Synthetic Opioids Research Articles

Estimated Number of Injection-Involved Overdose Deaths in US States From 2000 to 2020: Secondary Analysis of Surveillance Data.

In the United States, both drug overdose mortality and injection-involved drug overdose mortality have increased nationally over the past 25 years. Despite documented geographic differences in overdose mortality and substances implicated in overdose mortality trends, injection-involved overdose mortality has not been summarized at a subnational level. We aimed to estimate the annual number of injection-involved overdose deaths in each US state from 2000 to 2020. We conducted a stratified analysis that used data from drug treatment admissions (Treatment Episodes Data Set-Admissions; TEDS-A) and the National Vital Statistics System (NVSS) to estimate state-specific percentages of reported drug overdose deaths that were injection-involved from 2000 to 2020. TEDS-A collects data on the route of administration and the type of substance used upon treatment admission. We used these data to calculate the percentage of reported injections for each drug type by demographic group (race or ethnicity, sex, and age group), year, and state. Additionally, using NVSS mortality data, the annual number of overdose deaths involving selected drug types was identified by the following specific multiple-cause-of-death codes: heroin or synthetic opioids other than methadone (T40.1, T40.4), natural or semisynthetic opioids and methadone (T40.2, T40.3), cocaine (T40.5), psychostimulants with abuse potential (T43.6), sedatives (T42.3, T42.4), and others (T36-T59.0). We used the probabilities of injection with the annual number of overdose deaths, by year, primary substance, and demographic groups to estimate the number of overdose deaths that were injection-involved. In 2020, there were 91,071 overdose deaths among adults recorded in the United States, and 93.1% (84,753/91,071) occurred in the 46 jurisdictions that reported data to TEDS-A. Slightly less than half (38,253/84,753, 45.1%; 95% CI 41.1%-49.8%) of those overdose deaths were estimated to be injection-involved, translating to 38,253 (95% CI 34,839-42,181) injection-involved overdose deaths in 2020. There was large variation among states in the estimated injection-involved overdose death rate (median 14.72, range 5.45-31.77 per 100,000 people). The national injection-involved overdose death rate increased by 323% (95% CI 255%-391%) from 2010 (3.78, 95% CI 3.33-4.31) to 2020 (15.97, 95% CI 14.55-17.61). States in which the estimated injection-involved overdose death rate increased faster than the national average were disproportionately concentrated in the Northeast region. Although overdose mortality and injection-involved overdose mortality have increased dramatically across the country, these trends have been more pronounced in some regions. A better understanding of state-level trends in injection-involved mortality can inform the prioritization of public health strategies that aim to reduce overdose mortality and prevent downstream consequences of injection drug use.

Unmasking the Dual Threat of Fentanyl and Xylazine Abuse in America

IntroductionThe United States of America are currently facing a public health crisis characterized by the abuse of synthetic opioids, notably Fentanyl, and the veterinary sedative Xylazine. While each of these substances has been associated with significant risks, their current misuse presents a formidable challenge to healthcare professionals, law enforcement agencies and policymakers. While the opioid epidemic has long held the nation in its grip, the emergence of Xylazine as complementary agent in substance abuse has added a disturbing layer of complexity to an already terrible situation, due to its cost-cutting, an increase in its addictive properties and its ability to extend the duration of the opioid with which it is combined.ObjectivesThe authors intend to review the relevant and current literature in order to extend the knowledge about this condition and find the best conducts for clinical practice.MethodsNon-systematic literature reviewResults Various regions of the United States are facing a troubling surge in the co-abuse of Fentanyl, a potent synthetic opioid many times more potent than morphine, and Xylazine, a veterinary sedative and muscle relaxant, particularly in urban areas. The motivations for this combination appear to vary, ranging from the enhanced euphoria to cost-saving measures, further fueling its prevalence. However, the consequences are devastating. Both substances depress the central nervous system, with a sharp increase in overdose deaths and emergency medical services are strained to their limits in responding to these crises. Law enforcement agencies are facing a daunting task in curtailing the distribution of these substances, often grappling with clandestine networks that exploit the accessibility of these drugs.Conclusions The concurrent abuse of Fentanyl and Xylazine represents a critical public health challenge in the United States of America, demanding immediate attention and a multidisciplinary response. Failure to address this issue comprehensively will have profound implications for the well-being of individuals, families and communities across the nation. It is imperative to mobilize resources, foster interdisciplinary collaboration and develop evidence-based policies to combat this dual-threat crisis. Novel intervention strategies, including community education programs, targeted outreach efforts, and supervised consumption facilities, are urgently needed to address this complex issue.Disclosure of InterestNone Declared

