unmet needs and desire for additional harm reduction services.

Comparison of intranasal naloxone and intranasal nalmefene in a translational model assessing the impact of synthetic opioid overdose on respiratory depression and cardiac arrest

Introduction

Using a validated translational model that quantitatively predicts opioid-induced respiratory depression and cardiac arrest, we compared cardiac arrest events caused by synthetic opioids (fentanyl, carfentanil) following rescue by intranasal (IN) administration of the μ-opioid receptor antagonists naloxone and nalmefene.

Methods

This translational model was originally developed by Mann et al. (Clin Pharmacol Ther 2022) to evaluate the effectiveness of intramuscular (IM) naloxone. We initially implemented this model using published codes, reproducing the effects reported by Mann et al. on the incidence of cardiac arrest events following intravenous doses of fentanyl and carfentanil as well as the reduction in cardiac arrest events following a standard 2 mg IM dose of naloxone. We then expanded the model in terms of pharmacokinetic and µ-opioid receptor binding parameters to simulate effects of 4 mg naloxone hydrochloride IN and 3 mg nalmefene hydrochloride IN, both FDA-approved for the treatment of opioid overdose. Model simulations were conducted to quantify the percentage of cardiac arrest in 2000 virtual patients in both the presence and absence of IN antagonist treatment.

Results

Following simulated overdoses with both fentanyl and carfentanil in chronic opioid users, IN nalmefene produced a substantially greater reduction in the incidence of cardiac arrest compared to IN naloxone. For example, following a dose of fentanyl (1.63 mg) producing cardiac arrest in 52.1% (95% confidence interval, 47.3-56.8) of simulated patients, IN nalmefene reduced this rate to 2.2% (1.0-3.8) compared to 19.2% (15.5-23.3) for IN naloxone. Nalmefene also produced large and clinically meaningful reductions in the incidence of cardiac arrests in opioid naïve subjects. Across dosing scenarios, simultaneous administration of four doses of IN naloxone were needed to reduce the percentage of cardiac arrest events to levels that approached those produced by a single dose of IN nalmefene.

Conclusion

Simulations using this validated translational model of opioid overdose demonstrate that a single dose of IN nalmefene produces clinically meaningful reductions in the incidence of cardiac arrest compared to IN naloxone following a synthetic opioid overdose. These findings are especially impactful in an era when >90% of all opioid overdose deaths are linked to synthetic opioids such as fentanyl.

"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.

Co-administration of naloxone and dexmedetomidine to simultaneously reverse acute effects of fentanyl and methamphetamine in rats

BACKGROUND

The incidence of combination methamphetamine (METH)-opioid overdose has substantially increased in recent years. While agitation is uncommon after the naloxone (NLX) reversal of opioids, it is a major clinical concern in acute METH intoxication and can be physiologically antagonized by opioid-induced sedation. This study aimed to perform initial preclinical analysis of the safety and efficacy of dexmedetomidine (DEXMED) co-administered with NLX to attenuate METH-induced locomotor activity, as a rat model of agitation, after the reversal of fentanyl (FENT)-induced sedation.

METHODS

Male Sprague Dawley rats were administered subcutaneous (SC) 0.1mg/kg FENT ± 1mg/kg METH. Fifteen min later, SC 0.1mg/kg NLX ± an increasing (0, 0.032, 0.056, and 0.1mg/kg) DEXMED dose was administered prior to the measurement of locomotor activity. After a washout period, the FENT ± METH and NLX ± DEXMED administration with the highest dose of DEXMED was administered for measurement of blood oxygen saturation and heart rate.

RESULTS

After the NLX reversal of FENT-induced sedation, adjunct DEXMED substantially and significantly reduced METH-induced locomotor activity (p<0.05) at all doses tested. While the addition of DEXMED did not significantly reduce blood oxygenation in METH treated rats, it did so in the absence of METH. Also, DEXMED significantly reduced heart rate compared to non-DEXMED treated groups and resulted in further significant reductions in the animals not exposed to METH (p<0.05).

