The rising crisis of illicit fentanyl use, overdose, and potential therapeutic strategies

A Series of 8 Illicit Fentanyl Intoxication Deaths in Infants and Toddlers

ABSTRACT

We report 8 children younger than 2 years who died from acute illicit fentanyl intoxications in Connecticut between 2020 and 2022.The Connecticut Office of the Chief Medical Examiner (CT OCME) investigates all unexpected, violent, and suspicious deaths in Connecticut. The CT OCME's electronic database was searched for fentanyl deaths by age. All underwent autopsies and toxicology testing.The ages ranged from 28 days to 2 years (mean age, 12 months). The causes of death involved acute fentanyl intoxications with 1 having xylazine, 1 having para-fluorofentanyl, and 1 having cocaine and morphine. All the manners of death were certified as homicide. The postmortem fentanyl blood concentrations ranged from 0.40 to 46 ng/mL. Most of the children were found unresponsive after being put to sleep. Three were co-sleeping with adults (2 in bed; 1 on a recliner). There was a known history of parental/caregiver drug abuse in 7 of 8 of the fatalities.We summarize the key investigative, autopsy, and toxicological findings. As illicit fentanyl use increases, there is a potential for infant exposure and death. The investigation and certification of these deaths and the role of intentional administration versus inadvertent exposure due to caregiver neglect in the context of the certification of the manner of death are described.

Strong opioids-induced cardiac, neurologic, and respiratory disorders: a real-world study from 2004 to 2023 based on FAERS

Opioids are mainly used as adjuncts to the induction and maintenance of general anesthesia, postoperative analgesia, and treating moderate to severe cancer pain and chronic pain. However, the hazards of these drugs to various organ organs still need to be further explored. This study used the US FDA Adverse Event Reporting System (FAERS) database to determine whether commonly receiving opioids was higher than the baseline risk for all other medications. FAERS was asked about adverse events (AEs) for the opioids "morphine," "fentanyl," "oxycodone," "hydromorphone," "sufentanil," and "remifentanil" from the first quarter of 2004 (2004Q1) through the second quarter of 2023 (2023Q2). Disproportionality signaling analysis was performed by calculating reporting odds ratio (ROR), proportional reporting ratio (PRR), Bayesian confidence propagation neural network (BCPNN), and Empirical Bayesian Geometric Mean (EBGM). AEs with system organ classes (SOCs) of "cardiac disease," "neurologic disease," and "respiratory, thoracic, and mediastinal disease" were then screened. The statistical analysis included 12,819,518 reports in the FAERS database from 2004Q1 to 2023Q2, of which 236,619 AEs were reported as "primary suspect" for the six drugs mentioned above, which were selected as "cardiac disorders," "nervous system disorders," and "respiratory, thoracic and mediastinal disorders." Some AEs identified in this study are consistent with the drug labeling, such as bradycardia, respiratory depression, and somnolence. In addition, some unexpected and significant acute adverse drug reactions (ADRs), such as toxic leukoencephalopathy and coma, may occur. This study identified potential new and unexpected ADRs for opioids, providing valuable evidence for safety studies of opioids.

Functionalized Gold Nanoparticles and Halogen Bonding Interactions Involving Fentanyl and Fentanyl Derivatives

Fentanyl (FTN) and synthetic analogs of FTN continue to ravage populations across the globe, including in the United States where opioids are increasingly being used and abused and are causing a staggering and growing number of overdose deaths each year. This growing pandemic is worsened by the ease with which FTN can be derivatized into numerous derivatives. Understanding the chemical properties/behaviors of the FTN class of compounds is critical for developing effective chemical detection schemes using nanoparticles (NPs) to optimize important chemical interactions. Halogen bonding (XB) is an intermolecular interaction between a polarized halogen atom on a molecule and e--rich sites on another molecule, the latter of which is present at two or more sites on most fentanyl-type structures. Density functional theory (DFT) is used to identify these XB acceptor sites on different FTN derivatives. The high toxicity of these compounds necessitated a "fragmentation" strategy where smaller, non-toxic molecules resembling parts of the opioids acted as mimics of XB acceptor sites present on intact FTN and its derivatives. DFT of the fragments' interactions informed solution measurements of XB using 19F NMR titrations as well as electrochemical measurements of XB at self-assembled monolayer (SAM)-modified electrodes featuring XB donor ligands. Gold NPs, known as monolayer-protected clusters (MPCs), were also functionalized with strong XB donor ligands and assembled into films, and their interactions with FTN "fragments" were studied using voltammetry. Ultimately, spectroscopy and TEM analysis were combined to study whole-molecule FTN interactions with the functionalized MPCs in solution. The results suggested that the strongest XB interaction site on FTN, while common to most of the drug's derivatives, is not strong enough to induce NP-aggregation detection but may be better exploited in sensing schemes involving films.

Fentanyl abuse proportion in methadone maintenance treatment, and patients' knowledge about its risks

INTRODUCTION

Fentanyl is not yet routinely monitored among methadone maintenance treatment (MMT) patients in Israel. We aimed 1. to evaluate urine fentanyl proportion changes over 3 years and characterize patients' characteristics 2. To study patients' self-report on fentanyl usage, and compare knowledge about fentanyl risk, before and following brief educational intervention.

METHODS

Fentanyl in the urine of all current MMT patients was tested every 3 months year between 2021 and 2023, and patients with positive urine fentanyl were characterized. Current patients were interviewed using a fentanyl knowledge questionnaire (effects, indications, and risks) before and following an explanation session.

RESULTS

Proportion of fentanyl ranged between 9.8 and 15.1%, and patients with urine positive for fentanyl (September 2023) were characterized as having positive urine for pregabalin, cocaine, and benzodiazepine (logistic regression). Of the current 260 patients (87% compliance), 78(30%) self-reported of fentanyl lifetime use ("Ever"), and 182 "never" use. The "Ever" group had higher Knowledge scores than the "Never", both groups improved following the explanatory session (repeated measure). The "Ever" group patients were found with urine positive for cannabis and benzodiazepine on admission to MMT, they were younger, did not manage to gain take-home dose privileges and had a higher fentanyl knowledge score (logistic regression).

CONCLUSIONS

In the absence of routine fentanyl tests, a high knowledge score, shorter duration in MMT, benzodiazepine usage on admission, and current cannabis usage, may hint of the possibility of fentanyl abuse.

Correlates of overdose among 2711 people who use drugs and live in 7 rural US sites

BACKGROUND

Overdose rates in rural areas have been increasing globally, with large increases in the United States. Few studies, however, have identified correlates of non-fatal overdose among rural people who use drugs (PWUD). The present analysis describes correlates of nonfatal overdose among a large multistate sample of rural PWUD.

METHODS

This is a cross-sectional analysis of data gathered via surveys with PWUD recruited through seven Rural Opioid Initiative (ROI) sites. Descriptive analyses were conducted to assess the prevalence of past 30-day overdose. Generalized estimating equations were used to estimate a series of multivariable models quantifying relationships of select factors to past-month overdose; factors were selected using the Risk Environment Framework.

RESULTS

The multisite sample included 2711 PWUD, 6% of whom reported overdosing in the past 30 days. In the fully adjusted model, houselessness (AOR=2.27, 95%CI[1.48, 3.48]), a positive test result for Hepatitis C infection (AOR=1.73 95%CI[1.18, 2.52]) and heroin/fentanyl use (AOR= 8.58 95%CI [3.01, 24.50]) were associated with an increased risk of reporting past 30-day overdose, while having a high-school education or less was associated with reduced odds of overdose (AOR=0.52, 95% CI[0.37, 0.74]).

CONCLUSION

As in urban areas, houselessness, Hepatitis C infection, and the use of heroin and fentanyl were significant correlates of overdose. Widespread access to overdose prevention interventions - including fentanyl test strips and naloxone - is critical in this rural context, with particular outreach needed to unhoused populations, people living with Hepatitis C, and people using opioids.

Machine Learning Discrimination and Ultrasensitive Detection of Fentanyl Using Gold Nanoparticle-Decorated Carbon Nanotube-Based Field-Effect Transistor Sensors

The opioid overdose crisis is a global health challenge. Fentanyl, an exceedingly potent synthetic opioid, has emerged as a leading contributor to the surge in opioid-related overdose deaths. The surge in overdose fatalities, particularly due to illicitly manufactured fentanyl and its contamination of street drugs, emphasizes the urgency for drug-testing technologies that can quickly and accurately identify fentanyl from other drugs and quantify trace amounts of fentanyl. In this paper, gold nanoparticle (AuNP)-decorated single-walled carbon nanotube (SWCNT)-based field-effect transistors (FETs) are utilized for machine learning-assisted identification of fentanyl from codeine, hydrocodone, and morphine. The unique sensing performance of fentanyl led to use machine learning approaches for accurate identification of fentanyl. Employing linear discriminant analysis (LDA) with a leave-one-out cross-validation approach, a validation accuracy of 91.2% is achieved. Meanwhile, density functional theory (DFT) calculations reveal the factors that contributed to the enhanced sensitivity of the Au-SWCNT FET sensor toward fentanyl as well as the underlying sensing mechanism. Finally, fentanyl antibodies are introduced to the Au-SWCNT FET sensor as specific receptors, expanding the linear range of the sensor in the lower concentration range, and enabling ultrasensitive detection of fentanyl with a limit of detection at 10.8 fg mL-1.

