Intranasal drug delivery: an alternative to intravenous administration in selected emergency cases

Dexmedetomidine sedation vs. inhaled general anesthesia for pediatric MRI: A retrospective cohort study: Dexmedetomidine sedation vs. inhaled general anesthesia for MRI

OBJECTIVES

The objective of this study was to evaluate the feasibility and the efficacy of a dexmedetomidine-based protocol followed by anesthesiologists unaccustomed to using dexmedetomidine during pediatric magnetic resonance imaging (MRI) examinations compared to conventional halogenated general anesthesia.

METHODS

This was a single-center retrospective cohort study including patients younger than 18 years who underwent sedation for MRI between August 1, 2018 and March 31, 2019. Patients who received dexmedetomidine were included in the DEX group and patients who had general anesthesia formed the GA group. Patients were matched with a ratio of 2 GA:1 DEX, based on age and type of MRI examination.

RESULTS

Overall, 78 patients were included (DEX=26; GA=52). Dexmedetomidine was significantly associated with a decrease in invasive ventilation (p<0.001) with no impact on image quality. The sedation failure rate was 42% with dexmedetomidine vs. 0% with general anesthesia (p<0.001). All cases of failure followed the intranasal administration of dexmedetomidine.

CONCLUSION

Dexmedetomidine seems to be a suitable sedation option for pediatric MRI. It provides an alternative to halogenated general anesthesia with the aim of limiting exposure to conventional anesthetic agents and invasive ventilation.

AmyloLipid Nanovesicles: A self-assembled lipid-modified starch hybrid system constructed for direct nose-to-brain delivery of curcumin

AmyloLipid nanovesicles (ALNs) are new lipid-modified starch complex nanoparticles developed and presented as nanocarriers of curcumin for targeting the CNS via the intranasal route. Curcumin has been indicated as a promising active agent with a variety of pharmacological activities, including a potential ability to treat brain tumors, traumatic brain injury, and CNS disorders, such as Alzheimer's disease, as it may inhibit amyloid-β-protein (Aβ) aggregation and Aβ-induced inflammation. Although curcumin has a tremendous potential as a therapeutic agent for CNS disorders, its low bioavailability and its rapid total body clearance reduce any chance for therapeutic levels to reach the brain. By using an optimized (2% crosslinked starch) curcumin-loaded ALNs, which was fabricated from a microemulsion as a precursor, an average of 141.5 ± 55.9 ng/g brain levels and 11.9 ± 12.0 ng/ml plasma concentrations were detected, one hour following intranasal administration of 160 μg/kg dose of curcumin. In comparison, 1 h after IV administration of the same dose, no CUR was detected in the brain and the mean plasma level was approximately one half of the level monitored after intranasal ALNs, i.e., 7.25 ± 0.20 ng/ml. It has been clearly demonstrated, therefore, that a well-designed ALN formulation proved itself as a promising carrier for intranasal delivery and brain targeting of curcumin.

Mass Spectrometric Imaging of the Brain Demonstrates the Regional Displacement of 6-Monoacetylmorphine by Naloxone

Overdose is the main cause of mortality among heroin users. Many of these overdose-induced deaths can be prevented through the timely administration of naloxone (NLX), a nonselective mu (μ)-, kappa (κ)-, and delta (δ)-opioid receptor antagonist. NLX competitively inhibits opioid-overdose-induced respiratory depression without eliciting any narcotic effect itself. The aim of this study was to investigate the antagonistic action of NLX by comparing its distribution to that of 6-monacetylmorphine (6-MAM), heroin's major metabolite, in a rodent model using mass spectrometric imaging (MSI) in combination with liquid chromatography-tandem mass spectrometry (LC-MS/MS). Male Sprague-Dawley rats (n = 5) received heroin (10 mg kg^-1) intraperitoneally, NLX (10 mg kg^-1) intranasally, and NLX injected intranasally 5 min after heroin administration. The animals were sacrificed 15 min after dose and brain tissues were harvested. The MSI image analysis showed a region-specific distribution of 6-MAM in the brain regions including the corpus callosum, hippocampal formation, cerebral cortex, corticospinal tracts, caudate putamen, thalamus, globus pallidus, hypothalamus, and basal forebrain regions of the brain. The antagonist had a similar biodistribution throughout the brain in both groups of animals that received NLX or NLX after heroin administration. The MSI analysis demonstrated that the intensity of 6-MAM in these brain regions was reduced following NLX treatment. The decrease in 6-MAM intensity was caused by its displacement by the antagonist and its binding to these receptors in these specific brain regions, consequently enhancing the opioid elimination. These findings will contribute to the evaluation of other narcotic antagonists that might be considered for use in the treatment of drug overdose via MSI.

