Management of opioid analgesic overdose

Heroin-induced leukoencephalopathy: Chasing the imaging findings

We present a case of a 29-year-old male who was brought into the hospital due to unresponsiveness and found to have heroin inhalational leukoencephalopathy (HLE). HLE is one component of a broad spectrum of opioid encephalopathies that is associated with heroin inhalation and other opioids. There is considerable overlap of HLE with other toxic and hypoxic-ischemic encephalopathies; however, the specific territories of brain involvement help distinguish it from other cerebral insults. The goal of this study is to help elucidate the findings of HLE and compare these findings to other toxic and hypoxic-ischemic encephalopathies.

An Autonomous Implantable Device for the Prevention of Death from Opioid Overdose

Opioid overdose accounts for nearly 75,000 deaths per year in the United States, representing a leading cause of mortality amongst the prime working age population (25-54 years). At overdose levels, opioid-induced respiratory depression becomes fatal without timely administration of the rescue drug naloxone. Currently, overdose survival relies entirely on bystander intervention, requiring a nearby person to discover and identify the overdosed individual, and have immediate access to naloxone to administer. Government efforts have focused on providing naloxone in abundance but do not address the equally critical component for overdose rescue: a willing and informed bystander. To address this unmet need, we developed the Naloximeter: a class of life-saving implantable devices that autonomously detect and treat overdose, with the ability to simultaneously contact first-responders. We present three Naloximeter platforms, for both fundamental research and clinical translation, all equipped with optical sensors, drug delivery mechanisms, and a supporting ecosystem of technology to counteract opioid-induced respiratory depression. In small and large animal studies, the Naloximeter rescues from otherwise fatal opioid overdose within minutes. This work introduces life-changing, clinically translatable technologies that broadly benefit a susceptible population recovering from opioid use disorder.

Reversal of Opioid-Induced Respiratory Depression in Healthy Volunteers: Comparison of Intranasal Nalmefene and Intranasal Naloxone

An open-label, randomized, crossover study in healthy volunteers compared the reversal of remifentanil-induced respiratory depression by intranasal (IN) naloxone hydrochloride (4 mg) to IN nalmefene (2.7 mg) (NCT04828005). Subjects were administered a hypercapnic gas mixture which produces an elevation in minute ventilation (MV), a result of the ventilatory response to hypercapnia. Subjects breathed a hypercapnic gas mixture through a tight-fitting mask for an initial period of 46 min prior to a series of mask "holidays" introduced to reduce subject discomfort and encourage study completion. Ten minutes after initiating the hypercapnic gas mixture, a remifentanil bolus was administered, and an infusion continued for the study duration. Subjects were administered either naloxone or nalmefene 15 min after initiating the remifentanil infusion and MV monitored for 21 min followed by a mask holiday. Both nalmefene and naloxone produced a time-dependent reversal of remifentanil-induced reductions in MV measured 2.5-20 min post administration. At the primary endpoint (5 min post administration), nalmefene increases in MV (5.75 L/min) were nearly twice that produced by naloxone (3.01 L/min) (P < .0009); the point estimate favors nalmefene, demonstrating non-inferiority and superiority. In this model of opioid-induced respiratory depression, nalmefene has a more rapid onset of action than naloxone, which required 20 min to achieve a comparable reversal of respiratory depression. Both nalmefene and naloxone were well tolerated by healthy volunteers. This rapid onset of action may prove particularly valuable in an era when over 90% of fatalities are linked to synthetic opioid overdose.

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

Introduction

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

Methods

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

Results

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

Conclusion

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

Case of pediatric cerebellar, hippocampal, and basal nuclei transient edema with restricted diffusion (CHANTER) syndrome in a 2-year-old girl

Cerebellar, hippocampal, and basal nuclei transient edema with restricted diffusion (CHANTER) syndrome is a recently described entity that refers to a specific pattern of cerebellar edema with restricted diffusion and crowding of the fourth ventricle among other findings. The syndrome is commonly associated with toxic opioid exposure. While most commonly seen in adults, we present a case of a 2-year-old girl who survived characteristic history and imaging findings of CHANTER syndrome.

Total-body imaging of mu-opioid receptors with [11C]carfentanil in non-human primates

PURPOSE

Mu-opioid receptors (MORs) are widely expressed in the central nervous system (CNS), peripheral organs, and immune system. This study measured the whole body distribution of MORs in rhesus macaques using the MOR selective radioligand [11C]carfentanil ([11C]CFN) on the PennPET Explorer. Both baseline and blocking studies were conducted using either naloxone or GSK1521498 to measure the effect of the antagonists on MOR binding in both CNS and peripheral organs.

METHODS

The PennPET Explorer was used for MOR total-body PET imaging in four rhesus macaques using [11C]CFN under baseline, naloxone pretreatment, and naloxone or GSK1521498 displacement conditions. Logan distribution volume ratio (DVR) was calculated by using a reference model to quantitate brain regions, and the standard uptake value ratios (SUVRs) were calculated for peripheral organs. The percent receptor occupancy (%RO) was calculated to establish the blocking effect of 0.14 mg/kg naloxone or GSK1521498.

RESULTS

The %RO in MOR-abundant brain regions was 75-90% for naloxone and 72-84% for GSK1521498 in blocking studies. A higher than 90% of %RO were observed in cervical spinal cord for both naloxone and GSK1521498. It took approximately 4-6 min for naloxone or GSK1521498 to distribute to CNS and displace [11C]CFN from the MOR. A smaller effect was observed in heart wall in the naloxone and GSK1521498 blocking studies.

CONCLUSION

[11C]CFN total-body PET scans could be a useful approach for studying mechanism of action of MOR drugs used in the treatment of acute and chronic opioid use disorder and their effect on the biodistribution of synthetic opioids such as CFN. GSK1521498 could be a potential naloxone alternative to reverse opioid overdose.

A Wearable Device Towards Automatic Detection and Treatment of Opioid Overdose

Opioid-induced overdose is one of the leading causes of death among the US population under the age of 50. In 2021 alone, the death toll among opioid users rose to a devastating number of over 80,000. The overdose process can be reversed by the administration of naloxone, an opioid antagonist that rapidly counteracts the effects of opioid-induced respiratory depression. The idea of a closed-loop opioid overdose detection and naloxone delivery has emerged as a potential engineered solution to mitigate the deadly effects of the opioid epidemic. In this work, we introduce a wrist-worn wearable device that overcomes the portability issues of our previous work to create a closed-loop drug-delivery system, which includes (1) a Near-Infrared Spectroscopy (NIRS) sensor to detect a hypoxia-driven opioid overdose event, (2) a MOSFET switch, and (3) a Zero-Voltage Switching (ZVS) electromagnetic heater. Using brachial artery occlusion (BAO) with human subjects (n = 8), we demonstrated consistent low oxygenation events. Furthermore, we proved our device's capability to release the drug within 10 s after detecting a hypoxic event. We found that the changes in the oxyhemoglobin, deoxyhemoglobin and oxygenation saturation levels ( SpO2) were different before and after the low-oxygenation events ( 0.001). Although additional human experiments are needed, our results to date point towards a potential tool in the battle to mitigate the effects of the opioid epidemic.

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.

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.

Feeling safer: effectiveness, feasibility, and acceptability of continuous pulse oximetry for people who smoke opioids at overdose prevention services in British Columbia, Canada

BACKGROUND

Smoking is the most common mode of unregulated opioid consumption overall and implicated in fatal overdoses in British Columbia (BC). In part, perception of decreased risk (e.g., fewer who smoke carry naloxone kits) and limited smoking-specific harm reduction services contribute to overdose deaths. Overdose prevention services (OPS) offer supervised settings for drug use. Continuous pulse oximetry, common in acute care, allows real-time, remote oxygen monitoring. We evaluated the effectiveness of a novel continuous pulse oximetry protocol aimed at allowing physical distancing (as required by COVID-19, secluded spaces, and to avoid staff exposure to vaporized opioids), its feasibility, and acceptability at OPS for people who smoke opioids.

