Multiple Naloxone Administrations Among Emergency Medical Service Providers is Increasing

Time Course of Reversal of Fentanyl-Induced Respiratory Depression in Healthy Subjects by Intramuscular Nalmefene and Intramuscular and Intranasal Naloxone

The increase in opioid overdose deaths, particularly involving potent, long-acting synthetic opioids, has led to calls for stronger, longer-acting opioid-overdose-reversal agents. Using an opioid-induced respiratory depression model, we investigated the onset and time course of action of naloxone and a long-acting opioid antagonist, nalmefene, in reversing the effects of an ongoing intravenous fentanyl infusion over a period of up to 100 min. Healthy, moderately experienced opioid users received intramuscular (IM) nalmefene 1 mg, IM naloxone 2 mg, or intranasal (IN) naloxone 4 mg after fentanyl-induced respiratory depression was established based on reduction in respiratory minute volume (MV). Each participant received each opioid antagonist twice per a randomized crossover schedule. Reversal of respiratory depression, pharmacokinetics, and safety were investigated. Participants showed rapid increases in plasma opioid antagonist concentrations, and meaningful reversal of depressed MV tended to occur earlier with IM nalmefene and IM naloxone than with IN naloxone. Compared to naloxone, nalmefene provided extended exposure, and mean MV was maintained at a higher level. All participants experienced treatment-related adverse events, but none were severe, serious, or led to study drug discontinuation. This study provides evidence that IM nalmefene 1 mg achieves reversal of fentanyl-induced respiratory depression similar to or better than that achieved with standard-of-care naloxone treatments. No new safety concerns were raised for IM nalmefene at the tested dose. The pharmacokinetic and pharmacodynamic properties of IM nalmefene position it as an important treatment option in opioid overdose reversal, particularly given the increasing prevalence of overdoses involving potent, long-acting synthetic opioids.

Monoclonal Antibodies Engineered with Fc Region Mutations to Extend Protection against Fentanyl Toxicity

Fentanyl and other synthetic opioids are the leading cause of drug-related deaths in the United States. mAbs that selectively target fentanyl and fentanyl analogues offer a promising strategy for treating both opioid-related overdoses and opioid use disorders. To increase the duration of efficacy of a candidate mAb against fentanyl, we selected three sets of mutations in the Fc region of an IgG1 anti-fentanyl mAb (HY6-F9DF215, HY6-F9DHS, HY6-F9YTE) to increase binding to the neonatal Fc receptor (FcRn). The mAb mutants were compared against unmodified (wild-type [WT], HY6-F9WT) anti-fentanyl mAb for fentanyl binding, thermal stability, and FcRn affinity in vitro, and for efficacy against fentanyl and mAb half-life in vivo in mice. Biolayer interferometry showed a >10-fold increase in the affinity for recombinant FcRn of the three mutant mAbs compared with HY6-F9WT. During an acute fentanyl challenge in mice, all FcRn-mutated mAbs provided equal protection against fentanyl-induced effects, and all mAbs reduced brain fentanyl levels compared with the saline group. Serum persistence of the mutant mAbs was tested in Tg276 transgenic mice expressing human FcRn. After administration of 40 mg/kg HY6-F9WT, HY6-F9DF215, HY6-F9DHS, and HY6-F9YTE, the mAbs showed half-lives of 6.3, 26.4, 14.7, and 6.9 d, respectively. These data suggest that modification of mAbs against fentanyl to bind to FcRn with higher affinity can increase their half-life relative to WT mAbs while maintaining efficacy against the toxic effects of fentanyl, further supporting their potential role as a therapeutic treatment option for opioid use disorder and overdose.

Examining the association of rurality with opioid-related morbidity and mortality in Georgia: A geospatial analysis

INTRODUCTION

The US opioid epidemic continues to escalate, with overdose deaths being the most-used metric to quantify its burden. There is significant geographic variation in opioid-related outcomes. Rural areas experience unique challenges, yet many studies oversimplify rurality characterizations. Contextual factors, such as area deprivation, are also important to consider when understanding a community's need for treatment services and prevention programming. This study aims to provide a geospatial snapshot of the opioid epidemic in Georgia using several metrics of opioid-related morbidity and mortality and explore differences by rurality across counties.

METHODS

This was a spatial ecologic study. Negative binominal regression was used to model the relationship of county rurality with four opioid-related outcomes - overdose mortality, emergency department visits, inpatient hospitalizations, and overdose reversals - adjusting for county-level sex, racial/ethnic, and age distributions. Area Deprivation Index was also included.

RESULTS

There was significant geographic variation across the state for all four opioid-related outcomes. Counts remained highest among the metro areas. For rates, counties in the top quartile of rates varied by outcome and were often rural areas. In the final models, rurality designation was largely unrelated to opioid outcomes, with the exception of medium metro areas (inversely related to hospitalizations and overdose reversals) and non-core areas (inversely related to hospitalizations), as compared to large central metro areas. Higher deprivation was significantly related to increased ED visits and hospitalizations, but not overdose mortality and reversals.

CONCLUSIONS

When quantifying the burden of the opioid epidemic in a community, it is essential to consider multiple outcomes of morbidity and mortality. Understanding what outcomes are problematic for specific communities, in combination with their demographic and socioeconomic context, can provide insight into gaps in the treatment continuum and potential areas for intervention. Additionally, compared to demographic and socioeconomic factors, rurality may no longer be a salient predictor of the severity of the opioid epidemic in an area.

Whole body physiology model to simulate respiratory depression of fentanyl and associated naloxone reversal

BACKGROUND

Opioid use in the United States and abroad is an endemic part of society with yearly increases in overdose rates and deaths. In response, the use of the safe and effective reversal agent, naloxone, is being fielded and used by emergency medical technicians at a greater rate. There is evidence that repeated dosing of a naloxone nasal spray is becoming more common. Despite this we lack repeated dosing guidelines as a function of the amount of opiate the patient has taken.

METHODS

To measure repeat dosing guidelines, we construct a whole-body model of the pharmacokinetics and dynamics of an opiate, fentanyl on respiratory depression. We then construct a model of nasal deposition and administration of naloxone to investigate repeat dosing requirements for large overdose scenarios. We run a single patient through multiple goal directed resuscitation protocols and measure total naloxone administered.

RESULTS

Here we show that naloxone is highly effective at reversing the respiratory symptoms of the patient and recommend dosing requirements as a function of the fentanyl amount administered. We show that for increasing doses of fentanyl, naloxone requirements also increase. The rescue dose displays a nonlinear response to the initial opioid dose. This nonlinear response is largely logistic with three distinct phases: onset, rapid acceleration, and a plateau period for doses above 1.2 mg.

CONCLUSIONS

This paper investigates the total naloxone dose needed to properly reverse respiratory depression associated with fentanyl overdose. We show that the current guidelines for a rescue dose may be much lower than required.

At-risk patient documentation and naloxone dispersal for a rural statewide EMS "Naloxone Leave Behind" program

Objectives

For successful Naloxone Leave Behind (NLB) programs, Emergency Medical Services (EMS) must identify patients at-risk for opioid overdose. We describe the first year of Vermont's NLB program and report rates of EMS documentation of at-risk patients with subsequent distribution of NLB kits in the subgroup of those refusing transport to an emergency department (ED).

Methods

This retrospective cohort review of all EMS encounters over 1 year compared on-scene EMS documented to retrospective chart reviewidentified at-risk patients eligible for NLB kit dispersal. EMS was educated to identify at-risk patients through statewide mandatory training modules. At-risk patients were identified by electronic chart review using the same training criteria. As per protocol, patients identified as at-risk by EMS who refuse ED transport are eligible for NLB. NLB-appropriate patients by retrospective chart review without NLB protocol use documentation by EMS were considered "missed."

Results

Of 110,701 EMS encounters, 2507 (2.4%) were at-risk by chart review. Among these, 793 refused transport to an ED. In this chart-review at-risk non-transported group, EMS documented 407 (51.3%) patients as at-risk by documenting use of the NLB protocol. Of these 407, EMS provided 141 (34.6%) with NLB kits. Fifteen (3.7%) patients refused kits. There were 386 (48.7%) potentially "missed" opportunities for NLB dispersal.

Conclusion

EMS documented 51.3% of patients eligible for NLB dispersal, with 34.6% receiving kits. There was no documentation for 48.7% of chart-review at-risk patients, suggesting "missed" distribution opportunities. This study highlights the need for improved EMS identification of at-risk patients, EMS documentation adherence, and NLB kit provision.