An LC-MS/MS method for the determination of drugs of abuse included THC-COOH, EtG, and NPS, using a single hair extraction sample.

Hair analysis plays an important role in the determination of drugs of abuse in both forensic and clinical toxicology investigations. The analysis of different substances often requires the use of different sample preparation methods, thereby increasing the amount of hair sample and time required. In the present study, a fast method involving a combination of a single 25 mg hair extraction procedure and four liquid chromatography-tandem mass spectrometry methods using the same chromatographic phases and column was developed and validated. The target was the identification and quantification of various commonly abused drugs and their metabolites, including amphetamines, cocaine, opioids, cannabinoids, THC-COOH and EtG, and more than 140 new psychoactive substances, including synthetic cannabinoids, phenethylamines, synthetic opioids, methylphenidate, cathinone, piperidine, and tryptamines.

Opioid abuse, the escalating crisis, xylazine co-use, and the forensic toxicology challenges

Introduction: The opioid crisis represents a longstanding public health emergency, significantly worsened by the concurrent use of xylazine. This epidemic has led to a surge in opioid-related fatalities, marking it as a pressing health crisis with global implications. The combination of xylazine with fentanyl and its analogs significantly increases the risk of overdose deaths. This study aims to analyze the current situation by reviewing scientific and governmental publications on the topic. Methods: Our analysis, established on data from PubMed, Google Scholar, and Scopus, highlights the pharmacological risks related to the combination of xylazine and synthetic opioids, such as fentanyl. It underlines the increased chances of fatal overdoses due to this combination. Results: The research associates weaknesses in current forensic toxicology screenings that fail to effectively detect these dangerous compounds. The illegal synthesis of these substances is a key challenge in directing the emergency. The combination of xylazine with synthetic opioids shows a significant public health risk, worsening the already critical opioid crisis. There is a critical need for improved drug detection and analysis methods to combat this growing challenge. Conclusion: Developing forensic toxicology screenings to precisely identify the presence of these substances is crucial for both the diagnosis and prevention of fatal overdoses. Our findings emphasize the requirement for immediate and concerted efforts to address the complexities of the opioid epidemic and highlight the potential consequences of public health strategies intended to mitigate this crisis.

Illicitly Manufactured Fentanyl Use Among Individuals in the U.S., 2022

IntroductionWhile morbidity and mortality related to synthetic opioids such as illicitly manufactured fentanyl (IMF) are monitored in the U.S., there has been a lack of national survey data focusing on use. Survey data are important as self-report can help estimate prevalence of use among living persons. MethodsData were examined from the 2022 National Survey on Drug Use and Health, a nationally representative probability sample of noninstitutionalized individuals age ≥12 in the U.S. (N=59,069). Prevalence and correlates of past-year use of IMF were estimated. Data were analyzed in 2024. ResultsThe estimated prevalence of past-year IMF use was 0.23% (95% confidence interval [CI]: 0.17-0.31). Compared to no past-year use, individuals were at increased odds for IMF use if proxy-diagnosed with use disorder involving use of cannabis (aOR=3.72, 95% CI: 1.34-10.32), cocaine (aOR=11.96, 95% CI: 4.78-29.93), methamphetamine (aOR=5.60, 95% CI: 1.65-19.02), heroin (aOR=20.56, 95% CI: 8.90-47.52), and/or prescription opioids (aOR=10.65, 95% CI: 3.54-32.03). (Mis)use without use disorder was only significant for prescription opioids (aOR=5.77, 95% CI: 2.55-13.06). Those receiving treatment for substance use in the past year were also at increased odds for use (aOR=5.79, 95% CI: 2.58-13.00). ConclusionsPrevalence of IMF use is rare in the general U.S. population. While past-year (mis)use of other drugs (without use disorder) was not consistently associated with IMF use, cannabis, cocaine, methamphetamine, heroin, and prescription opioid use disorder was associated with higher odds of IMF use, suggesting that more “severe” use of various drugs is more of a risk factor than use.

