Clinical pharmacology of midazolam in neonates and children: effect of disease-a review

Antibiotics, Analgesic Sedatives, and Antiseizure Medications Frequently Used in Critically Ill Neonates: A Narrative Review

Antibiotic, analgesic sedative, and antiseizure medications are among the most commonly used medications in preterm/sick neonates, who are at high risk of nosocomial infections, central nervous system complications, and are exposed to numerous painful/stressful procedures. These severe and potentially life-threatening complications may have serious short- and long-term consequences and should be prevented and/or promptly treated. The reported variability in the medications used in neonates indicates the lack of adequate neonatal studies regarding their effectiveness and safety. Important obstacles contributing to inadequate studies in preterm/sick infants include difficulties in obtaining parental consent, physicians' unwillingness to recruit preterm infants, the off-label use of many medications in neonates, and other scientific and ethical concerns. This review is an update on the use of antimicrobials (antifungals), analgesics (sedatives), and antiseizure medications in neonates, focusing on current evidence or knowledge gaps regarding their pharmacokinetics, indications, safety, dosage, and evidence-based guidelines for their optimal use in neonates. We also address the effects of early antibiotic use on the intestinal microbiome and its association with long-term immune-related diseases, obesity, and neurodevelopment (ND). Recommendations for empirical treatment and the emergence of pathogen resistance to antimicrobials and antifungals are also presented. Finally, future perspectives on the prevention, modification, or reversal of antibiotic resistance are discussed.

Drug Disposition in Neonatal Göttingen Minipigs: Exploring Effects of Perinatal Asphyxia and Therapeutic Hypothermia

Asphyxiated neonates often undergo therapeutic hypothermia (TH) to reduce morbidity and mortality. Since both perinatal asphyxia (PA) and TH influence physiology, altered pharmacokinetics (PK) and pharmacodynamics (PD) are expected. Given that TH is the standard of care for PA with moderate to severe hypoxic-ischemic encephalopathy, disentangling the effect of PA versus TH on PK/PD is not possible in clinical settings. However, animal models can provide insights into this matter. The (neonatal) Göttingen Minipig, the recommended strain for nonclinical drug development, was selected as translational model. Four drugs-midazolam (MDZ), fentanyl (FNT), phenobarbital (PHB), and topiramate (TPM)-were intravenously administered under four conditions: control (C), therapeutic hypothermia (TH), hypoxia (H), and hypoxia plus TH (H+TH). Each group included six healthy male neonatal Göttingen Minipigs anesthetized for 24 hours. Blood samples were drawn at 0 (predose) and 0.5, 2, 2.5, 3, 4, 4.5, 6, 8, 12, and 24 hours post drug administration. Drug plasma concentrations were determined using validated bioanalytical assays. The PK parameters were estimated through compartmental and noncompartmental PK analysis. The study showed a statistically significant decrease in FNT clearance (CL; 66% decrease), with an approximately threefold longer half-life (t1/2) in the TH group. The H+TH group showed a 17% reduction in FNT CL, with a 62% longer t1/2 compared with the C group; however, it was not statistically significant. Although not statistically significant, trends toward lower CL and longer t1/2 were observed in the TH and H+TH groups for MDZ and PHB. Additionally, TPM demonstrated a 28% decrease in CL in the H group compared with controls. SIGNIFICANCE STATEMENT: The overarching goal of this study using the neonatal Göttingen Minipig model was to disentangle the effects of systemic hypoxia and TH on PK using four model drugs. Such insights can subsequently be used to inform and develop a physiologically based pharmacokinetic model, which is useful for drug exposure prediction in human neonates.

