Intranasal administration of naloxone by paramedics

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.

Evaluation of Naloxone Co-Prescribing Rates for Older Adults Receiving Opioids via a Meds-to-Beds Program

Over 10,000 older adults died from opioid overdose in 2019. Naloxone is an underutilized antidote that could prevent many opioid overdose-related deaths. There is a paucity of literature evaluating naloxone prescribing through meds-to-beds programs and in older adults. This single-center, retrospective, observational cohort study aimed to assess prescribing patterns of naloxone in patients 65 years and older who were prescribed opioids via a meds-to-beds program between December 2020 and November 2021. All patients 65 years and older dispensed an opioid via meds-to-beds were included. Patients receiving hospice or comfort care or those with unavailable records were excluded. The primary outcome was to assess the frequency of naloxone co-prescribing with opioid prescriptions via meds-to-beds. The 144 patients included were primarily females with a median age of 69 years old and opioid prescriptions for 45 morphine milligram equivalents daily. Two patients were prescribed naloxone (1.4%), one of whom was ultimately dispensed naloxone (0.7%). Of the 65 prescribers included in our study, the incidence of naloxone co-prescribing (2/65, 3.1%) was no different from a previously-reported rate among prescribers (3/179, 1.7%), p = 0.61. Naloxone co-prescribing for older adults receiving opioid prescriptions through a meds-to-beds program was low and opportunities for program enhancement exist.

The Effect of Overdose Education and Naloxone Distribution: An Umbrella Review of Systematic Reviews

Background. Opioids contribute to more than 60 000 deaths annually in North America. While the expansion of overdose education and naloxone distribution (OEND) programs has been recommended in response to the opioid crisis, their effectiveness remains unclear. Objectives. To conduct an umbrella review of systematic reviews to provide a broad-based conceptual scheme of the effect and feasibility of OEND and to identify areas for possible optimization. Search Methods. We conducted the umbrella review of systematic reviews by searching PubMed, Embase, PsycINFO, Epistemonikos, the Cochrane Database of Systematic Reviews, and the reference lists of relevant articles. Briefly, an academic librarian used a 2-concept search, which included opioid subject headings and relevant keywords with a modified PubMed systematic review filter. Selection Criteria. Eligible systematic reviews described comprehensive search strategies and inclusion and exclusion criteria, evaluated the quality or risk of bias of included studies, were published in English or French, and reported data relevant to either the safety or effectiveness of OEND programs, or optimal strategies for the management of opioid overdose with naloxone in out-of-hospital settings. Data Collection and Analysis. Two reviewers independently extracted study characteristics and the quality of included reviews was assessed in duplicate with AMSTAR-2, a critical appraisal tool for systematic reviews. Review quality was rated critically low, low, moderate, or high based on 7 domains: protocol registration, literature search adequacy, exclusion criteria, risk of bias assessment, meta-analytical methods, result interpretation, and presence of publication bias. Summary tables were constructed, and confidence ratings were provided for each outcome by using a previously modified version of the Royal College of General Practitioners' clinical guidelines. Main Results. Six systematic reviews containing 87 unique studies were included. We found that OEND programs produce long-term knowledge improvement regarding opioid overdose, improve participants' attitudes toward naloxone, provide sufficient training for participants to safely and effectively manage overdoses, and effectively reduce opioid-related mortality. High-concentration intranasal naloxone (> 2 mg/mL) was as effective as intramuscular naloxone at the same dose, whereas lower-concentration intranasal naloxone was less effective. Evidence was limited for other naloxone formulations, as well as the need for hospital transport after overdose reversal. The preponderance of evidence pertained persons who use heroin. Author's Conclusions. Evidence suggests that OEND programs are effective for reducing opioid-related mortality; however, additional high-quality research is required to optimize program delivery. Public Health Implications. Community-based OEND programs should be implemented widely in high-risk populations.

Rural Emergency Medical Service Providers Perceptions on the Causes of and Solutions to the Opioid Crisis: A Qualitative Assessment

Introduction:

The continuing opioid crisis poses unique challenges to remote and often under-resourced rural communities. Emergency medical service (EMS) providers serve a critical role in responding to opioid overdose for individuals living in rural or remote areas who experience opioid overdoses. They are often first at the scene of an overdose and are sometimes the only health care provider in contact with an overdose patient who either did not survive or refused additional care. As such, EMS providers have valuable perspectives to share on the causes and consequences of the opioid crisis in rural communities.

Methods:

EMS providers attending a statewide EMS conference serving those from greater Minnesota and surrounding states were invited to take a 2-question survey asking them to reflect upon what they believed to be the causes of the opioid crisis and what they saw as the solutions to the opioid crisis. Results were coded and categorized using a Consensual Qualitative Research approach.

Results:

EMS providers’ perceptions on causes of the opioid crisis were categorized into 5 main domains: overprescribing, ease of access, socioeconomic vulnerability, mental health concerns, and lack of resources and education. Responses focused on solutions to address the opioid crisis were categorized into 5 main domains: need for increased education, enhanced opioid oversight, increased access to treatment programs, alternative therapies for pain management, and addressing socioeconomic vulnerabilities.

Conclusion:

Along with the recognition that the opioid crisis was at least partially caused by overprescribing, rural EMS providers who participated in this study recognized the critical role of social determinants of health in perpetuating opioid-related harm. Participants in this study reported that education and increased access to treatment facilities and appropriate pain management, along with recognition of the role of social determinants of health in opioid dependency, were necessary steps to address the opioid crisis.