Implementation opportunities and challenges to piloting a community-based drug-checking intervention for sexual and gender minority men in Vancouver, Canada: a qualitative study

BACKGROUND

In response to the overdose crisis, a collaborative group of two community-based organizations, a health authority and a research institute in Vancouver, Canada, implemented a pilot community-based drug checking (CBDC) intervention for sexual and gender minority (SGM) men. This study identified key factors that influenced the implementation of the CBDC intervention, including opportunities and challenges.

METHODS

We conducted semi-structured interviews with seven pertinent parties involved in the CBDC, including policymakers, researchers and representatives from community-based organizations. These interviews were coded and analyzed using domains and constructs of the Consolidated Framework for Implementation Research.

RESULTS

While drug-related stigma was identified as a challenge to deliver drug checking services, participants described the context of the overdose crisis as a key facilitator to engage collaboration between relevant organizations (e.g., health authorities, medical health officers, community organizations) to design, resource and implement the CBDC intervention. The implementation of the CBDC intervention was also influenced by SGM-specific needs and resources (e.g., lack of information about the drug supply). The high level of interest of SGM organizations in providing harm reduction services combined with the need to expand drug checking into community spaces represented two key opportunities for the CBDC intervention. Here, SGM organizations were recognized as valued partners that fostered a broader culture of harm reduction. Participants' emphasis that knowing the composition of one's drugs is a "right to know", particularly in the context of a highly contaminated illicit drug market, emerged as a key implementation factor. Lastly, participants emphasized the importance of involving SGM community groups at all stages of the implementation process to ensure that the CBDC intervention is appropriately tailored to SGM men.

CONCLUSIONS

The context of the overdose crisis and the involvement of SGM organizations were key facilitators to the implementation of a drug checking intervention in SGM community spaces. This study offers contextualized understandings about how SGM knowledge and experiences can contribute to implement tailored drug checking interventions.

Psychostimulant drug co-ingestion in non-fatal opioid overdose

Introduction

In 2019, there were over 16,000 deaths from psychostimulant overdose with 53.5% also involving an opioid. Given the substantial mortality stemming from opioid and psychostimulant co-exposure, evaluation of clinical management in this population is critical but remains understudied. This study aims to characterize and compare clinical management and outcomes in emergency department (ED) overdose patients with analytically confirmed exposure to both opioids and psychostimulants with those exposed to opioids alone.

Methods

This was a secondary analysis of a prospective consecutive cohort of ED patients age 18+ with opioid overdose at 9 hospital sites from September 21, 2020 to August 17, 2021. Toxicologic analysis was performed using liquid chromatography quadrupole time-of-flight mass spectrometry. Patients were divided into opioid-only (OO) and opioid plus psychostimulants (OS) groups. The primary outcome was total naloxone bolus dose administered. Secondary outcomes included endotracheal intubation, cardiac arrest, troponin elevation, and abnormal presenting vital signs. We employed t-tests, chi-squared analyses and multivariable regression models to compare outcomes between OO and OS groups.

Results

Of 378 enrollees with confirmed opioid overdose, 207 (54.8%) had psychostimulants present. OO patients were significantly older (mean 45.2 versus 40.6 years, p < 0.01). OS patients had significantly higher total naloxone requirements (mean total dose 2.79 mg versus 2.12 mg, p = 0.009). There were no significant differences in secondary outcomes.

Conclusion

Approximately half of ED patients with confirmed opioid exposures were also positive for psychostimulants. Patients in the OS group required significantly higher naloxone doses, suggesting potential greater overdose severity.

Fact vs. fiction: naloxone in the treatment of opioid-induced respiratory depression in the current era of synthetic opioids

Opioid-induced respiratory depression (OIRD) deaths are ~80,000 a year in the US and are a major public health issue. Approximately 90% of fatal opioid-related deaths are due to synthetic opioids such as fentanyl, most of which is illicitly manufactured and distributed either on its own or as an adulterant to other drugs of abuse such as cocaine or methamphetamine. Other potent opioids such as nitazenes are also increasingly present in the illicit drug supply, and xylazine, a veterinary tranquilizer, is a prevalent additive to opioids and other drugs of abuse. Naloxone is the main treatment used to reverse OIRD and is available as nasal sprays, prefilled naloxone injection devices, and generic naloxone for injection. An overdose needs to be treated as soon as possible to avoid death, and synthetic opioids such as fentanyl are up to 50 times more potent than heroin, so the availability of new, higher-dose, 5-mg prefilled injection or 8-mg intranasal spray naloxone preparations are important additions for emergency treatment of OIRDs, especially by lay people in the community. Higher naloxone doses are expected to reverse a synthetic overdose more rapidly and the current formulations are ideal for use by untrained lay people in the community. There are potential concerns about severe withdrawal symptoms, or pulmonary edema from treatment with high-dose naloxone. However, from the perspective of first responders, the balance of risks would point to administration of naloxone at the dose required to combat the overdose where the risk of death is very high. The presence of xylazines as an adulterant complicates the treatment of OIRDs, as naloxone is probably ineffective, although it will reverse the respiratory depression due to the opioid. For these patients, hospitalization is particularly vital. Education about the benefits of naloxone remains important not only in informing people about how to treat emergency OIRDs but also how to obtain naloxone. A call to emergency services is also essential after administering naloxone because, although the patient may revive, they may overdose again later because of the short half-life of naloxone and the long-lasting potency of fentanyl and its analogs.

Two-year Opioid Prescription Trends in Local Sanitary Agency Naples 3 South, Campania Region, Italy. Descriptive Analyses and AI-based Translational Perspectives

Aims

This study delves into the two-year opioid prescription trends in the Local Sanitary Agency Naples 3 South, Campania Region, Italy. The research aims to elucidate prescribing patterns, demographics, and dosage categories within a population representing 1.7% of the national total. Perspectives on artificial intelligence research are discussed.

Methods

From the original dataset, spanning from January 2022 to October 2023, we processed multiple variables including demographic data, medications, dosages, drug consumption, and administration routes. The dispensing quantity was calculated as defined daily doses (DDD).

Results

The analysis reveals a conservative approach to opioid therapy. In subjects under the age of 20, prescriptions accounted for 2.1% in 2022 and declined to 1.4% in 2023. The drug combination paracetamol/codeine was the most frequently prescribed, followed by tapentadol. Approximately two-thirds of the consumption pertains to oral formulations. Transdermal formulations were 15% (fentanyl 9.8%, buprenorphine 5.1%) in 2022; and 16.6% (fentanyl 10%, buprenorphine 6.6%) in 2023. These data were confirmed by the DDD analysis. The trend analysis demonstrated a significant reduction ( p < 0.001) in the number of prescribed opioids from 2022 to 2023 in adults (40-69 years). The study of rapid-onset opioids (ROOs), drugs specifically used for breakthrough cancer pain, showed higher dosage (>267 mcg) consumption among women, whereas a lower dosage (<133 mcg) was calculated for men. Fentanyl pectin nasal spray accounted for approximately one-fifth of all ROOs.

Conclusion

Despite limitations, the study provides valuable insights into prescribing practices involving an important study population. The findings underscore the need for tailored approaches to prescribing practices, recognizing the complexities of pain management in different contexts. This research can contribute to the ongoing discourse on opioid use, advocating for innovative strategies that optimize therapeutic outcomes while mitigating potential risks.

The impact of civil commitment laws for substance use disorder on opioid overdose deaths

Objective

Our study analyzed the impact of civil commitment (CC) laws for substance use disorder (SUD) on opioid overdose death rates (OODR) in the U.S. from 2010-21.

Methods

We used a retrospective study design using the CDC Wide-ranging Online Data for Epidemiologic Research (WONDER) dataset to analyze overdose death rates from any opioid during 2010-21 using ICD-10 codes. We used t-tests and two-way ANOVA to compare the OODR between the U.S. states with the law as compared to those without by using GraphPad Prism 10.0.

Results

We found no significant difference in the annual mean age-adjusted OODR from 2010-21 between U.S. states with and without CC SUD laws. During the pre-COVID era (2010-19), the presence or absence of CC SUD law had no difference in age-adjusted OODR. However, in the post-COVID era (2020-21), there was a significant increase in OODR in states with a CC SUD law compared to states without the law (p = 0.032). We also found that OODR increased at a faster rate post-COVID among both the states with CC SUD laws (p < 0.001) and the states without the law (p = 0.019).