Anaesthetic management of paediatric patients undergoing electrophysiology study and ablation for supraventricular tachycardia: A focused narrative review

Every year, 80,000-100,000 ablation procedures take place in the United States and approximately 1% of these involve paediatric patients. As the paediatric population undergoing catheter ablation to treat dysrhythmia is constantly growing, involvement of anaesthesiologists in the cardiac electrophysiology laboratory is simultaneously increasing. Compared with the adult population, paediatric patients need deeper sedation or general anaesthesia (GA) to guarantee motionlessness and preserve comfort. As a result, the anaesthesiologist working in this setting should keep in mind heart physiopathology as well as possible interactions between anaesthetic drugs and arrhythmia. In fact, drug-induced suppression of accessory pathways (APs) conduction capacity is a major concern for completing a successful electrophysiology study (EPS). Nevertheless, the literature on this topic is scarce and the optimal type of anaesthesia in EPS and ablation procedures in children is still controversial. Thus, the main goal of the present review is to collect the literature published so far on the effects on cardiac conduction tissue of the drugs commonly employed for sedation/GA in the cath lab for EPS and ablation procedures to treat supraventricular tachycardia in patients aged <18 years.

The efficacy and safety of midazolam with fentanyl versus midazolam with ketamine for bedside invasive procedural sedation in pediatric oncology patients: A randomized, double-blinded, crossover trial

Children with cancer often require sedation before undergoing invasive procedures. Fentanyl, ketamine, and midazolam are effective drugs widely used for procedural sedation. This study aimed to investigate the efficacy and safety of midazolam-fentanyl (M-F) compared with midazolam-ketamine (M-K) for bedside procedural sedation among pediatric oncology patients. A randomized, double-blinded, crossover trial was conducted among children with cancer requiring procedural sedation for invasive procedures. Patients were randomly assigned either intravenous M-F or M-K and subsequently received the alternate regimens following the crossover design of the study. The efficacy and safety of the sedations including sedation time intervals, nausea score, vomiting episodes, pain score, adverse effects, and parent's satisfaction were evaluated. In all, 58 patients with 116 procedural sedations were enrolled. M-K provided a shorter induction time (0:58 vs. 1:23 min) (p = 0.005), but longer sedation (9:02 vs. 5:50 min) (p = 0.019) and emergence time (4:26 vs. 0:56 min) (p = 0.011) compared with M-F. Sedation routes affected the sedation time intervals. Patients had higher rates of vomiting (0, range 0-8 vs. 0, range 0-2) (p = 0.033) but experienced less pain (0 vs. 2) (p = 0.008) in the M-K group. Overall satisfaction and other adverse effects were comparable among both sedation regimens. Combined sedative drugs are recommended to improve the effectiveness of bedside procedural sedation. M-K provided shorter induction, but longer sedation and emergence time compared with M-F. These findings correlated with sedative routes. Patients receiving M-K experienced a higher rate of vomiting, but less painfulness compared with M-F. Overall satisfaction and tolerable side effects were comparable among both sedative regimens.

Neurocardiovascular coupling in congenital diaphragmatic hernia patients undergoing different types of surgical treatment

BACKGROUND

The effect of peri-operative management on the neonatal brain is largely unknown. Triggers for perioperative brain injury might be revealed by studying changes in neonatal physiology peri-operatively.

OBJECTIVE

To study neonatal pathophysiology and cerebral blood flow regulation peri-operatively using the neuro-cardiovascular graph.

DESIGN

Observational, prospective cohort study on perioperative neuromonitoring. Neonates were included between July 2018 and April 2020.

SETTING

Multicentre study in two high-volume tertiary university hospitals.

PATIENTS

Neonates with congenital diaphragmatic hernia were eligible if they received surgical treatment within the first 28 days of life. Exclusion criteria were major cardiac or chromosomal anomalies, or syndromes associated with altered cerebral perfusion or major neurodevelopmental impairment. The neonates were stratified into different groups by type of peri-operative management.

INTERVENTION

Each patient was monitored using near-infrared spectroscopy and EEG in addition to the routine peri-operative monitoring. Neurocardiovascular graphs were computed off-line.

MAIN OUTCOME MEASURES

The primary endpoint was the difference in neurocardiovascular graph connectivity in the groups over time.