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 dosage for opioid reversal: current evidence and clinical implications

Opioid-related mortality is a growing problem in the United States, and in 2015 there were over 33,000 opioid-related deaths. To combat this mortality trend, naloxone is increasingly being utilized in a pre-hospital setting by emergency personnel and prescribed to laypersons for out-of-hospital administration. With increased utilization of naloxone there has been a subsequent reduction in mortality following an opioid overdose. Reversal of opioid toxicity may precipitate an opioid-withdrawal syndrome. At the same time, there is a risk of inadequate response or re-narcotization after the administration of a single dose of naloxone in patients who have taken large doses or long-acting opioid formulations, as the duration of effect of naloxone is shorter than that of many opioid agonists. As out-of-hospital use of this medication is growing, so too is concern about effective but safe dosing.

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.

Oxytocin under opioid antagonism leads to supralinear enhancement of social attention

To provide new preclinical evidence toward improving the efficacy of oxytocin (OT) in treating social dysfunction, we tested the benefit of administering OT under simultaneously induced opioid antagonism during dyadic gaze interactions in monkeys. OT coadministered with a μ-opioid receptor antagonist, naloxone, invoked a supralinear enhancement of prolonged and selective social attention, producing a stronger effect than the summed effects of each administered separately. These effects were consistently observed when averaging over entire sessions, as well as specifically following events of particular social importance, including mutual eye contact and mutual reward receipt. Furthermore, attention to various facial regions was differentially modulated depending on social context. Using the Allen Institute's transcriptional atlas, we further established the colocalization of μ-opioid and κ-opioid receptor genes and OT genes at the OT-releasing sites in the human brain. These data across monkeys and humans support a regulatory relationship between the OT and opioid systems and suggest that administering OT under opioid antagonism may boost the therapeutic efficacy of OT for enhancing social cognition.

Perillyl Alcohol and Its Drug-Conjugated Derivatives as Potential Novel Methods of Treating Brain Metastases

Metastasis to the central nervous system remains difficult to treat, and such patients are faced with a dismal prognosis. The blood-brain barrier (BBB), despite being partially compromised within malignant lesions in the brain, still retains much of its barrier function and prevents most chemotherapeutic agents from effectively reaching the tumor cells. Here, we review some of the recent developments aimed at overcoming this obstacle in order to more effectively deliver chemotherapeutic agents to the intracranial tumor site. These advances include intranasal delivery to achieve direct nose-to-brain transport of anticancer agents and covalent modification of existing drugs to support enhanced penetration of the BBB. In both of these areas, use of the natural product perillyl alcohol, a monoterpene with anticancer properties, contributed to promising new results, which will be discussed here.

Metal Nanoparticles as Targeted Carriers Circumventing the Blood-Brain Barrier

Metal nanoparticles have been proposed as a carrier and a therapeutic agent in biomedical field because of their unique physiochemical properties. Due to these physicochemical properties, they can be used in different fields of biomedicine. In relation to this, plasmonic nanoparticles can be used for detection and photothermal destruction of tumor cells or toxic protein aggregates, and magnetic iron nanoparticles can be used for imaging and for hyperthermia of tumor cells. In addition, both therapy and imaging can be combined in one nanoparticle system, in a process called theranostics. Metal nanoparticles can be synthesized to modulate their size and shape, and conjugated with different ligands, which allow their application in drug delivery, diagnostics, and treatment of central nervous system diseases. This review is focused on the potential applications of metal nanoparticles and their capability to circumvent the blood-brain barrier (BBB). Although many articles have demonstrated delivery of metal nanoparticles to the brain by crossing the BBB after systemic administration, the percentage of the injected dose that reaches this organ is low in comparison to others, especially the liver and spleen. In connection with this drawback, we elaborate the architecture of the BBB and review possible mechanisms to cross this barrier by engineered nanoparticles. The potential uses of metal nanoparticles for treatment of disorders as well as related neurotoxicological considerations are also discussed. Finally, we bring up for discussion a direct and relatively simpler solution to the problem. We discuss this in detail after having proposed the use of the intranasal administration route as a way to circumvent the BBB. This route has not been extensively studied yet for metal nanoparticles, although it could be used as a research tool for mechanistic understanding and toxicity as well as an added value for medical practice.