Conclusion

We found higher age-adjusted OODR in states with a CC SUD law which could be due to the laws being enacted in response to the opioid crisis or physicians' opposition to or unawareness of the law's existence leading to underutilization. Recent enactment of CC SUD law(s), a lack of a central database for recording relapse rates, and disparities in opioid overdose rate reductions uncovers multiple variables potentially influencing OODR. Thus, further investigation is needed to analyze the factors influencing OODRs and long-term effects of the CC SUD laws.

Three noteworthy idiosyncrasies related to Canada's opioid-death crisis, and implications for public health-oriented interventions

Canada has been experiencing a prolonged public health-crisis of high rates of overdose deaths caused by exceptionally potent/toxic, illicit opioid use. While many key features of this drug death epidemic are well-documented, several idiosyncratic aspects with relevance for public health-oriented interventions are not adequately recognised. These include: (i) the discrepant opioid patterns pan-Canada, with large majorities of opioid deaths caused by illicit fentanyl drugs in Western, but not Eastern regions where prescription-type opioid prevail; (ii) the environments of overdose deaths, where vast majorities occur in 'residential' or other shelter-type settings, presenting barriers for emergency interventions rather than health protection; and (iii) shifting drug use modes, where now majorities of overdose deaths are associated with drug 'inhalation' (instead of 'injection') in contexts of potent/toxic drug supply. We briefly describe these factors and related implications for intervention programming towards an improved response to the drug death-crisis.

An automated group-housed oral fentanyl self-administration method in mice

RATIONALE AND OBJECTIVES

Social factors play a critical role in human drug addiction, and humans often consume drugs together with their peers. In contrast, in traditional animal models of addiction, rodents consume or self-administer the drug in their homecage or operant self-administration chambers while isolated from their peers. Here, we describe HOMECAGE ("Home-cage Observation and Measurement for Experimental Control and Analysis in a Group-housed Environment"), a translationally relevant method for studying oral opioid self-administration in mice. This setting reduces experimental confounds introduced by social isolation or interaction with the experimenter.

METHODS

We have developed HOMECAGE, a method in which mice are group-housed and individually monitored for their consumption of a drug vs. a reference liquid.

RESULTS

Mice in HOMECAGE preserve naturalistic aspects of behavior, including social interactions and circadian activity. The mice showed a preference for fentanyl and escalated their fentanyl intake over time. Mice preferred to consume fentanyl in bouts during the dark cycle. Mice entrained to the reinforcement schedule of the task, optimizing their pokes to obtain fentanyl rewards, and maintained responding for fentanyl under a progressive ratio schedule. HOMECAGE also enabled the detection of cage-specific and individual-specific behavior patterns and allowed the identification of differences in fentanyl consumption between co-housed control and experimental mice.

CONCLUSIONS

HOMECAGE serves as a valuable procedure for translationally relevant studies on oral opioid intake under conditions that more closely mimic the human condition. The method enables naturalistic investigation of factors contributing to opioid addiction-related behaviors and can be used to identify novel treatments.

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.

Comparative analysis of the metabolites and biotransformation pathways of fentanyl in the liver and brain of zebrafish

The rise of fentanyl has introduced significant new challenges to public health. To improve the examination and identification of biological samples in cases of fentanyl misuse and fatalities, this study utilized a zebrafish animal model to conduct a comparative investigation of the metabolites and biotransformation pathways of fentanyl in the zebrafish's liver and brain. A total of 17 fentanyl metabolites were identified in the positive ion mode using ultra-high-pressure liquid chromatography Q Exactive HF Hybrid Quadrupole-Orbitrap mass spectrometry (UHPLC-QE HF MS). Specifically, the zebrafish's liver revealed 16 fentanyl metabolites, including 6 phase I metabolites and 10 phase II metabolites. Conversely, the zebrafish's brain presented fewer metabolites, with only 8 detected, comprising 6 phase I metabolites and 2 phase II metabolites. Notably, M'4, a metabolite of dihydroxylation, was found exclusively in the brain, not in the liver. Through our research, we have identified two specific metabolites, M9-a (monohydroxylation followed by glucuronidation) and M3-c (monohydroxylation, precursor of M9-a), as potential markers of fentanyl toxicity within the liver. Furthermore, we propose that the metabolites M1 (normetabolite) and M3-b (monohydroxylation) may serve as indicators of fentanyl metabolism within the brain. These findings suggest potential strategies for extending the detection window and enhancing the efficiency of fentanyl detection, and provide valuable insights that can be referenced in metabolic studies of other new psychoactive substances.

Poppy Seed Consumption and Oral Fluid Opioids Detection: A Classroom Demonstration of Psychopharmacological Concepts

Psychopharmacological concepts such as pharmacokinetics, pharmacodynamics and drug interactions can be difficult to illustrate within the college classroom. In this demonstration, students consume poppy seed-containing food items, assess opioid content in their oral fluid using commercial drug test kits, and relate the findings to learned materials, its real-life applications, and relevant societal implications. This demonstration can clarify processes such as drug absorption, distribution, metabolism, and excretion (ADME), broaden the review of information relevant to opioids mechanisms of action, and facilitate the discussion of topics such as drug abuse, dependence, and addiction, as well as drug development, testing, policy, and enforcement. Instructors can employ different experimental designs, create dose-dependent/timeline detection plots, or allow students to construct their own experiments, assessing possible mediators of opioid detection. The demonstration can also be utilized to discuss scientific myths, truths, data misinterpretation and misrepresentation. Several optional protocols are provided, required materials are indicated, and discussion points are suggested.

Weathering the Storm: Syringe Services Program Laws and Human Immunodeficiency Virus During the COVID-19 Pandemic

BACKGROUND

Syringe services programs (SSPs) are community-based prevention programs that provide a range of harm reduction services to persons who inject drugs. Despite their benefits, SSP laws vary across the United States. Little is known regarding how legislation surrounding SSPs may have influenced HIV transmission over the COVID-19 pandemic, a period in which drug use increased. This study examined associations between state SSP laws and HIV transmission among the Medicaid population before and after the COVID-19 pandemic.

METHODS

State-by-month counts of new HIV diagnoses among the Medicaid population were produced using administrative claims data from the Transformed Medicaid Statistical Information System from 2019 to 2020. Data on SSP laws were collected from the Prescription Drug Abuse Policy System. Associations between state SSP laws and HIV transmission before and after the start of the COVID-19 pandemic were evaluated using an event study design, controlling for the implementation of COVID-19 nonpharmaceutical interventions and state and time fixed effects.

RESULTS

State laws allowing the operation of SSPs were associated with 0.54 (P = 0.044) to 1.18 (P = 0.001) fewer new monthly HIV diagnoses per 100,000 Medicaid enrollees relative to states without such laws in place during the 9 months after the start of the COVID-19 pandemic. The largest effects manifested for population subgroups disproportionately affected by HIV, such as male and non-Hispanic Black Medicaid enrollees.

CONCLUSION

Less restrictive laws on SSPs may have helped mitigate HIV transmission among the Medicaid population throughout the COVID-19 pandemic. Policymakers can consider implementing less restrictive SSP laws to mitigate HIV transmission resulting from future increases in injection drug use.

DISCLAIMER

The findings and conclusions in this report are those of the author(s) and do not necessarily represent the official position of the Centers for Disease Control and Prevention.

Immediate release fentanyl in general practices: Mostly off-label prescribing

BACKGROUND

The immediacy of the onset of opioids may be associated with the risk of dependency and accidental overdose. Nasal and oromucosal fentanyl dosage forms are so called immediate release fentanyl (IRF). These IRFs have been approved to treat breakthrough pain in patients with cancer who are on chronic opioid treatment only. There are signals of increased off-label prescribing of IRFs in general practices.

OBJECTIVES

This study aims to provide insight into the frequency of IRF prescription in Dutch general practices and the extent to which IRF is prescribed off-label.

METHODS

Routinely collected electronic health records of general practices (GPs) participating in Nivel Primary Care Database were used. Adult patients with IRF prescriptions in 2019 were selected from whom dispensing data on 2018 and 2019 was available. Diagnoses were recorded by GPs using International Classification of Primary Care. Descriptive analyses were performed.

RESULTS

This study included 342 GPs with a patient population of 1,297,942 patients, 1,368 patients received at least one IRF prescription in 2019, which is equal to 1.1 patients per 1,000 registered patients. Most patients (74.9%) with an IRF prescription received an off-label prescription. A slight majority had a cancer diagnosis but nearly 65.2% did not have a maintenance therapy and 14% were opioid-naive before receiving their first IRF prescription.