RESULTS

Thirty-six patients were included. The intraoperative graph connectivity decreased in all patients operated upon in the operation room (OR) with sevoflurane-based anaesthesia ( P  < 0.001) but remained stable in all patients operated upon in the neonatal intensive care unit (NICU) with midazolam-based anaesthesia. Thoracoscopic surgery in the OR was associated with the largest median connectivity reduction (0.33 to 0.12, P  < 0.001) and a loss of baroreflex and neurovascular coupling. During open surgery in the OR, all regulation mechanisms remained intact. Open surgery in the NICU was associated with the highest neurovascular coupling values.

CONCLUSION

Neurocardiovascular graphs provided more insight into the effect of the peri-operative management on the pathophysiology of neonates undergoing surgery. The neonate's clinical condition as well as the surgical and the anaesthesiological approach affected the neonatal physiology and CBF regulation mechanisms at different levels.

TRIAL REGISTRATION

NL6972, URL: https://www.trialre-gister.nl/trial/6972 .

Neonatal seizures treatment based on conventional multichannel EEG monitoring: an overview of therapeutic options

INTRODUCTION

Seizures are the main neurological emergency during the neonatal period and are mostly acute and focal. The prognosis mainly depends on the underlying etiology. Conventional multichannel video-electroencephalographic (cEEG) monitoring is the gold standard for diagnosis, but treatment remains a challenge.

AREAS COVERED

: This review, based on PubMed search over the last 4 decades, focuses on the current treatment options for neonatal seizures based on cEEG monitoring. There is still no consensus on seizure therapy, owing to poor scientific evidence. Traditionally, the first-line treatments are phenobarbital and phenytoin, followed by midazolam and lidocaine, but their efficacy is limited. Therefore, current evidence strongly suggests the use of alternative antiseizure medications. Randomized controlled trials of new drugs are ongoing.

EXPERT OPINION

: Therapy for neonatal seizures should be prompt and tailored, based on semeiology, mirror of the underlying cause, and cEEG features. Further research should focus on antiseizure medications that directly act on the etiopathogenetic mechanism responsible for seizures and are therefore more effective in seizure control.

Decoding the Synaptic Proteome with Long-Term Exposure to Midazolam during Early Development

The intensive use of anesthetic and sedative agents in the neonatal intensive care unit (NICU) has raised controversial concerns about the potential neurodevelopmental risks. This study focused on midazolam (MDZ), a common benzodiazepine regularly used as a sedative on neonates in the NICU. Mounting evidence suggests a single exposure to MDZ during the neonatal period leads to learning disturbances. However, a knowledge gap that remains is how long-term exposure to MDZ during very early stages of life impacts synaptic alterations. Using a preclinical rodent model system, we mimicked a dose-escalation regimen on postnatal day 3 (P3) pups until day 21. Next, purified synaptosomes from P21 control and MDZ animals were subjected to quantitative mass-spectrometry-based proteomics, to identify potential proteomic signatures. Further analysis by ClueGO identified enrichment of proteins associated with actin-binding and protein depolymerization process. One potential hit identified was alpha adducin (ADD1), belonging to the family of cytoskeleton proteins, which was upregulated in the MDZ group and whose expression was further validated by Western blot. In summary, this study sheds new information on the long-term exposure of MDZ during the early stages of development impacts synaptic function, which could subsequently perturb neurobehavioral outcomes at later stages of life.

Treatment of Neonatal Seizures: Comparison of Treatment Pathways From 11 Neonatal Intensive Care Units

OBJECTIVE

Seizures are a common neonatal neurologic emergency. Many centers have developed pathways to optimize management. We evaluated neonatal seizure management pathways at level IV neonatal intensive care units (NICUs) in the United States to highlight areas of consensus and describe aspects of variability.

METHODS

We conducted a descriptive analysis of 11 neonatal seizure management pathways from level IV NICUs that specialize in neonatal neurocritical care including guidelines for electroencephalography (EEG) monitoring, antiseizure medication (ASM) choice, timing, and dose.