Short peptide sequence enhances epithelial permeability through interaction with protein kinase C

We have identified a short peptide sequence (L-R5) acting as partial inhibitor of intracellular protein kinase C, capable of tight junction modulation in terms of reversible and non-toxic drug permeation enhancement. L-R5 is a pentapeptide with a cell-penetrating group at the N-terminus and of the sequence myristoyl-ARRWR. Apically applied in vitro, L-R5 transiently increased epithelial permeability within minutes, enhancing apical-to-basolateral (AB) transport of 4-kDa dextran and BCS class III drug naloxone. L-R5 was shown to be stable and effective at 37°C over a period of 24 hours. L-R5 was shown to be non-cytotoxic in consecutive exposure studies on primary human nasal epithelial cells by LDH release assay and ciliary beating frequency test. Finally, L-R5 by itself showed very low diffusion across epithelial monolayers, which is of advantage with regard to its expected negligible systemic bioavailability and side effects. Taken together, these data demonstrate the potential of short peptide partial inhibitor L-R5 to enhance the epithelial paracellular permeability via a reversible mechanism, and in a non-toxic manner.

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.

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.

Integrating naloxone education into an undergraduate nursing course: Developing partnerships with a local department of health

BACKGROUND

Substance misuse continues to be a significant concern in the United States, with over 700,000 lives lost from a drug overdose between 1999 and 2017. However, nursing curricula have failed to keep pace with the epidemic.

METHODS

The current study used a pre-post study design and involved a convenience sample of undergraduate nursing students (n = 37) enrolled in a community health nursing course. Students completed an 11-item online survey examining naloxone stigma, naloxone self-efficacy, and naloxone knowledge. A paired sample t test was conducted to evaluate the impact of the in-person training and education event.

RESULTS

There was a statistically significant increase in post-intervention naloxone knowledge scores from the pre-survey (M = 3.57, SD = 0.959) to the post-survey (M = 4.70, SD = 0.520). Stigma toward naloxone demonstrated a statistically significant increase in the post-intervention stigma survey (M = 9.00, SD = 1.312) compared with the pre-intervention stigma survey (M = 7.78, SD = 2.228). Naloxone self-efficacy also demonstrated a statistically significant increase in the post-intervention naloxone efficacy survey (M = 10.08, SD = 1.064) compared with the pre-intervention naloxone efficacy scores (M = 7.38, SD = 2.22).

CONCLUSIONS

The students' scores demonstrated a significant increase in naloxone knowledge, self-efficacy, and stigma. Future research is needed to explore the impact of integrating naloxone education in the undergraduate nursing curriculum.

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.

Intravenous and Intratracheal Thyrotropin Releasing Hormone and Its Analog Taltirelin Reverse Opioid-Induced Respiratory Depression in Isoflurane Anesthetized Rats

Thyrotropin releasing hormone (TRH) is a tripeptide hormone and a neurotransmitter widely expressed in the central nervous system that regulates thyroid function and maintains physiologic homeostasis. Following injection in rodents, TRH has multiple effects including increased blood pressure and breathing. We tested the hypothesis that TRH and its long-acting analog, taltirelin, will reverse morphine-induced respiratory depression in anesthetized rats following intravenous or intratracheal (IT) administration. TRH (1 mg/kg plus 5 mg/kg/h, i.v.) and talitrelin (1 mg/kg, i.v.), when administered to rats pretreated with morphine (5 mg/kg, i.v.), increased ventilation from 50% ± 6% to 131% ± 7% and 45% ± 6% to 168% ± 13%, respectively (percent baseline; n = 4 ± S.E.M.), primarily through increased breathing rates (from 76% ± 9% to 260% ± 14% and 66% ± 8% to 318% ± 37%, respectively). By arterial blood gas analysis, morphine caused a hypoxemic respiratory acidosis with decreased oxygen and increased carbon dioxide pressures. TRH decreased morphine effects on arterial carbon dioxide pressure, but failed to impact oxygenation; taltirelin reversed morphine effects on both arterial carbon dioxide and oxygen. Both TRH and talirelin increased mean arterial blood pressure in morphine-treated rats (from 68% ± 5% to 126% ± 12% and 64% ± 7% to 116% ± 8%, respectively; n = 3 to 4). TRH, when initiated prior to morphine (15 mg/kg, i.v.), prevented morphine-induced changes in ventilation; and TRH (2 mg/kg, i.v.) rescued all four rats treated with a lethal dose of morphine (5 mg/kg/min, until apnea). Similar to intravenous administration, both TRH (5 mg/kg, IT) and taltirelin (2 mg/kg, IT) reversed morphine effects on ventilation. TRH or taltirelin may have clinical utility as an intravenous or inhaled agent to antagonize opioid-induced cardiorespiratory depression.

Intranasal naloxone and related strategies for opioid overdose intervention by nonmedical personnel: a review

Deaths due to prescription and illicit opioid overdose have been rising at an alarming rate, particularly in the USA. Although naloxone injection is a safe and effective treatment for opioid overdose, it is frequently unavailable in a timely manner due to legal and practical restrictions on its use by laypeople. As a result, an effort spanning decades has resulted in the development of strategies to make naloxone available for layperson or "take-home" use. This has included the development of naloxone formulations that are easier to administer for nonmedical users, such as intranasal and autoinjector intramuscular delivery systems, efforts to distribute naloxone to potentially high-impact categories of nonmedical users, as well as efforts to reduce regulatory barriers to more widespread distribution and use. Here we review the historical and current literature on the efficacy and safety of naloxone for use by nonmedical persons, provide an evidence-based discussion of the controversies regarding the safety and efficacy of different formulations of take-home naloxone, and assess the status of current efforts to increase its public distribution. Take-home naloxone is safe and effective for the treatment of opioid overdose when administered by laypeople in a community setting, shortening the time to reversal of opioid toxicity and reducing opioid-related deaths. Complementary strategies have together shown promise for increased dissemination of take-home naloxone, including 1) provision of education and training; 2) distribution to critical populations such as persons with opioid addiction, family members, and first responders; 3) reduction of prescribing barriers to access; and 4) reduction of legal recrimination fears as barriers to use. Although there has been considerable progress in decreasing the regulatory and legal barriers to effective implementation of community naloxone programs, significant barriers still exist, and much work remains to be done to integrate these programs into efforts to provide effective treatment of opioid use disorders.