CONCLUSION

IRFs are not prescribed frequently in Dutch general practices. However, when prescribed, a relatively large portion of patients received an off-label prescription.

Severe and Fatal Fentanyl Poisonings from Transdermal Systems after On-Skin and Ingestion Application

In recent years, the administration of fentanyl (FNTL) implicitly in transdermal drug delivery systems (TDDS) has vastly increased in chronic pain treatment. Non-medical and uncontrolled use of FNTL in TFDS (transdermal fentanyl delivery systems) may reveal toxic effects by the route of exposure, dermal or alternative, by ingestion of patches, and drug release in the stomach. The purpose of this study was to present three different cases of FNTL poisonings, two of which resulted in death due to TFDS abuse. The first case is a 66-year-old woman treated for accidental FTNL poisoning resulting in acute respiratory distress syndrome. Two remaining cases are a 31-year-old woman and a 25-year-old man who died as a result of FNTL overdose after on-skin and ingestion application of the drug patches. During the hospitalization of the 66-year-old patient, in blood samples, FNTL was confirmed at a concentration of 10.0 ng/mL. Tests run on blood taken from the corpses of 25- and 31-year-old patients exhibited FNTL presence in concentrations of 29.1 ng/mL and 38.7 ng/mL, respectively. The various routes of administration and ultimately toxic effects are important to present because, in TDDS, fentanyl can be a reason for severe to fatal poisoning, as shown by the three cases above.

A protocol of a systematic review on deep brain stimulation surgery and its efficacy in addressing substance abuse addiction

Background

Pharmacotherapy and psychotherapeutic approaches are still the mainstay first line of treatment for substance use disorder. However, the path to rehabilitation and cessation of dependence often proves uncertain and laborious, with risks of relapse being considerable despite exposure to current therapeutic modalities. For cases of treatment-refractory addiction, deep brain stimulation (DBS) interventions can prove a more effective long term therapeutic solution for the patient.

Objectives

The aim of the study will be to systematically assess whether attempts at correcting substance use disorder via DBS neurosurgical interventions have been successful in inducing remission or ameliorating relapse rates.

Methods

The current study will analyze available literature from database inception up to 15th April 2023, reviewing all publications documenting results achieved with human patients undergoing DBS for substance use disorder in PubMed, Ovid, Cochrane, and Web of Science. The electronic database search will exclude animal studies in the field and focus solely on the application of DBS for the purposes of addressing addiction disorders.

Results

The expectation is for a reduced number of trial results to have been reported, namely due to the relatively recent application of DBS to address severe addiction. Nonetheless, numbers should be in sufficient amount to inform about the efficacy of the intervention.

Conclusion

This study will attempt to demonstrate the viability of DBS as a solution for tackling treatment-refractory substance use disorder, proposing it as a valid therapeutic option that can deliver robust results and help combat an expanding societal plague that is drug dependence.

Dexmedetomidine vs. Fentanyl-Midazolam Combination to Mitigate the Stress Response in Microlaryngoscopy: A Randomized Double-blind Clinical Trial

Background

Laryngoscopy is the most painful noxious stimulus during anesthesia and surgery. Dexmedetomidine is increasingly used as a sedative in surgeries involving microlaryngoscopy.

Objectives

This study aimed to evaluate the effect of dexmedetomidine and a combination of fentanyl and midazolam on mitigating the stress response in patients scheduled for microlaryngoscopy.

Methods

This randomized, double-blind clinical trial enrolled 60 patients (28 males and 32 females) aged 18 - 65 years with the American Society of Anesthesiologists (ASA) physical status I - III. The patients were scheduled for microlaryngoscopy and equally divided into 2 groups. Group D received 1 μg/kg of dexmedetomidine and saline bolus dose over 10 minutes before general anesthesia (GA) induction, followed by 0.5 μg/kg/h of dexmedetomidine and saline infusions after GA induction. Group MF received 0.8 μg/kg of fentanyl plus 0.05 mg/kg of midazolam over 10 minutes before GA induction, followed by 1 μg/kg/h of fentanyl plus 0.05 mg/kg/h of midazolam as an infusion. The heart rate (HR) and mean arterial blood pressure (MAP) pressure were recorded from baseline until the end of surgery. Infusions were stopped at the end of the surgery.

Results

The number of patients requiring propofol and intraoperative supplemental propofol was significantly lower in group D than in group MF. The heart rate was significantly lower in group D than in group MF (P = 0.022, 0.048, 0.032, 0.045, 0.041, 0.026, 0.030, and 0.036) from induction until the end of surgery; in addition, it was comparable between both groups at baseline and before induction. MAP was comparable between both groups for all measurements.

Conclusions

Dexmedetomidine mitigates the hemodynamic changes related to microlaryngoscopy more effectively than the fentanyl-midazolam combination.

Movement disorders associated with substance use in adults living in precarious housing or homelessness

OBJECTIVE

Many individuals living in precarious housing or homelessness have multimorbid illnesses, including substance use, psychiatric, and neurological disorders. Movement disorders (MDs) associated substance use are amongst the poorly studied subtopics of drug-induced MDs. The aim of the present study was, therefore, to determine the proportion affected and severity of different signs of MDs, as well as their associations with substance use in a community-based sample of precariously housed and homeless individuals.

METHODS

Participants were recruited from an impoverished urban neighborhood and were assessed for substance dependence and self-reported substance use (alcohol, cannabis, cocaine, methamphetamine, nicotine, and opioids), as well as for the severity of signs of MDs (akathisia, dyskinesia, dystonia, and parkinsonism). Adjusted regression models were used to estimate the associations of the severity of signs with the frequency of substance use over the past 4 weeks and with the baseline diagnosis of substance dependence.

RESULTS

The proportion of the sample with clinically relevant signs of MDs in any of the four categories was 18.6% (n = 401), and these participants demonstrated lower levels of functioning than those without signs. Of the different types of substance use, only methamphetamine (its frequency of use and dependence) was significantly associated with greater severity of overall signs of MDs. Frequency of methamphetamine use significantly interacted with age and sex, whereby older female participants exhibited the greatest overall severity with increased methamphetamine use. Of the different signs of MDs, methamphetamine use frequency was positively associated with the severity of trunk/limb dyskinesia and hypokinetic parkinsonism. Relative to no use, concurrent use of antipsychotics demonstrated lower severity of trunk/limb dyskinesia and greater severity of hypokinetic parkinsonism with methamphetamine use, and greater severity of dystonia with cocaine use.

CONCLUSIONS

Our study found a high proportion of MDs in a relatively young sample, and their severity was consistently associated with methamphetamine use, moderated by participant demographics and antipsychotic use. These disabling sequelae represent an important and understudied neurological condition that may affect quality of life and will require further study.

Using Social Media to Examine Themes Surrounding Fentanyl Misuse and Risk Indicators

Background: Opioid misuse is a crisis in the United States, and synthetic opioids such as fentanyl pose risks for overdose and mortality. Individuals who misuse substances commonly seek information and support online due to stigma and legal concerns, and this online networking may provide insight for substance misuse prevention and treatment. We aimed to characterize topics in substance-misuse related discourse among members of an online fentanyl community. Method: We investigated posts on a fentanyl-specific forum on the platform Reddit to identify emergent substance misuse-related themes potentially indicative of heightened risk for overdose and other adverse health outcomes. We analyzed 27 posts and 338 comments with a qualitative codebook established using a subset of user posts via inductive and deductive methods. Posts and comments were independently reviewed by two coders with a third coder resolving discrepancies. The top 200 subreddits with the most activity by r/fentanyl members were also inductively analyzed to understand interests of r/fentanyl users. Results: Functional/quality of life impairments due to substance misuse (29%) was the most commonly occurring theme, followed by polysubstance use (27%) and tolerance/dependence/withdrawal (20%). Additional themes included drug identification with photos, substances cut with other drugs, injection drugs, and past overdoses. Media-focused subreddits and other drug focused communities were among the communities most often followed by r/fentanyl users. Conclusion: Themes closely align with DSM-V substance use disorder symptoms for fentanyl and other substances. High involvement in media-focused subreddits and other substance-misuse-related communities suggests digital platforms as acceptable for overdose prevention and recovery support interventions.