RESULTS

Study center NICUs had a median of 70 beds (interquartile range: 52-96). All sites had 24/7 conventional EEG initiation, monitoring, and review capability. Management pathways uniformly included prompt EEG confirmation of seizures. Most pathways included a provision for intravenous benzodiazepine administration if either EEG or loading of ASM was delayed. Phenobarbital 20 mg/kg IV was the first-line ASM in all pathways. Pathways included either fosphenytoin or levetiracetam as the second-line ASM with variable dosing. Third-line ASMs were most commonly fosphenytoin or levetiracetam, with alternatives including topiramate or lacosamide. All pathways provided escalation to continuous midazolam infusion with variable dosing for seizures refractory to initial medication trials. Three pathways also included lidocaine infusion. Nine pathways discussed ASM discontinuation after resolution of acute symptomatic seizures with variable timing.

CONCLUSIONS

Despite a paucity of data from controlled trials regarding optimal neonatal seizure management, there are areas of broad agreement among institutional pathways. Areas of substantial heterogeneity that require further research include optimal second-line ASM, dosage, and timing of ASM discontinuation.

Palliative care for children and young people with stage 5 chronic kidney disease

Death from stage 5 chronic kidney disease (CKD 5) in childhood or adolescence is rare, but something that all paediatric renal physicians and most paediatricians will encounter. In this paper, we present the literature on three key areas of palliative care practice essential to good clinical management: shared decision-making, advance care planning, and symptom management, with particular reference to CKD 5 where kidney transplant is not an option and where a decision has been made to withdraw or withhold dialysis. Some areas of care, particularly with regard to symptom management, have not been well-studied in children and young people (CYP) with CKD 5 and recommendations with regard to drug choice and dose modification are based on adult literature, known pharmacokinetics, and clinical experience.

Premedication before laryngoscopy in neonates: Evidence-based statement from the French society of neonatology (SFN)

CONTEXT

Laryngoscopy is frequently required in neonatal intensive care. Awake laryngoscopy has deleterious effects but practice remains heterogeneous regarding premedication use. The goal of this statement was to provide evidence-based good practice guidance for clinicians regarding premedication before tracheal intubation, less invasive surfactant administration (LISA) and laryngeal mask insertion in neonates.

METHODS

A group of experts brought together by the French Society of Neonatology (SFN) addressed 4 fields related to premedication before upper airway access in neonates: (1) tracheal intubation; (2) less invasive surfactant administration; (3) laryngeal mask insertion; (4) use of atropine for the 3 previous procedures. Evidence was gathered and assessed on predefined questions related to these fields. Consensual statements were issued using the GRADE methodology.

RESULTS

Among the 15 formalized good practice statements, 2 were strong recommendations to do (Grade 1+) or not to do (Grade 1-), and 4 were discretionary recommendations to do (Grade 2+). For 9 good practice statements, the GRADE method could not be applied, resulting in an expert opinion. For tracheal intubation premedication was considered mandatory except for life-threatening situations (Grade 1+). Recommended premedications were a combination of opioid + muscle blocker (Grade 2+) or propofol in the absence of hemodynamic compromise or hypotension (Grade 2+) while the use of a sole opioid was discouraged (Grade 1-). Statements regarding other molecules before tracheal intubation were expert opinions. For LISA premedication was recommended (Grade 2+) with the use of propofol (Grade 2+). Statements regarding other molecules before LISA were expert opinions. For laryngeal mask insertion and atropine use, no specific data was found and expert opinions were provided.

CONCLUSION

This statement should help clinical decision regarding premedication before neonatal upper airway access and favor standardization of practices.

Intranasal Analgosedation for Infants in the Neonatal Intensive Care Unit: A Systematic Review

AIM

Pain management is important for newborns' immediate and long-term well-being. While intranasal analgesia and sedation have been well studied in children, their use could be extended to term and preterm infants. This systematic review aims to assess the use of intranasal medications for procedural analgesia or sedation in the neonatal intensive care unit.

METHODS

MEDLINE via Ovid, Scopus, Embase, and Cochrane Library were searched independently by two reviewers for clinical studies on sedation or analgesia given intranasally.