Clinical Pharmacokinetics and Pharmacodynamics of Naloxone.

Naloxone is a World Health Organization (WHO)-listed essential medicine and is the first choice for treating the respiratory depression of opioids, also by lay-people witnessing an opioid overdose. Naloxone acts by competitive displacement of opioid agonists at the μ-opioid receptor (MOR). Its effect depends on pharmacological characteristics of the opioid agonist, such as dissociation rate from the MOR receptor and constitution of the victim. Aim of treatment is a balancing act between restoration of respiration (not consciousness) and avoidance of withdrawal, achieved by titration to response after initial doses of 0.4-2 mg. Naloxone is rapidly eliminated [half-life (t1/2) 60-120 min] due to high clearance. Metabolites are inactive. Major routes for administration are intravenous, intramuscular, and intranasal, the latter primarily for take-home naloxone. Nasal bioavailability is about 50%. Nasal uptake [mean time to maximum concentration (Tmax) 15-30 min] is likely slower than intramuscular, as reversal of respiration lag behind intramuscular naloxone in overdose victims. The intraindividual, interindividual and between-study variability in pharmacokinetics in volunteers are large. Variability in the target population is unknown. The duration of action of 1 mg intravenous (IV) is 2 h, possibly longer by intramuscular and intranasal administration. Initial parenteral doses of 0.4-0.8 mg are usually sufficient to restore breathing after heroin overdose. Fentanyl overdoses likely require higher doses of naloxone. Controlled clinical trials are feasible in opioid overdose but are absent in cohorts with synthetic opioids. Modeling studies provide valuable insight in pharmacotherapy but cannot replace clinical trials. Laypeople should always have access to at least two dose kits for their interim intervention.

Genetic mouse models in opioid research: current status and future directions.

Synthetic and semi-synthetic opioids are prescribed for the management of severe pain conditions, but their long-term use is often leading to physical dependence and addiction disorders. Understanding the complex neurobiology of the opioid system in preclinical models will be essential for the development of safe and efficacious analgesics. With rising numbers of synthetic opioid users and overdose cases, a better understanding of the neuroanatomical and cellular pathways associated with physical dependence and addiction is expected to guide treatment approaches for opioid use disorders. In this commentary, we highlight the importance of advanced genetic mouse models for studying the regional effects of opioid receptors, and we discuss the need of genetic mouse models for the investigation of the regional, circuit and cell compartment-specific role of intracellular mediators of opioid actions.

NPS–EQA PART I: Four years’ experience in external quality assessment program in Italy for classical and new psychoactive substances analysis in oral fluid

In 2019, Italian National Institute of Health established an external quality assessment program (EQA) to evaluate the performance of oral fluid testing for classical and new psychoactive substances by laboratories participating in the National Early Warning System collaborative centres. This report presents the results of four rounds between 2019 and 2023. Eleven oral fluid specimens, including 3 blank samples, were prepared by adding different classes of and new psychoactive drugs at known concentrations to pre-screened drug-free oral fluid. False-negative and false-positive results were calculated for the qualitative data evaluation. The quantitative evaluation measured the imprecision and accuracy of the results, in terms of coefficient of variation (CV%) and percent error (ERR%), respectively, with respect to a mean value obtained by reference laboratories. Z-score values were then calculated. Over the years, there has been a significant improvement in false-negative results (from 42.7% in the first year to 19.4% in the last year), but not in false-positive results (from 33.3% in the first year to 22.2% in the last one). In addition to the classic drugs of abuse (e.g. cocaine, amphetamine, methadone), the substances found in false positive samples belonged to the class of synthetic cannabinoids (e.g 5-fluoro CUMYL-PINACA and 5-fluoro-EDMB-PICA), synthetic opioids (e.g butyrylfentanyl) and tryptamines (e.g. 5-methoxy-N-methyl-N-isopropyltryptamine). The four rounds yielded a mean ERR% of approximately 22.1% and a mean CV% of around 41.5%. The participating laboratories demonstrated variable performances in relation to the class of analysed psychoactive substances, as evidenced by the calculated Z-scores. Between 25% and 60% of the reported results in all rounds should be considered satisfactory. EQA is a crucial element of laboratory quality management systems. It promotes continuous improvement and maintains high standards in the field of forensic and clinical drug testing.