New Synthetic Opioids: Clinical Considerations and Dangers

Since the early 2010s, synthetic opioids have significantly contributed to overall opioid-related overdose mortalities. For point of reference, of the 68,630 opioid-related deaths recorded in 2020, 56,516 involved synthetic opioids. During much of this period, fentanyl has been the most commonly used synthetic opioid. This time when fentanyl was the most popular opioid has been called the "third wave" of the opioid crisis, partly because it led to a sharp rise in deaths from overdoses. Other synthetic opioids, such as carfentanil, protonitazene, and isotonitazene, have also become more widely diverted for nonmedical used. Carfentanil is an even more potent fentanyl derivative that was initially used in the mid-1980s as a general anesthetic for large animals such as elephants. Related to its strong affinity for mu opioid receptors, carfentanil is still utilized in medicine and science today as a radiotracer for positron emission tomography imaging. Protonitazene and isotonitazene belong to a novel class of synthetic opioids called benzimidazoles that were manufactured in the 1950s as novel analgesics. These agents have come under recent scrutiny as designer synthetic opioids becoming more prevalent. However, to date, there is incomplete data regarding the prevalence of synthetic opioids, as traditional toxicology screenings may not be sensitive to detect these compounds at such low doses post-mortem, particularly when blood is drawn from the periphery instead of central tissues such as the brain, lung, or heart. This narrative review aims to highlight the clinical challenges presented by these new synthetic opioids.

Binding preference at the μ-opioid receptor underlies distinct pharmacology of cyclopropyl versus valeryl analogs of fentanyl

Illicitly manufactured fentanyl is driving the current opioid crisis, and various fentanyl analogs are appearing in recreational drug markets worldwide. To assess the potential health risks posed by fentanyl analogs, it is necessary to understand structure-activity relationships for these compounds. Here we compared the pharmacology of two structurally related fentanyl analogs implicated in opioid overdose: cyclopropylfentanyl and valerylfentanyl. Cyclopropylfentanyl has a three-carbon ring attached to the carbonyl group on the fentanyl scaffold, whereas valerylfentanyl has a four-carbon chain at the same position. In vitro assays examining μ-opioid receptor (MOR) coupling to G proteins in CHO cells showed that cyclopropylfentanyl is a full agonist (EC50 = 8.6 nM, %Emax = 113%), with potency and efficacy similar to fentanyl (EC50 = 10.3 nM, %Emax = 113%). By contrast, valerylfentanyl is a partial agonist at MOR (EC50 = 179.8 nM, %Emax = 60%). Similar results were found in assays assessing MOR-mediated β-arrestin recruitment in HEK cells. In vivo studies in male CD-1 mice demonstrated that both fentanyl analogs induce naloxone-reversible antinociception and respiratory suppression, but cyclopropylfentanyl is 100-times more potent as an antinociceptive agent (ED50 = 0.04 mg/kg, s. c.) than valerylfentanyl (ED50 = 4.0 mg/kg, s. c.). Molecular simulation results revealed that the alkyl chain of valerylfentanyl cannot be well accommodated by the active state of MOR and may transition the receptor toward an inactive state, converting the fentanyl scaffold to a partial agonist. Taken together, our results suggest that cyclopropylfentanyl presents much greater risk of adverse effects when compared to valerylfentanyl. Moreover, the summed findings may provide clues to the design of therapeutic opioids with reduced adverse side effects.

Evaluation of the gap in delivery of opioid agonist therapy among individuals with opioid-related health problems: a population-based retrospective cohort study

AIMS

Although opioid-related harms have reached new heights across North America, the size of the gap in opioid agonist therapy (OAT) delivery for opioid-related health problems is unknown in most jurisdictions. This study sought to characterize the gap in OAT treatment using a cascade of care framework, and determine factors associated with engagement and retention in treatment.

DESIGN

A population-based retrospective cohort study.

SETTING

Ontario, Canada.

PARTICIPANTS

Individuals who sought medical care for opioid-related health problems or died from an opioid-related cause between 2005 and 2019.

MEASUREMENTS

Monthly treatment status for buprenorphine/naloxone or methadone OAT between 2013 and 2019 (i.e. 'off OAT', 'retained on OAT < 6 months', 'retained on OAT ≥ 6 months').

FINDINGS

Of 122 811 individuals in the cohort, 97 516 (79.4%) received OAT at least once during the study period. There was decreasing 6-month treatment retention over time. Model results indicated that males had higher odds of being on OAT each month [odds ratio (OR) = 1.26, 95% confidence interval (CI) = 1.23-1.28] but lower odds of OAT retention (OR = 0.90, 95% CI = 0.88-0.92), while the reverse was observed for older individuals (monthly: OR = 0.76 per 10-year increase, 95% CI = 0.76-0.77; retention: OR = 1.36 per 10-year increase, 95% CI = 1.34-1.38) and individuals with higher neighbourhood income (e.g. highest income quintile, monthly: OR = 0.79, 95% CI = 0.77-0.82; highest income quintile, retention: OR = 1.15, 95% CI = 1.11-1.20). Individuals residing in rural areas and with a history of mental health diagnoses had poorer outcomes overall, including lower odds of being on OAT each month (rural: OR = 0.75, 95% CI = 0.73-0.78; mental health: OR = 0.89, 95% CI = 0.87-0.92) and OAT retention (rural: OR = 0.79, 95% CI = 0.77-0.82; mental health: OR = 0.81, 95% CI = 0.78-0.83), as well as higher risk of starting/stopping OAT [rural, starting OAT: hazard ratio (HR) = 1.07, 95% CI = 1.05-1.10; mental health, starting OAT: HR = 1.20, 95% CI: 1.18-1.23; rural, stopping OAT: HR = 1.24, 95% CI: = 1.22-1.26; mental health, stopping OAT: HR = 1.11, 95% CI = 1.09-1.13]. Individuals with a history of mental health diagnoses also had a higher risk of death, regardless of OAT status (off OAT death: HR = 1.49, 95% CI = 1.33-1.66; on OAT death: HR = 1.20, 95% CI = 1.09-1.31).

CONCLUSIONS

Factors influencing engagement and declining retention in treatment with opioid agonist therapy in Ontario's health system include age, sex and neighbourhood income, as well as mental health diagnoses or residing in rural regions.

Years of Life Lost to Unintentional Drug Overdose Rapidly Rising in the Adolescent Population, 2016-2020

PURPOSE

Years of life lost (YLL) is an epidemiological estimate of premature death which provides increased weight to mortality at younger ages. This study aims to quantify the impact of overdose mortality in adolescents from 2016 to 2020 using YLL and document the role of illicitly manufactured fentanyl in rising overdose rates.

METHODS

Data were obtained from the Centers for Disease Control and Prevention's Wide-Ranging Online Data for Epidemiologic Research mortality file for years 2016-2020 to investigate unintentional overdose in adolescents aged 10-19. Unintentional overdose rates were investigated by year, gender, age, and substances involved. YLL was calculated using the Social Security Period of Life Table by age and year. YLL to unintentional overdoses was then compared to other leading causes of adolescent death.

RESULTS

The number of adolescent YLL to unintentional drug overdose in the United States more than doubled from 2019 to 2020 after remaining relatively stable between 2016 and 2019. In 2020, YLL to unintentional overdose accumulated to 84,179 YLL, surpassing that of cancer. Synthetic opioids including primarily illicitly manufactured fentanyl contributed to 81% of overdose deaths and 68,356 YLL, compared to 67% (26,628 YLL) in 2019. YLL to unintentional overdose during 2020 was higher for males (59,274) compared to females (24,905).

DISCUSSION

Mortality due to unintentional overdose in adolescents reached an all-time high in 2020. The majority of deaths (81%) involved fentanyl and other synthetic opioids. The trends depicted in this study signify the need for increased harm reduction approaches and treatment of opioid use disorder in adolescents.

Synergistic interaction between DAMGO-NH2 and NOP01 in peripherally acting antinociception in two mouse models of formalin pain

The most commonly used opioid analgesics are limited by their severe side-effects in the clinical treatment of pain. Preliminary reports indicate that the combination of classical opioids and N/OFQ receptor (NOP) ligands may be an effective strategy to reduce unwanted side-effects and improve antinociception. But the interaction of these two receptor ligands in pain regulation at the peripheral level remains unclear. In this study, the antinociception of a designed amide analogue of the mu opioid receptor (MOP) peptide agonist DAMGO, DAMGO-NH₂, and its antinociceptive interaction with the peripherally limited NOP peptide agonist NOP01 was investigated in two mouse models of formalin pain. Our results showed that DAMGO-NH₂ acted as a MOP agonist in in vitro functional assays. Moreover, local subcutaneous or intraplantar injection of DAMGO-NH₂ exerted dose-related antinociception in both phases of the formalin orofacial and intraplantar pain, which could be mediated by the classical opioid receptor. Peripheral but not central pretreatment with the peripherally restricted opioid antagonist naloxone methiodide inhibited local DAMGO-NH₂-induced antinociception, supporting the involvement of the peripheral opioid receptor in local DAMGO-NH₂-induced antinociception. Furthermore, co-administration of the inactive doses of DAMGO-NH₂ and NOP01 produced effective antinociception. More importantly, isobolographic analysis indicates that the combination of DAMGO-NH₂ and NOP01 elicited supra-additive antinociception in these two models of formalin pain. In addition, the combination of DAMGO-NH₂ and NOP01 did not change motor function of mice in rotarod test. In conclusion, these data suggest that peripheral DAMGO-NH₂ and particularly its combination therapy with NOP01 may be effective for pain management.