RESULTS

Seven studies, with 401 patients, were included. The studies described various molecules (midazolam, fentanyl, ketamine, or dexmedetomidine) for different procedures such as intubation in the delivery room, screening for retinopathy, or magnetic resonance imaging. All studies reported significant reduction in pain and sedation markers (based on clinical scales, skin conductance, and clinical variables such as heart rate and crying time). Adverse effects were uncommon and mostly consisted in desaturation, apnoea, hypotension, or paradoxical reactions.

DISCUSSION AND CONCLUSION

The intranasal route seems a potential alternative for procedural pain management and sedation in neonates, especially when intravenous access is not available. However, data about safety remain limited. Reported sides effects could be attributed to molecules used rather than the intranasal route. Optimal drugs and doses still need to be characterized. Further studies are needed to ensure safety before promoting a widespread use of intranasal medications in neonatology.

Ontogeny of Drug-Metabolizing Enzymes

Almost 50% of prescription drugs lack age-appropriate dosing guidelines and therefore are used "off-label." Only ~10% drugs prescribed to neonates and infants have been studied for safety or efficacy. Immaturity of drug metabolism in children is often associated with drug toxicity. This chapter summarizes data on the ontogeny of major human metabolizing enzymes involved in oxidation, reduction, hydrolysis, and conjugation of drugs. The ontogeny data of individual drug-metabolizing enzymes are important for accurate prediction of drug pharmacokinetics and toxicity in children. This information is critical for designing clinical studies to appropriately test pharmacological hypotheses and develop safer pediatric drugs, and to replace the long-standing practice of body weight- or surface area-normalized drug dosing. The application of ontogeny data in physiologically based pharmacokinetic model and regulatory submission are discussed.

Developing a SWATH capillary LC-MS/MS method for simultaneous therapeutic drug monitoring and untargeted metabolomics analysis of neonatal plasma

Most medications prescribed to neonatal patients are off-label uses. The pharmacokinetics and pharmacodynamics of drugs differ significantly between neonates and adults. Therefore, personalized pharmacotherapy guided by therapeutic drug monitoring (TDM) and drug response biomarkers are particularly beneficial to neonatal patients. Herein, we developed a capillary LC-MS/MS metabolomics method using a SWATH-based data-independent acquisition strategy for simultaneous targeted and untargeted metabolomics analysis of neonatal plasma samples. We applied the method to determine the global plasma metabolomics profiles and quantify the plasma concentrations of five drugs commonly used in neonatal intensive care units, including ampicillin, caffeine, fluconazole, vancomycin, and midazolam and its active metabolite α-hydroxymidazolam, in neonatal patients. The method was successfully validated and found to be suitable for the TDM of the drugs of interest. Moreover, the global metabolomics analysis revealed plasma metabolite features that could differentiate preterm and full-term neonates. This study demonstrated that the SWATH-based capillary LC-MS/MS metabolomics approach could be a powerful tool for simultaneous TDM and the discovery of neonatal plasma metabolite biomarkers.

The bedside practice of sonographic guided internal jugular vein access in critically ill premature infants

BACKGROUND

Intrahospital transport, general anesthesia, and the prolonged duration of the central venous catheterization (CVC) in unfavorable conditions pose a significant risk to a critically-ill premature infant. We aimed to demonstrate a minimalized and safe manner of CVC in this patient population.

METHODS

We worked on a prospective study in 51 critically-ill premature infants in which a 22 Gauge catheter was put in one of the central thoracic veins with the guidance of sonography as a bedside procedure. Of the patients, 27 (53%) were extremely premature, and 21 (41%) were extremely low birth weight infants (ELBW). The mean gestational age was 29 ± 5 weeks, and the mean weight at the time of the procedure was 1655 ± 1028 grams. While no anesthetic and sedative drugs were administered to ELBW infants during procedures, in the remainder of the cohort, procedures were carried out only under sedoanalgesia.