An <i>In-Silico</i> Study on the Molecular Docking of Various Natural and Synthetic Opioids to Mu-Opioid Receptors in <i>Homo sapiens</i>

Opium is a psychoactive substance, that is often involved in drug trafficking, drug abuse, and various other crimes. Its ability to induce sleep and relieve pain makes it prone to its consumption. This opium and its byproducts when consumed, are bound by the opium receptors, namely, alpha, delta, and mu receptors. Mu-opioid receptors (MOR) are involved in the pain-relieving mechanism in the human body. Therefore, molecular docking was performed to dock MOR with various natural and synthetic opioids with the help of software tools Python, MGL Tools, AutoDock, and Babel. With the help of the software Discovery Studio, the result was analyzed. The study showed the synthetic opioids Buprenorphine, Hydromorphone, and Oxymorphone with the lowest binding energy of -9.10, -8.39, and -8.39 respectively. ADME analysis of the drugs was done for better understanding by the SwissADME tool and was found that Oxycodone, Oxymorphone, Remifentanil, and Noscapine were found to be more absorbed in the intestines whereas, all the others were found to be permeable by the Blood-Brain Barrier.

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.

Evaluating cross-reactivity of new psychoactive substances (NPS) in human whole blood by enzyme-linked immunosorbent assay (ELISA).

Due to the increase in the use of novel psychoactive substances (NPS) and their overall prevalence, it is important to have effective and reliable screening technologies to detect NPS in biological matrices. Enzyme-linked immunosorbent assays (ELISA) are among the most popular screening methods. To evaluate the effectiveness of ELISA for NPS detection, five subclasses of NPS (novel synthetic opioids, fentanyl analogs, stimulants, benzodiazepines and hallucinogens) were evaluated in whole blood for their cross-reactivity on commercially available ELISA kits. A variety of novel synthetic opioids were tested at concentrations of 1-80 ng/mL and 50-2000 ng/mL and demonstrated no cross-reactivity to a morphine ELISA plate at either concentration range. Fentanyl analogs were tested at concentrations ranging from 0.01 to 1 ng/mL and had cross-reactivities ranging from 8% to 178% on the fentanyl ELISA kit used. Both para-chloro fentanyl (178%) and acryl fentanyl (164%) showed cross-reactivities well above that of fentanyl. Novel stimulants were tested at concentrations of 0.5-40 ng/mL and 20-2,000 ng/mL. 4-Fluoroamphetamine was the only novel stimulant with cross-reactivity (3,354%) to the amphetamine ELISA plate. Novel benzodiazepines were tested at concentrations of 1-40 ng/mL on a benzodiazepine plate. Cross-reactivities ranged from 36.1% to 263%, with desalkylflurazepam having the highest cross-reactivity. Finally, novel hallucinogens were tested at concentrations of 0.5-10 ng/mL on a phencyclidine (PCP) ELISA plate, which produced no cross-reactivity and then with 10-1,000 ng/mL, which gave results from 56.6% to 151%. Both hydroxy-PCP (151%) and chloro-PCP (137%) showed cross-reactivities above that of PCP. This research has demonstrated the utility of using ELISA-based screening for novel benzodiazepines, hallucinogens and for fentanyl analogs; however, there is limited application and risk of false-negative results for the other drug classes due to low or non-existent cross-reactivities.