Comparison of a New Intranasal Naloxone Formulation to Intramuscular Naloxone: Results from Hypothesis-generating Small Clinical Studies

Easy‐to‐use naloxone formulations are needed to help address the opioid overdose epidemic. The pharmacokinetics of i.v., i.m., and a new i.n. naloxone formulation (2 mg) were compared in six healthy volunteers. Relative to i.m. naloxone, geometric mean (90% confidence interval [CI]) absolute bioavailability of i.n. naloxone was modestly lower (55%; 90% CI, 43–70% vs. 41%; 90% CI, 27–62%), whereas average (±SE) mean absorption time was substantially shorter (74 ± 8.8 vs. 6.7 ± 4.9 min). The opioid‐attenuating effects of i.n. naloxone were compared with i.m. naloxone (2 mg) after administration of oral alfentanil (4 mg) to a separate group of six healthy volunteers pretreated with 240 mL of water or grapefruit juice. The i.m. and i.n. naloxone attenuated miosis by similar extents after water (40 ± 15 vs. 41 ± 21 h*%) and grapefruit juice (49 ± 18 vs. 50 ± 22 h*%) pretreatment. Results merit further testing of this new naloxone formulation.

Opiate addiction and overdose: experiences, attitudes, and appetite for community naloxone provision

BACKGROUND

More than 200 opiate overdose deaths occur annually in Ireland. Overdose prevention and management, including naloxone prescription, should be a priority for healthcare services. Naloxone is an effective overdose treatment and is now being considered for wider lay use.

AIM

To establish GPs' views and experiences of opiate addiction, overdose care, and naloxone provision.

DESIGN AND SETTING

An anonymous postal survey to GPs affiliated with the Department of Academic General Practice, University College Dublin, Ireland.

METHOD

A total of 714 GPs were invited to complete an anonymous postal survey. Results were compared with a parallel GP trainee survey.

RESULTS

A total of 448/714 (62.7%) GPs responded. Approximately one-third of GPs were based in urban, rural, and mixed areas. Over 75% of GPs who responded had patients who used illicit opiates, and 25% prescribed methadone. Two-thirds of GPs were in favour of increased naloxone availability in the community; almost one-third would take part in such a scheme. A higher proportion of GP trainees had used naloxone to treat opiate overdose than qualified GPs. In addition, a higher proportion of GP trainees were willing to be involved in naloxone distribution than qualified GPs. Intranasal naloxone was much preferred to single (P<0.001) or multiple dose (P<0.001) intramuscular naloxone. Few GPs objected to wider naloxone availability, with 66.1% (n = 292) being in favour.

CONCLUSION

GPs report extensive contact with people who have opiate use disorders but provide limited opiate agonist treatment. They support wider availability of naloxone and would participate in its expansion. Development and evaluation of an implementation strategy to support GP-based distribution is urgently needed.

When to Pick the Nose: Out-of-Hospital and Emergency Department Intranasal Administration of Medications

The intranasal route for medication administration is increasingly popular in the emergency department and out-of-hospital setting because such administration is simple and fast, and can be used for patients without intravenous access and in situations in which obtaining an intravenous line is difficult or time intensive (eg, for patients who are seizing or combative). Several small studies (mostly pediatric) have shown midazolam to be effective for procedural sedation, anxiolysis, and seizures. Intranasal fentanyl demonstrates both safety and efficacy for the management of acute pain. The intranasal route appears to be an effective alternative for naloxone in opioid overdose. The literature is less clear on roles for intranasal ketamine and dexmedetomidine.

Opioid Toxicity

In recent years, there has been a substantial increase in opioid use and abuse, and in opioid-related fatal overdoses. The increase in opioid use has resulted at least in part from individuals transitioning from prescribed opioids to heroin and fentanyl, which can cause significant respiratory depression that can progress to apnea and death. Heroin and fentanyl may be used individually, together, or in combination with other substances such as ethanol, benzodiazepines, or other drugs that can have additional deleterious effects on respiration. Suspicion that a death is drug-related begins with the decedent's medical and social history, and scene investigation, where drugs and drug paraphernalia may be encountered, and examination of the decedent, which may reveal needle punctures and needle track marks. At autopsy, the most significant internal finding that is reflective of opioid toxicity is pulmonary edema and congestion, and frothy watery fluid is often present in the airways. Various medical ailments such as heart and lung disease and obesity may limit an individual's physiologic reserve, rendering them more susceptible to the toxic effects of opioids and other drugs. Although many opioids will be detected on routine toxicology testing, more specialized testing may be warranted for opioid analogs, or other uncommon, synthetic, or semisynthetic drugs.