CONCLUSIONS

These data provide preclinical evidence that DEXMED may be a safe and effective chemical restraint for METH-induced agitation after NLX opioid reversal.

Prevalence of comorbid substance use disorders among people with opioid use disorder: A systematic review & meta-analysis

BACKGROUND

Comorbid substance use disorders (SUDs) among people with opioid use disorder (OUD) contribute to poor clinical outcomes, including overdose and mortality. We present the first systematic review and meta-analysis to estimate the prevalence of specific non-opioid SUDs among people with OUD.

METHODS

We searched Embase, PsycINFO, and MEDLINE from 1990 to 2022 for studies that used Diagnostic and Statistical Manual of Mental Disorders (DSM) or International Classification of Diseases (ICD) criteria to assess the prevalence of non-opioid SUDs among individuals with OUD. We used random-effects meta-analyses with 95% Confidence Intervals (CIs) to pool current and lifetime prevalence estimates separately. Meta-regressions and stratified meta-analyses were used to examine differences in prevalence estimates by sample characteristics and methodological factors.

RESULTS

Of the 36,971 publications identified, we included data from 194 studies and 77,212 participants with OUD. The prevalence of any comorbid SUD among people with OUD was 59.5% (95%CI 49.1-69.5%) for current non-opioid SUDs, with 72.0% (95%CI 52.5-87.9%) experiencing a comorbid SUD in their lifetime. Of the studies that examined current comorbid SUDs, cocaine use disorder (30.5%, 95%CI 23.0-38.7%) was most common, followed by alcohol (27.1%, 95%CI 24.4- 30.0%), cannabis (22.7%, 95%CI 19.0-26.6%), sedative (16.1%, 95%CI 13.1-19.3%), and methamphetamine (11.4%, 95%CI 6.8-17.1%) use disorders. Substantial heterogeneity (I2>90%) across estimates was observed. Substantial heterogeneity (I2>90%) was observed across estimates, with significant variations in prevalence identified across geographic locations, recruitment settings, and other study-level factors.

CONCLUSION

Findings from this study emphasize the importance of comorbid SUD treatment access for people with OUD. Our estimates can inform the provision of treatment and harm reduction strategies for people with OUD and specific subpopulations.

Implementation and evaluation of interprofessional overdose review team recommendations following intentional or accidental overdose events

Drug overdose death rates in the United States remain high despite efforts to mitigate this risk. Many communities and hospitals across the country have implemented overdose review teams, including local overdose fatality review teams or postoverdose intervention programs, to address the opioid crisis. The goal of most of these teams is to identify missed opportunities or patient-specific interventions to prevent future opioid overdose fatalities. Few overdose review teams review a combination of both fatal and nonfatal overdose events. The Veterans Affairs Tennessee Valley Healthcare System implemented a novel overdose review team (ORT) that collaboratively reviews all overdose incidents regardless of fatality, intent, or substance involved. This practice description characterizes reported facility overdose events and patient-specific risk-mitigation strategies recommended by the ORT, highlights the implementation rate and time to implementation of ORT recommendations, and discusses potential areas for process improvement. This practice highlights the potential impact of a pharmacist-led, interdisciplinary ORT following accidental or intentional overdose events involving any substance or medication. Key patient-specific interventions implemented following ORT recommendations included overdose prevention education and naloxone distribution, prescribing of medications for opioid use disorder and/or alcohol use disorder, reducing medication supply to limit lethal means access, and facilitation of mental health and/or substance use disorder specialty appointments. Further research to evaluate clinical outcomes related to specific ORT interventions should be considered.

Changes in injecting versus smoking heroin, fentanyl, and methamphetamine among people who inject drugs in San Diego, California, 2020-2023

BACKGROUND

Amidst an increasingly toxic drug supply in North America, people who inject drugs may be transitioning to smoking them. We aimed to assess changes in injecting and smoking opioids and methamphetamine among a cohort of people who inject drugs from San Diego, California.