Evaluation of polyanionic cyclodextrins as high affinity binding scaffolds for fentanyl

Cyclodextrins (CDs) have been previously shown to display modest equilibrium binding affinities (K_a ~ 100-200 M^-1) for the synthetic opioid analgesic fentanyl. In this work, we describe the synthesis of new CDs possessing extended thioalkylcarboxyl or thioalkylhydroxyl moieties and assess their binding affinity towards fentanyl hydrochloride. The optimal CD studied displays a remarkable affinity for the opioid of K_a = 66,500 M^-1, the largest value reported for such an inclusion complex to date. One dimensional ¹H Nuclear Magnetic Resonance (NMR) as well as Rotational Frame Overhauser Spectroscopy (2D-ROESY) experiments supported by molecular dynamics (MD) simulations suggest an unexpected binding behavior, with fentanyl able to bind the CD interior in one of two distinct orientations. Binding energies derived from the MD simulations work correlate strongly with NMR-derived affinities highlighting its utility as a predictive tool for CD candidate optimization. The performance of these host molecules portends their utility as platforms for medical countermeasures for opioid exposure, as biosensors, and in other forensic science applications.

Interprofessional Active Learning for Chronic Pain: Transforming Student Learning From Recall to Application

Chronic pain (CP) affects over 50 million Americans daily and represents a unique challenge for healthcare professionals due to its complexity. Across all health professions, only a small percentage of the curriculum is devoted to treating patients with CP. Unfortunately, much of the content is delivered passively via lecture without giving students an opportunity to practice the communication skills to effectively treat patients in the clinic. An interprofessional team of health educators identified 5 essential messages that students frequently struggle to convey to patients with CP. Those messages were based on interprofessional and profession-specific competencies to treat patients with CP from the International Association for the Study of Pain. The 5 messages highlighted the importance of (1) therapeutic alliance, (2) consistent interdisciplinary language, (3) patient prognosis, (4) evidence for pain medicine, surgery, and imaging, and (5) early referral to the interprofessional team. For each message, the team summarized relevant research supporting the importance of each individual message that could serve as a foundation for didactic content. The team then developed active learning educational activities that educators could use to have students practice the skills tied to each message. Each learning activity was designed to be delivered in an interprofessional manner.

Increased solitary drug use during COVID-19: An unintended consequence of social distancing

BACKGROUND

During the COVID-19 pandemic, overdose rates substantially increased in the United States. One possible contributor to this phenomenon may be solitary drug use resulting from social distancing efforts to prevent COVID-19 transmission.

METHODS

We surveyed 458 people who use drugs (PWUD) who were recruited from harm reduction and drug treatment providers located in nine states and the District of Columbia. We assessed if solitary drug use had increased since the start of COVID-19. Associations between increased solitary drug use and sociodemographic characteristics, drug use characteristics, and COVID-19 prevention behaviors were examined using multiple logistic regression.

RESULTS

Half the sample identified as men (52.7%), White (49.7%), and single (49.3%). The average age was 43.2 (SD:11.8) years. Two-thirds (66.8%) recently injected drugs. 44% reported increased solitary drug use since COVID-19. Significant correlates of increased solitary drug use included being single (adjusted Odds Ratio [aOR]=1.99, 95% Confidence Interval [CI]: 1.33, 2.98), increasing drug use (aOR=2.74, 95% CI: 1.72, 4.37), using more in private locations (aOR=1.91, 95% CI: 1.34, 2.72), and social distancing behaviors (aOR=1.31, 95% CI: 1.11, 1.54). Experiencing homelessness (aOR=0.45, 95% CI: 0.31, 0.65) and identifying as a sexual minority (aOR=0.53, 95% CI: 0.31, 0.93) were associated with being less likely to increase solitary drug use.

CONCLUSIONS

Solitary drug use increased during the COVID-19 pandemic. Increases in solitary drug use, in the context of a drug market increasingly permeated by fentanyl, indicates an urgent need for comprehensive harm reduction interventions to reduce overdose mortality.

Atypical Fentanyl Transdermal Patch Consumption and Fatalities: Case Report and Literature Review

Fentanyl is a synthetic L-opioid receptor agonist, approximately 100 times more potent than morphine, that is experiencing an upward trend in the field of abuse. Fentanyl patches' abusive consumption can occur either by transdermal absorption or through other atypical and ingenious routes. In the present case, a 29-year-old man with a history of illicit drug use was found dead in a suburban neighborhood of an Italian city. At autopsy, lungs appeared increased in weight and showed minute subpleural hemorrhages. Airways contained abundant reddish foamy material; in addition, a fentanyl patch protective film was found inside the left main bronchus. Toxicological analysis revealed the presence of morphine, fentanyl, BEG and ethyl alcohol in peripheric blood; 6-MAM was also revealed in urine. Findings collected during post-mortem investigations allowed us to identify fentanyl consumption as the cause of death. Fentanyl consumption presumably took place by chewing of a transdermal patch, with subsequent aspiration of the protective film. The pathophysiology of death can be identified as combined respiratory failure-both central suppression and a fentanyl-induced increase in muscular stiffness; a further minor contribution may be identified in the mechanical airflow obstruction caused by the presence of the protective film at the bronchial level.

Recent Scaffold Hopping Applications in Central Nervous System Drug Discovery

The concept of bioisosterism and the implementation of bioisosteric replacement is fundamental to medicinal chemistry. The exploration of bioisosteres is often used to probe key structural features of candidate pharmacophores and enhance pharmacokinetic properties. As the understanding of bioisosterism has evolved, capabilities to undertake more ambitious bioisosteric replacements have emerged. Scaffold hopping is a broadly used term in the literature referring to a variety of different bioisosteric replacement strategies, ranging from simple heterocyclic replacements to topological structural overhauls. In this work, we have highlighted recent applications of scaffold hopping in the central nervous system drug discovery space. While we have highlighted the benefits of using scaffold hopping approaches in central nervous system drug discovery, these are also widely applicable to other medicinal chemistry fields. We also recommend a shift toward the use of more refined and meaningful terminology within the realm of scaffold hopping.

Heroin pipe distribution to reduce high-risk drug consumption behaviors among people who use heroin: a pilot quasi-experimental study

BACKGROUND

Heroin pipe distribution may encourage people who use heroin (PWUH) to transition from injecting to smoking heroin, reducing harms associated with injection drug use. A syringe services program (SSP) in Seattle, Washington, led by people who use drugs developed a heroin pipe distribution program.

METHODS

We conducted a pretest-posttest quasi-experimental study to evaluate the impact of heroin pipe distribution on drug consumption behaviors among PWUH between March and December 2019. SSP clients were surveyed during three weeklong timepoints before and four weeklong timepoints after heroin pipe distribution. Primary outcomes were change in proportion of SSP clients who exclusively injected heroin, exclusively smoked heroin, and both injected and smoked heroin in the past seven days comparing the pre- and post-intervention periods.

RESULTS

Across the seven observation timepoints, 694 unique respondents completed 957 surveys. Multiple responses from a single respondent in a given period were collapsed, resulting in 360 pre-intervention and 430 post-intervention records. Heroin use was reported in over half of pre-intervention (56%, 201/360) and post-intervention records (58%, 251/430). Compared to pre-intervention behaviors, the proportion of respondents who exclusively injected heroin was lower after the start of heroin pipe distribution (32%, 80/251 vs 43%, 86/201, p = 0.02), while the proportion of respondents who both injected and smoked heroin was higher (45%, 113/251 vs 36%, 72/201, p = 0.048). Just under half (44%, 110/251) of respondents who used heroin during the post-intervention period used a heroin pipe obtained from the SSP, of which 34% (37/110) reported heroin pipe distribution had reduced their heroin injection frequency. Self-reported hospitalization for a pulmonary cause was not associated with using a heroin pipe.

CONCLUSIONS

The proportion of SSP clients who exclusively injected heroin was lower after implementation of heroin pipe distribution. Randomized studies with longer follow-up are needed to investigate whether heroin pipe distribution reduces heroin injection and improves health outcomes associated with drug use. Limited intervention exposure, loss to follow-up, and pipe availability from other sources pose methodological challenges to evaluations of route transition interventions in community settings. This pilot highlights the potential for organizations led by people who use drugs to develop, implement, and evaluate novel public health programming.