High-dose naloxone formulations are not as essential as we thought

Naloxone is an effective 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 investigates the adequacy of two doses of standard IM or IN naloxone in reversing fentanyl overdoses compared to newer high-dose naloxone formulations. Moreover, our initiative incorporates the experiences of people who use drugs, enabling a more practical and contextually-grounded analysis. The evidence indicates that the vast majority of fentanyl overdoses can be successfully reversed using two standard IM or IN dosages. Exceptions include cases of carfentanil overdose, which necessitates ≥ 3 doses for reversal. Multiple studies documented the risk of precipitated withdrawal using ≥ 2 doses of naloxone, notably including the possibility of recurring overdose symptoms after resuscitation, contingent upon the half-life of the specific opioid involved. We recommend distributing multiple doses of standard IM or IN naloxone to bystanders and educating individuals on the adequacy of two doses in reversing fentanyl overdoses. Individuals should continue administration until the recipient is revived, ensuring appropriate intervals between each dose along with rescue breaths, and calling emergency medical services if the individual is unresponsive after two doses. We do not recommend high-dose naloxone formulations as a substitute for four doses of IM or IN naloxone due to the higher cost, risk of precipitated withdrawal, and limited evidence compared to standard doses. Future research must take into consideration lived and living experience, scientific evidence, conflicts of interest, and the bodily autonomy of people who use drugs.

Reasons for contacting a crisis line and the initiation of emergency dispatches

OBJECTIVE

To better understand processes of mental health crisis line utilization by examining associations between reasons for contacting a crisis line with the initiation of emergency dispatches (i.e., activation of 911 or local emergency services) in a national sample.

METHODS

Contacts (i.e., calls, texts, email, and chats) to the Veterans Crisis Line (VCL) across 2017-2020 were used to examine associations among stated reasons for the contact and the use of an emergency dispatch. Hierarchical logistic regression models were used to determine the odds of an emergency dispatch by reason for the contact.

RESULTS

Suicidal thoughts/crisis were present in 61.5% of contacts that ended in emergency dispatches and were associated with the largest adjusted odds of a dispatch, (Adjusted Odds Ratio [AOR] [95% CI] = 9.34 [9.21, 9.48]), followed by homicidal thoughts/crisis (AOR [95% CI] = 3.84 [3.73, 3.95]), and third-party concerns (AOR [95% CI] = 2.42 [2.37, 2.47]). Substance use/ addiction (AOR [95% CI] = 2.14 [2.10, 2.18]), abuse and violence (AOR [95% CI] = 1.89 [1.82, 1.96]), and physical health (AOR [95% CI] = 1.87 [1.84, 1.91]) were also associated with increased odds of a dispatch.

CONCLUSIONS

Emergency dispatches are primarily used in response to imminent suicide risk but are also used in other potentially violent or lethal circumstances such as homicides, violence or abuse, and other crises. These findings highlight the role that crisis lines play in emergency service delivery, and the need to better understand how they are utilized under real world circumstances.

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.

Examination of naloxone dosing patterns for opioid overdose by emergency medical services in Kentucky during increased fentanyl use from 2018 to 2021

BACKGROUND

Fatal overdoses involving fentanyl/fentanyl analogs (F/FA) have increased in the US, raising questions about naloxone doses for F/FA overdose reversal. Emergency medical services (EMS) data provide an opportunity to examine naloxone administration changes as fentanyl increases in the illicit opioid supply.

METHODS

Administered naloxone intranasal-equivalent total dose (INTD) in milligrams (mg) was calculated for Kentucky EMS suspected opioid overdose (SOO) encounters (n=33,846), 2018-2021, and patterns of administration were examined. County-level F/FA availability was measured as 1) proportion of fatal drug overdoses involving F/FA, and 2) F/FA police seizures. Linear mixed models estimated changes in INTD in relation to local F/FA availability accounting for patient characteristics.

RESULTS

From 2018-2021, SOOs increased by 44% (6853 to 9888) with an average INTD increase from 4.5mg to 4.7mg, with more than 99% of encounters resulting in successful reversal each year. For SOO encounters examined by outcome at the scene (i.e., non-fatal fatal vs fatal), average INTD for non-fatal were 4.6mg compared to 5.9mg for fatal overdoses. Mixed modeling found no significant relationship between INTD and the two measures for local F/FA availability.

CONCLUSION

As F/FA-involved overdose risk increased, we observed a modest increase in INTD administered in SOO EMS encounters - just slightly higher than the 4mg standard dose. The lack of significant relationship between F/FA and naloxone dose suggests that naloxone utilization in SOO with EMS involvement remains effective for overdose reversal, and that EMS naloxone dosing patterns have not changed substantially.

Opioid overdose prevention training needs: Findings from emergency medical services providers in Baltimore County, Maryland

Emergency Medical Services (EMS) providers are on the frontlines of the opioid response. This study explored the EMS training needs in Baltimore County, Maryland. An online survey conducted between January-June 2021 assessed knowledge, attitudes, awareness, and self-efficacy to use opioid overdose prevention strategies; burnout, compassion fatigue, stress, and wellness; and training needs among EMS providers (N = 256). Participants reported positive attitudes toward the use of opioid treatment guidelines and confidence in their ability to use the guidelines. They indicated positive attitudes toward harm reduction, but less favorable attitudes toward opioid use disorder (OUD). Although the participants understood the role of a peer recovery specialist moderately well, they were not fully comfortable with making a referral. They reported relatively low levels of burnout and compassion fatigue and good wellness practices, but indicated a moderate level of stress associated with COVID-19. Perceived training needs included: lifetime fitness and wellness, trauma-informed care, stigma awareness, stages of change, and harm reduction. Offering these trainings and enhancing EMS providers' comfort to make referrals to peer recovery support services may strengthen the referral systems and connect overdose survivors to a continuum of care.

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.

Probing different paradigms of morphine withdrawal on sleep behavior in male and female C57BL/6J mice

Opioid misuse has dramatically increased over the last few decades resulting in many people suffering from opioid use disorder (OUD). The prevalence of opioid overdose has been driven by the development of new synthetic opioids, increased availability of prescription opioids, and more recently, the COVID-19 pandemic. Coinciding with increases in exposure to opioids, the United States has also observed increases in multiple Narcan (naloxone) administrations as a life-saving measures for respiratory depression, and, thus, consequently, naloxone-precipitated withdrawal. Sleep dysregulation is a main symptom of OUD and opioid withdrawal syndrome, and therefore, should be a key facet of animal models of OUD. Here we examine the effect of precipitated and spontaneous morphine withdrawal on sleep behaviors in C57BL/6 J mice. We find that morphine administration and withdrawal dysregulate sleep, but not equally across morphine exposure paradigms. Furthermore, many environmental triggers promote relapse to drug-seeking/taking behavior, and the stress of disrupted sleep may fall into that category. We find that sleep deprivation dysregulates sleep in mice that had previous opioid withdrawal experience. Our data suggest that the 3-day precipitated withdrawal paradigm has the most profound effects on opioid-induced sleep dysregulation and further validates the construct of this model for opioid dependence and OUD.

All Hands on Deck: We Need Multiple Approaches To Uncover the Neuroscience behind the Opioid Overdose Crisis

Opioid use disorder (OUD) affects millions of people throughout the United States, yet there are only three Food and Drug Administration-approved pharmacological treatments. Though these treatments have been shown to be effective, the number of overdose deaths continues to rise. The increase of fentanyl, fentanyl analogs, and adulterants in the illicit drug supply has further complicated treatment strategies. Preclinical researchers strive to model OUD to better understand this complicated disorder, and this research is a critical enabler for the development of novel treatments. As a result, there are many different preclinical models of OUD. Often, researchers form strong opinions on what they believe to be the "best" model to mimic the human condition. Here, we argue that researchers should be supportive of multiple models to promote new perspectives and discoveries and always consider the trends in human opioid use when designing preclinical studies. We describe the benefits of contingent and noncontingent models as well as models of opioid withdrawal and how each of these can help illuminate different components of OUD.

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.

Experiences with Medications for Addiction Treatment Among Emergency Department Patients with Opioid Use Disorder

INTRODUCTION

Medications for addiction treatment (MAT) are the evidence-based standard of care for treatment of opioid use disorder (OUD), but stigma continues to surround their use. We conducted an exploratory study to characterize perceptions of different types of MAT among people who use drugs.

