Randomized controlled trial comparing the effectiveness and safety of intranasal and intramuscular naloxone for the treatment of suspected heroin overdose

What is the Evidence for Using Intranasal Medicine in the Prehospital Setting? A Systematic Review

OBJECTIVES

Intranasal (IN) medications offer a safe non-invasive way to rapidly deliver drugs in situations where intravenous (IV) access and intramuscular (IM) administration is challenging or not feasible. In the prehospital setting, this can be an essential alternative in time critical situations including trauma management, seizures, and agitated patients. However, there is a paucity of evidence summarizing its efficacy in this environment. This systematic review aims to assess the current evidence supporting the use of IN medicine (midazolam, ketamine, fentanyl, morphine, glucagon, and naloxone) in the prehospital setting alone.

METHODS

A systematic literature search (PROSPERO CRD42023440713) of PubMed, Web of Science, OVID Medline, "Cochrane Central Register of Controlled Trials," Cochrane reviews and Embase was performed from inception to June 2023 to identify studies where IN medications were administered to patients in the prehospital setting. All randomized controlled trials, observational cohort studies, case series, and case reports were included. Papers not written in English, review articles, abstracts, and non-published data (including letters to the editor) were excluded. The methodological quality of the included studies was interpreted using the Cochrane risk of bias tool and rated using the Grading of Recommendations Assessment, Development, and Evaluation (GRADE) approach. No funding was received.

RESULTS

From 4818 studies, 39 were included (seven for midazolam, five for ketamine, twelve for fentanyl, one for diamorphine, two for glucagon, and twelve for naloxone). A total of 24,097 patients were treated with IN medications across all the studies. There were five moderate quality, four low quality, and thirty very low quality studies. The potential efficacy of IN fentanyl and ketamine was demonstrated consistently throughout the studies with less clear evidence for midazolam, morphine, glucagon, and naloxone. This review was severely limited by the study quality, with most studies demonstrating "high concerns" for bias.

CONCLUSIONS

Prehospital IN medication administration has wide-ranging potential, particularly for administering analgesia. There are likely to be certain populations, for example, pediatrics, that will benefit the most, although conclusions are limited by the quality of evidence currently available. We encourage additional research in this area, particularly with robust prospective double-blind RCTs.

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.

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.

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.

Acute opioid overdose in pediatric patients

Recent increases in pediatric and adolescent opioid fatalities mandate an urgent need for early consideration of possible opioid exposure and specific diagnostic and management strategies and interventions tailored to these unique populations. In contrast to adults, pediatric methods of exposure include accidental ingestions, prescription misuse, and household exposure. Early recognition, appropriate diagnostic evaluation, along with specialized treatment for opioid toxicity in this demographic are discussed. A key focus is on Naloxone, an essential medication for opioid intoxication, addressing its unique challenges in pediatric use. Unique pediatric considerations include recognition of accidental ingestions in our youngest population, critical social aspects including home safety and intentional exposure, and harm reduction strategies, mainly through Naloxone distribution and education on safe medication practices. It calls for a multifaceted approach, including creating pediatric-specific guidelines, to combat the opioid crisis among children and to work to lower morbidity and mortality from opioid overdoses.

Adverse Effects After Prehospital Administration of Naloxone by Bystanders: A Preliminary Study

OBJECTIVE

Opioid use disorder is a cause of significant morbidity and mortality. In order to reverse opioid overdose as quickly as possible, many institutions and municipalities have encouraged people with no professional medical training to carry and administer naloxone. This study sought to provide preliminary data for research into the rates of adverse effects of naloxone when administered by bystanders compared to Emergency Medical Services (EMS) personnel, since this question has not been studied previously.

METHODS

This was a retrospective cohort study performed at an urban, tertiary, academic medical center that operates its own EMS service. A consecutive sample of patients presenting to EMS with opioid overdose requiring naloxone was separated into two groups based on whether naloxone was administered by bystanders or by EMS personnel. Each group was analyzed to determine the incidence of four pre-specified adverse events.

RESULTS

There was no significant difference in the rate of adverse events between the bystander (19%) and EMS (16%) groups (OR = 1.23; 95% CI, 0.63 - 2.32; P = .499) in this small sample. Based on these initial results, a study would need a sample size of 6,188 in order to reach this conclusion with 80% power. Similarly, there were no significant differences in the rates of any of the individual adverse events. Secondary analysis of patients' demographics showed differences between the two groups which generate hypotheses for further investigation of disparities in naloxone administration.

CONCLUSIONS

This preliminary study provides foundational data for further investigation of naloxone administration by bystanders. Adverse events after the prehospital administration of naloxone are rare, and future studies will require large sample sizes. These preliminary data did not demonstrate a statistically significant difference in adverse event rates when comparing naloxone administration by bystanders and EMS clinicians. This study provides data that will be useful for conducting further research on multiple facets of this topic.

The impact of anaphylaxis on the absorption of intranasal epinephrine in anaesthetized non-naive beagle dogs

Background

Epinephrine delivery via an intranasal spray (neffy) is being evaluated as an additional option to treat severe allergic reaction and may provide clinical benefit by reducing the time to dosing in community settings by avoiding needles. Given that hypotension is a hallmark symptom of severe allergic reactions, a preclinical study was conducted to evaluate the impact of this factor on epinephrine absorption via neffy.

Objective

The objective of this study was to evaluate the absorption of epinephrine via neffy in a dog model of anaphylaxis with severe hypotension.

Methods

Epinephrine absorption via neffy was evaluated in anesthetized beagle dogs under both normal conditions and hypotension associated with anaphylaxis. A total of 14 dogs (10 males and 4 females) were dosed with neffy, 1.0 mg, under normal conditions, followed by neffy, 1.0 mg, under conditions of anaphylaxis.

Results

The mean maximum concentration of epinephrine was higher during anaphylaxis than under normal conditions (2,670 ± 2,150 pg/mL and 1,330 ± 739 pg/mL [P < .05]). Relative to normal conditions, anaphylaxis resulted in higher overall epinephrine exposure (area under the curve from 0 to 45 minutes = 54,400 ± 18,100 min × pg/mL and 34,300 ± 21,500 minutes × pg/mL [P < .05]), which is likely due to the increase in vascular permeability commonly observed during severe allergic reactions.

Conclusion

Taken together with real-world evidence from nasal naloxone treatment for opioid overdose demonstrating that the reduced blood flow or hypotension associated with overdose does not appear to suppress naloxone's efficacy, the current findings demonstrate that epinephrine is well absorbed following neffy delivery during the hypotension associated with severe anaphylaxis reactions.

2023 American Heart Association Focused Update on the Management of Patients With Cardiac Arrest or Life-Threatening Toxicity Due to Poisoning: An Update to the American Heart Association Guidelines for Cardiopulmonary Resuscitation and Emergency Cardiovascular Care

In this focused update, the American Heart Association provides updated guidance for resuscitation of patients with cardiac arrest, respiratory arrest, and refractory shock due to poisoning. Based on structured evidence reviews, guidelines are provided for the treatment of critical poisoning from benzodiazepines, β-adrenergic receptor antagonists (also known as β-blockers), L-type calcium channel antagonists (commonly called calcium channel blockers), cocaine, cyanide, digoxin and related cardiac glycosides, local anesthetics, methemoglobinemia, opioids, organophosphates and carbamates, sodium channel antagonists (also called sodium channel blockers), and sympathomimetics. Recommendations are also provided for the use of venoarterial extracorporeal membrane oxygenation. These guidelines discuss the role of atropine, benzodiazepines, calcium, digoxin-specific immune antibody fragments, electrical pacing, flumazenil, glucagon, hemodialysis, hydroxocobalamin, hyperbaric oxygen, insulin, intravenous lipid emulsion, lidocaine, methylene blue, naloxone, pralidoxime, sodium bicarbonate, sodium nitrite, sodium thiosulfate, vasodilators, and vasopressors for the management of specific critical poisonings.