Take-home naloxone treatment for opioid emergencies: a comparison of routes of administration and associated delivery systems

INTRODUCTION

Naloxone reversal of opioid-induced respiratory depression outside of medical facilities has become more prevalent because of the escalating opioid epidemic in the USA. Take-home naloxone for treatment of opioid emergencies is now being recommended by numerous federal, state, and professional organizations. Areas covered: The scope of the opioid overdose epidemic is reviewed along with practical, clinical, regulatory, and usability considerations for take-home naloxone routes of administration currently available and associated delivery systems. Specific opioid-related factors are discussed in detail with emphasis placed on life-threatening respiratory depression and naloxone antagonism. A clinical overview, including pharmacokinetic and FDA approval information for each take-home naloxone product is discussed in detail as well as the impact of take-home naloxone in the community. Finally, given these products are to be used in a panic-stricken, life-threatening opioid emergency, an analysis of available usability data is provided with proposed directions for further study. Expert opinion: Based on the available clinical evidence, auto-injectable naloxone should be the preferred administration route for take-home naloxone treatment until additional safety, efficacy, and comparative outcomes data are available for unconventional routes of administration that unequivocally provide equal or superior results.

Antidote Use in the Critically Ill Poisoned Patient

The proper use of antidotes in the intensive care setting when combined with appropriate general supportive care may reduce the morbidity and mortality associated with severe poisonings. The more commonly used antidotes that may be encountered in the intensive care unit ( N-acetylcysteine, ethanol, fomepizole, physostigmine, naloxone, flumazenil, sodium bicarbonate, octreotide, pyridoxine, cyanide antidote kit, pralidoxime, atropine, digoxin immune Fab, glucagon, calcium gluconate and chloride, deferoxamine, phytonadione, botulism antitoxin, methylene blue, and Crotaline snake antivenom) are reviewed. Proper indications for their use and knowledge of the possible adverse effects accompanying antidotal therapy will allow the physician to appropriately manage the severely poisoned patient.

Safety and efficacy of intranasally administered medications in the emergency department and prehospital settings

PURPOSE

The safety and efficacy of medications that may be administered via the intranasal route in adult patients in the prehospital and emergency department (ED) settings are reviewed.

SUMMARY

When medications of appropriate molecular character and concentration are delivered intranasally, they are quickly transported across this capillary network and delivered to the systemic circulation, thereby avoiding the absorption-limiting effects of first-pass metabolism. Therapeutic drug concentrations are rapidly attained in the cerebrospinal fluid, making intranasal administration a very effective mode of delivery. To optimize the bioavailability of intranasally administered drugs, providers must minimize the barriers to absorption, minimize the volume by maximizing the concentration, maximize the absorptive surface of the nasal mucosa, and use a delivery system that maximizes drug dispersion and minimizes drug runoff. Medications can be instilled into the nasal cavity with syringes or droppers by applying a few drops at a time or via atomization. The intranasal route of administration may be advantageous for patients who require analgesia, sedation, anxiolysis, termination of seizures, hypoglycemia management, narcotic reversal, and benzodiazepine reversal in the ED or prehospital settings. Medications that have been studied in the adult population include fentanyl, sufentanil, hydromorphone, ketamine, midazolam, haloperidol, naloxone, flumazenil, and glucagon. The available data do indicate, however, that intranasal administration may be a safe, effective, and well tolerated route of administration.

CONCLUSION

Based on the published literature, intranasal administration of fentanyl, sufentanil, ketamine, hydromorphone, midazolam, haloperidol, naloxone, glucagon, and, in limited cases, flumazenil may be a safe, effective, and well-tolerated alternative to intramuscular or intravenous administration in the prehospital and ED settings.

Naloxone without the needle - systematic review of candidate routes for non-injectable naloxone for opioid overdose reversal

INTRODUCTION

Deaths from opioid overdose can be prevented through administration of the antagonist naloxone, which has been licensed for injection since the 1970s. To support wider availability of naloxone in community settings, novel non-injectable naloxone formulations are being developed, suitable for emergency use by non-medical personnel.

OBJECTIVES

1) Identify candidate routes of injection-free naloxone administration potentially suitable for emergency overdose reversal; 2) consider pathways for developing and evaluating novel naloxone formulations.

METHODS

A three-stage analysis of candidate routes of administration was conducted: 1) assessment of all 112 routes of administration identified by FDA against exclusion criteria. 2) Scrutiny of empirical data for identified candidate routes, searching PubMed and WHO International Clinical Trials Registry Platform using search terms "naloxone AND [route of administration]". 3) Examination of routes for feasibility and against the inclusion criteria.

RESULTS

Only three routes of administration met inclusion criteria: nasal, sublingual and buccal. Products are currently in development and being studied. Pharmacokinetic data exist only for nasal naloxone, for which product development is more advanced, and one concentrated nasal spray was granted licence in the US in 2015. However, buccal naloxone may also be viable and may have different characteristics.

CONCLUSION

After 40 years of injection-based naloxone treatment, non-injectable routes are finally being developed. Nasal naloxone has recently been approved and will soon be field-tested, buccal naloxone holds promise, and it is unclear what sublingual naloxone will contribute. Development and approval of reliable non-injectable formulations will facilitate wider naloxone provision across the community internationally.

Clinical provision of improvised nasal naloxone without experimental testing and without regulatory approval: imaginative shortcut or dangerous bypass of essential safety procedures?

CONTEXT

Take-home naloxone is increasingly provided to prevent heroin overdose deaths. Naloxone 0.4-2.0 mg is licensed for use by injection. Some clinicians supply improvised nasal naloxone kits (outside licensed approval). Is this acceptable?

AIMS

(1) To consider provision of improvised nasal naloxone in clinical practice and (2) to search for evidence for pharmacokinetics and effectiveness (versus injection).

METHODS

(1) To document existing nasal naloxone schemes and published evidence of pharmacokinetics (systematic search of the CINAHL, Cochrane, EMBASE and MEDLINE databases and 18 records included in narrative synthesis). (2) To analyse ongoing studies investigating nasal naloxone (WHO International Clinical Trials Registry Platform and US NIH RePORT databases).