METHODS

This was a mixed methods survey study. We developed a continuous pulse oximetry protocol in collaboration with clinical experts and people with lived/living experience of substance use. We implemented our protocol from March to August 2021 at four OPS in BC permitting smoking. We included adults (≥ 18 years) presenting to OPS to smoke opioids. Peer researchers collected demographic, health, and substance use information, and conducted structured observations. OPS clients participating in our study, OPS staff, and peer researchers completed post-monitoring surveys. We analyzed responses using a thematic inductive approach and validated themes with peer researchers.

RESULTS

We included 599 smoking events. OPS clients participating in our study had a mean age of 38.5 years; 73% were male. Most (98%) reported using "down", heroin, or fentanyl; 48% concurrently used other substances (32% of whom reported stimulants); 76% reported smoking alone in the last 3 days; and 36% reported an overdose while smoking. Respondents reported that the protocol facilitated physical distancing, was easy to use, high satisfaction, improved confidence, improved sense of safety, and that they would use it again.

CONCLUSIONS

Continuous pulse oximetry allowed safe physical distancing, was feasible, and acceptable in monitoring people who smoke opioids at OPS.

Intranasal Naloxone Repeat Dosing Strategies and Fentanyl Overdose: A Simulation-Based Randomized Clinical Trial

Importance

Questions have emerged as to whether standard intranasal naloxone dosing recommendations (ie, 1 dose with readministration every 2-3 minutes if needed) are adequate in the era of illicitly manufactured fentanyl and its derivatives (hereinafter, fentanyl).

Objective

To compare naloxone plasma concentrations between different intranasal naloxone repeat dosing strategies and to estimate their effect on fentanyl overdose.

Design, Setting, and Participants

This unblinded crossover randomized clinical trial was conducted with healthy participants in a clinical pharmacology unit (Spaulding Clinical Research, West Bend, Wisconsin) in March 2021. Inclusion criteria included age 18 to 55 years, nonsmoking status, and negative test results for the presence of alcohol or drugs of abuse. Data analysis was performed from October 2021 to May 2023.

Intervention

Naloxone administered as 1 dose (4 mg/0.1 mL) at 0, 2.5, 5, and 7.5 minutes (test), 2 doses at 0 and 2.5 minutes (test), and 1 dose at 0 and 2.5 minutes (reference).

Main Outcomes and Measures

The primary outcome was the first prespecified time with higher naloxone plasma concentration. The secondary outcome was estimated brain hypoxia time following simulated fentanyl overdoses using a physiologic pharmacokinetic-pharmacodynamic model. Naloxone concentrations were compared using paired tests at 3 prespecified times across the 3 groups, and simulation results were summarized using descriptive statistics.

Results

This study included 21 participants, and 18 (86%) completed the trial. The median participant age was 34 years (IQR, 27-50 years), and slightly more than half of participants were men (11 [52%]). Compared with 1 naloxone dose at 0 and 2.5 minutes, 1 dose at 0, 2.5, 5, and 7.5 minutes significantly increased naloxone plasma concentration at 10 minutes (7.95 vs 4.42 ng/mL; geometric mean ratio, 1.95 [1-sided 97.8% CI, 1.28-∞]), whereas 2 doses at 0 and 2.5 minutes significantly increased the plasma concentration at 4.5 minutes (2.24 vs 1.23 ng/mL; geometric mean ratio, 1.98 [1-sided 97.8% CI, 1.03-∞]). No drug-related serious adverse events were reported. The median brain hypoxia time after a simulated fentanyl 2.97-mg intravenous bolus was 4.5 minutes (IQR, 2.1-∞ minutes) with 1 naloxone dose at 0 and 2.5 minutes, 4.5 minutes (IQR, 2.1-∞ minutes) with 1 naloxone dose at 0, 2.5, 5, and 7.5 minutes, and 3.7 minutes (IQR, 1.5-∞ minutes) with 2 naloxone doses at 0 and 2.5 minutes.

Conclusions and Relevance

In this clinical trial with healthy participants, compared with 1 intranasal naloxone dose administered at 0 and 2.5 minutes, 1 dose at 0, 2.5, 5, and 7.5 minutes significantly increased naloxone plasma concentration at 10 minutes, whereas 2 doses at 0 and 2.5 minutes significantly increased naloxone plasma concentration at 4.5 minutes. Additional research is needed to determine optimal naloxone dosing in the community setting.

Trial Registration

ClinicalTrials.gov Identifier: NCT04764630.

Opioid Misuse Harm Reduction

BACKGROUND/AIMS

The misuse of opioids by the public is a major health issue. Prescription opioids and nonprescription opioids, such as heroin and opium, are misused in epidemic proportions. When opioids are used incorrectly or illegally, they can lead to drug dependence, addiction, morbidity, and mortality. This program is in collaboration with the Jolt Foundation that provides resources to prevent opioid overdose deaths.

DESIGN/METHODS

This program involves community education on the dangers of opioid use and training on the use of naloxone rescue procedures to prevent overdose deaths. A pretest-posttest design was employed to determine if participants gained knowledge regarding the naloxone administration procedures.

PARTICIPANTS

The researcher presented 10 community naloxone trainings that included staff from 20 different social service agencies, two schools, and three local churches. Each agency received at least one naloxone kit.

FINDINGS

The outcomes were met and included educating 137 participants on the risk factors and signs and symptoms of opioid overdose and the proper procedure to administer naloxone. One hundred twenty-eight posttests were returned and showed that the objectives for the project were met. The overall mean score for the pretests was 65.00 ( n = 126) with a standard deviation of 19.01, and the overall mean for the posttests was 86.64 ( n = 128) with a standard deviation of 14.60.

CONCLUSIONS

Community social service agency staff were successfully educated to respond appropriately to overdose situations in a group training setting as evidenced by significant posttest scores.

Trends and correlates of naloxone possession and use among people who inject drugs in Seattle, Washington

BACKGROUND

Naloxone distribution has been implemented as an essential opioid overdose prevention measure for people who inject drugs (PWID), and many jurisdictions in the United States have implemented policy change to increase naloxone access. This project describes temporal trends in and correlates of naloxone possession and use among PWID in the Seattle area of Washington State.

METHODS

Using a repeat cross-sectional design, we utilized two sets of serial cross-sectional surveys of PWID, which included biennial surveys of Seattle area syringe service program (SSP) clients and community-based National HIV Behavioral Surveillance surveys of PWID (NHBS-PWID) conducted from 2012-2019. Survey participant characteristics were descriptively compared between participants reporting naloxone possession to those not reporting naloxone possession. Multivariable Poisson regression was used to calculate prevalence ratios for naloxone possession comparing later to earlier survey years, adjusting for age, gender, race/ethnicity, primary drug, and experiencing and witnessing an overdose in the past 12 months.

RESULTS

Naloxone possession and use increased in both survey populations. The prevalence of possessing naloxone was 2.8 times greater [2019 vs. 2013= 95% CI: 2.40-3.33] among SSP participants and 2.8 times greater [2018 vs. 2012=95% CI: 2.41-3.16] among NHBS-PWID participants for the most recent time period. The prevalence of naloxone use was 1.3 times greater [2019 vs. 2017= 95% CI: 1.13-1.58] and 2.1 times greater [2015 vs. 2012=95% CI:1.62-2.73] among SSP and NHBS-PWID participants, respectively, for the most recent time period.

CONCLUSION

Naloxone possession and use increased in PWID in the Seattle area from 2012-2019, and is, at least in part, likely the result of numerous policy and programmatic efforts to facilitate easier naloxone accessibility in the wake of dramatic increases in overdose mortality. Further research on disparities in naloxone possession are needed to ensure equitable access.

Association Between Naloxone Coprescription Mandates and Postoperative Outcomes

INTRODUCTION

The opioid epidemic is a public health issue in the United States. The objective of this study was to evaluate the association between naloxone coprescription mandates and postoperative outcomes.

BACKGROUND

Data on naloxone coprescription mandates show mixed evidence for fatal overdoses in the broader population. How these mandates have impacted surgical patients has not been fully explored.