Efficacy of the intranasal application of azaperone for sedation in weaned piglets

The aim of the study was to compare the efficacy of the intranasal and parenteral administration of azaperone in order to achieve pig sedation. A total of 32 weaned piglets divided into 4 groups (8 piglets in each group) were used. Group A was injected intramuscularly (i.m.) with azaperone (Stresnil®, 40 mg/ml inj.; Elanco Animal Health) at a dose of 2 mg/kg of body weight (b.w.). Group B received a dose of 2 mg/kg b.w. of azaperone intranasally. Group C was given azaperone intranasally at a dose of 4 mg/kg b.w. Group D was given 1 ml of saline intranasally and served as the control group. The response to the defined stimulus (a blunt blow of a metal rod into a metal edge of a pen), the degree of salivation, movement level, body temperature and serum azaperone concentration were included in the trial. We found that in order to induce an adequate level of sedation comparable to the standard method of application, i.e., 2 mg/kg b.w. i.m., the intranasal administration of azaperone at a dose of 4 mg/kg body weight is required.

Overcoming challenges in acute care hospitalizations for patients with opioid use disorder

BACKGROUND

Hospitalized patients with opioid use disorder (OUD) present unique challenges and opportunities for inpatient medical teams. Having the ability to initiate medications for opioid use disorder (MOUD) and linkage to outpatient treatment are key to improve inpatient care of patients with OUD.

OBJECTIVE

This study aimed to describe the process taken by a multidisciplinary work group to improve the acute care management of patients with OUD.

PRACTICE DESCRIPTION

In 2018, we identified that inpatient care teams at the University of Chicago Medicine (UCM) lacked a standardized approach to the management of hospitalized patients with OUD and that the care typically did not include evidence-based therapies. Herein, we describe the process taken to develop the OUD workgroup and the work completed by the workgroup.

PRACTICE INNOVATION

The OUD workgroup spearheaded the development of an OUD consult service, formulary revisions, education for health care workers (inpatient nurse training and X-waiver training for prescribers), and outpatient partnerships. Pharmacy-led initiatives included formulary management, electronic medication orders, naloxone co-prescribing decision support, and MOUD education.

EVALUATION METHODS

The OUD consult service was granted an Institutional Review Board exemption for quality improvement analysis through UCM. A data analytics dashboard was built to track consult service volumes and outcomes.

RESULTS

From July 2020 to April 2021, 296 OUD consults occurred. In total, 103 consult patients (35%) received and were discharged with buprenorphine. An additional 118 patients (40%) were managed with methadone and linked to outpatient care. Naloxone dispensing at discharge increased to over 65%, which did not include patients who opted out or were discharged to a facility.

CONCLUSION

The ongoing OUD epidemic presents a need for the development of services to improve management of patients with OUD in the acute care setting. The OUD workgroup has improved the management of patients admitted with OUD. Pharmacy-based initiatives are key to the development of safe and effective management of OUD in hospitalized patients.

Management of opioid use disorder, opioid withdrawal, and opioid overdose prevention in hospitalized adults: A systematic review of existing guidelines

BACKGROUND

Hospitalizations related to the consequences of opioid use are rising. National guidelines directing in-hospital opioid use disorder (OUD) management do not exist. OUD treatment guidelines intended for other treatment settings could inform in-hospital OUD management.

OBJECTIVE

Evaluate the quality and content of existing guidelines for OUD treatment and management.

DATA SOURCES

OVID MEDLINE, PubMed, Ovid PsychINFO, EBSCOhost CINHAL, ERCI Guidelines Trust, websites of relevant societies and advocacy organizations, and selected international search engines.

STUDY SELECTION

Guidelines published between January 2010 to June 2020 addressing OUD treatment, opioid withdrawal management, opioid overdose prevention, and care transitions among adults.

DATA EXTRACTION

We assessed quality using the Appraisal of Guidelines for Research and Evaluation (AGREE) II instrument.

DATA SYNTHESIS

Nineteen guidelines met the selection criteria. Most recommendations were based on observational studies or expert consensus. Guidelines recommended the use of nonstigmatizing language among patients with OUD; to assess patients with unhealthy opioid use for OUD using the Diagnostic Statistical Manual of Diseases-5th Edition criteria; use of methadone or buprenorphine to treat OUD and opioid withdrawal; use of multimodal, nonopioid therapy, and when needed, short-acting opioid analgesics in addition to buprenorphine or methadone, for acute pain management; ensuring linkage to ongoing methadone or buprenorphine treatment; referring patients to psychosocial treatment; and ensuring access to naloxone for opioid overdose reversal.

CONCLUSIONS

Included guidelines were informed by studies with various levels of rigor and quality. Future research should systematically study buprenorphine and methadone initiation and titration among people using fentanyl and people with pain, especially during hospitalization.

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.

Perioperative Opioids, the Opioid Crisis, and the Anesthesiologist

This review summarizes current evidence related to perioperative opioid prescription fulfillment and use and discusses the role of personalized anesthesia care in mitigating opioid-related harms without compromising analgesia.

Treatment of opioid overdose: current approaches and recent advances

BACKGROUND

The USA has recently entered the third decade of the opioid epidemic. Opioid overdose deaths reached a new record of over 74,000 in a 12-month period ending April 2021. Naloxone is the primary opioid overdose reversal agent, but concern has been raised that naloxone is not efficacious against the pervasive illicit high potency opioids (i.e., fentanyl and fentanyl analogs).

METHODS

This narrative review provides a brief overview of naloxone, including its history and pharmacology, and the evidence regarding naloxone efficacy against fentanyl and fentanyl analogs. We also highlight current advances in overdose treatments and technologies that have been tested in humans.

RESULTS AND CONCLUSIONS

The argument that naloxone is not efficacious against fentanyl and fentanyl analogs rests on case studies, retrospective analyses of community outbreaks, pharmacokinetics, and pharmacodynamics. No well-controlled studies have been conducted to test this argument, and the current literature provides limited evidence to suggest that naloxone is ineffective against fentanyl or fentanyl analog overdose. Rather a central concern for treating fentanyl/fentanyl analog overdose is the rapidity of overdose onset and the narrow window for treatment. It is also difficult to determine if other non-opioid substances are contributing to a drug overdose, for which naloxone is not an effective treatment. Alternative pharmacological approaches that are currently being studied in humans include other opioid receptor antagonists (e.g., nalmefene), respiratory stimulants, and buprenorphine. None of these approaches target polysubstance overdose and only one novel approach (a wearable naloxone delivery device) would address the narrow treatment window.

UNDERSTANDING PREFERENCES FOR TYPE OF TAKE-HOME NALOXONE DEVICE: INTERNATIONAL QUALITATIVE ANALYSIS OF THE VIEWS OF PEOPLE WHO USE OPIOIDS

Background

Take-home naloxone (THN) is provided to non-medically trained people to reverse potential opioid overdoses. There is an increasing range of effective intramuscular (IM) and intranasal (IN) naloxone devices and this paper explores the types preferred by people who use opioids, using consumer behaviour literature to interpret the findings.