FINDINGS

(1) Multiple studies report overdose reversals following administration of improvised intranasal naloxone. (2) Overdose reversal after nasal naloxone is frequent but may not always occur. (3) Until late 2015, the only commercially available naloxone concentrations were 0.4 mg/ml and 2 mg/2 ml. Nasal medications are typically 0.05-0.25 ml of fluid per nostril. The only published study of pharmacokinetics and bioavailability finds that nasal naloxone has poor bioavailability. QUESTIONS FOR DEBATE: (1) Why are pharmacokinetics and bioavailability data for nasal naloxone not available before incorporation into standard clinical practice? (2) Does nasal naloxone have the potential to become a reliable clinical formulation? (3) What pre-clinical and clinical studies should precede utilization of novel naloxone formulations as standard emergency medications?

CONCLUSIONS

The addictions treatment field has rushed prematurely into the use of improvised nasal naloxone kits. Evidence of adequate bioavailability and acceptable pharmacokinetic curves are vital preliminary steps, especially when effective approved formulations exist.

The promise and pitfalls of intranasally administering psychopharmacological agents for the treatment of psychiatric disorders

Accumulating research demonstrates the potential of intranasal delivery of psychopharmacological agents to treat a range of psychiatric disorders and symptoms. It is believed that intranasal administration offers both direct and indirect pathways to deliver psychopharmacological agents to the central nervous system. This administration route provides a unique opportunity to repurpose both old drugs for new uses and improve currently approved drugs that are indicated for other administration routes. Despite this promise, however, the physiology of intranasal delivery and related assumptions behind the bypassing of the blood brain barrier is seldom considered in detail in clinical trials and translational research. In this review, we describe the current state of the art in intranasal psychopharmacological agent delivery research and current challenges using this administration route, and discuss important aspects of nose-to-brain delivery that may improve the efficacy of these new therapies in future research. We also highlight current gaps in the literature and suggest how research can directly examine the assumptions of nose-to-brain delivery of psychopharmacological agents in humans.

Legal changes to increase access to naloxone for opioid overdose reversal in the United States

BACKGROUND

Opioid overdose, which has reached epidemic levels in the United States, is reversible by administration of the medication naloxone. Naloxone requires a prescription but is not a controlled substance and has no abuse potential. In the last half-decade, the majority of states have modified their laws to increase layperson access to the medication.

METHODS

We utilized a structured legal research protocol to systematically identify and review all statutes and regulations related to layperson naloxone access in the United States that had been adopted as of September, 2015. Each law discovered via this process was reviewed and coded by two trained legal researchers.

RESULTS

As of September, 2015, 43 states and the District of Columbia have passed laws intended to increase layperson naloxone access. We categorized these laws into three domains: (1) laws intended to increase naloxone prescribing and distribution, (2) laws intended to increase pharmacy naloxone access, and (3) laws intended to encourage overdose witnesses to summon emergency responders. These laws vary greatly across states in such characteristics as the types of individuals who can receive a prescription for naloxone, whether laypeople can dispense the medication, and immunity provided to those who prescribe, dispense and administer naloxone or report an overdose emergency.

CONCLUSIONS

Most states have now passed laws intended to increase layperson access to naloxone. While these laws will likely reduce overdose morbidity and mortality, the cost of naloxone and its prescription status remain barriers to more widespread access.

Development and process evaluation of an educational intervention for overdose prevention and naloxone distribution by general practice trainees

BACKGROUND

Overdose is the most common cause of fatalities among opioid users. Naloxone is a life-saving medication for reversing opioid overdose. In Ireland, it is currently available to ambulance and emergency care services, but General Practitioners (GP) are in regular contact with opioid users and their families. This positions them to provide naloxone themselves or to instruct patients how to use it. The new Clinical Practice Guidelines of the Pre-hospital Emergency Care Council of Ireland allows trained bystanders to administer intranasal naloxone. We describe the development and process evaluation of an educational intervention, designed to help GP trainees identify and manage opioid overdose with intranasal naloxone.

METHODS

Participants (N = 23) from one postgraduate training scheme in Ireland participated in a one-hour training session. The repeated-measures design, using the validated Opioid Overdose Knowledge (OOKS) and Attitudes (OOAS) Scales, examined changes immediately after training. Acceptability and satisfaction with training were measured with a self-administered questionnaire.

RESULTS

Knowledge of the risks of overdose and appropriate actions to be taken increased significantly post-training [OOKS mean difference, 3.52 (standard deviation 4.45); P < 0.001]; attitudes improved too [OOAS mean difference, 11.13 (SD 6.38); P < 0.001]. The most and least useful delivery methods were simulation and video, respectively.

CONCLUSION

Appropriate training is a key requirement for the distribution of naloxone through general practice. In future studies, the knowledge from this pilot will be used to inform a train-the-trainer model, whereby healthcare professionals and other front-line service providers will be trained to instruct opioid users and their families in overdose prevention and naloxone use.

Engaging Law Enforcement in Overdose Reversal Initiatives: Authorization and Liability for Naloxone Administration

Opioid overdose is reversible through the timely administration of naloxone, which has been used by emergency medical services for decades. Law enforcement officers (LEOs) are often the first emergency responders to arrive at an overdose, but they are not typically equipped with naloxone. This is rapidly changing; more than 220 law enforcement agencies in 24 states now carry naloxone. However, rollout in some departments has been hampered by concerns regarding officer and agency liability. We systematically examined the legal risk associated with LEO naloxone administration. LEOs can be authorized to administer naloxone through a variety of mechanisms, and liability risks related to naloxone administration are similar to or lower than those of other activities in which LEOs commonly engage.