METHODS

Healthcare claims data were used to identify all patients undergoing 1 of 50 common procedures between January 1, 2004, and June 30, 2019, and categorized as high risk for opioid overdose. The primary outcomes were an emergency department visit or hospital admission within 30 postoperative days. To reduce confounding, the association between this outcome and the implementation of naloxone coprescription mandates was estimated using a difference-in-differences approach.

RESULTS

The study included 429,878 surgical patients with an average age of 54.8 years (SD=15.9 years) and with 257,728 females (60.0%). There was no significant association between naloxone prescribing mandates and the primary outcomes. After adjustment for potential confounders, the incidence of hospital admission was 3.26% after implementation of a naloxone coprescription mandate compared with 3.33% before (difference change: -0.08%, 95% CI: -0.44% to 0.29%, P =0.68). The incidence of an emergency department visit was 7.06% after implementation of a naloxone coprescription mandate compared with 7.73% before (difference: -0.67%, 95% CI: -1.39% to 0.05%, P =0.07). These results were robust to a variety of sensitivity and subgroup analyses.

CONCLUSIONS

Naloxone coprescription mandates were not associated with a statistically or clinically significant change in emergency department visits or hospital admissions within 30 postoperative days.

Community pharmacists' naloxone counseling: A theory-informed qualitative study

BACKGROUND

Opioid-related overdose (ORO) deaths have reached a record high in the United States. Naloxone is an opioid antagonist that can rapidly reverse an opioid overdose. Pharmacists are in an ideal position to provide naloxone and related counseling, given their accessibility and expertise. However, minimal research is available on community pharmacists' naloxone counseling.

OBJECTIVES

The aim of this study was to investigate Georgia community pharmacists' naloxone counseling as well as explore their attitudes, subjective norms, and perceived behavioral control toward counseling.

METHODS

Semi-structured telephone interviews were conducted to elicit pharmacists' beliefs and practices regarding naloxone counseling. The interviews were guided by open-ended questions based on the theory of planned behavior (TPB). Thematic analysis was performed to identify the modal salient beliefs expressed by the pharmacists. The Consolidated Criteria for Reporting Qualitative Research was used to report the study findings.

RESULTS

A total of 12 community pharmacists participated. Pharmacists held mixed attitudes toward naloxone counseling. While they recognized it as a vital part of their profession to prevent ORO deaths, they also expressed concerns about offending patients. Regarding normative beliefs, pharmacists identified several groups, including regulatory agencies (e.g., Board of Pharmacy, CDC), managers, news/media, patients, and doctors, influencing their provision of naloxone counseling. Facilitators to counseling included receiving naloxone training and having access to counseling guidelines and resources. Reimbursement issues, high costs of naloxone, and lack of patient awareness were the most commonly cited barriers. Pharmacists reported participating in counseling and providing information on identifying signs of opioid overdose and administering naloxone.

CONCLUSIONS

The TPB is a useful framework for understanding community pharmacists' beliefs and practices regarding naloxone counseling. Capitalizing on facilitators and targeting barriers related to pharmacists' reimbursement issues, high costs of naloxone, and increasing patients' awareness of naloxone use and benefits may enhance pharmacists' naloxone counseling.

[Opioid overdose prevention and naloxone diffusion (POP program): Results of an overview conducted among addiction specialized centres]

INTRODUCTION

In France, opioids are responsible for the majority of overdose deaths in France. The antidote naloxone is available in France in take home formulations since 2016. Addiction specialized centres are in front-line for naloxone diffusion. The objective was to provide an overview of professional practices, difficulties and needs regarding overdose prevention and naloxone diffusion in these centres of the Provence-Alpes-Côte d'Azur (PACA) region.

METHODS

The POP programme "Prevention and harm reduction of opioid overdoses in PACA region" aims to improve the care of patients at risk of overdose and facilitate naloxone diffusion. The 75 addiction specialized centres of the PACA region were invited to respond to a semi-structured interview or a telephone questionnaire. Data collected included 2020 centres' activity and professionals' perceptions of overdose risk in their active file, their practices, difficulties and needs.

RESULTS

Overall, 33 centres answered. Among them, 22 were dispensing naloxone with a mean of 20 kits dispensed in 2020 (min-max: 1-100). Two strategies were pointed out: systematically offering of naloxone to all opioids users or targeting people considered at risk. Several difficulties limiting naloxone diffusion were expressed: a lack of knowledge from opioids users, refusal from people not feeling concerned or refusing the injectable formulation, a lack of training of some professionals to be comfortable with the tool or reglementary or time constraints.

CONCLUSION

Naloxone diffusion is incrementally getting into common practices. However barriers are persisting. On the basis of expressed difficulties and needs, information and training materials were co-designed and diffused.

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

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

High-Dose Naloxone Formulations Are Not as Essential as We Thought

Naloxone is a U.S. Food and Drug Administration (FDA) approved opioid antagonist for reversing opioid overdoses. Naloxone is available to the public, and can be administered through intramuscular (IM), intravenous (IV), and intranasal spray (IN) routes. Our literature review aimed to improve understanding regarding the adequacy of the regularly distributed two doses of low-dose IM or IN naloxone in effectively reversing fentanyl overdoses and whether high-dose naloxone formulations (HDNF) formulations are an optimal solution to this problem. Moreover, our initiative incorporated the perspectives and experiences of people who use drugs (PWUD), enabling a more practical and contextually-grounded analysis. We began by discussing the knowledge and perspectives of Tennessee Harm Reduction, a small peer-led harm reduction organization. A comprehensive literature review was then conducted to gather relevant scholarly works on the subject matter. The evidence indicates that, although higher doses of naloxone have been administered in both clinical and community settings, the vast majority of fentanyl overdoses can be successfully reversed using standard IM dosages with the exception of carfentanil overdoses and other more potent fentanyl analogs, which necessitate three or more doses for effective reversal. Multiple studies documented the risk of precipitated withdrawal using high doses of naloxone. Notably, the possibility of recurring overdose symptoms after resuscitation exists, contingent upon the half-life of the specific opioid. Considering these findings and the current community practice of distributing multiple doses, we recommend providing at least four standard doses of IN or IM naloxone to each potential bystander, and training them to continue administration until the recipient achieves stability, ensuring appropriate intervals between each dose. Based on the evidence, we do not recommend HDNF in the place of providing four doses of standard naloxone due to the higher cost, risk of precipitated withdrawal and limited evidence compared to standard IN and IM. All results must be taken into consideration with the inclusion of the lived experiences, individual requirements, and consent of PWUD as crucial factors. It is imperative to refrain from formulating decisions concerning PWUD in their absence, as their participation and voices should be integral to the decision-making process.

Experiences Administering Naloxone Among People in Different Social Roles: People Who Use Opioids and Family Members and Friends

Unintentional drug overdose deaths continue to be a critical public health issue. Naloxone, a nonscheduled, safe, and effective drug that reverses opioid-involved overdoses is available to non-medically trained individuals ("lay people"), but there is scant information about how people in different social roles experience naloxone administration. We conducted 24 in-depth interviews with people who use opioids (PWUO; n = 15) and family members and friends of people who use opioids (FF; n = 9) who had administered naloxone in response to an opioid overdose. Compared with PWUO, members of the FF group were less reticent to administer naloxone in response to an overdose. PWUO and FF had different perspectives of law enforcement and demonstrated varied knowledge of the Good Samaritan Law. While PWUO found that having and administering naloxone was empowering, FF took a more pragmatic approach, reporting the need for naloxone as an unfortunate reality of their loved one's drug use.

The Opioid Overdose Resuscitation Education for Addiction Counselors and Trainees (Opioid Overdose REACT) naloxone response education pilot project improved confidence and knowledge among addiction counselors and trainees

INTRODUCTION

Community programs to teach nonmedical laypeople how to recognize an opioid overdose and effectively resuscitate the victim using naloxone have proliferated recently as a significant component of harm-reduction efforts. Although many such programs target laypeople like first responders or friends and family members of people who use drugs, there are currently no programs that specifically target addiction counselors, despite their work with a client population at high risk of an opioid overdose.