Methods

Data derive from two unconnected qualitative studies involving audio-recorded semi-structured interviews. Study 1 was conducted in the United States (n=21 users of non-medical/illicit opioids). Study 2 was conducted in Australia (n=42 users of non-medical/illicit or prescribed opioids).

Findings

Most participants preferred IN naloxone. Preferences were based on the ease, speed, safety and comfort of each device and underpinned by accounts of overdose revivals as being very rushed and frightening situations. Preferences related to complex interactions between the naloxone device ('product'); the knowledge, skills, experience and attitudes of the lay responder ('consumer'), and when, where and how naloxone was to be used ('usage situation').

Conclusions

THN programs should offer choice of device when possible and nasal naloxone if resources permit. Asking people which devices they prefer and why and treating them as valued consumers of naloxone products can generate insights that improve future naloxone technology and increase THN uptake and usage.

Adverse events related to bystander naloxone administration in cases of suspected opioid overdose in British Columbia: An observational study

Introduction

Take-Home Naloxone programs have been introduced across North America in response to rising opioid overdose deaths. There is currently limited real-world data on bystander naloxone administration, overdose outcomes, and evidence related to adverse events following bystander naloxone administration.

Methods

The research team used descriptive statistics from Take-Home Naloxone administration forms. We explored reported demographic variables and adverse events among people who received by-stander administered naloxone in a suspected opioid overdose event between August 31, 2012 and December 31, 2018 in British Columbia. We examined and contextualized differences across years given policy, program and drug toxicity changes. We used multivariate logistic regression to examine whether an association exists between number of ampoules of naloxone administered and the odds that the recipient will experience withdrawal symptoms.

Results

A large majority (98.1%) of individuals who were administered naloxone survived their overdose and 69.2% had no or only mild withdrawal symptoms. Receiving three (Adjusted Odds Ratio (AOR) 1.64 (95% Confidence Interval (CI): 1.08–2.48)) or four or more (AOR 2.19 (95% CI: 1.32–3.62)) ampoules of naloxone was significantly associated with odds of moderate or severe withdrawal compared to receiving one ampoule of naloxone.

Conclusions

This study provides evidence from thousands of bystander reversed opioid overdoses using Take-Home Naloxone kits in British Columbia, and suggests bystander-administered naloxone is safe and effective for opioid overdose reversal. Data suggests an emphasis on titration during bystander naloxone training in situations where the person experiencing overdose can be adequately ventilated may help avoid severe withdrawal symptoms. We identified a decreasing trend in the likelihood of moderate or severe withdrawal over the study period.

Understanding opioid overdose risk and response preparedness among people who use cocaine and other drugs: Mixed-methods findings from a large, multi-city study

BACKGROUND

Fatal overdoses involving cocaine (powdered or crack) and fentanyl have increased nationally and in Massachusetts. It is unclear how overdose risk and preparedness to respond to an overdose differs by patterns of cocaine and opioid use. Methods: From 2017 to 2019, we conducted a nine-community mixed-methods study of Massachusetts residents who use drugs. Using survey data from 465 participants with past-month cocaine and/or opioid use, we examined global differences (p < 0.05) in overdose risk and response preparedness by patterns of cocaine and opioid use. Qualitative interviews (n = 172) contextualized survey findings. Results: The majority of the sample (66%) used cocaine and opioids in the past month; 18.9% used opioids alone; 9.2% used cocaine and had no opioid use history; and 6.2% used cocaine and had an opioid use history. Relative to those with a current/past history of opioid use, significantly fewer of those with no opioid use history were aware of fentanyl in the drug supply, carried naloxone, and had received naloxone training. Qualitative interviews documented how people who use cocaine and have no history of opioid use are largely unprepared to recognize and respond to an overdose. Conclusions: Public health efforts are needed to increase fentanyl awareness and overdose prevention preparedness among people primarily using cocaine.

S-ketamine and intranasal application: alternatives for the castration of male suckling piglets?

Background

The intramuscular injection of ketamine and azaperone was proposed as a suitable anaesthesia for male suckling piglets for surgical castration. However, this can be opposed by massive defensive movements, hypothermia and tachycardia during castration and a long recovery period. The aim of the present study was to test whether the use of S-ketamine and/or a change in the route of application from intramuscular to intranasal could reduce stress responses and the duration of recovery compared to the intramuscular route and the use of racemic ketamine. Seventy-eight healthy, five-day-old male piglets were randomized to six treatment groups in a blinded experimental study, matched by litter and weight. Experimental groups were A (15 mg kg-1 S-ketamine + 2 mg kg-1 azaperone, i.m., surgical castration), B (15 mg kg-1 R/S-ketamine racemate + 2 mg kg-1 azaperone, i.m., surgical castration), C (30 mg kg-1 S-ketamine + 2 mg kg-1 azaperone, i.n., surgical castration), D (15 mg kg-1 R/S-ketamine racemate + 2 mg kg-1 azaperone, i.m.; not castrated), E (positive control group; no anesthesia, surgical castration) and F (negative control group; no anesthesia, not castrated).

Results

S-ketamine reduced the defensive movement score during castration to a similar extent to racemic ketamine when administered intramuscularly but not via the intranasal route. However, the effects of S-ketamine (both routes) on the increase in cortisol levels and decrease in body temperature were similar to those induced by racemic ketamine. A reduction of the long recovery time known for ketamine-azaperone anaesthesia could not be achieved with S-ketamine in the given dosage, regardless of the route of application. The intranasal administration of ketamine was difficult with the available formulation as the necessary amount exceeded the capacity of the nose cavity.

Conclusions

Neither the use of S-ketamine nor intranasal administration can be suitable alternatives for the anaesthesia of male suckling piglets for castration.

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.

Management of pharmaceutical and recreational drug poisoning

BACKGROUND

Poisoning is one of the leading causes of admission to the emergency department and intensive care unit. A large number of epidemiological changes have occurred over the last years such as the exponential growth of new synthetic psychoactive substances. Major progress has also been made in analytical screening and assays, enabling the clinicians to rapidly obtain a definite diagnosis.

METHODS

A committee composed of 30 experts from five scientific societies, the Société de Réanimation de Langue Française (SRLF), the Société Française de Médecine d'Urgence (SFMU), the Société de Toxicologie Clinique (STC), the Société Française de Toxicologie Analytique (SFTA) and the Groupe Francophone de Réanimation et d'Urgences Pédiatriques (GFRUP) evaluated eight fields: (1) severity assessment and initial triage; (2) diagnostic approach and role of toxicological analyses; (3) supportive care; (4) decontamination; (5) elimination enhancement; (6) place of antidotes; (7) specificities related to recreational drug poisoning; and (8) characteristics of cardiotoxicant poisoning. Population, Intervention, Comparison, and Outcome (PICO) questions were reviewed and updated as needed, and evidence profiles were generated. Analysis of the literature and formulation of recommendations were then conducted according to the GRADE® methodology.

RESULTS

The SRLF-SFMU guideline panel provided 41 statements concerning the management of pharmaceutical and recreational drug poisoning. Ethanol and chemical poisoning were excluded from the scope of these recommendations. After two rounds of discussion and various amendments, a strong consensus was reached for all recommendations. Six of these recommendations had a high level of evidence (GRADE 1±) and six had a low level of evidence (GRADE 2±). Twenty-nine recommendations were in the form of expert opinion recommendations due to the low evidences in the literature.