METHODS

We conducted this qualitative study in adults with a history of non-medical opioid use who presented to an emergency department for complications of OUD. A semi-structured interview that explored knowledge, perceptions, and attitudes toward MAT was administered, and applied thematic analysis conducted.

RESULTS

We enrolled 20 adults. All participants had prior experience with MAT. Among participants indicating a preferred treatment modality, buprenorphine was the commonly favored agent. Previous experience with prolonged withdrawal symptoms upon MAT discontinuation and the perception of "trading one drug for another" were common reasons for reluctance to engage in agonist or partial-agonist therapy. While some participants preferred treatment with naltrexone, others were unwilling to initiate antagonist therapy due to fear of precipitated withdrawal. Most participants strongly considered the aversive nature of MAT discontinuation as a barrier to initiating treatment. Participants overall viewed MAT positively, but many had strong preferences for a particular agent.

CONCLUSION

The anticipation of withdrawal symptoms during initiation and cessation of treatment affected willingness to engage in a specific therapy. Future educational materials for people who use drugs may focus on comparisons of respective benefits and drawbacks of agonists, partial agonists, and antagonists. Emergency clinicians must be prepared to answer questions about MAT discontinuation to effectively engage patients with OUD.

Probing different paradigms of morphine withdrawal on sleep behavior in male and female C57BL/6J mice

Opioid misuse has dramatically increased over the last few decades resulting in many people suffering from opioid use disorder (OUD). The prevalence of opioid overdose has been driven by the development of new synthetic opioids, increased availability of prescription opioids, and more recently, the COVID-19 pandemic. Coinciding with increases in exposure to opioids, the United States has also observed increases in multiple Narcan (naloxone) administrations as life-saving measures for respiratory depression, and, thus, consequently, naloxone-precipitated withdrawal. Sleep dysregulation is a main symptom of OUD and opioid withdrawal syndrome, and therefore, should be a key facet of animal models of OUD. Here we examine the effect of precipitated and spontaneous morphine withdrawal on sleep behaviors in C57BL/6J mice. We find that morphine administration and withdrawal dysregulate sleep, but not equally across morphine exposure paradigms. Furthermore, many environmental triggers promote relapse to drug-seeking/taking behavior, and the stress of disrupted sleep may fall into that category. We find that sleep deprivation dysregulates sleep in mice that had previous opioid withdrawal experience. Our data suggest that the 3-day precipitated withdrawal paradigm has the most profound effects on opioid-induced sleep dysregulation and further validates the construct of this model for opioid dependence and OUD.

Highlights

Morphine withdrawal differentially dysregulates the sleep of male and female mice3-day precipitated withdrawal results in larger changes than spontaneous withdrawalOpioid withdrawal affects responses to future sleep deprivation differently between sexes.

Perceptions of prescription opioid use among rural farming and ranching communities: Preliminary implications for outreach and treatment

Background: In 2017, 45% of rural adults reported being directly impacted by the opioid epidemic. While research on the experiences of those using prescription opioids in rural communities is increasing, less is known about a unique sub-population who may have high rates of exposure: rural agricultural workers. The purpose of this study was to explore the prevalence and perceptions related to prescription opioids among rural producers and farmworkers. Methods: A questionnaire was mailed in spring 2019 and spring 2020 to rural residents living in one of two agricultural-based states in the Upper Midwest. Individuals were eligible to participate if any member of their family was involved in the agricultural industry. A total of 1116 questionnaires were returned for a 27.9% response rate. Results: Participants were 68.1 years old on average. The majority identified as white, male, and married. Prescription opioid use was found in 8.2% of households currently, and 15.7% in the past year. There were no gender differences in prevalence of use, but women and older individuals reported significantly more perceived risk than men and younger individuals. Nearly half used alternative pain management, and received most information about prescription opioids from the radio (65.5%) and newsletters (13.5%). Conclusions. Despite their elevated age and working in an occupation at high risk of injury and chronic pain, study participants reported few opioid prescriptions and moderate use of alternative pain management. Perceived risk of prescription opioids may explain low prevalence. Outreach efforts that increase access to healthcare services and alternative pain management treatments for agricultural workers may mitigate the experience of chronic pain that can interfere with their overall quality of life.

Comparison of intranasal and intramuscular naloxone in opioid overdoses managed by ambulance staff: a double-dummy, randomised, controlled trial

AIMS

To measure and evaluate clinical response to nasal naloxone in opioid overdoses in the pre-hospital environment.

DESIGN

Randomised, controlled, double-dummy, blinded, non-inferiority trial, and conducted at two centres.

SETTING

Participants were included by ambulance staff in Oslo and Trondheim, Norway, and treated at the place where the overdose occurred.

PARTICIPANTS

Men and women age above 18 years with miosis, rate of respiration ≤8/min, and Glasgow Coma Score <12/15 were included. Informed consent was obtained through a deferred-consent procedure.

INTERVENTION AND COMPARATOR

A commercially available 1.4 mg/0.1 mL intranasal naloxone was compared with 0.8 mg/2 mL naloxone administered intramuscularly.

MEASUREMENTS

The primary end-point was restoration of spontaneous respiration of ≥10 breaths/min within 10 minutes. Secondary outcomes included time to restoration of spontaneous respiration, recurrence of overdose within 12 hours and adverse events.

FINDINGS

In total, 201 participants were analysed in the per-protocol population. Heroin was suspected in 196 cases. With 82% of the participants being men, 105 (97.2%) in the intramuscular group and 74 (79.6%) in the intranasal group returned to adequate spontaneous respiration within 10 minutes after one dose. The estimated risk difference was 17.5% (95% CI, 8.9%-26.1%) in favour of the intramuscular group. The risk of receiving additional naloxone was 19.4% (95% CI, 9.0%-29.7%) higher in the intranasal group. Adverse reactions were evenly distributed, except for drug withdrawal reactions, where the estimated risk difference was 6.8% (95% CI, 0.2%-13%) in favour of the intranasal group in a post hoc analysis.

CONCLUSION

Intranasal naloxone (1.4 mg/0.1 mL) was less efficient than 0.8 mg intramuscular naloxone for return to spontaneous breathing within 10 minutes in overdose patients in the pre-hospital environment when compared head-to-head. Intranasal naloxone at 1.4 mg/0.1 mL restored breathing in 80% of participants after one dose and had few mild adverse reactions.

Real-world study of multiple naloxone administration for opioid overdose reversal among bystanders

Background

The increasing prevalence of highly potent, illicitly manufactured fentanyl and its analogues (IMF) in the USA is exacerbating the opioid epidemic which has worsened during the COVID-19 pandemic. Narcan® (naloxone HCl) Nasal Spray has been approved by the US Food and Drug Administration as a treatment for opioid-related overdoses. Due to the high potency of IMF, multiple naloxone administrations (MNA) may be needed per overdose event. It is essential to determine the patterns of naloxone use, including MNA, and preferences among bystanders who have used naloxone for opioid overdose reversal.

Methods

A cross-sectional web-based survey was administered to 125 adult US residents who administered 4 mg Narcan® Nasal Spray during an opioid overdose in the past year. The survey asked about the most recent overdose event, the use of Narcan® during the event and the associated withdrawal symptoms, and participant preferences regarding dosages of naloxone nasal spray. An open-ended voice survey was completed by 35 participants.

Results

Participants were mostly female (70%) and white (78%), while reported overdose events most frequently occurred in people who were males (54%) and white (86%). Most events (95%) were successfully reversed, with 78% using ≥ 2 doses and 30% using ≥ 3 doses of Narcan® Nasal Spray. Over 90% were worried that 1 Narcan® box may not be enough for a successful future reversal. Reported withdrawal symptoms were similar in overdose events where 1 versus ≥ 2 sprays were given. Eighty-six percent of participants reported more confidence in an 8 mg versus a 4 mg naloxone nasal spray and 77% reported a stronger preference for 8 mg over 4 mg.

Conclusions

MNA occurred in most overdose events, often involving more sprays than are provided in one Narcan® nasal spray box, and participants predominantly expressed having a stronger preference for and confidence in an 8 mg compared to a 4 mg nasal spray. This suggests the need and desire for a higher dose naloxone nasal spray formulation option. Given that bystanders may be the first to administer naloxone to someone experiencing an opioid overdose, ensuring access to an adequate naloxone supply is critical in addressing the opioid overdose epidemic.