RESULTS

Vascular access was achieved in 48 (94%) of the patients after a mean number of 1.47 ± 0.75 attempts. Body heat loss of the patients at the end of the procedures was not statistically significant (p=0.164). However, ELBW infants lost their body heat significantly more than the rest of the cohort (p=0.032). We experienced clinically insignificant common carotid artery puncture in three patients and hemothorax in one patient.

CONCLUSIONS

CVC of critically ill premature infants can be safely and successfully achieved in incubators using sonography guidance, protecting them from hypothermia and anesthetic drugs.

Neonatal administration of a subanaesthetic dose of JM-1232(-) in mice results in no behavioural deficits in adulthood

In animal models, neonatal exposure of general anaesthetics significantly increases apoptosis in the brain, resulting in persistent behavioural deficits later in adulthood. Consequently, there is growing concern about the use of general anaesthetics in obstetric and paediatric practice. JM-1232(−) has been developed as a novel intravenous anaesthetic, but the effects of JM-1232(−) on the developing brain are not understood. Here we show that neonatal administration of JM-1232(−) does not lead to detectable behavioural deficits in adulthood, contrarily to other widely-used intravenous anaesthetics. At postnatal day 6 (P6), mice were injected intraperitoneally with a sedative-equivalent dose of JM-1232(−), propofol, or midazolam. Western blot analysis of forebrain extracts using cleaved poly-(adenosine diphosphate-ribose) polymerase antibody showed that JM-1232(−) is accompanied by slight but measurable apoptosis 6 h after administration, but it was relatively small compared to those of propofol and midazolam. Behavioural studies were performed in adulthood, long after the neonatal anaesthesia, to evaluate the long-term effects on cognitive, social, and affective functions. P6 administration to JM-1232(−) was not accompanied by detectable long-term behavioural deficits in adulthood. However, animals receiving propofol or midazolam had impaired social and/or cognitive functions. These data suggest that JM-1232(−) has prospects for use in obstetric and paediatric practice.

Effectiveness and adverse drug reactions of levetiracetam and midazolam in refractory neonatal seizure: A cross-sectional comparative study

BACKGROUND

Neonatal seizure (NS) reflects serious underlying brain injury, requiring immediate evaluation and early treatment. In neonates, phenobarbitone and phenytoin are used primarily to control the seizures. If uncontrolled, widespread off-label use of midazolam and levetiracetam was practiced. These drugs gained popularity though there are no such studies available on literature search comparing them. The present study was designed to explore these lacunae using these two drugs in refractory cases. To study the efficacy and adverse drug reactions (ADRs) of midazolam and levetiracetam not responding to usual line of therapy.

MATERIALS AND METHODS

This was a prospective cross-sectional study conducted on 69 neonates in the NICU and Department of Pharmacology in Burdwan Medical College and Hospital, West Bengal. Patients receiving midazolam or levetiracetam when uncontrolled with first line antiepileptics, namely, phenobarbitone and phenytoin, were considered eligible. The study variables were time to control seizure, seizure recurrence and frequency, and treatment-related adverse events. analysis used Mann-Whitney U-test were applied Comparison with respect to time to control and Chi-square test were applied to detect difference in proportion for ADRs. The SPSS Statistics 17.0 was used for analysis.

RESULTS

We compared the time periods to control neonatal seizure for effectiveness between levetiracetam and midazolam showing no significant difference (P = 0.190). Comparing the portion of recurrences in two groups gives statistically nonsignificant (P = 0.878) result. Only respiratory depression was seen in the levetiracetam group (12.90%) and midazolam group (18.42%). All adverse events were 'probable' as per the WHO-UMC criteria, and there was no statistically significant difference between the two drugs (P = 0.533).

CONCLUSIONS

Both midazolam and levetiracetam are equally effective and safe in NS not responding to usual line of treatment.