METHODS

Over five six-month periods spanning October 2020-April 2023, we assessed prevalence of injecting and smoking opioids or methamphetamine and whether participants used these drugs more frequently by smoking than injecting. Multivariable Poisson regression via generalized estimating equations was used to examine time trends.

RESULTS

Of 362 participants, median age was 40 years; a minority were female (29%), Hispanic/Latinx/Mexican (45%), and housed (33%). Among this cohort, of whom 100% injected (and 84% injected and smoked) in period one (October 2020-April 2021), by period five (November 2022-April 2023), 34% only smoked, 59% injected and smoked, and 7% only injected. By period five, the adjusted relative risk (aRR) of injecting opioids was 0.41 (95% Confidence Interval [CI]: 0.33, 0.51) and the aRR for injecting methamphetamine was 0.50 (95% CI: 0.39, 0.63) compared to period one. Risks for smoking fentanyl rose significantly during period three (aRR=1.44, 95% CI: 1.06, 1.94), four (aRR=1.65, 95% CI: 1.24, 2.20) and five (aRR=1.90, 95% CI: 1.43, 2.53) compared to period one. Risks for smoking heroin and methamphetamine more frequently than injecting these drugs increased across all periods.

CONCLUSIONS

Opioid and methamphetamine injection declined precipitously, with notable increases in smoking these drugs. Research is needed to understand the health consequences of these trends.

Understanding and Addressing Widening Racial Inequalities in Drug Overdose

The fourth wave of the United States overdose crisis-driven by the polysubstance use of fentanyl with stimulants and other synthetic substances-has driven sharply escalating racial/ethnic inequalities in drug overdose death rates. Here the authors present a detailed portrait of the latest overdose trends and synthesize the literature to describe where, how, and why these inequalities are worsening. By 2022 overdose deaths among Native and Black Americans rose to 1.8 and 1.4 times the rate seen among White Americans, respectively. This reflects that Black and Native Americans have been disproportionately affected by fentanyl and the combination of fentanyl and stimulants at the national level and in virtually every state. The highest overdose deaths rates are currently seen among Black Americans 55-64 years of age as well as younger cohorts of Native Americans 25-44 years of age. In 2022-the latest year of data available-deaths among White Americans decreased relative to 2021, whereas rates among all other groups assessed continued to rise. Moving forward, Fundamental Cause Theory shows us a relevant universal truth of implementation science: in socially unequal societies, new technologies typically end up favoring more privileged groups first, thereby widening inequalities unless underlying social inequalities are addressed. Therefore, interventions designed to reduce addiction and overdose death rates that are not explicitly designed to also improve racial/ethnic inequalities will often unintentionally end up worsening them. Well-funded community-based programs, with Black and Native leadership, providing harm reduction resources, naloxone, and medications for opioid use disorder in the context of comprehensive, culturally appropriate healthcare and other services, represent the highest priority interventions to decrease inequalities.

Enantiomeric contributions to methamphetamine's bidirectional effects on basal and fentanyl-depressed respiration in mice

RATIONALE

Fentanyl remains the primary cause of fatal overdoses, and its co-use with methamphetamine (METH) is a growing concern. We previously demonstrated that racemic METH can either enhance or mitigate opioid-induced respiratory depression (OIRD) dependent upon whether a low or high dose is administered. The optical isomers of METH, dextromethamphetamine (d-METH) and levomethamphetamine (l-METH), differ substantially in their selectivity and potency to activate various monoamine (MA) receptors, and these pharmacological differences may underlie the bidirectional effects of the racemate. Since it is unknown which of METH's MA receptor mechanisms mediate these respiratory effects, examination of METH's pharmacologically distinct enantiomers may provide insight into treatment targets for OIRD.

METHODS

The two optical isomers of METH, d-METH and l-METH, were tested in adult male mice to determine their effects on basal and fentanyl-depressed respiratory frequency, tidal volume, and minute ventilation (MVb; i.e., respiratory frequency x tidal volume) using whole-body plethysmography.