CONCLUSIONS

The experts reached a substantial consensus for several strong recommendations for optimal management of pharmaceutical and recreational drug poisoning, mainly regarding the conditions and effectiveness of naloxone and N-acetylcystein as antidotes to treat opioid and acetaminophen poisoning, respectively.

NTNU intranasal naloxone trial (NINA-1) study protocol for a double-blind, double-dummy, non-inferiority randomised controlled trial comparing intranasal 1.4 mg to intramuscular 0.8 mg naloxone for prehospital use

INTRODUCTION

Intranasal (IN) naloxone is widely used to treat opioid overdoses. The advantage of nasal administration compared with injection lies in its suitability for administration by lay people as it is needless. Approved formulations of nasal naloxone with bioavailability of approximately 50% have only undergone trials in healthy volunteers, while off-label nasal sprays with low bioavailability have been studied in patients. Randomised clinical trials are needed to investigate efficacy and safety of approved IN naloxone in patients suffering overdose. This study investigates whether the administration of 1.4 mg naloxone in 0.1 mL per dose is non-inferior to 0.8 mg intramuscular injection in patients treated for opioid overdose.

METHODS AND ANALYSIS

Sponsor is the Norwegian University of Science and Technology. The study has been developed in collaboration with user representatives. The primary endpoint is the restoration of spontaneous respiration≥10 breaths/min based on a sample of 200 opioid overdose cases. Double-dummy design ensures blinding, which will be maintained until the database is locked.

ETHICS AND DISSEMINATION

The study was approved by the Norwegian Medicines Agency and Regional Ethics Committees (REC: 2016/2000). It adheres to the Good Clinical Practice guidelines as set out by the International Council for Harmonisation of Technical Requirements for Pharmaceuticals for Human Use.Informed consent will be sought through a differentiated model. This allows for deferred consent after inclusion for patients who have regained the ability to consent. Patients who are unable to consent prior to discharge by emergency services are given written information and can withdraw at a later date in line with user recommendations. Metadata will be published in the Norwegian University of Science and Technology Open repository. Deidentified individual participant data will be made available to recipients conditional of data processor agreement being entered.

TRIAL REGISTRATION NUMBERS

EudraCT Registry (2016-004072-22) and Clinicaltrials.gov Registry (NCT03518021).

Intranasal versus intramuscular naloxone for opioid overdose

Review of: Dietze P, Jauncey M, Salmon A. Effect of intranasal vs intramuscular naloxone on opioid overdose: a randomised clinical trial. JAMA Network Open 2019;2:e1914977.

Protocol for Take-home naloxone In Multicentre Emergency (TIME) settings: feasibility study

Background

Opioids, such as heroin, kill more people worldwide by overdose than any other type of drug, and death rates associated with opioid poisoning in the UK are at record levels (World Drug Report 2018 [Internet]. [cited 2019 Nov 19]. Available from: http://www.unodc.org/wdr2018/; Deaths related to drug poisoning in England and Wales - Office for National Statistics [Internet]. [cited 2019 Nov 19]. Available from: https://www.ons.gov.uk/peoplepopulationandcommunity/birthsdeathsandmarriages/deaths/bulletins/deathsrelatedtodrugpoisoninginenglandandwales/2018registrations). Naloxone is an opioid antagonist which can be distributed in ‘kits’ for administration by witnesses in an overdose emergency. This intervention is known as take-home naloxone (THN). We know that THN can save lives on an individual level, but there is currently limited evidence about the effectiveness of THN distribution on an aggregate level, in specialist drug service settings or in emergency service settings. Notably, we do not know whether THN kits reduce deaths from opioid overdose in at-risk populations, if there are unforeseen harms associated with THN distribution or if THN is cost-effective. In order to address this research gap, we aim to determine the feasibility of a fully powered cluster randomised controlled trial (RCT) of THN distribution in emergency settings.

Methods

We will carry out a feasibility study for a RCT of THN distributed in emergency settings at four sites, clustered by Emergency Department (ED) and catchment area within its associated ambulance service. THN is a peer-administered intervention. At two intervention sites, emergency ambulance paramedics and ED clinical staff will distribute THN to adult patients who are at risk of opioid overdose. At two control sites, practice will carry on as usual. We will develop a method of identifying a population to include in an evaluation, comprising people at risk of fatal opioid overdose, who may potentially receive naloxone included in a THN kit.

We will gather anonymised outcomes up to 1 year following a 12-month ‘live’ trial period for patients at risk of death from opioid poisoning. We expect approximately 100 patients at risk of opioid overdose to be in contact with each service during the 1-year recruitment period. Our outcomes will include deaths, emergency admissions, intensive care admissions, and ED attendances. We will collect numbers of eligible patients attended by participating in emergency ambulance paramedics and attending ED, THN kits issued, and NHS resource usage. We will determine whether to progress to a fully powered trial based on pre-specified progression criteria: sign-up of sites (n = 4), staff trained (≥ 50%), eligible participants identified (≥ 50%), THN provided to eligible participants (≥ 50%), people at risk of death from opioid overdose identified for inclusion in follow-up (≥ 75% of overdose deaths), outcomes retrieved for high-risk individuals (≥ 75%), and adverse event rate (< 10% difference between study arms).

Discussion

This feasibility study is the first randomised, methodologically robust investigation of THN distribution in emergency settings. The study addresses an evidence gap related to the effectiveness of THN distribution in emergency settings. As this study is being carried out in emergency settings, obtaining informed consent on behalf of participants is not feasible. We therefore employ novel methods for identifying participants and capturing follow-up data, with effectiveness dependent on the quality of the available routine data.

Trial registration

ISRCTN13232859 (Registered 16/02/2018)

Effects of Intranasal Epinephrine on Cerebrospinal Fluid Epinephrine Pharmacokinetics, Nasal Mucosa, Plasma Epinephrine Pharmacokinetics, and Cardiovascular Changes

PURPOSE

We aimed to assess intranasal (IN) epinephrine effects on cerebrospinal fluid (CSF) absorption, nasal mucosa quality, plasma epinephrine pharmacokinetics (PK), and cardiovascular changes in dogs.

METHODS

CSF epinephrine concentration was measured and nasal mucosa quality was evaluated after IN epinephrine 4 mg and one or two 4 mg doses (21 min apart), respectively. Maximum plasma concentration [C_max], time to C_max [T_max], area under the curve from 0 to 120 min [AUC_0-120], and cardiovascular effects were evaluated after epinephrine IN (4 and 5 mg) and intramuscular (IM; 0.3 mg). Clinical observations were assessed.

RESULTS

After epinephrine IN, there were no changes in CSF epinephrine or nasal mucosa. C_max, T_max, and AUC_1-120 were similar following epinephrine IN and IM. Epinephrine IN versus IM increased plasma epinephrine at 1 min (mean ± SEM, 1.15 ± 0.48 for 4 mg IN and 1.7 ± 0.72 for 5 mg IN versus 0.47 ± 0.11 ng/mL for 0.3 mg IM). Epinephrine IN and IM produced similar heart rate and ECG results. Clinical observations included salivation and vomiting.

CONCLUSIONS

Epinephrine IN did not alter CSF epinephrine or nasal tissue and had similar cardiovascular effects as epinephrine IM. Epinephrine IN rapidly increased plasma epinephrine concentration versus epinephrine IM.