A review of intranasal formulations for the treatment of seizure emergencies

Epileptic seizure emergencies are life-threatening conditions, which in their most severe form, status epilepticus, have a high mortality rate if not quickly terminated. Treatment requires rapid delivery of anti-epileptics such as benzodiazepines to the brain. The nasal route is attractive due to its non-invasiveness, potential for direct nose to brain delivery, high vascularity, relatively large absorptive surface area, and avoidance of intestinal/liver metabolism. However, the limited volume of the nasal cavity and poor water solubility of anti-epileptics restrict absorption, leading to insufficient therapeutic brain levels. This review covers various formulation approaches adopted to improve nasal delivery of drugs, especially benzodiazepines, used to treat seizure emergencies. Other general topics such as nasal anatomy, challenges to nasal delivery, and drug/formulation considerations for nose to brain delivery are also discussed.

Wilderness Medical Society practice guidelines for the treatment of acute pain in remote environments: 2014 update

The Wilderness Medical Society convened an expert panel to develop evidence-based guidelines for the management of pain in austere environments. Recommendations are graded on the basis of the quality of supporting evidence as defined by criteria put forth by the American College of Chest Physicians. This is an updated version of the original WMS Practice Guidelines for the Treatment of Acute Pain in Remote Environments published in Wilderness & Environmental Medicine 2014;25(1):41-49.

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.

Intranasal administration of carbamazepine to mice: a direct delivery pathway for brain targeting

The currently available antiepileptic drugs are typically administered via oral or intravenous (IV) routes which commonly exhibit high systemic distribution into non-targeted tissues, leading to peripheral adverse effects and limited brain uptake. In order to improve the efficacy and tolerability of the antiepileptic drug therapy, alternative administration strategies have been investigated. The purpose of the present study was to assess the pharmacokinetics of carbamazepine administered via intranasal (IN) and IV routes to mice, and to investigate whether a direct transport of the drug from nose to brain could be involved. The similar pharmacokinetic profiles obtained in all matrices following both administration routes indicate that, after IN delivery, carbamazepine reaches quickly and extensively the bloodstream, achieving the brain predominantly via systemic circulation. However, the uneven biodistribution of carbamazepine through the brain regions with higher concentrations in the olfactory bulb and frontal cortex following IN instillation, in comparison with the homogenous brain distribution pattern after IV injection, strongly suggests the involvement of a direct transport of carbamazepine from nose to brain. Therefore, it seems that IN delivery represents a suitable and promising alternative route to administer carbamazepine not only for the chronically use of the drug but also in emergency conditions.

Wilderness Medical Society practice guidelines for the treatment of acute pain in remote environments

The Wilderness Medical Society convened an expert panel to develop evidence-based guidelines for the management of pain in austere environments. Recommendations are graded based on the quality of supporting evidence as defined by criteria put forth by the American College of Chest Physicians.

Prehospital medication administration: a randomised study comparing intranasal and intravenous routes

Introduction. Opioid overdose is an ever-increasing problem globally. Recent studies have demonstrated that intranasal (IN) naloxone is a safe and effective alternative to traditional routes of naloxone administration for reversal of opioid overdose. Aims. This randomised controlled trial aimed to compare the time taken to deliver intranasal medication with that of intravenous (IV) medication by advanced paramedic trainees. Methods. 18 advanced paramedic trainees administered either an IN or IV medication to a mannequin model in a classroom-based setting. The time taken for medication delivery was compared. End-user satisfaction was assessed using a 5-point questionnaire regarding ease of use and safety for both routes. Results. The mean time taken for the IN and IV group was 87.1 seconds and 178.2 seconds respectively. The difference in mean time taken was 91.1 seconds (95% confidence interval 55.2 seconds to 126.9 seconds, P ≤ 0.0001). 89% of advanced paramedic trainees reported that the IN route was easier and safer to use than the IV route. Conclusion. This study demonstrates that, amongst advanced paramedic trainees, the IN route of medication administration is significantly faster, better accepted and perceived to be safer than using the IV route. Thus, IN medication administration could be considered more frequently when administering emergency medications in a pre-hospital setting.