Comparative Usability Study of a Novel Auto-Injector and an Intranasal System for Naloxone Delivery

Introduction

The standard of care for reversal of opioid-induced respiratory depression associated with opioid overdose is injectable naloxone. This study compared the usability of two naloxone delivery devices, a naloxone auto-injector (NAI) and a naloxone intranasal delivery system (NXN), in the administration of naloxone during a simulated opioid overdose emergency. NAI (EVZIO^®; kaleo, Inc., Richmond, VA, USA) is a Food and Drug Administration approved single-use pre-filled auto-injector containing 0.4 mg of naloxone.

Methods

Study participants were randomly assigned to administer naloxone using NAI and NXN, sequentially. The primary endpoint was successful administration of a simulated dose of naloxone into a mannequin during a simulated opioid emergency, both before and after receiving training. Secondary endpoints included using the NAI or NXN in accordance with the instructions-for-use and the comparative measurement of successful completion time of administration for both NAI and NXN.

Results

A total of 42 healthy participants aged 18–65 years were enrolled in the study. The proportion of participants able to successfully administer a simulated dose of naloxone was significantly greater for NAI compared to NXN both before (90.5% vs. 0.0%, respectively, P < 0.0001) and after (100% vs. 57.1%, respectively, P < 0.0001) participant training. The proportion of participants able to administer a simulated dose of naloxone in accordance with the instructions-for-use was also significantly greater for NAI compared to NXN before (85.7% vs. 0.0%, respectively, P < 0.0001) and after (100% vs. 0.0%, respectively, P < 0.0001) participant training. The average time to task completion for administration attempt before training was 0.9 ± 0.25 min for NAI versus 6.0 ± 4.76 min for NXN and after training was 0.5 ± 0.15 min for NAI versus 2.0 ± 2.15 min for NXN.

Conclusion

Laypersons experienced substantially greater success administering a simulated dose of naloxone, both before and after training, using NAI versus NXN during a simulated opioid overdose emergency. No participants correctly used NXN without training.

Electronic supplementary material

The online version of this article (doi:10.1007/s40122-015-0035-9) contains supplementary material, which is available to authorized users.

Review of naloxone safety for opioid overdose: practical considerations for new technology and expanded public access

Opioid overdose and mortality have increased at an alarming rate prompting new public health initiatives to reduce drug poisoning. One initiative is to expand access to the opioid antidote naloxone. Naloxone has a long history of safe and effective use by organized healthcare systems and providers in the treatment of opioid overdose by paramedics/emergency medicine technicians, emergency medicine physicians and anesthesiologists. The safety of naloxone in a prehospital setting administered by nonhealthcare professionals has not been formally established but will likely parallel medically supervised experiences. Naloxone dose and route of administration can produce variable intensity of potential adverse reactions and opioid withdrawal symptoms: intravenous administration and higher doses produce more adverse events and more severe withdrawal symptoms in those individuals who are opioid dependent. More serious adverse reactions after naloxone administration occur rarely and may be confounded by the effects of other co-intoxicants and the effects of prolonged hypoxia. One component of the new opioid harm reduction initiative is to expand naloxone access to high-risk individuals (addicts, abusers, or patients taking high-dose or extended-release opioids for pain) and their close family or household contacts. Patients or their close contacts receive a naloxone prescription to have the medication on their person or in the home for use during an emergency. Contacts are trained on overdose recognition, rescue breathing and administration of naloxone by intramuscular injection or nasal spraying of the injection prior to the arrival of emergency medical personnel. The safety profile of naloxone in traditional medical use must be considered in this new context of outpatient prescribing, dispensing and treatment of overdose prior to paramedic arrival. New naloxone delivery products are being developed for this prehospital application of naloxone in treatment of opioid overdose and prevention of opioid-induced mortality.

Emergency medical services naloxone access: a national systematic legal review

OBJECTIVES

Fatal opioid overdose in the United States is at epidemic levels. Naloxone, an effective opioid antidote, is commonly administered by advanced emergency medical services (EMS) personnel in the prehospital setting. While states are rapidly moving to increase access to naloxone for community bystanders, the EMS system remains the primary source for out-of-hospital naloxone access. Many communities have limited advanced EMS response capability and therefore may not have prehospital access to the medication indicated for opioid overdose reversal. The goal of this research was to determine the authority of different levels of EMS personnel to administer naloxone for the reversal of opioid overdose in the United States, Guam, and Puerto Rico.

METHODS

The authors systematically reviewed the scope of practice of EMS personnel regarding administration of naloxone for the reversal of opioid overdose. All relevant laws, regulations, and policies from the 50 U. S. states, the District of Columbia, Guam, and Puerto Rico in effect in November 2013 were identified, reviewed, and coded to determine the authority of EMS personnel at four levels (in increasing order of training: emergency medical responders [EMRs], emergency medical technicians [EMTs], intermediate/advanced EMTs, and paramedics) to administer naloxone. Where available, protocols governing route and dose of administration were also identified and analyzed.

RESULTS

All 53 jurisdictions license or certify EMS personnel at the paramedic level, and all permit paramedics to administer naloxone. Of the 48 jurisdictions with intermediate-level EMS personnel, all but one authorized those personnel to administer naloxone as of November 2013. Twelve jurisdictions explicitly permitted EMTs and two permitted EMRs to administer naloxone. At least five jurisdictions modified law or policy to expand EMT access to naloxone in 2013. There is wide variation between states regarding EMS naloxone dosing protocol and route of administration.

CONCLUSIONS

Naloxone administration is standard for paramedic and intermediate-level EMS personnel, but most states do not allow basic life support (BLS) personnel to administer this medication. Standards consistent with available medical evidence for naloxone administration, dosing, and route of administration should be implemented at each EMS level of certification.