Influent wastewater analysis to investigate emerging trends of new psychoactive substances use in Europe

Wastewater-based epidemiology (WBE) can provide objective and timely information on the use of new psychoactive substances (NPS), originally designed as legal alternatives of internationally controlled drugs. NPS have rapidly emerged on the global drug market, posing a challenge to drug policy and constituting a risk to public health. In this study, a WBE approach was applied to monitor the use of more than 300 NPS, together with fentanyl and its main metabolite norfentanyl, in influent wastewater collected from 12 European cities during March-June 2021. Quantitative and qualitative analysis of NPS in composite 24 h influent wastewater samples were based on solid phase extraction and liquid chromatography-mass spectrometry. In-sample stability tests demonstrated the suitability of most investigated biomarkers, except for a few synthetic opioids, synthetic cannabinoids and phenetylamines. Fentanyl, norfentanyl and eight NPS were quantified in influent wastewater and at least three substances were found in each city, demonstrating their use in Europe. N,N-dimethyltryptamine and 3-methylmethcathinone (3-MMC) were the most common NPS found, with the latter having the highest mass loads (up to 24.8 mg/day/1000 inhabitants). Seven additional substances, belonging to five categories of NPS, were identified in different cities. Spatial trends of NPS use were observed between cities and countries, and a changing weekly profile of use was observed for 3-MMC. WBE is a useful tool to rapidly evaluate emerging trends of NPS use, complementing common indicators (i.e. population surveys, seizures) and helping to establish measures for public health protection.

Analysis of over 250 novel synthetic opioids and xylazine by LC-MS-MS in blood and urine.

Novel Synthetic Opioids (NSO) are frequently found in postmortem (PM) and human performance (HP) forensic toxicology casework, resulting in impairment and fatal overdoses. Developing a broad NSO method benefits public health, as it can be used to identify trends in potent opioid use to develop risk management programs. This project aimed to design a comprehensive, rapid and routine method for the selective analysis of over 250 novel synthetic opioids in blood and urine. This method rapidly extracted 150 µL of blood or urine via protein precipitation followed by size-exclusion filtration, evaporation and reconstitution. Separation and data acquisition were achieved on a 12 min LC-MS-MS method using an F5 column. Data processing was expedited with a custom built-in query created in-house that automated processing and enhanced quality assurance. Validation according to ASB/ANSI Standard 036 was performed and applicability of the method was assessed using proficiency test and authentic casework samples. Assessed in blood and urine qualitatively were 261 unique analytes including fentanyl analogs (fentalogs), nitazenes and other miscellaneous synthetic opioids. As 59 isomeric target analytes were placed into groups due to co-elution, there were 202 distinct acquired targets or target - groups. To demonstrate applicability, 27 proficiency test blood samples received over an approximate 4-year period were analyzed with 126 expected results assessed comprising 25 unique target analytes. Additionally, 617 fatal accidental overdoses within San Francisco in 2022 were retroactively analyzed by this method with almost 10% of cases containing a new NSO substance(s). Such trends and NSO substances were previously unknown in this community.

Development and validation of a liquid chromatography-tandem mass spectrometry (LC-MS/MS) method including 25 novel synthetic opioids in hair and subsequent analysis of a Swiss opioid consumer cohort.

Major public health concern is raised by the evidence that common drugs like heroin are now frequently laced or replaced with highly potent novel synthetic opioids (NSOs). The objective of this study was to explore the prevalence and patterns of NSOs in a cohort of Swiss opioid users by hair analysis. Hair analysis is considered an ideal tool for retrospective consumption monitoring. Hair samples from 439 opioid users in Zurich were analyzed. Study inclusion required a previous positive hair test result for heroin metabolites, oxycodone, fentanyl, methadone, or tramadol. The samples were extracted with a two-step extraction procedure, followed by a targeted LC-MS/MS (QTRAP® 6500+) analysis in multiple reaction monitoring mode for a total of 25 NSOs. The method underwent full validation and demonstrated good selectivity and sensitivity with limits of detection (LOD) as low as 0.1pg/mg. The analyzed sample cohort demonstrated a positivity rate for NSOs of 2.5%, including the following NSOs: butyrylfentanyl, acrylfentanyl, furanylfentanyl, methoxyacetylfentanyl, ocfentanil, U-47700, isobutyrylfentanyl and benzylfentanyl. Furthermore, we were able to identify specific consumption patterns among drug users. The results indicate that hair analysis is a valuable tool for investigating the prevalence of NSOs in drug-using populations, which seems to be low in the case of Swiss opioid users. Nevertheless, the results highlight the need for sensitive analytical detection methods in forensic toxicology to identify and monitor substance distribution in different populations.