METHODS

The four-hour curriculum designed by the authors covered opioid agonist and antagonist pharmacology; opioid toxidrome signs; legal implications and indications for using the naloxone kits; and hands-on training. Participants were two cohorts of addiction counselors and addiction counseling trainees at our institution and an affiliated Opioid Treatment Program methadone clinic. Surveys testing participant knowledge and confidence were conducted at baseline, immediately post-training, six months post-training, and 12 months post-training.

RESULTS

Overall, opioid and naloxone pharmacology knowledge, as well as the confidence to intervene in an overdose emergency, improved among participants in both cohorts. Knowledge scores at baseline (n = 36, median 5/10) improved significantly immediately post-training (n = 31, median 7/10, P < 0.0001, Wilcoxon signed-rank test) and were sustained six (n = 19) and 12 months (n = 11) later. Two participants reported using their naloxone kits to successfully reverse a client overdose in the 12 months after taking the course.

DISCUSSION

These results from our knowledge translation pilot project suggest that our educational program to train addiction counselors in opioid pharmacology and toxicology, allowing them to recognize and respond to an opioid overdose, is feasible and could be effective. Specific barriers to implementing such educational programs include cost, stigma, and unclear best practice for designing and conducting these programs.

CONCLUSIONS

Further study of providing opioid pharmacology education and overdose and naloxone training to addiction counselors and counseling trainees appears to be warranted.

Comparison of rhabdomyolysis in acutely intoxicated patients with psychotropic and chemical substances

INTRODUCTION

Rhabdomyolysis is characterized by a muscle injury that leads to the release of intracellular muscle contents/constituents into the systemic circulation.

A pharmacologically pre-contracted smooth muscle bowel model for the study of highly-potent opioid receptor agonists and antagonists

Isolated organ models are a versatile tool for pharmacological and toxicological research. Small bowel has been used to assess the inhibition of smooth muscle contraction by opioids. In the present study, we set out to establish a pharmacologically stimulated rat bowel model. The effects of carfentanil, remifentanil and the new synthetic opioid U-48800 and their respective antagonists naloxone, nalmefene and naltrexone were studied in a small bowel model in rats. The IC₅₀ values of the tested opioids were as follows: carfentanil (IC₅₀ = 0.02 µmol/L, CI 0.02-0.03 µmol/L) ≫ remifentanil (IC₅₀ = 0.51 µmol/L, CI 0.40-0.66 µmol/L) ≫ U-48800 (IC₅₀ = 1.36 µmol/L, CI 1.20-1.54 µmol/L). The administration of the opioid receptor antagonists naloxone, naltrexone and nalmefene led to progressive, parallel rightward shifts of the dose-response curves. Naltrexone was most potent in antagonizing the effects of U-48800, whereas naltrexone and nalmefene were most effective in antagonizing the effects of carfentanil. In summary, the current model seems to be a robust tool to study opioid effects in a small bowel model without the necessity of using electrical stimulation.

The human neurosecretome: extracellular vesicles and particles (EVPs) of the brain for intercellular communication, therapy, and liquid-biopsy applications

Emerging evidence suggests that brain derived extracellular vesicles (EVs) and particles (EPs) can cross blood-brain barrier and mediate communication among neurons, astrocytes, microglial, and other cells of the central nervous system (CNS). Yet, a complete understanding of the molecular landscape and function of circulating EVs & EPs (EVPs) remain a major gap in knowledge. This is mainly due to the lack of technologies to isolate and separate all EVPs of heterogeneous dimensions and low buoyant density. In this review, we aim to provide a comprehensive understanding of the neurosecretome, including the extracellular vesicles that carry the molecular signature of the brain in both its microenvironment and the systemic circulation. We discuss the biogenesis of EVPs, their function, cell-to-cell communication, past and emerging isolation technologies, therapeutics, and liquid-biopsy applications. It is important to highlight that the landscape of EVPs is in a constant state of evolution; hence, we not only discuss the past literature and current landscape of the EVPs, but we also speculate as to how novel EVPs may contribute to the etiology of addiction, depression, psychiatric, neurodegenerative diseases, and aid in the real time monitoring of the "living brain". Overall, the neurosecretome is a concept we introduce here to embody the compendium of circulating particles of the brain for their function and disease pathogenesis. Finally, for the purpose of inclusion of all extracellular particles, we have used the term EVPs as defined by the International Society of Extracellular Vesicles (ISEV).

Catalytic Antibody Blunts Carfentanil-Induced Respiratory Depression

Carfentanil, the most potent of the fentanyl analogues, is at the forefront of synthetic opioid-related deaths, second to fentanyl. Moreover, the administration of the opioid receptor antagonist naloxone has proven inadequate for an increasing number of opioid-related conditions, often requiring higher/additional doses to be effective, as such interest in alternative strategies to combat more potent synthetic opioids has intensified. Increasing drug metabolism would be one strategy to detoxify carfentanil; however, carfentanil's major metabolic pathways involve N-dealkylation or monohydroxylation, which do not lend themselves readily to exogenous enzyme addition. Herein, we report, to our knowledge, the first demonstration that carfentanil's methyl ester when hydrolyzed to its acid was found to be 40,000 times less potent than carfentanil in activating the μ-opioid receptor. Physiological consequences of carfentanil and its acid were also examined through plethysmography, and carfentanil's acid was found to be incapable of inducing respiratory depression. Based upon this information, a hapten was chemically synthesized and immunized, allowing the generation of antibodies that were screened for carfentanil ester hydrolysis. From the screening campaign, three antibodies were found to accelerate the hydrolysis of carfentanil's methyl ester. From this series of catalytic antibodies, the most active underwent extensive kinetic analysis, allowing us to postulate its mechanism of hydrolysis against this synthetic opioid. In the context of potential clinical applications, the antibody, when passively administered, was able to reduce respiratory depression induced by carfentanil. The data presented supports further development of antibody catalysis as a biologic strategy to complement carfentanil overdose reversal.

Public health and medical preparedness for mass casualties from the deliberate release of synthetic opioids

The large amounts of opioids and the emergence of increasingly potent illicitly manufactured synthetic opioids circulating in the unregulated drug supply in North America and Europe are fueling not only the ongoing public health crisis of overdose deaths but also raise the risk of another type of disaster: deliberate opioid release with the intention to cause mass harm. Synthetic opioids are highly potent, rapidly acting, can cause fatal ventilatory depression, are widely available, and have the potential to be disseminated for mass exposure, for example, if effectively formulated, via inhalation or ingestion. As in many other chemical incidents, the health consequences of a deliberate release of synthetic opioid would manifest quickly, within minutes. Such an incident is unlikely, but the consequences could be grave. Awareness of the risk of this type of incident and preparedness to respond are required to save lives and reduce illness. Coordinated planning across the entire local community emergency response system is also critical. The ability to rapidly recognize the opioid toxidrome, education on personal protective actions, and training in medical management of individuals experiencing an opioid overdose are key components of preparedness for an opioid mass casualty incident.

"It's just another tool on my toolbelt": New York state law enforcement officer experiences administering naloxone

BACKGROUND

Although naloxone is widely acknowledged as a life-saving intervention and a critical tool for first responders, there remains a need to explore how law enforcement officers have adapted to a shifting scope of work. Past research has focused mainly on officer training, their abilities to administer naloxone, and to a lesser extent on their experiences and interactions working with people who use drugs (PWUD).

METHODS

A qualitative approach was used to explore officer perspectives and behaviors surrounding responses to incidents of suspected opioid overdose. Between the months of March and September 2017, semi-structured interviews were conducted with 38 officers from 17 counties across New York state (NYS).

RESULTS

Analysis of in-depth interviews revealed that officers generally considered the additional responsibility of administering naloxone to have become "part of the job". Many officers reported feeling as though they are expected to wear multiple hats, functioning as both law enforcement and medical personnel and at times juggling contradictory roles. Evolving views on drugs and drug use defined many interviews, as well as the recognition that a punitive approach to working with PWUD is not the solution, emphasizing the need for cohesive, community-wide support strategies. Notable differences in attitudes toward PWUD appeared to be influenced by an officer's connection to someone who uses drugs and/or due to a background in emergency medical services.