RESULTS

When tested at dose ranges of 1.0-10 mg/kg, d-METH elevated MVb and l-METH decreased basal MVb. A dose of 30 mg/kg l-METH increased basal MVb. Under fentanyl-depressed conditions, the bidirectional effects of racemic METH were observed with d-METH treatment while l-METH significantly exacerbated OIRD at 1.0 and 3.0 mg/kg.

CONCLUSIONS

d-METH and l-METH differentially contribute to the bidirectional respiratory modulation observed by the racemate, with d-METH exhibiting predominantly stimulatory effects and l-METH exhibiting primarily depressant effects depending on dose.

Examining disparities in regional anaesthesia and pain medicine

In high-resource countries, health disparities exist in both treatment approaches and health outcomes. Race and ethnicity can serve as proxies for other socioeconomic factors and social determinants of health such as income, education, social support, and residential neighbourhood, which strongly influence health outcomes and disparities. In regional anaesthesia and pain medicine, disparities exist across several surgical specialties including obstetrics, paediatrics, and orthopaedic surgery. Understanding these disparities will facilitate development of solutions aimed at eliminating disparities at the patient, physician/provider, and healthcare system levels.

Trends in pediatric prescription-opioid overdoses in U.S. emergency departments from 2008-2020: An epidemiologic study of pediatric opioid overdose ED visits

BACKGROUND

Opioid overdose was declared a public health emergency in the United States, but much of the focus has been on adults. Child and adolescent exposure and access to unused prescription-opioid medications is a big concern. More research is needed on the trend of pediatric (age 0-17) prescription-opioid overdose emergency department (ED) visits in the United States, particularly during the COVID-19 pandemic year.

METHODS

This retrospective epidemiological study used the 2008-2020 Nationwide Emergency Department Sample to provide a national estimate of ED visits related to prescription-opioid overdose. Inclusion criteria were 0-17-year-old patients treated at the ED due to prescription-opioid overdose. Eligible visits were identified if their medical records included any administrative billing codes for prescription-opioid overdose. National estimates were broken down by age groups, sex, geographic region, primary payer, median household income by zip code, ED disposition, and hospital location/teaching status. Incidence rate per 100,000 U.S. children was calculated for age groups, sex, and geographic region.

RESULTS

Overall, the prescription-opioid overdose ED visits for patients from 0-17 years old in the United States decreased by 22% from 2008 to 2019, then increased by 12% in 2020. Most patients were discharged to home following their ED visit; however, there was a 42% increase in patients admitted from 2019 to 2020. The prescription-opioid overdose rate per 100,000 U.S. children was highest in the 0 to 1 and 12 to 17 age groups, with the 12 to 17 group increasing by 27% in 2020. ED visits in the West and Midwest saw prescription-opioid visits increase by 58% and 20%, respectively, from 2019-2020.

CONCLUSIONS

Prescription-opioid overdose ED visits among U.S. children and adolescents decreased over the past decade until 2019. However, there was a substantial increase in ED visits from 2019 to 2020, suggesting the potential impact due to the then-emerging COVID-19 pandemic. Findings suggest focusing on young children and adolescents to reduce further prescription-opioid overdoses in the United States.

Comparative effectiveness of extended release naltrexone and sublingual buprenorphine for treatment of opioid use disorder among Medicaid patients

Aims

To compare the real-world effectiveness of extended release naltrexone (XR-NTX) and sublingual buprenorphine (SL-BUP) for the treatment of opioid use disorder (OUD).

Design

An observational active comparator, new user cohort study.

Setting

Medicaid claims records for patients in New Jersey and California, 2016-2019.

Participants/Cases

Adult Medicaid patients aged 18-64 years who initiated XR-NTX or SL-BUP for maintenance treatment of OUD and did not use medications for OUD in the 90-days before initiation.

Comparators

New initiation with XR-NTX versus SL-BUP for the treatment of OUD.