Intranasal epinephrine in dogs: Pharmacokinetic and heart rate effects

Epinephrine is the standard of care for the treatment of severe allergy and anaphylaxis. Epinephrine is most often administered through the intramuscular (IM) route via autoinjector. The current study aimed to evaluate an alternative method of epinephrine treatment through intranasal (IN) delivery in dogs. The pharmacokinetic (PK) parameters of maximum plasma concentration (Cmax ), time to reach maximum plasma concentration (Tmax ), and area under the plasma concentration-time curve from 0 to 90 minutes (AUC0-90 ) were observed after IN epinephrine (2, 3, 4, 5, 10, and 20 mg) and IM epinephrine via autoinjector (0.15 and 0.3 mg) for 90 minutes. Heart rate effects were measured after IN (2 and 5 mg) and IM (0.15 and 0.3 mg) epinephrine administration. IN epinephrine (5 mg) demonstrated significantly greater plasma epinephrine concentration at 1 minute as compared with IM epinephrine (0.3 mg) (1.68 ± 0.65 ng/mL vs 0.21 ± 0.08 ng/mL, P = .03). There were no significant differences in Cmax , Tmax , and AUC0-90 between 2-mg IN and 0.15-mg IM epinephrine or between 5-mg IN and 0.3-mg IM epinephrine. IN epinephrine reduced heart rate increases, as compared to IM epinephrine. IN and IM epinephrine were both well-tolerated. Overall, IN epinephrine demonstrated advantages over IM epinephrine, including the rapid increase in plasma epinephrine and lack of increased heart rate over time.

Protocol for a multi-site study of the effects of overdose prevention education with naloxone distribution program in Skåne County, Sweden

BACKGROUND

Continuously high rates of overdose deaths in Sweden led to the decision by the Skåne County to initiate the first regional take-home naloxone program in Sweden. The project aims to study the effect of overdose prevention education and naloxone distribution on overdose mortality in Skåne County. Secondary outcome measures include non-fatal overdoses and overdose-related harm in the general population, as well as cohort-specific effects in study participants regarding overdoses, mortality and retention in naloxone program.

METHODS

Implementation of a multi-site train-the-trainer cascade model was launched in June 2018. Twenty four facilities, including opioid substitution treatment units, needle exchange programs and in-patient addiction units were included for the first line of start-up, aspiring to reach a majority of individuals at-risk within the first 6 months. Serving as self-sufficient naloxone hubs, these units provide training, naloxone distribution and study recruitment. During 3 years, questionnaires are obtained from initial training, follow up, every sixth month, and upon refill. Estimated sample size is 2000 subjects. Naloxone distribution rates are reported, by each unit, every 6 months. Medical diagnoses, toxicological raw data and data on mortality and cause of death will be collected from national and regional registers, both for included naloxone recipients and for the general population. Data on vital status and treatment needs will be collected from registers of emergency and prehospital care.

DISCUSSION

Despite a growing body of literature on naloxone distribution, studies on population effect on mortality are scarce. Most previous studies and reports have been uncontrolled, thus not being able to link naloxone distribution to survival, in relation to a comparison period. As Swedish registers present the opportunity to monitor individuals and entire populations over time, conditions for conducting systematic follow-ups in the Swedish population are good, serving the opportunity to study the impact of large scale overdose prevention education and naloxone distribution and thus fill the knowledge gap.

TRIAL REGISTRATION

Naloxone Treatment in Skåne County - Effect on Drug-related Mortality and Overdose-related Complications, NCT03570099, registered on 26 June 2018.

Pharmacokinetic and pharmacodynamic considerations in developing a response to the opioid epidemic

Introduction: Opioids continue to be used widely for pain management. Widespread availability of prescription opioids has led to opioid abuse and addiction. Besides steps to reduce inappropriate prescribing, exploiting opioid pharmacology to make their use safer is important.Areas covered: This article discusses the pathology and factors underlying opioid abuse. Pharmacokinetic and pharmacodynamic properties affecting abuse liability of commonly abused opioids have been highlighted. These properties inform the development of ideal abuse deterrent products. Mechanisms and cost-effectiveness of available abuse deterrent products have been reviewed in addition to the pharmacology of medications used to treat addiction.Expert opinion: The opioid crisis presents unique challenges to managing pain effectively given the limited repertoire of strong analgesics. The 5-point strategy to combat the opioid crisis calls for better preventive, treatment, and recovery services, better data, better pain management, better availability of overdose-reversing drugs and better research. There is an urgent need to decrease the cost of abuse deterrent opioids which deters their cost-effectiveness. In addition, discovery of novel analgesics, further insight into central and peripheral pain mechanisms, understanding genomic risk profiles for efficient targeted efforts, and education will be key to winning this fight against the opioid crisis.

Take-Home Naloxone for the Emergency Interim Management of Opioid Overdose: The Public Health Application of an Emergency Medicine

Naloxone is a well-established essential medicine for the treatment of life-threatening heroin/opioid overdose in emergency medicine. Over two decades, the concept of 'take-home naloxone' has evolved, comprising pre-provision of an emergency supply to laypersons likely to witness an opioid overdose (e.g. peers and family members of people who use opioids as well as non-medical personnel), with the recommendation to administer the naloxone to the overdose victim as interim care while awaiting an ambulance. There is an urgent need for more widespread naloxone access considering the growing problem of opioid overdose deaths, accounting for more than 100,000 deaths worldwide annually. Rises in mortality are particularly sharp in North America, where the ongoing prescription opioid problem is now overlaid with a rapid growth in overdose deaths from heroin and illicit fentanyl. Using opioids alone is dangerous, and the mortality risk is clustered at certain times and contexts, including on prison release and discharge from hospital and residential care. The provision of take-home naloxone has required the introduction of new legislation and new naloxone products. These include pre-filled syringes and auto-injectors and, crucially, new concentrated nasal sprays (four formulations recently approved in different countries) with speed of onset comparable to intramuscular naloxone and relative bioavailability of approximately 40-50%. Choosing the right naloxone dose in the fentanyl era is a matter of ongoing debate, but the safety margin of the approved nasal sprays is superior to improvised nasal kits. New legislation in different countries permits over-the-counter sales or other prescription-free methods of provision. However, access remains uneven with take-home naloxone still not provided in many countries and communities, and with ongoing barriers contributing to implementation inertia. Take-home naloxone is an important component of the response to the global overdose problem, but greater commitment to implementation will be essential, alongside improved affordable products, if a greater impact is to be achieved.

Regional and temporal effects of naloxone access laws on opioid overdose mortality

BACKGROUND

Naloxone is a drug that reverses opioid overdose. Naloxone Access Laws (NALs) increase public access to naloxone and have been considered as one promising solution to reducing opioid-related harm. However, previous studies on whether NALs are effective in reducing opioid overdose mortality found somewhat contradictory results. Our study attempts to provide a more definitive answer to this question by utilizing an approach that matches NAL vs non-NAL states and stratifies by US region and years of implementation. Methods: We assess the causal impact of NALs on state-level opioid-related mortality rate by constructing a comparison group using matching to produce a valid counterfactual scenario, and estimating the effects of NAL using a semi-dynamic staggered difference in differences (DID) model that allows heterogeneous effects across regions and years of implementation. State-level opioid-related mortality data from CDC's WONDER database and NALs effective from 1999 to 2014 were utilized. Results: We find that NAL effects have reduced fatal opioid-related overdose in western states and have produced minimal or no effects for other regions. Conclusions: The effects of NALs vary across regions and years of implementation. It is important to study the successful experience of the western states.