Are carfentanil and acrylfentanyl naloxone resistant?

The rapid rise in deaths since 2012 due to opioid poisoning is correlated with the proliferation of potent synthetic opioid agonists such as fentanyl, acrylfentanyl, and carfentanil. The efficacy of frontline antidotes such as naloxone in reversing such poisoning events has been questioned, and the possibility of naloxone-resistant synthetic opioids has been raised. In this manuscript, we applied in vitro techniques to establish the median effective inhibitory concentrations for fentanyl, acrylfentanyl, and carfentanil and subsequently evaluate naloxone's ability to reverse agonist-receptor interactions.

Exploring the topic structure and abuse trends of new psychoactive Substance since the 21st century from a bibliometric perspective

Nowadays, NPS abuse are continuing to expand in terms of harm and scope, due to its cheap and easy to manufacture anywhere in the world. This study reviewed articles related to seven heavily abused NPS to analyze the structure and trends of NPS abuse. A total of 2476 articles were retrieved based on the search strategy for bibliometric analysis. A significant trend of research in recent years was the increasing number of research on synthetic opioids and designer benzodiazepines, but synthetic cannabinoid and synthetic cathinone still dominate, which were mainly concerned with the development of metabolic models and determining methods as well as their abuse characteristics and reasons. However, with the introduction of class-wide ban on synthetic cannabinoid in China and a series of enhancements in other countries, the abuse of it might decrease to some extent, but more than 20 kinds of synthetic cannabinoid beyond the scope of ban in China still reminded researchers of their potential threats. As for synthetic cathinone, an important phenomenon was some of the drugs first identified during certain period might be more widely distributed in the future. Besides, several problems such as the regulation and prevention mode of emerging NPS, development of testing technologies as well as the interpretation and identification of multiple NPS combinations were also worth paying attention to. This study could help entrants better understand the structure of NPS abuse and provided direction for future research in forensic toxicology.

Routes of Drug Use Among Drug Overdose Deaths - United States, 2020-2022.

Preliminary reports indicate that more than 109,000 drug overdose deaths occurred in the United States in 2022; nearly 70% of these involved synthetic opioids other than methadone, primarily illegally manufactured fentanyl and fentanyl analogs (IMFs). Data from the western United States suggested a transition from injecting heroin to smoking IMFs. CDC analyzed data from the State Unintentional Drug Overdose Reporting System to describe trends in routes of drug use in 27 states and the District of Columbia among overdose deaths that occurred during January 2020-December 2022, overall and by region and drugs detected. From January-June 2020 to July-December 2022, the percentage of overdose deaths with evidence of injection decreased 29.1%, from 22.7% to 16.1%, whereas the percentage with evidence of smoking increased 73.7%, from 13.3% to 23.1%. The number of deaths with evidence of smoking increased 109.1%, from 2,794 to 5,843, and by 2022, smoking was the most commonly documented route of use in overdose deaths. Trends were similar in all U.S. regions. Among deaths with only IMFs detected, the percentage with evidence of injection decreased 41.6%, from 20.9% during January-June 2020 to 12.2% during July-December 2022, whereas the percentage with evidence of smoking increased 78.9%, from 10.9% to 19.5%. Similar trends were observed among deaths with both IMFs and stimulants detected. Strengthening public health and harm reduction services to address overdose risk related to diverse routes of drug use, including smoking and other noninjection routes, might reduce drug overdose deaths.