Naloxone therapy in opioid overdose patients: intranasal or intravenous? A randomized clinical trial

INTRODUCTION

This study was designed to compare the effects of intranasal (IN) and intravenous (IV) administration of naloxone in patients who had overdosed on opioids.

MATERIAL AND METHODS

This randomized clinical trial study was conducted in the Department of Poisoning Emergencies at Noor and Ali Asghar (PBUH) University Hospital. One hundred opioid overdose patients were assigned by random allocation software into two study groups (n = 50). Both groups received 0.4 mg naloxone: one group IN and the other IV. Outcomes included change in the level of consciousness (measured using a descriptive scale and the Glasgow Coma Scale (GCS)), time to response, vital signs (blood pressure, heart rate and respiratory rate), arterial blood O2 saturation before and after naloxone administration, side-effects (agitation) and length of hospital stay.

RESULTS

Patients who had been administered IN naloxone demonstrated significantly higher levels of consciousness than those in the IV group using both descriptive and GCS scales (p < 0.001). There was a significant difference in the heart rate between IN and IV groups (p = 0.003). However, blood pressure, respiratory rate and arterial O2 saturation were not significantly different between the two groups after naloxone administration (p = 0.18, p = 0.17, p = 0.32). There was also no significant difference in the length of hospital stay between the two groups (p = 0.14).

CONCLUSIONS

Intranasal naloxone is as effective as IV naloxone in reversing both respiratory depression and depressive effects on the central nervous system caused by opioid overdose.

Sub-dissociative-dose intranasal ketamine for moderate to severe pain in adult emergency department patients

BACKGROUND

There are currently no studies assessing effectiveness of sub-dissociative intranasal (IN) ketamine as the initial analgesic for adult patients in the ED.

OBJECTIVE

The study aims to examine the effectiveness of sub-dissociative IN ketamine as a primary analgesic agent for adult patients in the ED.

METHOD

This is a prospective, observational study of adult ED patients presenting with severe pain (≥6 on 11-point scale at triage). IN ketamine dose was 0.7 mg/kg, with secondary dose of 0.5 mg/kg at 15 min if pain did not improve. After 6 months, initial dose was increased to 1.0 mg/kg with the same optional secondary dose.

PRIMARY OUTCOMES

The primary outcomes are change in VAS rating at 30 min; percentage of patients reporting clinically significant reduction in VAS (≥20 mm) at 30 min; dose resulting in clinically significant pain reduction.

RESULTS

Of the 72 patients available for analysis, median age was 34.5 years and 64% were men. Median initial VAS rating was 76 mm (interquartile range [IQR]: 65-82). Median total dose of IN ketamine for all patients was 0.98 mg/kg (IQR: 0.75-1.15, range: 0.59-1.57). Median reduction in VAS rating at 30 min was 24 mm (IQR: 2-45). Forty (56%, 95% CI: 44.0-66.7) reported VAS reduction ≥20 mm, these patients having had a total median ketamine dose of 0.94 mg/kg (IQR: 0.72-1.04).

CONCLUSION

IN ketamine, at a dose of about 1 mg/kg, was an effective analgesic agent in 56% of study patients. The place of IN ketamine in analgesic guidelines for adults requires further investigation.

Naloxone for opioid overdose prevention: pharmacists' role in community-based practice settings

BACKGROUND

Deaths related to opioid overdose have increased in the past decade. Community-based pharmacy practitioners have worked toward overcoming logistic and cultural barriers to make naloxone distribution for overdose prevention a standard and accepted practice.

OBJECTIVE

To describe outpatient naloxone dispensing practices, including methods by which practitioners implement dispensing programs, prescribing patterns that include targeted patient populations, barriers to successful implementation, and methods for patient education.

METHODS

Interviews were conducted with providers to obtain insight into the practice of dispensing naloxone. Practitioners were based in community pharmacies or clinics in large metropolitan cities across the country.

RESULTS

It was found that 33% of participating pharmacists practice in a community-pharmacy setting, and 67% practice within an outpatient clinic-based location. Dispensing naloxone begins by identifying patient groups that would benefit from access to the antidote. These include licit users of high-dose prescription opioids (50%) or injection drug users and abusers of prescription medications (83%). Patients were identified through prescription records or provider screening tools. Dispensing naloxone required a provider's prescription in 5 of the 6 locations identified. Only 1 pharmacy was able to exercise pharmacist prescriptive authority within their practice.

CONCLUSION

Outpatient administration of intramuscular and intranasal naloxone represents a means of preventing opioid-related deaths. Pharmacists can play a vital role in contacting providers, provision of products, education of patients and providers, and dissemination of information throughout the community. Preventing opioid overdose-related deaths should become a major focus of the pharmacy profession.

A response to the opioid overdose epidemic: naloxone nasal spray

Opioid overdose morbidity and mortality is recognized to have epidemic proportions. Medical and public health agencies are adopting opioid harm reduction strategies to reduce the morbidity and mortality associated with overdose. One strategy developed by emergency medical services and public health agencies is to deliver the opioid antidote naloxone injection intranasally to reverse the effects of opioids. Paramedics have used this route to quickly administer naloxone in a needle-free system and avoiding needle-stick injuries and contracting a blood-born pathogen disease such as hepatitis or human immunodeficiency virus. Public health officials advocate broader lay person access since civilians are likely witnesses or first responders to an opioid overdose in a time-acute setting. The barrier to greater use of naloxone is that a suitable and optimized needlefree drug delivery system is unavailable. The scientific basis for design and study of an intranasal naloxone product is described. Lessons from nasal delivery of opioid analgesics are applied to the consideration of naloxone nasal spray.