Noradrenergic circuits and signaling in substance use disorders

The central noradrenergic system innervates almost all regions of the brain and, as such, is well positioned to modulate many neural circuits implicated in behaviors and physiology underlying substance use disorders. Ample pharmacological evidence demonstrates that α1, α2, and β adrenergic receptors may serve as therapeutic targets to reduce drug -seeking behavior and drug withdrawal symptoms. Further, norepinephrine is a key modulator of the stress response, and stress has been heavily implicated in reinstatement of drug taking. In this review, we discuss recent advances in our understanding of noradrenergic circuitry and noradrenergic receptor signaling in the context of opioid, alcohol, and psychostimulant use disorders.

Real-world study of multiple naloxone administrations for opioid overdose reversal among emergency medical service providers

Background: The increasing rates of highly potent, illicit synthetic opioids (i.e., fentanyl) in the US is exacerbating the ongoing opioid epidemic. Multiple naloxone administrations (MNA) may be required to successfully reverse opioid overdoses. We conducted a real-world study to assess the rate of MNA for opioid overdose and identify factors associated with MNA. Methods: Data from the 2015-2020 National Emergency Medical Services Information System was examined to determine trends in events requiring MNA. Logistic regression analysis was performed to determine factors associated with MNA. Results: The percentage of individuals receiving MNA increased from 18.4% in 2015 to 28.4% in 2020. The odds of an event requiring MNA significantly increased by 11% annually. The adjusted odds ratio (aOR) for MNA were greatest among males, when advanced life support (ALS) was provided, and when the dispatch complaint indicated there was a drug poisoning event. Conclusions: The 54% increase in MNA since 2015 parallels the rise in overdose deaths attributable to synthetic opioids. This growth is visible in all regions of the country, including the West, where the prevalence of illicitly manufactured synthetic opioids is intensifying. Given this phenomenon, higher naloxone formulations may fulfill an unmet need in addressing the opioid overdose crisis.

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.

The need for multiple naloxone administrations for opioid overdose reversals: A review of the literature

Background A growing challenge in the opioid epidemic is the rise of highly potent synthetic opioids, (i.e., illicitly manufactured fentanyl [IMF]) entering the US non-prescription opioid market. Successful reversal may require multiple doses of naloxone, the standard of care for opioid overdose. We conducted a narrative literature review to summarize the rates of multiple naloxone administrations (MNA) for opioid overdose reversal. Methods: A MEDLINE search was conducted for published articles using MESH search terms: opioid overdose, naloxone and multiple naloxone administration. Of the 2,101 studies identified, articles meeting inclusion/exclusion criteria were reviewed, categorized by primary and secondary outcomes of interest and summarized by data source and study design. Results: A total of 24 articles meeting eligibility criteria were included. Among EMS-based studies, MNA rates ranged from 9% to 53%; in general, bystander-reported studies were notably higher, from 16% to 89%. Variation in study design, data sources, year and geography, may have contributed to these ranges. Three studies that included longitudinal results reported a significant percent increase between 26% and 43% in annual MNA rates or a significant increase in mean naloxone doses over time (p < .001). Conclusions: This summary found that multiple naloxone administrations during opioid overdose encounters vary widely, have occurred in up to 89% of all opioid overdoses, and have significantly increased over time. Higher naloxone formulations may fulfill an unmet need in opioid overdose reversals, given the rising rates of overdoses involving IMF. Further studies are needed to gain a better understanding of MNA during opioid overdose encounters, particularly across a wider geographic region in the US in order to inform continuing efforts to combat the opioid epidemic.

Substance abuse and neurotransmission

The number of people who suffer from a substance abuse disorder has continued to rise over the last decade; particularly, the number of drug-related overdose deaths has sharply increased during the COVID-19 pandemic. Converging lines of clinical observations, supported by imaging and neuropsychological performance testing, have demonstrated that substance abuse-induced dysregulation of neurotransmissions in the brain is critical for development and expression of the addictive properties of abused substances. Recent scientific advances have allowed for better understanding of the neurobiological processes that mediates drugs of abuse and addiction. This chapter presents the past classic concepts and the recent advances in our knowledge about how cocaine, amphetamines, opioids, alcohol, and nicotine alter multiple neurotransmitter systems, which contribute to the behaviors associated with each drug. Additionally, we discuss the interactive effects of HIV-1 or COVID-19 and substance abuse on neurotransmission and neurobiological pathways. Finally, we introduce therapeutic strategies for development of pharmacotherapies for substance abuse disorders.

Treatment of overdose in the synthetic opioid era

Overdose deaths are often viewed as the leading edge of the opioid epidemic which has gripped the United States over the past two decades (Skolnick, 2018a). This emphasis is perhaps unsurprising because opioid overdose is both the number-one cause of death for individuals between 25 and 64 years old (Dezfulian et al., 2021) and a significant contributor to the decline in average lifespan (Dowell et al., 2017). Exacerbated by the COVID 19 pandemic, it was estimated there were 93,400 drug overdose deaths in the United States during the 12 months ending December 2020, with more than 69,000 (that is, >74%) of these fatalities attributed to opioid overdose (Ahmad et al., 2021). However, the focus on mortality statistics (Ahmad et al., 2021; Shover et al., 2020) tends to obscure the broader medical impact of nonfatal opioid overdose. Analyses of multiple databases indicate that for each opioid-induced fatality, there are between 6.4 and 8.4 non-fatal overdoses, exacting a significant burden on both the individual and society. Over the past 7-8 years, there has been an alarming increase in the misuse of synthetic opioids ("synthetics"), primarily fentanyl and related piperidine-based analogs. Within the past 2-3 years, a structurally unrelated class of high potency synthetics, benzimidazoles exemplified by etonitazene and isotonitazene ("iso"), have also appeared in illicit drug markets (Thompson, 2020; Ujvary et al. 2021). In 2020, it was estimated that over 80% of fatal opioid overdoses in the United States now involve synthetics (Ahmad et al., 2021). The unique physicochemical and pharmacological properties of synthetics described in this review are responsible for both the morbidity and mortality associated with their misuse as well as their widespread availability. This dramatic increase in the misuse of synthetics is often referred to as the "3rd wave" (Pardo et al., 2019; Volkow and Blanco, 2020) of the opioid epidemic. Among the consequences resulting from misuse of these potent opioids is the need for higher doses of the competitive antagonist, naloxone, to reverse an overdose. The development of more effective reversal agents such as those described in this review is an essential component of a tripartite strategy (Volkow and Collins, 2017) to reduce the biopsychosocial impact of opioid misuse in the "synthetic era".

Fentanyl causes naloxone-resistant vocal cord closure: A platform for testing opioid overdose treatments

BACKGROUND

High doses of the synthetic opioid fentanyl cause rapid and sustained vocal cord closure (VCC) leading to airway obstruction that prevents overdose victims from breathing. This airway effect is not caused by morphine-derived opiates (e.g. heroin), is distinct from respiratory depression, resistant to naloxone, and can be lethal. However, VCC has not been previously included in animal models of opioid overdose.

METHODS

Video laryngoscopy was used to monitor vocal cord movement in anesthetized Sprague-Dawley rats. Rats were administered saline, fentanyl (5, 25, or 50 μg/kg) or morphine (5 mg/kg) in an intravenous (IV) bolus delivered over a 10 s period. The mu opioid receptor (MOR) antagonist naloxone was administered as a pre-treatment (1 mg/kg, IV) 5 min prior to fentanyl (25 μg/kg) or a post-treatment (1 and 2 mg/kg) 1 min after fentanyl (25 μg/kg).

RESULTS

Fentanyl (25 and 50 μg/kg) caused sustained and lethal VCC within 10 s. Morphine (5 mg/kg) and fentanyl (5 μg/kg) caused only brief laryngospasm with full recovery. Pre-treatment with naloxone (1 mg/kg) prevented fentanyl-induced VCC, but naloxone (1 and 2 mg/kg) was unable to reverse VCC when administered after fentanyl.

CONCLUSIONS

These results indicate sustained VCC is a lethal physiological reaction, specific to fentanyl and resistant to naloxone treatment. While pre-treatment with naloxone prevented fentanyl-induced VCC, naloxone was unable to reverse the effect, suggesting a non-opioid receptor-mediated mechanism. These findings demonstrate the necessity of VCC inclusion in animal models of synthetic opioid overdose and the urgent need for more effective treatments for fentanyl-related overdoses.