Sex-Differences in Pain and Opioid Use Disorder Management: A Cross-Sectional Real-World Study

(1) Background: It is essential to focus attention on sex-specific factors which are clinically relevant in pain management, especially with regards to opioid use disorder (OUD) risk. The aim of this study was to explore potential sex-differences in chronic non-cancer pain (CNCP) outpatients. (2) Methods: An observational cross-sectional study was conducted under CNCP outpatients with long-term prescribed opioids (n = 806), wherein 137 patients had an OUD diagnosis (cases, 64% females) and 669 did not (controls, 66% females). Socio-demographic, clinical, and pharmacological outcomes were analyzed. (3) Results: Female controls presented an older age and less intensive pain therapy but higher psychotropic prescriptions and emergency department visits compared to male controls. Meanwhile, cases demonstrated a younger age, higher work disability, double morphine equivalent daily dose, and benzodiazepine use compared with controls. Here, female cases showed an 8% greater substance use disorder (OR 2.04 [1.11–3.76]) and 24% lower tramadol use, while male cases presented a 22% higher fentanyl use (OR 2.97 [1.52–5.81]) and reported the highest number of adverse drug reactions (24%, OR 2.40 [1.12–5.16]) compared with controls. (4) Conclusions: An OUD individual risk profile was evidenced with sex-differences to take into consideration to design equal prevention programs.

Pharmacotherapy of Opioid Use Disorder-Update and Current Challenges

The incidence of opioid use disorder (OUD) and overdose deaths is rising yearly within the United States. Many cases are associated with illicitly manufactured fentanyl use. In addition to offering patients medications for OUD (methadone, buprenorphine, and naltrexone), the approach to this epidemic should involve increasing provider awareness and education about substance use disorders, expanding urine toxicology screens to test for fentanyl, and using low-threshold treatment approaches.

Escalation of Opioid Withdrawal Frequency and Subsequent AMA Rates in Hospitalized Patients From 2017 to 2020

OBJECTIVE

To measure trends for the emergence of opioid withdrawal (OW) and leaving against medical advice (AMA) among hospitalized patients.

METHOD

Retrospective time-series of hospitalized patients with OW, defined by a Clinical Opioid Withdrawal score ≥8, using electronic health record data at a tertiary health system and of patients with a discharge status of AMA from January 1, 2017 to December 31, 2020.

RESULTS

The average number of monthly hospitalizations with OW showed a year-to-year increment of 15% in 2018, 21% in 2019, and 34% from 2019 to 2020, whereas the total monthly hospitalizations remained stable. The segmented regression analysis showed that the upward trend in hospitalizations with OW became significant after January 2019 (slope: 1.14, 95% confidence interval [CI]: 0.70, 1.57). After August 2019, Fentanyl was added to the hospital urine drug testing panel and was identified in most OW patients. The monthly proportion of patients who left AMA was significantly higher among the OW patients than among all other admitted patients. There was a significant increase of 0.39 (95% CI: 0.29-0.49, P ≤ 0.001) per month in %AMA among patients with OW. The estimated difference in %AMA among OW patients versus all other patients was 7.25 (95% CI: 5.12-9.38) in January 2017, and 16.92 (95% CI: 14.6019.24) in December 2020.

CONCLUSIONS

The number of hospitalized patients either presenting with or developing OW increased between 2017 and 2020 with a significant rise occurring after January 2019. The percentage of patients who left AMA among those who developed OW steadily worsened during the entire study period.

Feasibility and Acceptability of a Group Counseling Intervention for Opioid Use Disorder: An Exploratory Study

The goal of the current exploratory study was to examine the feasibility and acceptability of an evidence-based group counseling intervention for individuals with opioid use disorders (OUD) reporting mental health issues and using medications for OUD. The intervention combines motivational interviewing and cognitive-behavioral therapy. Qualitative research methodology, specifically focus group interviewing, with seven individuals was used to examine the feasibility and acceptability of the intervention. Qualitative analysis of the focus group yielded four themes: Intervention Format, Group Counseling Factors, Comorbid Mental Health Issues, and Counselor Factors. The intervention proposed was found to be acceptable and feasible for addressing OUD and co-occurring mental health conditions, specifically depression, anxiety, and stress. [Journal of Psychosocial Nursing and Mental Health Services, 60(6), 7-10.].

Variability in the unregulated opioid market in the context of extreme rates of overdose

BACKGROUND

Drug checking uses analytical chemistry technologies to report on the composition of drugs from the unregulated market to reduce substance use-related risks, while additionally allowing for monitoring and reporting of the supply. In the context of an overdose crisis linked to fentanyl, we used drug checking data to examine variability within the illicit opioid supply.

METHODS

In this time-series analysis, data was collected from a drug checking service in Victoria, Canada from November 2020 to July 2021. Drugs reported as opioids by participants of the service (N = 454) were analyzed to determine sample composition and paper spray mass spectroscopy was used to quantify low-concentration actives. Interquartile and statistical process control (SPC) analysis, namely standard deviation control charts, were used to examine the degree of variability among samples.

RESULTS

Fentanyl was found in 96% of samples reported to be opioids, with a median concentration of 9%. Concentrations varied significantly, with a standard deviation of 7% for fentanyl and where nearly 20% of data points fell outside the control limits. Over half of the samples contained an additional and unexpected active, most commonly etizolam (43% of samples). Etizolam also showed a large level of variability, uncorrelated to that of fentanyl.

CONCLUSIONS

Based on our chemical quantification and SPC analysis, a high degree of variability was found in opioid samples from the unregulated market in both the drugs detected and the concentrations of those drugs. This demonstrated the opioid crisis to be less attributable to a bad batch of drugs but rather the general variability found in the unregulated market.

S-Nitroso-L-Cysteine Stereoselectively Blunts the Deleterious Effects of Fentanyl on Breathing While Augmenting Antinociception in Freely-Moving Rats

Endogenous and exogenously administered S-nitrosothiols modulate the activities of central and peripheral systems that control breathing. We have unpublished data showing that the deleterious effects of morphine on arterial blood-gas chemistry (i.e., pH, pCO2, pO2, and sO2) and Alveolar-arterial gradient (i.e., index of gas exchange) were markedly diminished in anesthetized Sprague Dawley rats that received a continuous intravenous infusion of the endogenous S-nitrosothiol, S-nitroso-L-cysteine. The present study extends these findings by showing that unanesthetized adult male Sprague Dawley rats receiving an intravenous infusion of S-nitroso-L-cysteine (100 or 200 nmol/kg/min) markedly diminished the ability of intravenous injections of the potent synthetic opioid, fentanyl (10, 25, and 50 μg/kg), to depress the frequency of breathing, tidal volume, and minute ventilation. Our study also found that the ability of intravenously injected fentanyl (10, 25, and 50 μg/kg) to disturb eupneic breathing, which was measured as a marked increase of the non-eupneic breathing index, was substantially reduced in unanesthetized rats receiving intravenous infusions of S-nitroso-L-cysteine (100 or 200 nmol/kg/min). In contrast, the deleterious effects of fentanyl (10, 25, and 50 μg/kg) on frequency of breathing, tidal volume, minute ventilation and non-eupneic breathing index were fully expressed in rats receiving continuous infusions (200 nmol/kg/min) of the parent amino acid, L-cysteine, or the D-isomer, namely, S-nitroso-D-cysteine. In addition, the antinociceptive actions of the above doses of fentanyl as monitored by the tail-flick latency assay, were enhanced by S-nitroso-L-cysteine, but not L-cysteine or S-nitroso-D-cysteine. Taken together, these findings add to existing knowledge that S-nitroso-L-cysteine stereoselectively modulates the detrimental effects of opioids on breathing, and opens the door for mechanistic studies designed to establish whether the pharmacological actions of S-nitroso-L-cysteine involve signaling processes that include 1) the activation of plasma membrane ion channels and receptors, 2) selective intracellular entry of S-nitroso-L-cysteine, and/or 3) S-nitrosylation events. Whether alterations in the bioavailability and bioactivity of endogenous S-nitroso-L-cysteine is a key factor in determining the potency/efficacy of fentanyl on breathing is an intriguing question.

Unique Pharmacology, Brain Dysfunction, and Therapeutic Advancements for Fentanyl Misuse and Abuse

Fentanyl is a fully synthetic opioid with analgesic and anesthetic properties. It has become a primary driver of the deadliest opioid crisis in the United States and elsewhere, consequently imposing devastating social, economic, and health burdens worldwide. However, the neural mechanisms that underlie the behavioral effects of fentanyl and its analogs are largely unknown, and approaches to prevent fentanyl abuse and fentanyl-related overdose deaths are scarce. This review presents the abuse potential and unique pharmacology of fentanyl and elucidates its potential mechanisms of action, including neural circuit dysfunction and neuroinflammation. We discuss recent progress in the development of pharmacological interventions, anti-fentanyl vaccines, anti-fentanyl/heroin conjugate vaccines, and monoclonal antibodies to attenuate fentanyl-seeking and prevent fentanyl-induced respiratory depression. However, translational studies and clinical trials are still lacking. Considering the present opioid crisis, the development of effective pharmacological and immunological strategies to prevent fentanyl abuse and overdose are urgently needed.