Can nebulized naloxone be used safely and effectively by emergency medical services for suspected opioid overdose?

BACKGROUND

Emergency medical services (EMS) traditionally administer naloxone using a needle. Needleless naloxone may be easier when intravenous (IV) access is difficult and may decrease occupational blood-borne exposure in this high-risk population. Several studies have examined intranasal naloxone, but nebulized naloxone as an alternative needleless route has not been examined in the prehospital setting.

OBJECTIVE

We sought to determine whether nebulized naloxone can be used safely and effectively by prehospital providers for patients with suspected opioid overdose.

METHODS

We performed a retrospective analysis of all consecutive cases administered nebulized naloxone from January 1 to June 30, 2010, by the Chicago Fire Department. All clinical data were entered in real time into a structured EMS database and data abstraction was performed in a systematic manner. Included were cases of suspected opioid overdose, altered mental status, and respiratory depression; excluded were cases where nebulized naloxone was given for opioid-triggered asthma and cases with incomplete outcome data. The primary outcome was patient response to nebulized naloxone. Secondary outcomes included need for rescue naloxone (IV or intramuscular), need for assisted ventilation, and adverse antidote events. Kappa interrater reliability was calculated and study data were analyzed using descriptive statistics.

RESULTS

Out of 129 cases, 105 met the inclusion criteria. Of these, 23 (22%) had complete response, 62 (59%) had partial response, and 20 (19%) had no response. Eleven cases (10%) received rescue naloxone, no case required assisted ventilation, and no adverse events occurred. The kappa score was 0.993.

CONCLUSION

Nebulized naloxone is a safe and effective needleless alternative for prehospital treatment of suspected opioid overdose in patients with spontaneous respirations.

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

AIMS

Traditionally, the opiate antagonist naloxone has been administered parenterally; however, intranasal (i.n.) administration has the potential to reduce the risk of needlestick injury. This is important when working with populations known to have a high prevalence of blood-borne viruses. Preliminary research suggests that i.n. administration might be effective, but suboptimal naloxone solutions were used. This study compared the effectiveness of concentrated (2 mg/ml) i.n. naloxone to intramuscular (i.m.) naloxone for suspected opiate overdose.

METHODS

This randomized controlled trial included patients treated for suspected opiate overdose in the pre-hospital setting. Patients received 2 mg of either i.n. or i.m. naloxone. The primary outcome was the proportion of patients who responded within 10 minutes of naloxone treatment. Secondary outcomes included time to adequate response and requirement for supplementary naloxone. Data were analysed using multivariate statistical techniques.

RESULTS

A total of 172 patients were enrolled into the study. Median age was 29 years and 74% were male. Rates of response within 10 minutes were similar: i.n. naloxone (60/83, 72.3%) compared with i.m. naloxone (69/89, 77.5%) [difference: -5.2%, 95% confidence interval (CI) -18.2 to 7.7]. No difference was observed in mean response time (i.n.: 8.0, i.m.: 7.9 minutes; difference 0.1, 95% CI -1.3 to 1.5). Supplementary naloxone was administered to fewer patients who received i.m. naloxone (i.n.: 18.1%; i.m.: 4.5%) (difference: 13.6%, 95% CI 4.2-22.9).

CONCLUSIONS

Concentrated intranasal naloxone reversed heroin overdose successfully in 82% of patients. Time to adequate response was the same for both routes, suggesting that the i.n. route of administration is of similar effectiveness to the i.m. route as a first-line treatment for heroin overdose.

Saved by the nose: bystander-administered intranasal naloxone hydrochloride for opioid overdose

Administering naloxone hydrochloride (naloxone) during an opioid overdose reverses the overdose and can prevent death. Although typically delivered via intramuscular or intravenous injection, naloxone may be delivered via intranasal spray device. In August 2006, the Boston Public Health Commission passed a public health regulation that authorized an opioid overdose prevention program that included intranasal naloxone education and distribution of the spray to potential bystanders. Participants were taught by trained nonmedical needle exchange staff. After 15 months, the program provided training and intranasal naloxone to 385 participants who reported 74 successful overdose reversals. Problems with intranasal naloxone were uncommon. Overdose prevention education with distribution of intranasal naloxone is a feasible public health intervention to address opioid overdose.

Population pharmacokinetics of intravenous, intramuscular, and intranasal naloxone in human volunteers

To investigate the pharmacokinetics of naloxone in healthy volunteers, we undertook an open-label crossover study in which six male volunteers received naloxone on five occasions: intravenous (0.8 mg), intramuscular (0.8 mg), intranasal (0.8 mg), intravenous (2 mg), and intranasal (2 mg). Samples were collected for 4 hours after administration for 128 samples in total. A population pharmacokinetic analysis was undertaken using NONMEM. The data were best described by a three-compartment model with first-order absorption for intramuscular and intranasal administration, between-subject variability on clearance and central volume, lean body weight on clearance, and weight on central volume. Relative bioavailability of intramuscular and intranasal naloxone was 36% and 4%, respectively. The final parameter estimates were clearance, 91 L/hr; central volume, 2.87 L; first peripheral compartment volume, 1.49 L, second peripheral compartment volume, 33.6 L; first intercompartmental clearance, 5.66 L/hr; second intercompartmental clearance, 29.8 L/hr; Ka (intramuscular), 0.65; and Ka (intranasal), 1.52. Median time to peak concentration for intramuscular naloxone was 12 minutes and for intranasal, 6 to 9 minutes. A combination of intravenous and intramuscular naloxone provided immediate high and then detectable concentrations for 4 hours. Intranasal naloxone had poor bioavailability compared with intramuscular. Combined intravenous and intramuscular administration may be a useful alternative to naloxone infusions.