The effectiveness of substance use interventions for homeless and vulnerably housed persons: A systematic review of systematic reviews on supervised consumption facilities, managed alcohol programs, and pharmacological agents for opioid use disorder

BACKGROUND

Substance use is disproportionately high among people who are homeless or vulnerably housed. We performed a systematic overview of reviews examining the effects of selected harm reduction and pharmacological interventions on the health and social well-being of people who use substances, with a focus on homeless populations.

METHODS AND FINDINGS

We searched MEDLINE, EMBASE, PsycINFO, Joanna Briggs Institute EBP, Cochrane Database of Systematic Reviews and DARE for systematic reviews from inception to August 2019. We conducted a grey literature search and hand searched reference lists. We selected reviews that synthesized evidence on supervised consumption facilities, managed alcohol programs and pharmacological interventions for opioid use disorders. We abstracted data specific to homeless or vulnerably housed populations. We assessed certainty of the evidence using the GRADE approach. Our search identified 483 citations and 30 systematic reviews met all inclusion criteria, capturing the results from 442 primary studies. This included three reviews on supervised consumption facilities, 24 on pharmacological interventions, and three on managed alcohol programs. Supervised consumption facilities decreased lethal overdoses and other high risk behaviours without any significant harm, and improved access to care. Pharmaceutical interventions reduced mortality, morbidity, and substance use, but the impact on retention in treatment, mental illness and access to care was variable. Managed alcohol programs reduced or stabilized alcohol consumption. Few studies on managed alcohol programs reported deaths.

CONCLUSIONS

Substance use is a common chronic condition impacting homeless populations. Supervised consumption facilities reduce overdose and improve access to care, while pharmacological interventions may play a role in reducing harms and addressing other morbidity. High quality evidence on managed alcohol programs is limited.

Intranasal versus Intramuscular/Intravenous Naloxone for Pre-hospital Opioid Overdose: A Systematic Review and Meta-analysis

Context:

The present systematic review and meta-analysis aims to perform an extensive search in databases to compare the efficacy of the intranasal administration of naloxone with its intramuscular/intravenous administration in the pre-hospital management of opioid overdose.

Evidence acquisition:

This meta-analysis included controlled trials conducted on the efficacy of naloxone administration in the pre-hospital management of opioid overdose. A search was carried out in electronic databases on relevant articles published by the end of 2018. After data collection, analyses were performed in STATA 14.0 software and the efficacy and side-effects of the two administration routes of naloxone, i.e. intranasal and intramuscular/intravenous, were compared. An overall effect size with 95% confidence interval (95% CI) was provided for each section.

Results:

Eventually, data from six studies were included in this meta-analysis. The success rate of the intranasal and intramuscular/intravenous administration of naloxone in the management of opioid overdose in pre-hospital settings was 82.54% (95% CI: 57.97 to 97.89%) and 80.39% (95% CI: 57.38 to 96.04%), respectively. There was no difference between injectable (intramuscular/intravenous) naloxone and intranasal naloxone in the pre-hospital management of opioid overdose (Odds Ratio=1.01; 95% CI: 0.42 to 2.43; P=0.98). The onset of action of intranasal naloxone, however, was slightly longer than injectable naloxone (Standardized Mean Difference=0.63; 95% CI: 0.07 to 1.19; P=0.03). Additionally, the odds of needing a rescue dose was 2.17 times higher for intranasal naloxone than intramuscular/intravenous naloxone (OR=2.17; 95% CI: 1.53 to 3.09; P<0.0001). The prevalence of major side-effects was non-significant for both intranasal (0.00%) and intramuscular/intravenous (0.05%) routes of naloxone administration and there was no difference in the prevalence of major (OR=1.18; 95% CI: 0.38 to 3.69; P=0.777) and minor (OR=0.64; 95% CI: 0.17 to 2.34; P=0.497) side-effects between the two routes.

Conclusion:

The present meta-analysis demonstrated that intranasal naloxone is as effective as injectable naloxone in the pre-hospital management of opioid overdose complications. Consequently, intranasal naloxone may be an appropriate alternative to injectable naloxone.

Effect of Intranasal vs Intramuscular Naloxone on Opioid Overdose: A Randomized Clinical Trial

IMPORTANCE

Previous unblinded clinical trials suggested that the intranasal route of naloxone hydrochloride was inferior to the widely used intramuscular route for the reversal of opioid overdose.

OBJECTIVE

To test whether a dose of naloxone administered intranasally is as effective as the same dose of intramuscularly administered naloxone in reversing opioid overdose.

DESIGN, SETTING, AND PARTICIPANTS

A double-blind, double-dummy randomized clinical trial was conducted at the Uniting Medically Supervised Injecting Centre in Sydney, Australia. Clients of the center were recruited to participate from February 1, 2012, to January 3, 2017. Eligible clients were aged 18 years or older with a history of injecting drug use (n = 197). Intention-to-treat analysis was performed for all participants who received both intranasal and intramuscular modes of treatment (active or placebo).

INTERVENTIONS

Clients were randomized to receive 1 of 2 treatments: (1) intranasal administration of naloxone hydrochloride 800 μg per 1 mL and intramuscular administration of placebo 1 mL or (2) intramuscular administration of naloxone hydrochloride 800 μg per 1 mL and intranasal administration of placebo 1 mL.

MAIN OUTCOMES AND MEASURES

The primary outcome measure was the need for a rescue dose of intramuscular naloxone hydrochloride (800 μg) 10 minutes after the initial treatment. Secondary outcome measures included time to adequate respiratory rate greater than or equal to 10 breaths per minute and time to Glasgow Coma Scale score greater than or equal to 13.

RESULTS

A total of 197 clients (173 [87.8%] male; mean [SD] age, 34.0 [7.82] years) completed the trial, of whom 93 (47.2%) were randomized to intramuscular naloxone dose and 104 (52.8%) to intranasal naloxone dose. Clients randomized to intramuscular naloxone administration were less likely to require a rescue dose of naloxone compared with clients randomized to intranasal naloxone administration (8 [8.6%] vs 24 [23.1%]; odds ratio, 0.35; 95% CI, 0.15-0.66; P = .002). A 65% increase in hazard (hazard ratio, 1.65; 95% CI, 1.21-2.25; P = .002) for time to respiratory rate of at least 10 and an 81% increase in hazard (hazard ratio, 1.81; 95% CI, 1.28-2.56; P = .001) for time to Glasgow Coma Scale score of at least 13 were observed for the group receiving intranasal naloxone compared with the group receiving intramuscular naloxone. No major adverse events were reported for either group.

CONCLUSIONS AND RELEVANCE

This trial showed that intranasally administered naloxone in a supervised injecting facility can reverse opioid overdose but not as efficiently as intramuscularly administered naloxone can, findings that largely replicate those of previous unblinded clinical trials. These results suggest that determining the optimal dose and concentration of intranasal naloxone to respond to opioid overdose in real-world conditions is an international priority.

TRIAL REGISTRATION

anzctr.org.au Identifier: ACTRN12611000852954.

One single large intramuscular dose of naloxone is effective and safe in suspected heroin poisoning

OBJECTIVE

Naloxone is an established antidote for the treatment of heroin poisoning; however, dosing regimens vary widely, with a current trend towards small titrated intravenous dosing. This study aims to characterise naloxone use in the treatment of patients presenting with suspected heroin poisoning.