Cerebral Oxygenation and Activity During Surgical Repair of Neonates With Congenital Diaphragmatic Hernia: A Center Comparison Analysis

Background and aim: Neonatal brain monitoring is increasingly used due to reports of brain injury perioperatively. Little is known about the effect of sedatives (midazolam) and anesthetics (sevoflurane) on cerebral oxygenation (rScO₂) and cerebral activity. This study aims to determine these effects in the perioperative period. Methods: This is an observational, prospective study in two tertiary pediatric surgical centers. All neonates with a congenital diaphragmatic hernia received perioperative cerebral oxygenation and activity measurements. Patients were stratified based on intraoperatively administrated medication: the sevoflurane group (continuous sevoflurane, bolus fentanyl, bolus rocuronium) and the midazolam group (continuous midazolam, continuous fentanyl, and continuous vecuronium). Results: Intraoperatively, rScO₂ was higher in the sevoflurane compared to the midazolam group (84%, IQR 77-95 vs. 65%, IQR 59-76, p = < 0.001), fractional tissue oxygen extraction was lower (14%, IQR 5-21 vs. 31%, IQR 29-40, p = < 0.001), the duration of hypoxia was shorter (2%, IQR 0.4-9.6 vs. 38.6%, IQR 4.9-70, p = 0.023), and cerebral activity decreased more: slow delta: 2.16 vs. 4.35 μV ² (p = 0.0049), fast delta: 0.73 vs. 1.37 μV ² (p = < 0.001). In the first 30 min of the surgical procedure, a 3-fold increase in fast delta (10.48-31.22 μV ²) and a 5-fold increase in gamma (1.42-7.58 μV ²) were observed in the midazolam group. Conclusion: Sevoflurane-based anesthesia resulted in increased cerebral oxygenation and decreased cerebral activity, suggesting adequate anesthesia. Midazolam-based anesthesia in neonates with a more severe CDH led to alarmingly low rScO₂ values, below hypoxia threshold, and increased values of EEG power during the first 30 min of surgery. This might indicate conscious experience of pain. Integrating population-pharmacokinetic models and multimodal neuromonitoring are needed for personalized pharmacotherapy in these vulnerable patients. Trial Registration: https://www.trialregister.nl/trial/6972, identifier: NL6972.

Potential Relationship between Cerebral Fractional Tissue Oxygen Extraction (FTOE) and the Use of Sedative Agents during the Perioperative Period in Neonates and Infants

Fractional tissue oxygen extraction (FTOE) by means of cerebral near-infrared spectroscopy (NIRS) provides information about oxygen uptake in the brain. Experimental animal data suggest that sedative agents decrease cerebral oxygen demand. The aim of the present study was to investigate the association between the cerebral FTOE and the use of pre and intraoperative sedative agents in infants aged 1-90 days. Cerebral NIRS was continuously applied during open major non-cardiac surgery in 46 infants. The main outcomes were the mean intraoperative FTOE and the percentage (%) of time of intraoperative hyperoxia_FTOE relative to the total duration of anesthesia. Hyperoxia_FTOE was defined as FTOE ≤ 0.1. Cumulative doses of sedative agents (benzodiazepines and morphine), given up to 24 h preoperatively, correlated with the mean intraoperative FTOE (Spearman's rho = -0.298, p = 0.0440) and were predictive for the % of time of intraoperative hyperoxia_FTOE (β (95% CI) 47.12 (7.32; 86.92)) when adjusted for the patients' age, type of surgery, preoperative hemoglobin, intraoperative sevoflurane and fentanyl dose, mean intraoperative arterial blood pressure, and end-tidal CO₂ by multivariate 0.75 quantile regression. There was no association with 0.5 quantile regression. We observed the suggestive positive association of decreased fractional cerebral tissue oxygen extraction and the use of sedative agents in neonates and infants undergoing surgery.

Intranasal midazolam sedation as an effective sedation route in pediatric patients for radiologic imaging in the emergency ward: A single-blind randomized trial

OBJECTIVES:

Prevention and reduction of pain, anxiety, and fear during medical procedures is one of the most important factors that should be considered in pediatric emergencies. The aim of this study was to compare the efficacy of oral versus intranasal midazolam in sedation during radiologic imaging in the largest province of Iran, Kerman.