A drug-related Good Samaritan Law and calling emergency medical services for drug overdoses in a Canadian setting

Background

People who use drugs (PWUD) are known to fear calling emergency medical services (EMS) for drug overdoses. In response, drug-related Good Samaritan Laws (GSLs) have been widely adopted in the USA and Canada to encourage bystanders to call emergency medical services (EMS) in the event of a drug overdose. However, the effect of GSLs on EMS-calling behaviours has been understudied. We sought to identify factors associated with EMS-calling, including the enactment of the Canadian GSL in May 2017, among PWUD in Vancouver, Canada, a setting with an ongoing overdose crisis.

Methods

Data were derived from three prospective cohort studies of PWUD in Vancouver in 2014–2018. Multivariable logistic regression was used to determine factors associated with EMS-calling among PWUD who witnessed an overdose event. An interrupted time series (ITS) analysis was employed to assess the impact of GSL on monthly prevalence of EMS-calling.

Results

Among 540 eligible participants, 321 (59%) were males and 284 (53%) reported calling EMS. In multivariable analysis, ever having administered naloxone three or more times (adjusted odds ratio [AOR] 2.00; 95% confidence interval [CI] 1.08–3.74) and residence in the Downtown Eastside (DTES) neighbourhood of Vancouver (AOR 1.96; 95% CI 1.23–3.13) were positively associated with EMS-calling, while living in a single occupancy hotel (SRO) was negatively associated with EMS-calling (AOR 0.51; 95% CI 0.30–0.86). The post-GSL enactment period was not associated with EMS-calling (AOR 0.81; 95% CI 0.52–1.25). The ITS found no significant difference in the monthly prevalence of EMS-calling between pre- and post-GSL enactment periods.

Conclusion

We observed EMS being called about half the time and the GSL did not appear to encourage EMS-calling. We also found that individuals living in SROs were less likely to call EMS, which raises concern given that fatal overdose cases are concentrated in SROs in our setting. The link between many naloxone administrations and EMS-calling could indicate that those with prior experience in responding to overdose events were more willing to call EMS. Increased efforts are warranted to ensure effective emergency responses for drug overdoses among PWUD.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12954-021-00537-w.

Opioid-related incident severity and emergency medical service naloxone administration by sex in Massachusetts, 2013-2019

BACKGROUND

A Cross-sectional study of all emergency ambulance runs reported by licensed Emergency Medical Services (EMS) providers between 2013 and 2019 was undertaken to determine if the sex of a patient experiencing opioid-related symptoms had an impact on their odds of receiving naloxone from EMS. Methods: All runs within Massachusetts for individuals 11 years and older with a reported sex between 2013 and 2019 (n = 5,533,704 runs) were included. Covariates modeled were patient age, year of the incident, and county of the incident. Runs were separated into those that were opioid-related versus not; opioid-related runs were further subdivided into five severity categories including dead on arrival, acute opioid overdose, opioid intoxicated, opioid withdrawal, and other opioid-related incident. Results: Among opioid-related runs, women had 24% lower odds (95% CI 0.68-0.86) of appearing in the dead on arrival category and 20% lower odds (95% CI 0.78-0.82) of appearing in the acute opioid overdose category than men. Among acute opioid overdoses, runs where patient symptoms met Massachusetts EMS guidelines for naloxone administration, women had 18% lower odds (95% CI 0.76-0.89) of receiving naloxone than men. Conclusions: Sex-related differences persist in the odds of naloxone administration by EMS providers when controlling for symptom presentation.

Overdoses due to fentanyl and its analogues (F/FAs) push naloxone to the limit

WHAT IS KNOWN AND OBJECTIVE

Food and Drug Administration (FDA) risk evaluation and mitigation strategies (REMs) encourage emergency responders, paramedics, law enforcement agents, and even laypeople to be trained in the administration of naloxone with the intent of rescuing individuals from a known or suspected opioid overdose.

COMMENT

Although naloxone is generally safe and effective at reversing respiratory depression caused by a conventional opioid such as morphine or heroin by competing with the opioid and displacing it from the μ-opioid receptor, questions increasingly are arising as to whether naloxone can adequately reverse opioid overdoses that may involve the potent opioids fentanyl and its analogues (F/FAs). In other words, as more and more opioid overdoses involve F/FAs, can naloxone keep up?

WHAT IS NEW AND CONCLUSION

As a competitive antagonist at μ-opioid receptors, naloxone is often a life-saving agent in cases of overdose caused by conventional opioids, but it may not be versatile or powerful enough to combat the rising tide of overdoses due to fentanyl and its illicit analogues, or in cases of overdose involving combinations of opioids and non-opioids.

The dawn of a new synthetic opioid era: the need for innovative interventions

BACKGROUND

Overdose deaths related to illegal drugs in North American markets are now dominated by potent synthetic opioids such as fentanyl, a circumstance foreshadowed by often-overlooked events in Estonia since the turn of the century. Market transitions generate important and far-reaching implications for drug policy.

ARGUMENT AND ANALYSIS

The supplier-driven introduction of illegally manufactured synthetic opioids into street opioids is elevating the risk of fatal overdose. Using the most recent overdose mortality and drug seizure data in North America, we find that overdose deaths and seizures involving synthetic opioids are geographically concentrated, but this might be changing. Examination here suggests that in some places fentanyl and its analogues have virtually displaced traditional opioids, such as heroin. The concealing of synthetic opioids in powders sold as heroin or pressed into counterfeit medications substantially increases harms. The nature and scale of the challenge posed by synthetic opioids is unprecedented in recent drug policy history.

CONCLUSIONS

There is urgent need for policy and technological innovation to meet the challenges posed by illegally produced synthetic opioids. Novel interventions worth examining include supervising drug use, proactively deterring on-line distribution and new technologies aimed at improving transparency, such as point-of-use drug content testing. Continuing to approach this problem only with existing policies and available methods, such as naloxone, is unlikely to be enough and will result in many premature deaths.

Refusal to accept emergency medical transport following opioid overdose, and conditions that may promote connections to care

BACKGROUND

Opioid overdose is a leading cause of death in the United States. Emergency medical services (EMS) encounters following overdose may serve as a critical linkage to care for people who use drugs (PWUD). However, many overdose survivors refuse EMS transport to hospitals, where they would presumably receive appropriate follow-up services and referrals. This study aims to (1) identify reasons for refusal of EMS transport after opioid overdose reversal; (2) identify conditions under which overdose survivors might be more likely to accept these services; and (3) describe solutions proposed by both PWUD and EMS providers to improve post-overdose care.

METHODS

The study comprised 20 semi-structured, qualitative in-depth interviews with PWUD, followed by two semi-structured focus groups with eight EMS providers.

RESULTS

PWUD cited intolerable withdrawal symptoms; anticipation of inadequate care upon arrival at the hospital; and stigmatizing treatment by EMS and hospital providers as main reasons for refusal to accept EMS transport. EMS providers corroborated these descriptions and offered solutions such as titration of naloxone to avoid harsh withdrawal symptoms; peer outreach or community paramedicine; and addressing provider burnout. PWUD stated they might accept EMS transport after overdose reversal if they were offered ease for withdrawal symptoms, at either a hospital or non-hospital facility, and treated with respect and empathy.

CONCLUSION

Standard of care by EMS and hospital providers following overdose reversal should include treatment for withdrawal symptoms, including buprenorphine induction; patient-centered communication; and effective linkage to prevention, treatment, and harm reduction services.

Increases in Naloxone Administrations by Emergency Medical Services Providers During the COVID-19 Pandemic: Retrospective Time Series Study

BACKGROUND

The opioid crisis in the United States may be exacerbated by the COVID-19 pandemic. Increases in opioid use, emergency medical services (EMS) runs for opioid-related overdoses, and opioid overdose deaths have been reported. No study has examined changes in multiple naloxone administrations, an indicator of overdose severity, during the COVID-19 pandemic.

OBJECTIVE

This study examines changes in the occurrence of naloxone administrations and multiple naloxone administrations during EMS runs for opioid-related overdoses during the COVID-19 pandemic in Guilford County, North Carolina (NC).

METHODS

Using a period-over-period approach, we compared the occurrence of opioid-related EMS runs, naloxone administrations, and multiple naloxone administrations during the 29-week period before (September 1, 2019, to March 9, 2020) and after NC's COVID-19 state of emergency declaration (ie, the COVID-19 period of March 10 to September 30, 2020). Furthermore, historical data were used to generate a quasi-control distribution of period-over-period changes to compare the occurrence of each outcome during the COVID-19 period to each 29-week period back to January 1, 2014.