Measurements

We examined two outcomes up to 180 days after medication initiation, 1) composite of medication discontinuation and death, and 2) composite of overdose and death.

Findings

Our cohort included 1,755 XR-NTX and 9,886 SL-BUP patients. In adjusted analyses, treatment with XR-NTX was more likely to result in discontinuation or death by the end of follow-up than treatment with SL-BUP: cumulative risk 76% (95% confidence interval [CI] 75%, 78%) versus 62% (95% CI 61%, 63%), respectively (risk difference 14 percentage points, 95% CI 13, 16). There was minimal difference in the cumulative risk of overdose or death by the end of follow-up: XR-NTX 3.8% (95% CI 2.9%, 4.7%) versus SL-BUP 3.3% (95% 2.9%, 3.7%); risk difference 0.5 percentage points, 95%CI -0.5, 1.5. Results were consistent across sensitivity analyses.

Conclusions

Longer medication retention is important because risks of negative outcomes are elevated after discontinuation. Our results support selection of SL-BUP over XR-NTX. However, most patients discontinued medication by 6 months indicating that more effective tools are needed to improve medication retention, particularly after initiation with XR-NTX, and to identify which patients do best on which medication.

Paths Forward for Clinicians Amidst the Rise of Unregulated Clinical Decision Support Software: Our Perspective on NarxCare

Amidst the US overdose epidemic, policymakers, law enforcement agencies, and healthcare institutions have contributed to a decrease in opioid prescribing, assuming reduced mortality would result-an assumption we now understand was oversimplified. At this intersection between public health and public safety domains as they relate to opioid prescribing, unregulated and proprietary clinical decision support tools have emerged without rigorous external validation or public data sharing. In the following piece, we discuss challenges facing clinicians practicing medicine amidst unregulated clinical decision support tools, using the case of Bamboo Health's NarxCare-a prescription drug monitoring program-based analytics platform marketed as a clinical decision support tool-that is already positioned to impact over 1 billion patient encounters annually. We argue that sufficient evidence does not yet exist to support NarxCare's wide implementation, and that clinical decision support tools like NarxCare have flourished in recent years due to a lack of federal regulatory oversight and shielding by their proprietary formulas, which have facilitated their unchecked and outsized influence on patient care. Finally, we suggest specific actions by federal regulatory agencies, healthcare institutions, individual clinicians, and researchers, as well as academic journals, to mitigate potential harms associated with unregulated clinical decision support tools.

Performance of Fentanyl Immunoassays in an ED Patient Population

BACKGROUND

Fentanyl is a synthetic opioid fueling the current opioid crisis in the United States. While emergency department (ED) visits due to opioid-related overdoses, injection complications, and withdrawals become increasingly more frequent, fentanyl is not detected in routine toxicology testing. We evaluated 2 FDA-approved fentanyl immunoassays in a sampled ED population.

METHODS

De-identified, remnant urine specimens (n = 213) collected from patients presenting to a large ED were analyzed using ARK Fentanyl II (ARK II) and Immunalysis SEFRIA (SEFRIA) fentanyl immunoassays on an Architect c16000 (Abbott) analyzer. All discrepant specimens were evaluated by LC-MS/MS. Additionally, polysubstance abuse patterns and trends were analyzed.

RESULTS

While intra-assay imprecision was comparable for ARK II and SEFRIA, inter-assay imprecision for ARK II and SEFRIA varied from 8.0% to 1.8% and from 37% to 12.5%, respectively. SEFRIA had a marginally higher false-positivity rate (3%) than ARK II (1%). Both assays had equivalent sensitivity of 95%, with ARK II (99%) having greater specificity than SEFRIA (97%). Fentanyl was detected in 13.7% of drug-panel-positive patient samples and most frequently observed in patients also testing positive for amphetamines and cocaine. Notably, fentanyl was detected in 5.3% of patient samples that were negative for all other drugs in our standard toxicology panel.