METHODS

This was a retrospective review of poisoned patients presenting to a clinical toxicology unit in Brisbane from January 2015 to December 2017. Patient demographics, clinical effects, naloxone dosing, observation periods and complications were extracted from the patient's medical records.

RESULTS

There were 117 presentations accounted for by 108 patients. Prehospital naloxone was provided to 57 (49%) patients, 46 of which received a standardised 1.6 mg i.m. dose. The remaining 60 (51%) patients received their first naloxone in hospital, with 58 (97%) receiving this by titrated i.v. doses. A subsequent naloxone infusion was required significantly more often in those treated with i.v. titrated naloxone compared to i.m. dose (27/69 [39%] vs 5/48 [10%], P = 0.0006). The need for parenteral sedation to manage acute behavioural disturbance following naloxone provision was rare (3/117 [3%]).

CONCLUSIONS

In this retrospective observational study, a single large i.m. dose of naloxone reversed the toxicity of suspected heroin overdose in the majority of patients. In addition, patients were less likely to require repeated intermittent doses or naloxone infusion than those treated solely with i.v. naloxone. Further comparison in a prospective study is warranted to validate these observations in confirmed heroin overdose. Requirement for sedation secondary to acute behavioural disturbance was rare regardless of the route.

Effect of Formulation Variables on the Nasal Permeability and Stability of Naloxone Intranasal Formulations

Naloxone is an opioid antagonist with high affinity for μ-opioid receptor, and for this reason it is used for the emergency treatment of opioid overdose. Originally, it was available only as an injectable product. However, for the ease of administration, intranasal (IN) formulations have also become available. These IN formulations contain preservatives and stabilizers such as benzalkonium chloride (BKC), benzyl alcohol (BA), and ethylenediaminetetraacetic acid (EDTA). Some of these ingredients are known to affect permeability of drugs. This study focuses on investigating the effect of formulation variables including choice of preservatives, stabilizer, and pH on the permeability and stability of naloxone IN formulations. The in vitro permeability of naloxone was evaluated employing EpiAirway™ tissue-mounted Ussing chambers. BKC was found to enhance the apparent permeability (P_app) of naloxone significantly (p < 0.05) at very low concentration, while BA caused similar enhancement at a much higher concentration. EDTA was found to decrease P_app of naloxone by lowering the pH, and the P_app of naloxone was found to decrease approximately 51-fold with the decrease in formulation pH from 6.0 to 4.0. The product stability was, however, found optimal only below pH 5.0. Thus, selection of formulation ingredients, buffering agent, and pH of IN formulation is a balancing act for achieving desired permeability and optimal stability to achieve reasonable shelf life of naloxone IN formulation.

Naloxone interventions in opioid overdoses: a systematic review protocol

BACKGROUND

North America is in the midst of an unabated opioid overdose epidemic due to the increasing non-medical use of fentanyl and ultra-potent opioids. Naloxone is an effective antidote to opioid toxicity, yet its optimal dosing in the context of fentanyl and ultra-potent opioid overdoses remains unknown. This review aims to determine the relationship between the first empiric dose of naloxone and reversal of toxicity, adverse events, and the total cumulative dose required among patients with undifferentiated opioid overdoses and those with suspected toxicity from ultra-potent opioids. Secondary objectives include evaluating the relationship between the cumulative naloxone dose and toxicity reversal and adverse events, among patients with undifferentiated opioid overdoses and those with suspected toxicity from ultra-potent opioids.

METHODS

To identify studies, we will search MEDLINE, Embase, CENTRAL, DARE, CDAG, CINAHL, Science Citation Index, multiple trial registries, and the gray literature. Included studies will evaluate patients with suspected or confirmed opioid toxicity from undifferentiated opioids and ultra-potent opioids, who received an empiric and possibly additional doses of naloxone. The main outcomes of interest are the relationship between naloxone dose and toxicity reversal and adverse events. We will include controlled and non-controlled interventional studies, observational studies, case reports/series, and reports from poison control centers. We will extract data and assess study quality in duplicate with discrepancies resolved by consensus or a third party. We will use the Downs and Black and Cochrane risk of bias tools for observational and randomized controlled studies. If we find sufficient variation in dose, we will fit a random effects one-stage model to estimate a dose-response relationship. We will conduct multiple subgroup analyses, including by type of opioid used and by suspected high and low prevalence of ultra-potent opioid use based on geographic location and time of the original studies.

DISCUSSION

Our review will include the most up-to-date available data including ultra-potent opioids to inform the current response to the opioid epidemic, addressing the limitations of recent reviews. We anticipate limitations relating to study heterogeneity. We will disseminate study results widely to update overdose treatment guidelines and naloxone dosing in Take Home Naloxone programs.

Pharmacokinetics of a novel, approved, 1.4-mg intranasal naloxone formulation for reversal of opioid overdose-a randomized controlled trial

BACKGROUND AND AIMS

Intranasal (i.n.) naloxone is an established treatment for opioid overdose. Anyone likely to witness an overdose should have access to the antidote. We aimed to determine whether an i.n. formulation delivering 1.4 mg naloxone hydrochloride would achieve systemic exposure comparable to that of 0.8 mg intramuscular (i.m.) naloxone.

DESIGN

Open, randomized four-way cross-over trial.

SETTING

Clinical Trials Units in St Olav's Hospital, Trondheim and Rikshospitalet, Oslo, Norway.

PARTICIPANTS

Twenty-two healthy human volunteers, 10 women, median age = 25.8 years.

INTERVENTION AND COMPARATOR

One and two doses of i.n. 1.4 mg naloxone compared with i.m. 0.8 mg and intravenous (i.v.) 0.4 mg naloxone.

MEASUREMENTS

Quantification of plasma naloxone was performed by liquid chromatography tandem mass spectrometry. Pharmacokinetic non-compartment analyses were used for the main analyses. A non-parametric pharmacokinetic population model was developed for Monte Carlo simulations of different dosing scenarios.

FINDINGS

Area under the curve from administration to last measured concentration (AUC_0-last ) for i.n. 1.4 mg and i.m. 0.8 mg were 2.62 ± 0.94 and 3.09 ± 0.64 h × ng/ml, respectively (P = 0.33). Maximum concentration (C_max ) was 2.36 ± 0.68 ng/ml for i.n. 1.4 mg and 3.73 ± 3.34 for i.m. 0.8 mg (P = 0.72). Two i.n. doses showed dose linearity and achieved a C_max of 4.18 ± 1.53 ng/ml. T_max was reached after 20.2 ± 9.4 minutes for i.n. 1.4 mg and 13.6 ± 15.4 minutes for i.m. 0.8 mg (P = 0.098). The absolute bioavailability for i.n. 1.4 mg was 0.49 (±0.24), while the relative i.n./i.m. bioavailability was 0.52 (±0.25).

CONCLUSION

Intranasal 1.4 mg naloxone provides adequate systemic concentrations to treat opioid overdose compared with intramuscular 0.8 mg, without statistical difference on maximum plasma concentration, time to maximum plasma concentration or area under the curve. Simulations support its appropriateness both as peer administered antidote and for titration of treatment by professionals.

[Feedback from two French addiction centers and national survey on the intranasal naloxone (Nalscue®) in the prevention of opioid overdoses]

OBJECTIVE

France has temporarily authorized addictology centers to use a form of intranasal naloxone (Nalscue^®) to prevent opioid overdoses. The objectives of this work are to present both the characteristics of the patients included in this device in two hospitals centers and the results of the national survey on addiction center's contribution to this new risk reduction tool.