CONCLUSION

Law enforcement officers in NYS are emerging as an integral part of the continuum of care for PWUD. Our findings are capturing a time of transition as more traditional approaches to law enforcement appear to be shifting toward those prioritizing prevention and diversion. Widespread adoption of naloxone administration by law enforcement officers in NYS is a powerful example of the successful integration of a public health intervention into police work.

DO HIGHER DOSES OF NALOXONE INCREASE THE RISK OF PULMONARY COMPLICATIONS?

BACKGROUND

Although naloxone has proven to be an effective opioid reversal agent, concern that high doses of naloxone can cause pulmonary edema may prevent health care providers from administering it in initial high doses.

OBJECTIVE

Our aim was to determine whether increased doses of naloxone are correlated with an increase in pulmonary complications in patients presenting to the emergency department (ED) after an opioid overdose.

METHODS

This was a retrospective study of patients treated with naloxone by emergency medical services (EMS) or in the ED at an urban level I trauma center and three associated freestanding EDs. Data were queried from EMS run reports and the medical record and included demographic characteristics, naloxone dosing, administration route, and pulmonary complications. Patients were grouped by naloxone dose received, defined as low (≤ 2 mg), moderate (> 2 mg to ≤ 4 mg), and high (> 4 mg).

RESULTS

Of the 639 patients included, 13 (2.0%) were diagnosed with a pulmonary complication. There was no difference in the development of pulmonary complications across groups (p = 0.676). There was no difference in pulmonary complications based on the route of administration (p = 0.342). The administration of higher doses of naloxone was not associated with longer hospital stays (p = 0.0327).

CONCLUSIONS

Study results suggest that the reluctance of many health care providers to administer larger doses of naloxone on initial treatment may not be warranted. In this investigation, there were no poor outcomes associated with an increase in naloxone administration. Further investigation in a more diverse population is warranted.

High-potency benzodiazepine misuse in opioid-dependent patients: use naloxone with care

The misuse of highly potent benzodiazepines is increasing in the UK, particularly among the opioid-using population in Scotland. Differentiating opioid from benzodiazepine toxicity is not always straightforward in patients with reduced level of consciousness following drug overdose. Patients on long-term opioid substitution who present with acute benzodiazepine intoxication and are given naloxone may develop severe opioid withdrawal while still obtunded from benzodiazepines. This situation can be difficult to manage, and these patients may be at increased risk of vomiting while still unable to protect their airway. Fortunately, the short half-life of naloxone means that the situation is generally short-lived. Naloxone should never be withheld from patients with life-threatening respiratory depression where opioids may be contributing, particularly in community and prehospital settings; however, where appropriate clinical experience exists, naloxone should ideally be administered in small incremental intravenous doses with close monitoring of respiratory function. Increased awareness of the potential risks of naloxone in opioid-dependent patients acutely intoxicated with benzodiazepines may reduce the risk of iatrogenic harm in an already very vulnerable population.

Patching holes in the mechanism of opioid tolerance

Tolerance is a significant obstacle to use of opioids as safe pain relieving drugs, but the cellular processes that result in tolerance have remained elusive. A new study by Maza and colleagues identifies the protein Patched domain-containing 1 (PTCHD1) and its effects on cellular cholesterol as potential targets for preventing opioid tolerance.

College students' knowledge about opioids and implications for the opioid crisis

OBJECTIVE

This study assessed undergraduate unhealthy substance use, levels of knowledge about opioid pharmacology, unhealthy use and safety, and students' perceptions about their level of knowledge.

PARTICIPANTS

Participants were undergraduate students at a large, private university in the Northeast.

METHODS

This study employed a cross-sectional study design using an online survey. A convenience sample of undergraduate students (N = 317) described their actual and perceived levels of opioid knowledge and their self-reported substance use.

RESULTS

Objective answers to quiz-style questions about opioids showed knowledge deficits. Participants rated themselves as slightly less knowledgeable than the "average student." Ten percent of students surveyed had used opioids unhealthily at some point in their lifetime. Those reporting unhealthy opioid use had higher subjective and objective opioid knowledge scores.

CONCLUSIONS

University students' subjective and objective knowledge of opioids warrants more effective and engaging substance use education on college campuses.

Intention to seek emergency medical services during community overdose events in British Columbia, Canada: a cross-sectional survey

Introduction

Canada and the United States continue to experience increasing overdose deaths attributed to highly toxic illicit substances, driven by fentanyl and its analogues. Many bystanders report being hesitant to call 9-1-1 at an overdose due to fears around police presence and arrests. In Canada, a federal law was enacted in 2017, the Good Samaritan Drug Overdose Act (GSDOA), to provide protection from simple drug possession and related charges when 9-1-1 is called to an overdose. There is limited evidence, however, that the GSDOA has improved rates of intention to call 9-1-1 at overdose events. We therefore sought to examine intent to call 9-1-1 among persons who received GSDOA education and were at risk of witnessing an overdose.

Methods

A cross-sectional survey was conducted with people at risk of witnessing an overdose recruited at 19 Take Home Naloxone (THN) program sites across British Columbia as well as online through Foundry from October 2020 to April 2021. Descriptive statistics were used to examine intention to call 9-1-1 at future overdoses. Multivariable logistic regression models were built in hierarchical fashion to examine factors associated with intention to call 9-1-1.

Results

Overall, 89.6% (n = 404) of the eligible sample reported intention to call 9-1-1. In the multivariable model, factors positively associated with intention to call 9-1-1 included identifying as a cisgender woman (adjusted odds ratio [AOR]: 3.37; 95% CI: 1.19–9.50) and having previous GSDOA awareness ([AOR]: 4.16; 95% CI: 1.62–10.70). Having experienced a stimulant overdose in the past 6 months was negatively associated with intention to call 9-1-1 ([AOR]: 0.24; 95% CI: 0.09–0.65).

Conclusion

A small proportion of the respondents reported that, despite the enactment of GSDOA, they did not intend to call 9-1-1 and those who were aware of the act were more likely to report an intention to call at future overdose events. Increasing GSDOA awareness and/or additional interventions to support the aims of the GSDOA could address ongoing reluctance to seek emergency medical care by people who use drugs.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13011-022-00484-0.

Naloxone administration by law enforcement officers in New York State (2015-2020)

BACKGROUND

The COVID-19 pandemic has amplified the need for wide deployment of effective harm reduction strategies in preventing opioid overdose mortality. Placing naloxone in the hands of key responders, including law enforcement officers who are often first on the scene of a suspected overdose, is one such strategy. New York State (NYS) was one of the first states to implement a statewide law enforcement naloxone administration program. This article provides an overview of the law enforcement administration of naloxone in NYS between 2015 and 2020 and highlights key characteristics of over 9000 opioid overdose reversal events.

METHODS

Data in naloxone usage report forms completed by police officers were compiled and analyzed. Data included 9133 naloxone administration reports by 5835 unique officers located in 60 counties across NYS. Descriptive statistics were used to examine attributes of the aided individuals, including differences between fatal and non-fatal incidents. Additional descriptive analyses were conducted for incidents in which law enforcement officers arrived first at the scene of suspected overdose. Comparisons were made to examine year-over-year trends in administration as naloxone formulations were changed. Quantitative analysis was supplemented by content analysis of officers' notes (n = 2192).

RESULTS

In 85.9% of cases, law enforcement officers arrived at the scene of a suspected overdose prior to emergency medical services (EMS) personnel. These officers assessed the likelihood of an opioid overdose having occurred based on the aided person's breathing status and other information obtained on the scene. They administered an average of 2 doses of naloxone to aided individuals. In 36.8% of cases, they reported additional administration of naloxone by other responders including EMS, fire departments, and laypersons. Data indicated the aided survived the suspected overdose in 87.4% of cases.