CONCLUSIONS

A sizable portion of drug-positive samples from our ED were positive for fentanyl, with a subset of patients testing positive for fentanyl alone. Implementation of fentanyl testing into routine toxicology panels can elucidate polysubstance abuse paradigms and capture ED patients that would go undetected in standard panels.

Changes in injecting versus smoking heroin, fentanyl, and methamphetamine among people who inject drugs in San Diego, California, 2020 to 2023

Background

Amidst a rapidly evolving drug supply in North America, people who inject drugs may be transitioning to smoking them. We aimed to assess changes in injecting and smoking heroin, fentanyl and methamphetamine among a cohort of people who injected drugs at baseline from San Diego, California.

Methods

Over five six-month periods spanning October 2020-April 2023, we assessed prevalence of injecting and smoking opioids or methamphetamine and whether participants used these drugs more frequently by smoking than injecting. Multivariable Poisson regression via Generalized Estimating Equations was used to examine time trends.

Results

Of 362 participants, median age was 40 years; most were male (72%), non-Hispanic (55%), and unhoused (67%). Among this cohort, of whom 100% injected (or injected and smoked) at baseline, by period five (two years later), 34% reported only smoking, while 59% injected and smoked, and 7% only injected. By period five, the adjusted relative risk (aRR) of injecting opioids was 0.41 (95% Confidence Interval [CI]: 0.33, 0.51) compared to period one, and the aRR for injecting methamphetamine was 0.50 (95% CI: 0.39, 0.63). Compared to period one, risks for smoking fentanyl rose significantly during period three (aRR=1.44, 95% CI: 1.06, 1.94), four (aRR=1.65, 95% CI: 1.24, 2.20) and five (aRR=1.90, 95% CI: 1.43, 2.53). Risks for smoking heroin and methamphetamine more frequently than injecting these drugs increased across all periods.

Conclusions

Opioid and methamphetamine injection declined precipitously, with notable increases in smoking these drugs. Research is urgently needed to understand the health consequences of these trends.

Series of (([1,1'-Biphenyl]-2-yl)methyl)sulfinylalkyl Alicyclic Amines as Novel and High Affinity Atypical Dopamine Transporter Inhibitors with Reduced hERG Activity

Currently, there are no FDA-approved medications for the treatment of psychostimulant use disorders (PSUD). We have previously discovered "atypical" dopamine transporter (DAT) inhibitors that do not display psychostimulant-like behaviors and may be useful as medications to treat PSUD. Lead candidates (e.g., JJC8-091, 1) have shown promising in vivo profiles in rodents; however, reducing hERG (human ether-à-go-go-related gene) activity, a predictor of cardiotoxicity, has remained a challenge. Herein, a series of 30 (([1,1'-biphenyl]-2-yl)methyl)sulfinylalkyl alicyclic amines was synthesized and evaluated for DAT and serotonin transporter (SERT) binding affinities. A subset of analogues was tested for hERG activity, and the IC50 values were compared to those predicted by our hERG QSAR models, which showed robust predictive power. Multiparameter optimization scores (MPO > 3) indicated central nervous system (CNS) penetrability. Finally, comparison of affinities in human DAT and its Y156F and Y335A mutants suggested that several compounds prefer an inward facing conformation indicating an atypical DAT inhibitor profile.

Impact of Potential Case Misclassification by Administrative Diagnostic Codes on Outcome Assessment of Observational Study for People Who Inject Drugs

Introduction

Initiation of medications for opioid use disorder (MOUD) within the hospital setting may improve outcomes for people who inject drugs (PWID) hospitalized because of an infection. Many studies used International Classification of Diseases (ICD) codes to identify PWID, although these may be misclassified and thus, inaccurate. We hypothesized that bias from misclassification of PWID using ICD codes may impact analyses of MOUD outcomes.