Wastewater-based monitoring of the nitazene analogues: First detection of protonitazene in wastewater

Synthetic opioids, particularly the nitazene analogues class, have become a public health concern due to their high potency. Wastewater-based epidemiology can detect community use of these compounds. The objective of this work was to detect nitazene analogues in wastewater from samples collected from eight sites in the United States. Influent wastewater samples were collected from eight sites in seven states (Arizona, Oregon, New Mexico, Illinois, New Jersey, Washington and Georgia) in the United States. Samples were collected from each site on three days between 27 December 2022 and 4 January 2023, acidified on collection, stored frozen and shipped to Arizona State University (Tempe, AZ) for sample processing. Samples were then shipped to The University of Queensland (Brisbane, Australia) for sample analysis. Protonitazene was found in samples collected from two sites in Washington and Illinois. The concentration was estimated up to 0.5 ng/L, with estimated excreted mass loads up to 0.3 mg/day/1000 people. This work has shown that it is possible to detect nitazene analogues in wastewater using a combination of sample pre-concentration and sensitive instrumentation, thereby further expanding the utility of wastewater-based epidemiology.

In Vitro Functional Profiling of Fentanyl and Nitazene Analogs at the μ-Opioid Receptor Reveals High Efficacy for Gi Protein Signaling.

Novel synthetic opioids (NSOs), including both fentanyl and non-fentanyl analogs that act as μ-opioid receptor (MOR) agonists, are associated with serious intoxication and fatal overdose. Previous studies proposed that G-protein-biased MOR agonists are safer pain medications, while other evidence indicates that low intrinsic efficacy at MOR better explains the reduced opioid side effects. Here, we characterized the in vitro functional profiles of various NSOs at the MOR using adenylate cyclase inhibition and β-arrestin2 recruitment assays, in conjunction with the application of the receptor depletion approach. By fitting the concentration-response data to the operational model of agonism, we deduced the intrinsic efficacy and affinity for each opioid in the Gi protein signaling and β-arrestin2 recruitment pathways. Compared to the reference agonist [d-Ala2,N-MePhe4,Gly-ol5]enkephalin, we found that several fentanyl analogs were more efficacious at inhibiting cAMP production, whereas all fentanyl analogs were less efficacious at recruiting β-arrestin2. In contrast, the non-fentanyl 2-benzylbenzimidazole (i.e., nitazene) analogs were highly efficacious and potent in both the cAMP and β-arrestin2 assays. Our findings suggest that the high intrinsic efficacy of the NSOs in Gi protein signaling is a common property that may underlie their high risk of intoxication and overdose, highlighting the limitation of using in vitro functional bias to predict the adverse effects of opioids. In addition, the extremely high potency of many NSOs now infiltrating illicit drug markets further contributes to the danger posed to public health.

A Practical Guide to Implementing an Evidenced-Based Hands-On Naloxone Training

ABSTRACT Synthetic opioids contribute to the majority of opioid overdose-related deaths in the United States. Expansion of naloxone training to community laypersons is one strategy to mitigate opioid overdose-related deaths. A hands-on naloxone training demonstrated efficacy in improving opioid knowledge and overdose response in baccalaureate nursing students, Greek-affiliated students, and rural clinicians and staff post-training. The purpose of this practical guide is to provide detailed steps to implement an evidence-based hands-on naloxone training for laypersons in community settings. The hands-on naloxone training consisted of five components: evaluator training, a validated pre-post opioid knowledge questionnaire, an opioid lecture, a performance evaluation, and a satisfaction survey. Post-training, trainees demonstrated increased knowledge related to opioids and overdose response, and they felt comfortable administering naloxone to someone experiencing an opioid overdose. Researchers, educators, and community health nurses can adapt this evidence-based practical guide to train peers and acquaintances who are likely to witness an opioid overdose. Virtual training and multi-lingual protocols should be considered to successfully train diverse groups of community laypersons. An active hands-on naloxone training can improve confidence for community health nurses and other health care professionals, and it may reduce delays in response time and naloxone administration. Nurses can use this hands-on training to educate students, families, community members, and stakeholders how to respond to an opioid overdose event.