CONCLUSIONS

With appropriate training, law enforcement personnel were able to recognize opioid overdoses and prevent fatalities by administering naloxone and carrying out time-sensitive medical interventions. These officers provided life-saving services to aided individuals alongside other responders including EMS, fire departments, and bystanders. Further expansion of law enforcement naloxone administration nationally and internationally could help decrease opioid overdose mortality.

Selected Political Criminal Poisonings in the Years 1978-2020: Detection and Treatment

Criminal poisonings are among the least frequently detected crimes in the world. Lack of suspicion of this type of event by police officers and prosecutors, clinical symptoms imitating many somatic diseases and technical difficulties in diagnostics, as well as high research costs make the actual frequency of these events difficult to estimate. The substance used for criminal poisoning is often characterized by: lack of taste, color and smell, delayed action, easy availability and difficulty to detect. The aim of the study was to analyze selected cases of political poisoning that took place in the years 1978-2020, to describe the mechanisms of action of the substances used and to evaluate the diagnosis and treatment. The analyzed cases of criminal poisoning concerned: Georgi Markov (ricin), Khalid Maszal (fentanyl), Wiktor Yushchenko (TCDD dioxin), Jasir Arafat (polonium ²¹⁰Po isotope), Alexander Litvinenko (polonium ²¹⁰Po isotope), Kim Jong-Nam (VX), Sergei Skripal (Novichok) and Alexei Navalny (Novichok). Contemporary poisons, to a greater extent than in the past, are based on the use of synthetic substances from the group of organophosphorus compounds and radioactive substances. The possibility of taking appropriate and effective treatment in such cases is the result of many factors, including the possibility of quick and competent rescue intervention, quick and reliable detection of the toxic substance and the possibility of using an antidote.

A randomized clinical trial of the effects of brief versus extended opioid overdose education on naloxone utilization outcomes by individuals with opioid use disorder

BACKGROUND

Overdose education and naloxone distribution (OEND) trains people who use opioids (PWUO) in how to intervene in cases of opioid overdose but best practices have not been assessed empirically.

METHODS

PWUO along with a significant other (SO) were randomized to one of three training conditions. In the Treatment-as-Usual (TAU) condition, participants were randomized to receive minimal overdose-related education. In the extended training (ET) condition, PWUO received an extended training, while their SO received no overdose training. In the final condition, both the participant and SO received the extended overdose training (ETwSO). Outcome measures were naloxone use and overdose knowledge and competency assessed immediately before and after training, and at 1-, 3-, 6-, and 12-month timepoints following training.

RESULTS

Three hundred and twenty-one PWUO (w/ a SO) were randomized. All intensities of OD training were associated with sustained increases in OD knowledge/ competency (versus pre-training baseline p's < 0.01). PWUO intervened in 166 ODs. The 12-month incidence of naloxone use did not significantly differ between groups. Extended training (ET + ETwSO) compared to TAU resulted in significantly greater naloxone utilization by: 30 days (10.1% vs 4.1%, p = 0.041), 60 days (16.4% vs 5.2%, p<0.001) and 90 days (17.9% vs 9.5%, p = 0.039).

CONCLUSIONS

All intensities of OD training were associated with sustained increases in OD knowledge and competency, and equivalent rates of successful naloxone use. More extensive training increased naloxone utilization during the first 3 months. However, the benefits of more comprehensive training should be balanced against feasibility.

Factors associated with naloxone availability and dispensing through Michigan's pharmacy standing order

Background: Pharmacy standing order policies allow pharmacists to dispense naloxone, thereby increasing access to naloxone. Objectives: To describe pharmacy standing order participation and associations of pharmacy and community characteristics that predict naloxone availability and dispensing across eight counties in Michigan. Methods: We conducted a telephone survey of 662 standing order pharmacies with a response rate of 81% (n = 539). Pharmacies were linked with census tract-level demographics, overdose fatality rates, and dispensing data. County maps were created to visualize pharmacy locations relative to fatality rates. Regression models analyzed associations between pharmacy type, neighborhood characteristics, fatality rates, and these outcomes: naloxone availability, having ever dispensed naloxone, and counts of naloxone dispensed. Results: The prevalence of standing order pharmacies was 54% (n = 662/1231). Maps revealed areas with higher fatality rates had fewer pharmacies participating in the standing order or lacked any pharmacy access. Among standing order pharmacies surveyed, 85% (n = 458/539) had naloxone available and 82% had ever dispensed (n = 333/406). The mean out-of-pocket cost of Narcan_® was $127.77 (SD: 23.93). National chains were more likely than regional chains to stock naloxone (AOR = 3.75, 95%CI = 1.77, 7.93) and to have ever dispensed naloxone (AOR 3.02, 95%CI = 1.21,7.57). Higher volume of naloxone dispensed was associated in neighborhoods with greater proportions of public health insurance (IRR = 1.38, 95%CI = 1.21, 1.58) and populations under 44 years old (IRR = 1.24, 95%CI = 1.04, 1.48). There was no association with neighborhood overdose fatality rates or race in regression models. Conclusion: As deaths from the opioid epidemic continue to escalate, efforts to expand naloxone access through greater standing order pharmacy participation are warranted.

Impact of a publicly funded pharmacy-dispensed naloxone program on fatal opioid overdose rates: A population-based study

BACKGROUND

Studies examining the impact of pharmacy-dispensed naloxone programs on fatal opioid overdose rates are lacking. We examined the impact of the publicly funded Ontario Naloxone Program for Pharmacies (ONPP), implemented in June 2016, on provincial rates of opioid overdose deaths.

METHODS

We conducted a population-based interrupted time-series study between July 1, 2012 and December 31, 2018. We considered a parsimonious model with terms for time, ONPP implementation, and time following the ONPP implementation. Models were adjusted for population characteristics, number of pharmacies and rate of naloxone distributed through non-pharmacy sites within provincial public health units.

RESULTS

In the parsimonious model, the ONPP was associated with a non-significant 9% reduction in the level of fatal opioid overdoses (rate ratio [RR] 0.91; 95% confidence interval [CI] 0.79-1.06), a finding that was most pronounced in regions in the lowest tertile of implementation (RR 0.75; 95% CI 0.62-0.91). Following multivariable adjustment, there was an increase in the level (RR 1.06; 95% CI 0.94-1.19) and slope change (RR 1.06; 95% CI 1.02-1.10) of fatal overdose rates.

CONCLUSION

The ONPP is insufficient as a single intervention to meaningfully reduce rates of fatal opioid overdoses during a period in which the cause of these deaths shifted from prescription opioids to highly potent fentanyl analogs. Access to additional harm reduction, treatment, and other interventions is necessary to prevent deaths and optimize the health of people who use drugs.

Naloxone administration among opioid-involved overdose deaths in 38 United States jurisdictions in the State Unintentional Drug Overdose Reporting System, 2019

BACKGROUND

The majority of drug overdose deaths in the United States involve opioids, and synthetic opioid-involved overdose death rates are increasing. Naloxone is a key prevention strategy yet estimates of its administration are limited.

METHODS

We analyzed 2019 data from 37 states and the District of Columbia in CDC's State Unintentional Drug Overdose Reporting System to estimate the percentage of decedents, by sociodemographic subgroup, who experienced a fatal opioid-involved overdose and had no evidence of naloxone administration.

RESULTS

A total of 77.3% of 33,084 opioid-involved overdose deaths had no evidence of naloxone administration. Statistically significant subgroup differences were observed for all sociodemographic groups examined except housing status. The highest percentages of decedents lacking evidence of naloxone administration were those with highest educational attainment (doctorate or professional degree, 87.0%), oldest (55-64 years, 83.4%; ≥65 years, 87.3%) and youngest ages (<15 years, 87.5%), and single marital status (84.5%). The lowest percentages of no evidence of naloxone administration were observed for non-Hispanic American Indian/Alaskan Native persons (66.2%) and those ages 15-24 years (70.8%).