RESULTS

All outcomes increased during the COVID-19 period. Compared to the previous 29 weeks, the COVID-19 period experienced increases in the weekly mean number of opioid-related EMS runs (25.6, SD 5.6 vs 18.6, SD 6.6; P<.001), naloxone administrations (22.3, SD 6.2 vs 14.1, SD 6.0; P<.001), and multiple naloxone administrations (5.0, SD 1.9 vs 2.7, SD 1.9; P<.001), corresponding to proportional increases of 37.4%, 57.8%, and 84.8%, respectively. Additionally, the increases during the COVID-19 period were greater than 91% of all historical 29-week periods analyzed.

CONCLUSIONS

The occurrence of EMS runs for opioid-related overdoses, naloxone administrations, and multiple naloxone administrations during EMS runs increased during the COVID-19 pandemic in Guilford County, NC. For a host of reasons that need to be explored, the COVID-19 pandemic appears to have exacerbated the opioid crisis.

Association of Patient Sex and Pregnancy Status With Naloxone Administration During Emergency Department Visits

OBJECTIVE

To evaluate the association of sex and pregnancy status with rates of naloxone administration during opioid overdose-related emergency department (ED) visits by using the Nationwide Emergency Department Sample.

METHODS

A retrospective cohort study was conducted using the Nationwide Emergency Department Sample 2016 and 2017 data sets. Eligible records included men and women, 15-49 years of age, with an opioid overdose-related ED visit; records for women were stratified by pregnancy status (International Classification of Diseases, Tenth Revision O codes). A multivariable logistic regression model was used to assess the primary outcome of naloxone administration (Current Procedural Terminology code: J2310). Secondary outcomes included subsequent admission and mortality. A subgroup analysis compared pregnant women who did receive naloxone compared with those who did not receive naloxone.

RESULTS

Records from 443,714 men, 304,364 nonpregnant women, and 25,056 pregnant women were included. Nonpregnant women had lower odds for naloxone administration (1.70% vs 2.10%; adjusted odds ratio [aOR] 0.86 [95% CI 0.83-0.89]) and mortality (2.21% vs 2.99%; aOR 0.71 [95% CI 0.69-0.73]) but higher odds of subsequent admission (30.22% vs 27.18%; aOR 1.04 [95% CI 1.03-1.06]) compared with men. Pregnant women had lower odds for naloxone administration (0.27% vs 1.70%; aOR 0.16 [95% CI 0.13-0.21]) and mortality (0.41% vs 2.21%; aOR 0.28 [95% CI 0.23-0.35]) but higher odds of subsequent admission (40.50% vs 30.22%; aOR 2.04 [95% CI 2.00-2.10]) compared with nonpregnant women. Pregnant women who received naloxone had higher odds of mortality (14% vs 0.39%; aOR 6.30 [95% CI 2.11-18.78]) compared with pregnant women who did not receive naloxone. Pregnant women who did not receive naloxone were more likely to have Medicaid as their expected insurance payer, be in the lowest quartile of median household income for residence ZIP codes, and have a concurrent mental health diagnosis compared with pregnant women who did receive naloxone.

CONCLUSION

Reproductive-aged women who are nonpregnant and pregnant were less likely to receive naloxone during opioid overdose-related ED visits compared with reproductive-aged men. Naloxone administration for reproductive-aged women should be prioritized in the efforts to reduce opioid- and pregnancy-related morbidity and mortality in the United States.

Are opioid receptor antagonists adequate for "Opioid" overdose in a changing reality?

WHAT IS KNOWN AND OBJECTIVE

Deaths due to opioid-induced respiratory depression (OIRD) continue to rise despite intense regulatory and professional actions. COVID-19 has only worsened this situation.¹ An opioid receptor antagonist (ORA) such as naloxone is the most common intervention for OIRD. However, with increasing overdose from highly potent illicit opioids and polysubstance abuse, appraisal of the adequacy of ORA seems warranted and timely.

COMMENT

OIRD results from the binding of an excess number of agonist molecules to opioid receptors. Mechanistically, it makes sense to reverse this by displacing agonist molecules by administering an ORA. But realistically, the trend to higher-potency agonists and polysubstance abuse diminishes the effectiveness of this approach. We are left facing a crisis without a solution.

WHAT IS NEW AND CONCLUSION

For the increasingly common OIRD from highly potent illicit agonists and polysubstance overdose, ORAs are correspondingly less effective. Alternatives are needed-soon.

Outcomes following Naloxone Administration by Bystanders and First Responders

Background: Naloxone is widely available to bystanders and first responders to treat patients with suspected opioid overdose. In these patients, the prognostic factors and potential benefits associated with additional naloxone administered by emergency medical services (EMS) are uncertain. Objectives: We sought to identify prognostic factors for admission to the hospital following prehospital administration of naloxone for suspected opioid overdose by bystanders and first responders. We secondarily examined whether administration of additional naloxone by paramedics after initial treatment by non-EMS personnel was associated with improvement in level of consciousness prior to hospital arrival. Methods: This is a retrospective cross-sectional study of patients treated within a single urban EMS system from 2013 to 2016. Inclusion criteria were administration of naloxone by bystanders or first responders and transport to one of three academic medical centers. For the secondary analysis, only patients with a Glasgow Coma Scale (GCS) score ≤12 on paramedic arrival were included. We performed univariate and multivariable analyses examining a primary outcome of hospital admission and secondary outcome of improvement in consciousness as defined by GCS >12 in patients with initial GCS ≤12. Results: Of 359 patients identified for the primary analysis, 60 were admitted to the hospital. Factors associated with increased rate of admission included higher total naloxone dosage (OR 1.36, 95% CI 1.09-1.70) and presence of alternate/additional non-opioid central nervous system (CNS) depressants (OR 2.51, 95% CI 1.13-5.56). Among 178 patients who had poor neurologic status (GCS ≤12) on paramedic arrival following naloxone administered by bystander or first responder, administration of additional naloxone was not associated with a better rate of neurologic improvement prior to hospital arrival (77% improved with additional naloxone, 81% improved without additional naloxone; OR 0.82, 95% CI 0.39-1.76). Conclusions: Among patients with suspected opioid overdose treated with naloxone by bystanders and first responders, a higher total dose of naloxone and polysubstance intoxication with additional CNS depressants were predictors of admission. Administration of additional naloxone by paramedics was not associated with a higher rate of neurologic improvement prior to hospital arrival, suggesting a ceiling effect on naloxone efficacy in opioid overdose.

Opioid-Associated Out-of-Hospital Cardiac Arrest: Distinctive Clinical Features and Implications for Health Care and Public Responses: A Scientific Statement From the American Heart Association

Opioid overdose is the leading cause of death for Americans 25 to 64 years of age, and opioid use disorder affects >2 million Americans. The epidemiology of opioid-associated out-of-hospital cardiac arrest in the United States is changing rapidly, with exponential increases in death resulting from synthetic opioids and linear increases in heroin deaths more than offsetting modest reductions in deaths from prescription opioids. The pathophysiology of polysubstance toxidromes involving opioids, asphyxial death, and prolonged hypoxemia leading to global ischemia (cardiac arrest) differs from that of sudden cardiac arrest. People who use opioids may also develop bacteremia, central nervous system vasculitis and leukoencephalopathy, torsades de pointes, pulmonary vasculopathy, and pulmonary edema. Emergency management of opioid poisoning requires recognition by the lay public or emergency dispatchers, prompt emergency response, and effective ventilation coupled to compressions in the setting of opioid-associated out-of-hospital cardiac arrest. Effective ventilation is challenging to teach, whereas naloxone, an opioid antagonist, can be administered by emergency medical personnel, trained laypeople, and the general public with dispatcher instruction to prevent cardiac arrest. Opioid education and naloxone distributions programs have been developed to teach people who are likely to encounter a person with opioid poisoning how to administer naloxone, deliver high-quality compressions, and perform rescue breathing. Current American Heart Association recommendations call for laypeople and others who cannot reliably establish the presence of a pulse to initiate cardiopulmonary resuscitation in any individual who is unconscious and not breathing normally; if opioid overdose is suspected, naloxone should also be administered. Secondary prevention, including counseling, opioid overdose education with take-home naloxone, and medication for opioid use disorder, is important to prevent recurrent opioid overdose.