Methods

We analyzed a cohort of 36 868 cases of patients diagnosed with Staphylococcus aureus bacteremia at 124 US Veterans Health Administration hospitals between 2003 and 2014. To identify PWID, we implemented an ICD code-based algorithm and a natural language processing (NLP) algorithm for classification of admission notes. We analyzed outcomes of prescribing MOUD as an inpatient using both approaches. Our primary outcome was 365-day all-cause mortality. We fit mixed-effects Cox regression models with receipt or not of MOUD during the index hospitalization as the primary predictor and 365-day mortality as the outcome.

Results

NLP identified 2389 cases as PWID, whereas ICD codes identified 6804 cases as PWID. In the cohort identified by NLP, receipt of inpatient MOUD was associated with a protective effect on 365-day survival (adjusted hazard ratio, 0.48; 95% confidence interval, .29-.81; P < .01) compared with those not receiving MOUD. There was no significant effect of MOUD receipt in the cohort identified by ICD codes (adjusted hazard ratio, 1.00; 95% confidence interval, .77-1.30; P = .99).

Conclusions

MOUD was protective of all-cause mortality when NLP was used to identify PWID, but not significant when ICD codes were used to identify the analytic subjects.

Health risks associated with smoking versus injecting fentanyl among people who use drugs in California

BACKGROUND

Given the attention, funding, and services that seek to reduce overdose mortality from fentanyl, it is important to understand whether a potential solution is for more people to switch from injecting to smoking fentanyl. As such, we set out to conduct a study to compare health and healthcare utilization outcomes associated with different modes of illicit fentanyl administration.

METHODS

From January to February 2023, we recruited people who use drugs from 34 syringe services programs across California, USA (N=999) and surveyed their substance use, health outcomes, and healthcare utilization. We compared health risks among people who injected fentanyl (78% of whom also smoked) to people who solely smoked fentanyl (n=563).

RESULTS

Of the 563 participants, forty-one percent injected fentanyl and 59% only smoked fentanyl. People who injected fentanyl were 40% more likely to have experienced a non-fatal overdose in the past 3 months (27% vs. 19%; aRR=1.40; 95% CI=1.03, 1.93) and 253% more likely to have had a skin and soft tissue infection in the past 3 months (39% vs. 15%; aRR=2.53; 95% CI=1.74, 3.67), compared to people who only smoked fentanyl. The average number of nights spent in the hospital was higher among people who injected fentanyl (average 1.2 nights vs. 0.7 nights; aIRR=1.78; 95% CI=1.02, 3.09; p=0.04).There were non-significant associations between mode of fentanyl administration and number of emergency department visits and probability of hospitalization.

CONCLUSIONS

Findings suggested that people who injected fentanyl were at higher risk for overdose and skin and soft tissue infections than people who only smoked fentanyl. Distribution of safe smoking supplies may facilitate transitions from injecting to smoking fentanyl, thereby reducing health risks associated with fentanyl use.

Vaccines to Treat Substance Use Disorders: Current Status and Future Directions

Addiction, particularly in relation to psychostimulants and opioids, persists as a global health crisis with profound social and economic ramifications. Traditional interventions, including medications and behavioral therapies, often encounter limited success due to the chronic and relapsing nature of addictive disorders. Consequently, there is significant interest in the development of innovative therapeutics to counteract the effects of abused substances. In recent years, vaccines have emerged as a novel and promising strategy to tackle addiction. Anti-drug vaccines are designed to stimulate the immune system to produce antibodies that bind to addictive compounds, such as nicotine, cocaine, morphine, methamphetamine, and heroin. These antibodies effectively neutralize the target molecules, preventing them from reaching the brain and eliciting their rewarding effects. By obstructing the rewarding sensations associated with substance use, vaccines aim to reduce cravings and the motivation to engage in drug use. Although anti-drug vaccines hold significant potential, challenges remain in their development and implementation. The reversibility of vaccination and the potential for combining vaccines with other addiction treatments offer promise for improving addiction outcomes. This review provides an overview of anti-drug vaccines, their mechanisms of action, and their potential impact on treatment for substance use disorders. Furthermore, this review summarizes recent advancements in vaccine development for each specific drug, offering insights for the development of more effective and personalized treatments capable of addressing the distinct challenges posed by various abused substances.