CONCLUSIONS

More than three-quarters of opioid-involved overdose deaths had no evidence of naloxone administration, underscoring the need to ensure sufficient naloxone access and capacity for utilization. While fatal overdose data cannot fully characterize sociodemographic disparities in naloxone administration, naloxone education and access efforts can be informed by apparent inequities. Public health partners can assist persons who use drugs (PWUD) by maintaining naloxone supply and amplifying messages about the high risk of using drugs alone among PWUD and their social networks.

Naloxone-associated pulmonary edema in a 3-year-old with opioid overdose

Background

Annually, close to 5000 children under age 6 years are treated in emergency departments or admitted for care due to opioid exposures. Naloxone is effectively used to treat opioid overdose in both children and adults. Non-cardiogenic pulmonary edema is a rare but serious adverse effect of naloxone administration that has been reported in adults.

Case Report

We present the case of a 3-year-old male with suspected opioid overdose who developed acute hypoxia due to pulmonary edema after administration of naloxone following a likely prolonged downtime.

Why Should an Emergency Physician Be Aware of This?

The copious fluid in the airway made for difficult intubation at a pediatric tertiary care center. Given the incidence of opioid exposures in children, clinicians should be aware of this rare, but dangerous adverse effect of naloxone and consider airway precautions and pediatric critical care availability early in the presentation.

Where Opioid Overdose Patients Live Far From Treatment: Geospatial Analysis of Underserved Populations in New York State

BACKGROUND

Opioid addiction and overdose have a large burden of disease and mortality in New York State (NYS). The medication naloxone can reverse an overdose, and buprenorphine can treat opioid use disorder. Efforts to increase the accessibility of both medications include a naloxone standing order and a waiver program for prescribing buprenorphine outside a licensed drug treatment program. However, only a slim majority of NYS pharmacies are listed as participating in the naloxone standing order, and less than 7% of prescribers in NYS have a buprenorphine waiver. Therefore, there is a significant opportunity to increase access.

OBJECTIVE

Identifying the geographic regions of NYS that are farthest from resources can help target interventions to improve access to naloxone and buprenorphine. To maximize the efficiency of such efforts, we also sought to determine where these underserved regions overlap with the largest numbers of actual patients who have experienced opioid overdose.

METHODS

We used address data to assess the spatial distribution of naloxone pharmacies and buprenorphine prescribers. Using the home addresses of patients who had an opioid overdose, we identified geographic locations of resource deficits. We report findings at the high spatial granularity of census tracts, with some neighboring census tracts merged to preserve privacy.

RESULTS

We identified several hot spots, where many patients live far from the nearest resource of each type. The highest density of patients in areas far from naloxone pharmacies was found in eastern Broome county. For areas far from buprenorphine prescribers, we identified subregions of Oswego county and Wayne county as having a high number of potentially underserved patients.

CONCLUSIONS

Although NYS is home to thousands of naloxone pharmacies and potential buprenorphine prescribers, access is not uniform. Spatial analysis revealed census tract areas that are far from resources, yet contain the residences of many patients who have experienced opioid overdose. Our findings have implications for public health decision support in NYS. Our methods for privacy can also be applied to other spatial supply-demand problems involving sensitive data.

Unspecified opioids among opioid overdoses in Oslo, Norway

OBJECTIVE

Since 2017, an increasing number of opioid overdoses in Oslo, Norway, has been categorized as involving unspecified opioids, as noted in the patient records by the doctor treating the patient. In this study we compare the characteristics of overdoses involving unspecified opioids, long-acting opioids, and heroin. Data on patients presenting with opioid overdose was retrospectively collected from 1 October 2013 to 31 December 2019 at the Oslo Accident and Emergency Outpatient Clinic.

RESULTS

Among 2381 included cases, 459 (19.3%) involved unspecified opioids, 134 (5.6%) long-acting opioids, and 1788 (75.1%) heroin. Overdoses involving unspecified opioids needed longer observation, median 5 h 29 min vs. 4 h 54 min (long-acting opioids) and 4 h 49 min (heroin) (p < 0.001), and had a lower Glasgow coma scale score, median 10 vs. 13 in both the other groups (p < 0.001). Naloxone was given in 23.3% of cases involving unspecified opioids, vs. 12.7% involving long-acting opioids and 30.2% involving heroin (p < 0.001). A larger proportion of patients were transferred to hospital care when unspecified or long-acting opioids were involved compared to heroin, 16.3% and 18.7% respectively vs. 10.1% (p < 0.001). Our results indicate that the category "unspecified opioids" encompasses a substantial proportion of opioids acting longer than heroin.

Wartime toxicology: the spectre of chemical and radiological warfare in Ukraine

The unprovoked invasion of Ukraine by the Russian Federation has resulted in the largest humanitarian crisis in Europe since World War II. As fighting intensifies throughout Ukraine, there is an increasing concern that the Russian Federation may consider the direct use of chemical or radiological weapons against military personnel and civilians in Ukraine. Despite prohibition of chemical weapons from the Chemical Weapons Convention of 1997, recent evidence has demonstrated that state actors will continue to use these agents as weapons of war and terror, despite publicly denying their use. We review chemical weapons produced and used by the Russian Federation (or its allies) to identify plausible risks in the Russian war in Ukraine. We also provide rapid assessment and treatment guidelines to recognize and manage these acute exposures.

Evaluating the population-level effects of overdose prevention sites and supervised consumption sites in British Columbia, Canada: Controlled interrupted time series

Background

On 14 April 2016, British Columbia’s Provincial Medical Health Officer declared the overdose crisis a public health emergency, sanctioning the implementation of new overdose prevention sites (OPS) and supervised consumption sites (SCS) across the province.

Methods

We used the BC Centre for Disease Control’s Provincial Overdose Cohort of all overdose events between 1 January 2015 and 31 December 2017 to evaluate the population-level effects of OPSs and SCSs on acute health service use and mortality. We matched local health areas (LHA) that implemented any site with propensity score matched controls and conducted controlled interrupted time series analysis.

Results

During the study period, twenty-five OPSs and SCSs opened across fourteen of British Columbia’s 89 LHAs. Results from analysis of LHAs with matched controls (i.e. excluding Vancouver DTES) were mixed. Significant declines in reported overdose events, paramedic attendance, and emergency department visits were observed. However, there were no changes to trends in monthly hospitalization or mortality rates. Extensive sensitivity analyses found these results persisted.

Conclusions

We found OPSs and SCSs reduce opioid-related paramedic attendance and emergency department visit rates but no evidence that they reduce local hospitalization or mortality rates.

Pharmacokinetic considerations for community-based dosing of nasal naloxone in opioid overdose in adults

INTRODUCTION

The administration of the opioid antagonist naloxone in the community is a measure to prevent death from opioid overdose. Approved nasal naloxone sprays deliver initial doses of 0.9 to 8 mg. The level of the initial community dose is controversial, as the scientific base is weak.In this review knowledge of the pharmacokinetics of nasal, both approved and improvised nasal sprays, and intramuscular naloxone will be utilized to evaluate dose-effect relationships in previous studies of opioid overdose outcomes.

AREAS COVERED

The aim was to present scientifically based considerations on the initial nasal naloxone doses currently available, which reasonably balances the effect and adverse outcomes, given that at least two doses are at hand. Also included in these considerations is the challenge by illicitly manufactured fentanyl and analogs.This paper is based on both peer-reviewed and grey literature identified by several searches, of such as naloxone pharmacokinetics/formulations/outcomes/emergency medical services, in PubMed and Embase.

EXPERT OPINION

There is little scientific evidence that supports the use of initial systemic dosing that exceeds 0.8 mg in the community. Higher doses increase the risk of withdrawal symptoms feared in people who use opioids. Many obstacles may reduce the potential of community-administered naloxone.

Exposure to immediate-release tramadol in children 6 years and under - a nationwide French poison control center study

INTRODUCTION

Data regarding immediate-release (IR)-tramadol exposures in children remain sparse. We aimed to investigate the incidence of IR-tramadol exposures in ≤6-year-old children, to describe the characteristics and resulting outcome of ingestions involving IR-tramadol alone, and to estimate a clinically relevant toxic dose in this population.