Internet search and medicaid prescription drug data as predictors of opioid emergency department visits

The primary contributors to the opioid crisis continue to rapidly evolve both geographically and temporally, hampering the ability to halt the growing epidemic. To address this issue, we evaluated whether integration of near real-time social/behavioral (i.e., Google Trends) and traditional health care (i.e., Medicaid prescription drug utilization) data might predict geographic and longitudinal trends in opioid-related Emergency Department (ED) visits. From January 2005 through December 2015, we collected quarterly State Drug Utilization Data; opioid-related internet search terms/phrases; and opioid-related ED visit data. Modeling was conducted using least absolute shrinkage and selection operator (LASSO) regression prediction. Models combining Google and Medicaid variables were a better fit and more accurate (R2 values from 0.913 to 0.960, across states) than models using either data source alone. The combined model predicted sharp and state-specific changes in ED visits during the post 2013 transition from heroin to fentanyl. Models integrating internet search and drug utilization data might inform policy efforts about regional medical treatment preferences and needs.

Polysubstance use in the U.S. opioid crisis

Interventions to address the U.S. opioid crisis primarily target opioid use, misuse, and addiction, but because the opioid crisis includes multiple substances, the opioid specificity of interventions may limit their ability to address the broader problem of polysubstance use. Overlap of opioids with other substances ranges from shifts among the substances used across the lifespan to simultaneous co-use of substances that span similar and disparate pharmacological categories. Evidence suggests that nonmedical opioid users quite commonly use other drugs, and this polysubstance use contributes to increasing morbidity and mortality. Reasons for adding other substances to opioids include enhancement of the high (additive or synergistic reward), compensation for undesired effects of one drug by taking another, compensation for negative internal states, or a common predisposition that is related to all substance consumption. But consumption of multiple substances may itself have unique effects. To achieve the maximum benefit, addressing the overlap of opioids with multiple other substances is needed across the spectrum of prevention and treatment interventions, overdose reversal, public health surveillance, and research. By addressing the multiple patterns of consumption and the reasons that people mix opioids with other substances, interventions and research may be enhanced.

A qualitative study of repeat naloxone administrations during opioid overdose intervention by people who use opioids in New York City

BACKGROUND

Take-home naloxone (THN) kits have been designed to provide community members (including people who use drugs, their families and/or significant others) with the necessary resources to address out-of-hospital opioid overdose events. Kits typically include two doses of naloxone. This 'twin-pack' format means that lay responders need information on how to use each dose. Advice given tends to be based on dosage algorithms used by medical personnel. However, little is currently known about how and why people who use drugs, acting as lay responders, decide to administer the second dose contained within single THN kits. The aim of this article is to explore this issue.

METHODS

Data were generated from a qualitative semi-structured interview study that was embedded within a randomised controlled trial examining the risks and benefits of Overdose Education and Naloxone Distribution (OEND) training in New York City (NYC). Analysis for this article focuses upon the experiences of 22 people who use(d) opioids and who provided repeat naloxone administrations (RNA) during 24 separate overdose events. The framework method of analysis was used to compare the time participants believed had passed between each naloxone dose administered ('subjective response interval') with the 'recommended response interval' (2-4 minutes) given during OEND training. Framework analysis also charted the various reasons and rationale for providing RNA during overdose interventions.

RESULTS

When participants' subjective response intervals were compared with the recommended response interval for naloxone dosing, three different time periods were reported for the 24 overdose events: i. 'two doses administered in under 2 minutes' (n = 10); ii. 'two doses administered within 2-4 minutes' (n = 7), and iii. 'two doses administered more than 4 minutes apart' (n = 7). A variety of reasons were identified for providing RNA within each of the three categories of response interval. Collectively, reasons for RNA included panic, recognition of urgency, delays in retrieving naloxone kit, perceptions of recipients' responsiveness/non-responsiveness to naloxone, and avoidance of Emergency Response Teams (ERT).

CONCLUSION

Findings suggest that decision-making processes by people who use opioids regarding how and when to provide RNA are influenced by factors that relate to the emergency event. In addition, the majority of RNA (17/24) occurred outside of the recommended response interval taught during OEND training. These findings are discussed in terms of evidence-based intervention and 'evidence-making intervention' with suggestions for how RNA guidance may be developed and included within future/existing models of OEND training.

Prehospital Naloxone and Emergency Department Adverse Events: A Dose-Dependent Relationship

BACKGROUND

The purpose of this study was to evaluate prehospital and emergency department (ED) interventions and outcomes of patients who received prehospital naloxone for a suspected opioid overdose.

OBJECTIVES

The primary objective was to evaluate if the individual dose, individual route, total dose, number of prehospital naloxone administrations, or occurrence of a prehospital adverse event (AE) were associated with the occurrence of AEs in the ED. Secondary objectives included a subset analysis of patients who received additional naloxone while in the ED, or were admitted to an intensive care or step-down unit (ICU).

METHODS

This was a retrospective, observational chart review of adult patients who received prehospital naloxone and were transported by ambulance to a suburban academic tertiary care center between 2014 and 2017. Descriptive, univariate, and multivariate statistics were used, with p < 0.05 indicating significance.

RESULTS

There were 513 patients included in the analysis, with a median age of 29 years, and median total prehospital naloxone dose of 2 mg. An increasing number of prehospital naloxone doses, an occurrence of a prehospital AE, and a route of administration other than intranasally for the first dose of prehospital naloxone were significantly associated with an increased likelihood of an ED AE. Patients who received < 2 mg of prehospital naloxone had the least likelihood of being admitted to an ICU, whereas patients who received at least 6 mg had a dramatically increased likelihood of ICU admission.

CONCLUSIONS

Our results suggest that an increasing number of prehospital naloxone doses was significantly associated with an increased likelihood of an ED adverse event.

A review of performance assessment tools for rescuer response in opioid overdose simulations and training programs

Since the 1990s, more than 600 overdose response training and education programs have been implemented to train participants to respond to an opioid overdose in the United States. Given this substantial investment in overdose response training, valid assessment of a potential rescuers' proficiency in responding to an opioid overdose is important. The aim of this article is to review the current state of the literature on outcome measures utilized in opioid overdose response training. Thirty-one articles published between 2014 and 2020 met inclusion criteria. The reviewed articles targeted laypersons, healthcare providers, and first responders. The assessment tools included five validated questionnaires, fifteen non-validated questionnaires, and nine non-validated simulation-based checklists (e.g., completion of critical tasks and time to completion). Validated multiple choice knowledge assessment tools were commonly used to assess the outcomes of training programs. It is unknown how scores on these assessment tools may correlate with actual rescuer performance responding to an overdose. Seven studies reported ceiling effects most likely attributed to participants' background medical knowledge or experience. The inclusion of simulation-based outcome measures of performance, including the commission of critical errors and the time to naloxone administration, provides better insight into rescuer skill proficiency.

A mixed-methods approach to understanding overdose risk-management strategies among a nationwide convenience sample

BACKGROUND

This mixed-methods study compared drug use histories between individuals who had a reported non-fatal overdose to individuals who did not and described the overdose risk-management strategies as they were experienced by a sample of people who use drugs (PWUD). Shifts from non-medical prescription opioid use (NMPOU) to the use of heroin and synthetic opioids have been implicated in national increases in overdose incidences in the United States. However, relatively limited data exists regarding the narrative experiences of the evolving overdose risk management strategies among a nationwide sample of PWUD.

METHODS

Data recruitment was conducted via Amazon's mTurk crowdsourcing technology and was collected through semi-structured interviews that occurred in 2019. Participants (N = 60) with a history of NMPOU with transition to heroin or fentanyl use were recruited.

RESULTS

Participants reporting a previous non-fatal overdose were more likely to report a history of injection drug use, a history of heroin injection, greater overdose risk knowledge, and current medication for opioid use disorder (MOUD) use. Qualitative analysis revealed that participants attempted to mitigate overdose risk in primarily three ways: 1) self-regulation; 2) harm reduction; and 3) passive approach. Self-regulatory measures included administering small or incremental dosing, being mindful of personal tolerance limits, and avoiding the initiation of injection drug use. Harm reduction measures used to protect from overdose included carrying Narcan and relying on trusted drug-suppliers as references to drug purity. A passive approach indicated that participants relied on "luck" or divine support systems where religiosity and faith were endorsed as factors that mitigated personal overdose risk.