Baseline Characteristics and Postdischarge Outcomes by Medication for Opioid Use Disorder Status Among Women with Polysubstance Use in Residential Treatment

Background

Within residential treatment, medication for opioid use disorder (MOUD) is rarely offered, so little is known about group differences by MOUD status. This study characterizes samples of women receiving and not receiving MOUD and explores postdischarge outcomes.

Methods

This is a secondary exploratory analysis of a residential clinical trial comparing women receiving treatment as usual (TAU) with those who also received computer-based training for cognitive behavioral therapy (CBT4CBT). Participants were N = 41 adult women with substance use disorder (SUD) who self-reported lifetime polysubstance use. Because 59.0% were prescribed MOUD (MOUD n = 24, no MOUD n = 17), baseline variables were compared by MOUD status; outcomes at 12 weeks postdischarge were compared by MOUD status and treatment condition using chi square and Mann-Whitney U tests.

Results

Participants were middle-aged (41.7 ± 11.6 years) and non-Latinx Black (80.4%). Most used substances in the No MOUD group were alcohol, cocaine, and cannabis, and in the MOUD group, most used substances were opioids, cannabis, and cocaine. Women in the MOUD group tended to have more severe SUD. Postdischarge substance use recurrence rates were twice as high in the MOUD group than in the No MOUD group. Among the women in the No MOUD group, those in the CBT4CBT condition increased the number of coping strategies twice as much as those receiving TAU.

Conclusion

Postdischarge substance use recurrence differed by MOUD status. CBT4CBT may be a helpful adjunct to personalized residential SUD treatment. The parent study is registered at [www.clinicaltrials.gov (ClinicalTrials.gov identifier: NCT03678051)].

Gabapentinoids in Ireland 2010 to 2020: An observational study of trends in gabapentinoid prescribing, law enforcement drug seizures and postmortem toxicology

AIMS

We explored trends in gabapentinoid prescribing, drug seizures and postmortem toxicology using a national pharmacy claims database, law enforcement drug seizures data and a population-based postmortem toxicology database.

METHODS

Gabapentinoid prescribing rates per 100 000 eligible population (2010-2020), annual number of drug seizures involving gabapentinoids (2012-2020) and gabapentinoid detection (positive) rates per 100 postmortem toxicology case (2013-2020) were calculated. Negative binomial regression models were used to evaluate longitudinal trends for gabapentin and pregabalin separately.

RESULTS

Gabapentin (adjusted rate ratio [RR] 1.06, 95% confidence interval [CI] 1.05-1.06, P < .001) and pregabalin (adjusted RR 1.08, 95% CI 1.08-1.09, P < .001) prescribing increased annually, with higher rates of pregabalin (vs. gabapentin) observed every year. Drug seizures involving pregabalin also increased over time (RR 1.54 95% CI 1.25-1.90, P < .0001). Of the 26 317 postmortem toxicology cases, 0.92% tested positive for gabapentin, and 6.37% for pregabalin. Detection rates increased for both gabapentin (RR 1.28, 95% CI 1.11-1.48, P < .001) and pregabalin (RR 1.13, 95% CI 1.11-1.48, P < .001) between 2013 and 2020. A total of 1901 cases (7.2%) tested positive for heroin/methadone; this sub-group had a higher detection rate for pregabalin (n = 528, 27.8%) and gabapentin (n = 41, 2.2%) over the study period, with a high burden of codetections for pregabalin with benzodiazepines (peaking at 37.3% in 2018), and pregabalin with prescription opioids (peaking at 28.9% in 2020).

CONCLUSION

This study raises concerns regarding the wide availability of pregabalin in Ireland, including a growing illicit supply, and the potential for serious harm arising from poly drug use involving pregabalin among people who use heroin or methadone.