Systemic delivery of insulin via the nasal route using a new microemulsion system: In vitro and in vivo studies

The main purpose of this study was to investigate the nasal absorption of insulin from a new microemulsion spray preparation in rabbits. The bioavailability of insulin lispro via the nasal route using a W/O microemulsion was found to reach 21.5% relative to subcutaneous administration, whereas the use of an inverse microemulsion as well as a plain solution yielded less than 1% bioavailability. The profile of plasma glucose levels obtained after nasal spray application of the microemulsion (1IU/kg lispro) was similar to the subcutaneous profile of 0.5IU/kg at the first 90min after application and resulted in a 30-40% drop in glucose levels. The microemulsion system was characterized by DLS, TEM, viscosity measurements, and by construction of pseudo-ternary phase diagram. The average droplet size of an insulin-unloaded and insulin-loaded microemulsions containing 20% aqueous phase (surfactants-to-oil ratio=87:13) was 2nm and 2.26nm in diameter, respectively. In addition, the effect of the microemulsion on FITC-labeled insulin permeation was examined across the porcine nasal mucosa in vitro. The permeability coefficient of FITC-insulin via the microemulsion was 0.210±0.048cm/h with a lag time of 10.9±6.5min, whereas the permeability coefficient from a plain solution was 0.082±0.043cm/h with a lag time of 36.3±10.1min. In view of the absorption differences of insulin between 20%, 50% water-containing microemulsions and an aqueous solution obtained in vitro and in vivo, it has been concluded that the acceleration in the intramucosal transport process is the result of encapsulating insulin within the nano-droplet clusters of a W/O microemulsion, while the microemulsion ingredients seems to have no direct role.

The implementation of intranasal fentanyl for children in a mixed adult and pediatric emergency department reduces time to analgesic administration

OBJECTIVES

The objective was to determine whether the introduction of intranasal (IN) fentanyl for children with acute pain would reduce the time to analgesic administration in a mixed adult and pediatric emergency department (ED).

METHODS

A protocol for IN fentanyl (1.5 microg/ kg) for children age 1-15 years presenting with acute pain was introduced to the department. All children who received intravenous (IV) morphine in the 7 months prior to the introduction of the protocol and either IV morphine or IN fentanyl in the 7 months after the introduction of the protocol were identified from drug registers. Time to analgesic administration, time to see a doctor, and the ages of patients were compared between the periods before and after the introduction of IN fentanyl.

RESULTS

Following implementation, 81 patients received IN fentanyl and 37 received IV morphine, compared to 63 patients receiving morphine in the previous 7 months. The median time to analgesic administration for IN fentanyl was significantly shorter than for morphine (32 minutes vs. 63 minutes, p = 0.001). Children receiving fentanyl were significantly younger than those receiving morphine (median = 8.5 years vs. 12 years, p < 0.001).

CONCLUSIONS

This study demonstrates that children treated with IN fentanyl received analgesic medication faster than those treated with IV morphine in a mixed ED. Younger children were more likely to receive opioid analgesia following the introduction of fentanyl.

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.

Intranasal dexmedetomidine premedication is comparable with midazolam in burn children undergoing reconstructive surgery