METHODS

Retrospective analysis of IR-tramadol exposures in ≤6-year-old children, collected by the French Poison Control Centers (PCCs) in 2003-2019. The incidence was estimated using IR-tramadol prescription data from the Health Improvement Network database (the French version of THIN). The Poison severity score (PSS) was used to grade severity.

RESULTS

We found 1260 IR-tramadol exposures in ≤6-year-old children. The number of cases per 100,000 IR-tramadol-treated patients increased over time (p < .0001). One hundred forty-five cases involving IR-tramadol alone were analyzed. The median age was 3.0 years (IQR: 1.9, 4.0), the M/F ratio was 1.5 and the median dose was 5.0 mg/kg (IQR 3.3-11.1). Half of the children (49.7%) remained asymptomatic (PSS0) while 29.6% and 14.5% developed minor (PSS1) or moderate-to-severe (PSS2-PSS3) neurological symptoms, respectively. Twelve children developed respiratory depression. No seizures and no fatality were reported. All symptomatic children recovered within 24 h. The ingested IR-tramadol dose was positively correlated with the PSS (p < .0001). Using a receiver operating characteristic (ROC) curve approach (area under the curve, 0.92; p < .001), ingestion of ≥7.4 mg/kg IR-tramadol was appropriate to recommend hospital referral (sensitivity, 100% [95% confidence interval (CI), 85-100]; specificity, 73% [95% CI, 64-80]; predictive positive value, 39% [95% CI, 35-57]; negative predictive value, 100% [95% CI, 96-100]). Children who ingested <7.4 mg/kg IR-tramadol developed no (n = 68) or minor (n = 22) neurological symptoms.

CONCLUSIONS

Despite increasing tramadol prescriptions in adults during the study period in France, oral exposure to IR-tramadol in ≤6-year-old children was rare but possibly responsible for severe toxicity. Children with no underlying disease and concomitant medication ingesting <7.4 mg/kg IR-tramadol alone could be observed at home. However, given the observed variability in the onset of seizures after tramadol ingestion, which can occur at ingested tramadol doses below 7.4 mg and even at therapeutic doses, parents or guardians should be specifically warned about the risk of seizures.

Prevalences of and characteristics associated with single- and polydrug-involved U.S. Emergency Department Visits in 2018

INTRODUCTION

Nonfatal and fatal drug overdoses have recently increased. There are limited data describing the range of illicit, prescribed, and over-the-counter drugs involved in overdoses presenting to U.S. emergency departments (EDs).

METHODS

Using 2018 Healthcare Cost and Utilization Project (HCUP) Nationwide ED Sample (NEDS) data, we calculated weighted counts and percentages by drug among overdose-related ED visits. Overdose-related ED visits were those having an International Classification of Diseases, 10th Revision, Clinical Modification (ICD-10-CM) drug poisoning code falling under parent codes T36-T50 (codes involving alcohol were not explicitly queried). We identified the top 30 mutually exclusive polydrug combinations and compared characteristics of visits by polydrug status.

RESULTS

In 2018, 908,234 ED visits had a T36-T50 drug poisoning code. The most frequently reported drugs involved were opioids (30.3% of visits; heroin: 15.2%), benzodiazepines (11.0%), stimulants (7.9%), other/unspecified antidepressants (7.1%), 4-aminophenol derivatives (6.6%), and other/unspecified drugs, medicaments, and biological substances (11.8%). Overdose was uncommon for most other drug classes (e.g., antibiotics). Polydrug visits were more likely to involve females (prevalence ratio [PR]: 1.14, 95% confidence interval [CI]: 1.12-1.16), be coded intentional self-harm (PR: 1.81, 95% CI: 1.77-1.85), and result in hospitalization (PR: 1.84, 95% CI: 1.79-1.89) or death (PR: 1.37, 95% CI: 1.22-1.53) compared to single-drug overdose-related visits. Benzodiazepines, opioids, and/or stimulants were most frequently involved in polydrug overdoses.

CONCLUSION

Opioids, benzodiazepines, and stimulants were most commonly reported in both single-drug and polydrug overdose-involved ED visits. Other drugs involved in overdoses included antidepressants and 4-aminophenol derivatives. Jurisdictions can use data on drugs involved in overdoses to better tailor prevention strategies to emerging needs.

Opioid use disorder and the brain: a clinical perspective

Opioid use disorder (OUD) has gained increasing publicity and interest during recent years, with many countries describing problems of epidemic proportions with regard to opioid use and deaths related to opioids. While opioids are not themselves acutely neurotoxic, the chronic relapsing and remitting nature of this disorder means that individuals are often exposed to exogenous opioids for lengthy periods of time (either illicit or prescribed as treatment). We are increasingly characterizing the effect of such long-term opioid exposure on the brain. This narrative review aims to summarize the literature regarding OUD and the brain from a clinical perspective. Alterations of brain structure and function are discussed, as well as neurological and psychiatric disorders in OUD. Finally, we review current and new directions for assessment and treatment.

Naloxone and nalmefene absorption delivered by hollow microneedles compared to intramuscular injection

Naloxone and nalmefene were administered to seven research beagle dogs (mean weight approximately 12 kg) at doses of 0.04 mg/kg and 0.014 mg/kg for naloxone and nalmefene, respectively. Each dose was administered intramuscularly (IM) with a standard IM injection and with a hollow microneedle device array using needles of 1 mm in length. The IM injection was delivered in the epaxial muscles, and the microneedle injection was delivered in the skin over the shoulder of each dog. Each dog received the same injections in a crossover design. Following the injection, blood samples were collected for plasma analysis of naloxone and nalmefene by high-pressure liquid chromatography with mass spectrometry detection (LCMS). The plasma sample concentrations were plotted for observed patterns of absorption and analyzed with non-compartmental pharmacokinetic methods (NCA). The results showed that the injection of naloxone from the microneedle device produced a higher peak concentration (CMAX) by 2.15 × compared the IM injection of the same dose, and time to peak concentration (TMAX) was similar. For the nalmefene injection, the peak was not as high (lower CMAX) by 0.94 × for the microneedle injection compared to the IM injection of the same dose. The microneedle produced an exposure, measured by area under the curve (AUC), that was 0.85 × and 0.58 × as high for naloxone and nalmefene, respectively, than the injection by the IM route. We also observed that although the dose for naloxone was approximately 3 × higher for naloxone compared to nalmefene, the mean peak concentration achieved from the naloxone injection was more than 12 × higher than that from the nalmefene injection. These studies were designed to test the feasibility of using the hollow microneedle array as an effective method of naloxone and nalmefene delivery for emergency treatment of opioid-induced respiratory depression (OIRD). The results of these studies will form the basis of future studies, using the dog as a model, for development of hollow microneedle microarray devices to deliver opioid antagonists for treatment of OIRD in people.

Time-Series Analysis of Fentanyl Concentration in the Unregulated Opioid Drug Supply in a Canadian Setting

North America has been contending with an unregulated street drug supply in which opioids are often adulterated with illicitly manufactured fentanyl. The unpredictability of composition may result in an increased risk of overdose due to unexpected elevated concentrations of the high-potency drug. Using data from a community-based drug-checking project, we evaluated trends in fentanyl concentration of illicit opioids in the context of an overdose epidemic. Using a quantification model for fentanyl hydrochloride, historical Fourier-transform infrared spectra from opioid drug-checking samples were analyzed to determine fentanyl concentrations. Median monthly fentanyl concentrations were plotted, and polynomial and autoregressive time-series analyses were performed to examine trends over time. A total of 3,621 fentanyl-positive samples were included in the study, spanning November 2017 to December 2019. Monthly median fentanyl concentrations ranged from 4.5% to 10.4%. Time-series analyses indicated that a third-degree polynomial model fit the data well (R2 = 0.639), suggesting a cyclical pattern in median concentration over time. Notably, absolute variance in fentanyl concentration decreased by an average 0.1% per month (P < 0.001). Future research should explore the relationship between fentanyl concentration and overdose to identify potential targeted harm-reduction interventions that can respond to changes in observed fentanyl concentration.