METHODS

Patient data are those requested under Nalscue^® study (inclusion period July 2016 to January 2018). The survey is an online questionnaire distributed to all addiction centers with an email address.

RESULTS

Over this period, in the two addiction centers, 370 kits (35% of the national total) were distributed to 330 patients including 312 opioid users. Of these users, 15% report injecting and 85% are poly-consumers. In 14% of the cases, a patient's relative was formed to administrate the Nalscue^®. Forty kits (30 given away, 6 lost, 4 administered) were renewed to 35 users. Of the 462 addiction centers contacted, 82 (18%) responded. Among 76 structures specialized in opioid addictions, two did not feel concerned and one had no knowledge of the antidote. Fifty-five structures were formed by the pharmaceutical firm. Nine hundred forty-seven patients (58% of the total) were included by 37 centers. Forty-four centers ordered 2458 kits and dispensed 1116 (including kits given out of study). Thirteen structures reported use of Nalscue^®.

CONCLUSION

The interest of intranasal naloxone is no longer to be demonstrated in a context of opioid overdose, but the preauthorized framework did not allow a major diffusion of the antidote within the population most at risk. Let us hope that the availability in pharmacy can promote its distribution and thus reduce the number of deaths.

Reversal of Pediatric Opioid Toxicity with Take-Home Naloxone: a Case Report

BACKGROUND

Take-home naloxone, an opioid antagonist, has become part of a multimodal approach to curbing opioid-related mortality. However, there is little information about the utility of take-home naloxone in pediatric patients. We report a case of opioid toxicity after exposure to methadone in a pediatric patient, which was successfully reversed with take-home naloxone.

CASE

A previously healthy 22-month-old girl ingested an unknown amount of liquid methadone. The child became progressively somnolent. The mother administered intranasal naloxone at home with reversal of somnolence. The patient presented to the emergency department and had recurrence of symptoms. The patient was placed on a naloxone infusion and discharged from a tertiary care facility, uneventfully, 2 days after ingestion.

RESULTS

To our knowledge, we report the first case of pediatric opioid toxicity reversed by take-home naloxone. In the setting of rising opioid-related mortality, providers and public health officials should consider expanding access of take-home naloxone for children at high risk for opioid overdose.

Overdose Education and Naloxone Distribution Program Attendees: Who Attends, What Do They Know, and How Do They Feel?

CONTEXT

The United States is in the midst of an opioid overdose epidemic. Opioids killed more than 28 000 people in 2014, more than any year on record. One approach to addressing this growing epidemic is Opioid Overdose Education and Naloxone Distribution (OEND) training. Little is known about these programs' participants and their effectiveness across different demographic groups.

OBJECTIVES

To examine (1) whether knowledge and attitudes improved over the course of the training programs; (2) whether training outcomes differ by demographics; and (3) what overdose experiences do attendees have, and whether those experiences influence their knowledge and attitudes.

DESIGN

A pre- and posttest survey was used to collect data on participants' demographics, overdose experiences, and opioid overdose knowledge and attitudes.

SETTING

Surveys that took place at community-wide OEND programs were offered throughout Erie County, New York, during October and November 2015.

PARTICIPANTS

Community members who elected to attend the training programs, were at least 18 years of age, spoke English, and were willing and able to participate were included in the sample (N = 198).

INTERVENTION

N/A.

MAIN OUTCOME MEASURE

The Opioid Overdose Knowledge and Attitudes Scale.

RESULTS

Knowledge and attitude scores significantly improved from pre- to posttest assessments, increasing by 23.1% and 15.4%, respectively (Ps < .001). There were significant demographic differences in knowledge and attitudes at the pretest assessment, but these differences were ameliorated by the OEND program and did not persist at posttest assessment. In addition, 62.9% of participants had never experienced, witnessed, or known someone who had overdosed.

CONCLUSION

Results indicate that OEND programs are effective at improving knowledge and attitudes toward opioid overdose. These results indicate that OEND programs are not reaching the highest risk individuals but are instead attracting concerned family and significant others. Future programs should focus on reaching current opioid users, overdose victims, and their families to ensure OEND programs are reaching the target audiences.

Government Patent Use to Address the Rising Cost of Naloxone: 28 U.S.C. § 1498 and Evzio

The rising cost of the opioid antagonist and overdose reversal agent naloxone is an urgent public health problem. The recent and dramatic price increase of Evzio, a naloxone auto-injector produced by Kaléo, shows how pharmaceutical manufacturers entering the naloxone marketplace rely on market exclusivity guaranteed by the patent system to charge prices at what the market can bear, which can restrict access to life-saving medication. We argue that 28 U.S.C. § 1498, a section of the federal code that allows the government to use patent-protected products for its own purposes in exchange for reasonable compensation, could be used to procure generic naloxone auto-injectors, or at least bring Kaléo to the negotiating table. Precedent exists for the use of § 1498 to procure pharmaceuticals, and it could give meaning to the federal government's recent declaration of a public health emergency around the opioid epidemic, discourage new market entrants from charging exorbitant prices, and yield important public health benefits.

Pharmacokinetic properties of intranasal and injectable formulations of naloxone for community use: a systematic review

Aim: To assess the pharmacokinetic properties of community-use formulations of naloxone for emergency treatment of opioid overdose. Methods: Systematic literature review based on searches of established databases and congress archives. Results: Seven studies met inclusion criteria: two of US FDA-approved intramuscular (im.)/subcutaneous (sc.) auto-injectors, one of an FDA-approved intranasal spray, two of unapproved intranasal kits (syringe with atomizer attachment) and two of intranasal products in development. Conclusion: The pharmacokinetics of im./sc. auto-injector 2 mg and approved intranasal spray (2 and 4 mg) demonstrated rapid uptake and naloxone exposure exceeding that of the historic benchmark (0.4 mg im.), indicating that naloxone exposure was adequate for reversal of opioid overdose.

Pharmacokinetics and -dynamics of intramuscular and intranasal naloxone: an explorative study in healthy volunteers

PURPOSE

This study aimed to develop a model for pharmacodynamic and pharmacokinetic studies of naloxone antagonism under steady-state opioid agonism and to compare a high-concentration/low-volume intranasal naloxone formulation 8 mg/ml to intramuscular 0.8 mg.

METHODS

Two-way crossover in 12 healthy volunteers receiving naloxone while receiving remifentanil by a target-controlled infusion for 102 min. The group were subdivided into three different doses of remifentanil. Blood samples for serum naloxone concentrations, pupillometry and heat pain threshold were measured.

RESULTS

The relative bioavailability of intranasal to intramuscular naloxone was 0.75. Pupillometry showed difference in antagonism; the effect was significant in the data set as a whole (p < 0.001) and in all three subgroups (p < 0.02-p < 0.001). Heat pain threshold showed no statistical difference.

CONCLUSIONS

A target-controlled infusion of remifentanil provides good conditions for studying the pharmacodynamics of naloxone, and pupillometry was a better modality than heat pain threshold. Intranasal naloxone 0.8 mg is inferior for a similar dose intramuscular. Our design may help to bridge the gap between studies in healthy volunteers and the patient population in need of naloxone for opioid overdose.

TRIAL REGISTRATION

clinicaltrials.gov : NCT02307721.