CONCLUSION

Participants reported successful overdose mitigation via self-regulation, which may suggest that PWUDs were capable at managing their drug use amid the overdose crisis. The importance of the drug-supplier relationship was critical to many in reducing their overdose risk as formal harm reduction services (e.g., safe injection sites) remain inaccessible in the U.S. Implications for drug policy and harm reduction interventions are discussed.

A Framework for EMS Outreach for Drug Overdose Survivors: A Case Report of the Houston Emergency Opioid Engagement System

OBJECTIVE

Fatalities from drug-induced overdoses in the United States have taken greater than 292,000 lives in the last five years, and nearly two-thirds of these are opioid-related. The burden on prehospital emergency medical services (EMS) to respond to these incidents is growing. The standard of care typically involves overdose reversal and rapid transport, although a few agencies have begun to use community paramedicine to more proactively follow-up, initiate treatment, and refer patients to addiction medicine providers. Methods: In this manuscript we share the details of an outreach case study to serve as a blueprint for other agencies and municipalities to adopt and refine. The University of Texas Health Science Center, in partnership with the Houston Fire Department and other local first responder agencies, developed a program in Houston, Texas based on rapid response to post-overdose survivors using available incident data from the primary municipal agencies. Results: The Houston Emergency Opioid Engagement System (HEROES) was created to more comprehensively address the opioid epidemic. By utilizing data extracted from the patient care record system, a team comprised of a peer recovery coach and a paramedic is dispatched to the home location of a recent overdose (OD) incident to provide outreach. Conclusions: Outreach dialog and motivational interviewing techniques are used to provide awareness of treatment options and to engage individuals into a treatment program. A case report of this program and recommendations for broader adoption are presented.

Inhibitory transmission in the bed nucleus of the stria terminalis in male and female mice following morphine withdrawal

The United States is experiencing an opioid crisis imposing enormous fiscal and societal costs and driving the staggering overdose death rate. While prescription opioid analgesics are essential for treating acute pain, cessation of use in individuals with a physical dependence induces an aversive withdrawal syndrome that promotes continued drug use to alleviate/avoid these symptoms. Additionally, repeated bouts of withdrawal often lead to an increased propensity for relapse. Understanding the neurobiology underlying withdrawal is essential for providing novel treatment options to alleviate physiological and affective components accompanying the cessation of opiate use. Here, we administered morphine and precipitated withdrawal with naloxone to investigate behavioral and cellular responses in C57BL/6J male and female mice. Following 3 days of administration, both male and female mice demonstrated sensitized withdrawal symptoms. Since the bed nucleus of the stria terminalis (BNST) plays a role in mediating withdrawal-associated behaviors, we examined plastic changes in inhibitory synaptic transmission within this structure 24 hours following the final precipitated withdrawal. In male mice, morphine withdrawal increased spontaneous GABAergic signaling compared with controls. In contrast, morphine withdrawal decreased spontaneous GABAergic signaling in female mice. Intriguingly, these opposing GABAergic effects were contingent upon activity-dependent dynamics within the ex vivo slice. Our findings suggest that male and female mice exhibit some divergent cellular responses in the BNST following morphine withdrawal, and alterations in BNST inhibitory signaling may contribute to the expression of behaviors following opioid withdrawal.

One year mortality of patients treated with naloxone for opioid overdose by emergency medical services

Study objective: Prehospital use of naloxone for presumed opioid overdose has increased markedly in recent years because of the current opioid overdose epidemic. In this study, we determine the 1-year mortality of suspected opioid overdose patients who were treated with naloxone by EMS and initially survived. Methods: This was a retrospective observational study of patients using three linked statewide datasets in Massachusetts: emergency medical services (EMS), a master demographics file, and death records. We included all suspected opioid overdose patients who were treated with naloxone by EMS. The primary outcome measures were death within 3 days of treatment and between 4 days and 1 year of treatment. Results: Between July 1, 2013 and December 31, 2015, there were 9734 individuals who met inclusion criteria and were included for analysis. Of these, 807 (8.3% (95% confidence interval (CI) 7.7-8.8%)) died in the first 3 days, 668 (6.9% (95% CI 6.4-7.4%)) died between 4 days and 1 year, and 8259 (84.8% (95% CI 84.1-85.6%)) were still alive at 1 year. Excluding those who died within 3 days, 668 of the remaining 8927 individuals (7.5% (95% CI 6.9-8.0%)) died within 1 year. Conclusion: The 1-year mortality of those who are treated with naloxone for opioid overdose by EMS is high. Communities should focus both on primary prevention and interventions for this patient population, including strengthening regional treatment centers and expanding access to medication for opioid use disorder.

The spatio-temporal distribution of naloxone administration events in rural Ohio 2010-16

INTRODUCTION

In 2017, Ohio had the second highest rate of drug overdose deaths in the United States. Current opioid related epidemiologic literature has begun to uncover the environmental level influences on the opioid epidemic and how the end results may ultimately manifest over space and time. This work is still nascent however, with most clustering research conducted at a spatial unit such as county level, which (1) can obscure differences between urban and rural communities, (2) does not consider dynamics that cross county lines, and (3) is difficult to interpret directly into strategic and localized intervention efforts. We address this gap by describing, at the Census block level, the spatial-temporal clustering of opioid related events in rural Ohio.

METHODS

We use the outcome of the administration of naloxone emergency medical service (EMS) calls in rural Ohio Census blocks during 2010-16 in a Poisson model of spatial scan statistics.

RESULTS

We found that naloxone event clustering in rural Ohio in the recent decade was widely dispersed over time and space, with clusters that average 17 times the risk of having an event compared to areas outside the cluster. Many of the larger spatial clusters crossed administrative boundaries (i.e., county lines) suggesting that opioid misuse may be less responsive to county level policies than to other factors.

DISCUSSION

Timely identification of localized overdose event clustering can guide affected communities toward rapid interventions aimed at minimizing the morbidity and mortality resulting from contagious opioid misuse.

Strengths and weaknesses of existing data sources to support research to address the opioids crisis

Better opioid prescribing practices, promoting effective opioid use disorder treatment, improving naloxone access, and enhancing public health surveillance are strategies central to reducing opioid-related morbidity and mortality. Successfully advancing and evaluating these strategies requires leveraging and linking existing secondary data sources. We conducted a scoping study in Fall 2017 at RAND, including a literature search (updated in December 2018) complemented by semi-structured interviews with policymakers and researchers, to identify data sources and linking strategies commonly used in opioid studies, describe data source strengths and limitations, and highlight opportunities to use data to address high-priority public health research questions. We identified 306 articles, published between 2005 and 2018, that conducted secondary analyses of existing data to examine one or more public health strategies. Multiple secondary data sources, available at national, state, and local levels, support such research, with substantial breadth in data availability, data contents, and the data's ability to support multi-level analyses over time. Interviewees identified opportunities to expand existing capabilities through systematic enhancements, including greater support to states for creating and facilitating data use, as well as key data challenges, such as data availability lags and difficulties matching individual-level data over time or across datasets. Multiple secondary data sources exist that can be used to examine the impact of public health approaches to addressing the opioid crisis. Greater data access, improved usability for research purposes, and data element standardization can enhance their value, as can improved data availability timeliness and better data comparability across jurisdictions.

Endogenous opiates and behavior: 2017

This paper is the fortieth consecutive installment of the annual anthological review of research concerning the endogenous opioid system, summarizing articles published during 2017 that studied the behavioral effects of molecular, pharmacological and genetic manipulation of opioid peptides and receptors as well as effects of opioid/opiate agonists and antagonists. The review is subdivided into the following specific topics: molecular-biochemical effects and neurochemical localization studies of endogenous opioids and their receptors (1), the roles of these opioid peptides and receptors in pain and analgesia in animals (2) and humans (3), opioid-sensitive and opioid-insensitive effects of nonopioid analgesics (4), opioid peptide and receptor involvement in tolerance and dependence (5), stress and social status (6), learning and memory (7), eating and drinking (8), drug abuse and alcohol (9), sexual activity and hormones, pregnancy, development and endocrinology (10), mental illness and mood (11), seizures and neurologic disorders (12), electrical-related activity and neurophysiology (13), general activity and locomotion (14), gastrointestinal, renal and hepatic functions (15), cardiovascular responses (16), respiration and thermoregulation (17), and immunological responses (18).