Epidemiological trends in opioid-only and opioid/polysubstance-related death rates among American Indian/Alaska Native populations from 1999 to 2019: a retrospective longitudinal ecological study

OBJECTIVES

The rate of drug overdose deaths in the USA has more than tripled since the turn of the century, and rates are disproportionately high among the American Indian/Alaska Native (AI/AN) population. Little is known about the overall historical trends in AI/AN opioid-only and opioid/polysubstance-related mortality. This study will address this gap.

DESIGN

This is a retrospective longitudinal ecological study.

SETTING

US death records from 1999 to 2019 using the Centers for Disease Control and Prevention Wide-Ranging Online Data for Epidemiologic Research.

PARTICIPANTS

US non-Hispanic AI/AN people age 12 years and older.

MEASURES

The primary outcomes, identified via the 10th revision of the International Statistical Classification of Diseases and Related Health Problems codes, included overdose deaths due to (1) opioids only, opioids in combination with any other substance, all-opioid related overdoses; (2) combinations of opioids and alcohol, opioids and methamphetamine, opioids and cocaine, opioids and benzodiazepines; and (3) specific types of opioids.

RESULTS

From 1999 to 2019, opioid-only mortality rates increased from 2.8 to 15.8 per 100 000 (p<0.001) for AI/AN women and 4.6 to 25.6 per 100 000 (p<0.001) for AI/AN men. All opioid-related mortality rates increased significantly (p<0.001) from 5.2 to 33.9 per 100 000 AI/AN persons, 3.9 to 26.1 for women and 6.5 to 42.1 for men. AI/AN also exhibited significant increases in mortality rates due to opioids and alcohol, opioids and benzodiazepines, opioids and methamphetamine, and AI/AN men experienced substantial increases in mortality due to opioids and cocaine. Mortality rates by individual opioid types increased significantly over time for heroin, natural and semi-synthetic (prescription), and synthetic opioids (fentanyl/fentanyl analogues) other than methadone.

CONCLUSIONS

These findings highlight magnification over time in opioid-related deaths and may point to broader systemic factors that may disproportionately affect members of AI/AN communities and drive inequities.

Reports of Adverse Events Associated with Use of Novel Psychoactive Substances, 2017-2020: A Review

An important role of modern forensic and clinical toxicologists is to monitor the adverse events of novel psychoactive substances (NPS). Following a prior review from 2013 to 2016, this critical literature review analyzes and evaluates published case reports for NPS from January 2017 through December 2020. The primary objective of this study is to assist in the assessment and interpretation of these cases as well as provide references for confirmation methods. Chemistry, pharmacology, adverse events and user profiles (e.g., polypharmacy) for NPS are provided including case history, clinical symptoms, autopsy findings and analytical results. Literature reviews were performed in PubMed and Google Scholar for publications using search terms such as NPS specific names, general terms (e.g., ‘designer drugs’ and ‘novel psychoactive substances’), drug classes (e.g., ‘designer stimulants’) and outcome-based terms (e.g., ‘overdose’ and ‘death’). Government and website drug surveillance databases and abstracts published by professional forensic science organizations were also searched. Toxicological data and detailed case information were extracted, tabulated, analyzed and organized by drug category. Case reports included overdose fatalities (378 cases), clinical treatment and hospitalization (771 cases) and driving under the influence of drugs (170 cases) for a total of 1,319 cases providing details of adverse events associated with NPS. Confirmed adverse events with associated toxidromes of more than 60 NPS were reported including synthetic cannabinoid, NPS stimulant, NPS hallucinogen, NPS benzodiazepine and NPS opioid cases. Fifty of these NPS were reported for the first time in January 2017 through December 2020 as compared to the previous 4 years surveyed. This study provides insight and context of case findings described in the literature and in digital government surveillance databases and websites during a recent 4-year period. This review will increase the awareness of adverse events associated with NPS use to better characterize international emerging drug threats.

The Potential of Methocinnamox as a Future Treatment for Opioid Use Disorder: A Narrative Review

The opioid epidemic is an ongoing public health crisis, and the United States health system is overwhelmed with increasing numbers of opioid-related overdoses. Methocinnamox (MCAM) is a novel mu opioid receptor antagonist with an extended duration of action. MCAM has potential to reduce the burden of the opioid epidemic by being used as an overdose rescue treatment and a long-term treatment for opioid use disorder (OUD). The currently available treatments for OUD include naloxone, naltrexone, and methadone. These treatments have certain limitations, which include short duration of action, patient non-compliance, and diversion. A narrative review was conducted using PubMed and Google Scholar databases covering the history of the opioid epidemic, pain receptors, current OUD treatments and the novel drug MCAM. MCAM could potentially be used as both a rescue and long-term treatment for opioid misuse. This is due to its pseudo-irreversible antagonism of the mu opioid receptor, abnormally long duration of action of nearly two weeks, and the possibility of using kappa or delta opioid receptor agonists for pain management during OUD treatment. MCAM’s novel pharmacokinetic and pharmacodynamic properties open a new avenue for treating opioid misuse.

Prehospital Buprenorphine Treatment for Opioid Use Disorder by Paramedics: First Year Results of the EMS Buprenorphine Use Pilot

Background: Prehospital initiation of buprenorphine treatment for Opioid Use Disorder (OUD) by paramedics is an emerging potential intervention to reach patients at greatest risk for opioid-related death. Emergency Medical Services (EMS) patients who are at high risk for overdose deaths may never engage in treatment as they frequently refuse transport to the hospital after naloxone reversal. The potentially important role of EMS as the initiator for medication for opioid use disorder (MOUD) in the most high-risk patients has not been well described. Setting: This project relies on four interventions: a public access naloxone distribution program, an electronic trigger and data sharing program, an "Overdose Receiving Center," and a paramedic initiated buprenorphine treatment. For the final intervention, paramedics followed a protocol based pilot which had an EMS physician consultation prior to administration. Results: There were 36 patients enrolled in the trial study in the first year who received buprenorphine. Of those patients receiving buprenorphine, only one patient signed out against medical advice on scene. All other patients were transported to an emergency department and their clinical outcome and 7 and 30 day follow ups were determined by the substance use navigator (SUN.) 36 of 36 patients had follow up data obtained in the short term and none experienced any precipitated withdrawal or other adverse outcomes. Patients had a 50% (18/36) rate of treatment retention at 7 days and 36% (14/36) were in treatment at 30 days. Conclusion: In this small pilot project, paramedic initiated buprenorphine in the setting of data sharing and linkage with treatment appears to be a safe intervention with a high rate of ongoing outpatient treatment for risk of fatal opioid overdoses.

Computational analyses of the vibrational spectra of fentanyl, carfentanil and remifentanil

The infrared (IR) spectra of fentanyl, carfentanil and remifentanil, and protonated salts, are computed using quantum chemistry methods. New experimental FTIR spectra are also reported and compared to the calculations. The accuracy of two density functional theory methods, B3LYP and M06-2X, are tested against higher level theories (MP2) and the experimental data. Gas phase IR spectra are calculated for both the neutral and protonated molecules in order to compare with the experimental data measured for various salts of fentanyl and its analogues. Key vibrational modes are selected and studied in detail using a vibrational mode locality calculation. The main contributing atomic movements in these vibrational modes are identified.

Community based buprenorphine micro-induction in the context of methadone maintenance treatment and fentanyl - Case report

INTRODUCTION

The micro-induction method of initiating buprenorphine is becoming a popular method for initiating buprenorphine in patients with Opioid Use Disorder, who are on full opioid agonists, either prescribed or non-prescribed, in order to avoid precipitated withdrawal. Given the rising concerns around illicit fentanyl use, this method of initiating buprenorphine has become another tool for clinicians to help patients with Opioid Use Disorder, even when multiple full opioid agonists are involved. While the process for initiating buprenorphine through this process is well studied, the characteristics of patients who are able to tolerate this initiation method in an outpatient setting is not.

CASE(S)

We present the cases of two patients with Opioid Use Disorder in a community-based methadone maintenance program in whom micro-induction methods were used to initiate buprenorphine without lowering the methadone dose. Both patients successfully transitioned to buprenorphine without precipitated withdrawal. One of the patients was also using fentanyl at the time of induction and was able to abstain from fentanyl use following the induction process.

CONCLUSION

Initiating Buprenorphine using micro-induction strategies in a community based outpatient clinic in patients who are already on full opioid agonists is feasible, in these particular cases, the methadone dose or concurrent fentanyl use did not affect the outcome. We present the characteristics of the patient and the community clinic hoping that this helps more clinicians in replicating this induction strategy.