Preoperative anxiety and emergence delirium in children continue to be common even with midazolam premedication. Midazolam is unpleasant tasting even with a flavored vehicle and as a result, patient acceptance is sometimes poor. As an alternative, we evaluated dexmedetomidine administered intranasally. Dexmedetomidine an alpha-2 adrenergic agonist is tasteless, odorless, and painless when administered by this route. Alpha-2 adrenergic agonists produce sedation, facilitate parental separation, and improve conditions for induction of general anesthesia, while preserving airway reflexes. Institutional review board approval was obtained to study 100 pediatric patients randomized to intranasal dexmedetomidine (2 microg/kg) or oral midazolam (0.5 mg/kg) administered 30 to 45 minutes before the surgery. Subjects received general anesthesia with oxygen, nitrous oxide, isoflurane, and analgesics (0.05-0.1 mg/kg morphine or 0.1 mg/kg methadone). Nurses and anesthetists were blinded to the drug administered and evaluated patients for preoperative sedation, conditions for induction of general anesthesia, emergence from anesthesia, and postoperative pain. Responses of 100 patients (50 dexmedetomidine and 50 midazolam) were analyzed. Dexmedetomidine (P=.003) was more effective than midazolam at inducing sleep preoperatively. Dexmedetomidine and midazolam were comparable for conditions at induction (P>0.05), emergence from anesthesia (P>0.05), or postoperative pain (P>0.05). Both drugs were equieffective in these regards. In pediatric patients, dexmedetomidine 2 microg/kg administered intranasally and midazolam 0.5 mg/kg administered orally produced similar conditions during induction and emergence of anesthesia. Intranasal administration of dexmedetomidine is more effective at inducing sleep and in some circumstances offers a useful alternative to oral midazolam in children.

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.

Intranasal naloxone for the treatment of suspected heroin overdose

AIMS

This paper reviews available literature regarding the effectiveness, safety and utility of intranasal (i.n.) naloxone for the treatment of heroin overdose.

METHODS

Scientific literature in the form of published articles during the period January 1984 to August 2007 were identified by searching several databases including Medline, Cinahl and Embase for the following terms: naloxone, narcan, intranasal, nose. The data extracted included study design, patient selection, numbers, outcomes and adverse events.

RESULTS

Reports of the pharmacological investigation and administration of i.n. naloxone for heroin overdose are included in this review. Treatment of heroin overdose by administration of i.n. naloxone has been introduced as first-line treatment in some jurisdictions in North America, and is currently under investigation in Australia.

CONCLUSION

Currently there is not enough evidence to support i.n. naloxone as first-line intervention by paramedics for treatment of heroin overdose in the pre-hospital setting. Further research is required to confirm its clinical effectiveness, safety and utility. If proved effective, the i.n. route may be useful for drug administration in community settings (including peer-based administration), as it reduces risk of needlestick injury in a population at higher risk of blood-borne viruses. Problematically, naloxone is not manufactured currently in an ideal form for i.n. administration.

Intranasal delivery: physicochemical and therapeutic aspects

Interest in intranasal (IN) administration as a non-invasive route for drug delivery continues to grow rapidly. The nasal mucosa offers numerous benefits as a target issue for drug delivery, such as a large surface area for delivery, rapid drug onset, potential for central nervous system delivery, and no first-pass metabolism. A wide variety of therapeutic compounds can be delivered IN, including relatively large molecules such as peptides and proteins, particularly in the presence of permeation enhancers. The current review provides an in-depth discussion of therapeutic aspects of IN delivery including consideration of the intended indication, regimen, and patient population, as well as physicochemical properties of the drug itself. Case examples are provided to illustrate the utility of IN dosing. It is anticipated that the present review will prove useful for formulation scientists considering IN delivery as a delivery route.

Update on the acute management of status epilepticus in children

PURPOSE OF REVIEW

Status epilepticus is the most common neurologic emergency in children. The understanding of its less recognizable forms, its pharmacologic management, the role of electroencephalography and the long-term morbidity and mortality as a result of status epilepticus are consistently evolving. This review frames the current understanding of several issues as they apply to acute management in the emergency department.

RECENT FINDINGS

Researchers are working to define less recognizable forms of status epilepticus such as nonconvulsive, autonomic and psychogenic. Buccal and intranasal forms of midazolam are emerging as suitable alternatives to rectal diazepam in the initial treatment of status epilepticus. Valproic acid, chloral hydrate and newer-generation antiepileptics are being proposed as safe and effective alternatives to the traditional drugs used to treat status epilepticus. The role of electroencephalography in diagnosis is being elucidated. Risk factors for neurologic sequelae and mortality after status epilepticus remain an area of research with conflicting findings and no real consensus.

SUMMARY

The understanding of different types of status epilepticus, the options for pharmacologic treatment, the tools for diagnosis and the morbidity and mortality of the disease are still evolving. As a result, several areas for further research remain that will help clinicians in their approach to this complex condition.