MATERIALS AND METHODS:

Eighty children were enrolled in this single-blind clinical trial based on convenience sampling and were divided into two groups receiving 0.5 mg/kg midazolam in oral route administration and 0.2 mg/kg midazolam in intranasal route administration. Finally, 75 patients remained for evaluating medication acceptability, sedation level, onset time of sedation, additional sedative dose, adverse effects of sedation, and provider satisfaction.

RESULTS:

Children in the intranasal group accepted medication more easily (89.8% vs. 36.9%; P ≤ 0.001), while these children received a lower sedation dose, but the sedation level in both methods was similar (P = 0.72). Our findings showed that children in the intranasal sedation group had a faster onset of sedation compared to the oral group (17.94 ± 8.99 vs. 34.50 ± 11.45; P ≤ 0.001). The frequency of midazolam side effects had no difference between the groups (29.7% vs. 15.8%; P = 0.15).

CONCLUSION:

Intranasal midazolam with a lower sedation dose induces a faster onset and better acceptance. Intranasal midazolam can be used as an effective sedative method for pediatric patients, especially in emergency wards.

Voltage dependent allosteric modulation of IPSCs by benzodiazepines

GABA_A receptors (GABA_AR) are inhibitory ion channels ubiquitously expressed in the central nervous system and play critical roles in brain development and function. Benzodiazepines are positive allosteric modulators of GABA_AR, enhancing channel opening frequency when GABA is bound to the receptor. Midazolam is a commonly used benzodiazepine. It is frequently used for premature infants, but the long-term consequences of its use in this patient population are not well established. Here, we studied the acute effects of midazolam on immature synapses. Using a rodent organotypic hippocampal slice preparation, we evaluated how midazolam affects inhibitory synaptic transmission onto CA1 pyramidal neurons. We found that 1 μM midazolam enhances evoked inhibitory post synaptic currents (eIPSCs) at a holding potential of -60 mV. Similarly, 1 μM midazolam enhances miniature IPSCs (mIPSCs) in CA1 pyramidal neurons at holding potentials of -60 mV and -30 mV. At depolarized holding potentials, however, midazolam no longer enhances mIPSCs. Depolarization of the postsynaptic cell by itself increases mIPSC decay, which occludes the allosteric effects of midazolam. These results provide insight into how a benzodiazepine and membrane voltage may modulate GABA_AR function in developing circuits.

First dose in neonates: pharmacokinetic bridging study from juvenile mice to neonates for drugs metabolized by CYP3A

First dose prediction is challenging in neonates. Our objective in this proof-of-concept study was to perform a pharmacokinetic (PK) bridging study from juvenile mice to neonates for drugs metabolized by CYP3A. We selected midazolam and clindamycin as model drugs. We developed juvenile mice population PK models using NONMEM. The PK parameters of these two drugs in juvenile mice were used to bridge PK parameters in neonates using different correction methods. The bridging results were evaluated by the fold-error of 0.5- to 1.5-fold. Simple allometry with and without a correction factor for maximum lifespan potential could be used for a bridging of clearance (CL) and volume of distribution (V_d), respectively, from juvenile mice to neonates. Simulation results demonstrated that for midazolam, 100% of clinical studies for which both the predictive CL and V_d were within 0.5- to 1.5-fold of the observed. For clindamycin, 75% and 100% of clinical studies for which the predictive CL and V_d were within 0.5- to 1.5-fold of the observed. A PK bridging of drugs metabolized by CYP3A is feasible from juvenile mice to neonates. It could be a complement to the ADE and PBPK models to support the first dose in neonates.

Dexmedetomidine Alleviates Neurogenesis Damage Following Neonatal Midazolam Exposure in Rats through JNK and P38 MAPK Pathways

Midazolam, a widely used anesthetic, inhibits proliferation of neural stem cells (NSCs) and induces neuroapoptosis in neonates. Dexmedetomidine, an effective auxiliary medicine in clinical anesthesia, protects the developing brain against volatile anesthetic-induced neuroapoptosis. Whether dexmedetomidine protects against neurogenesis damage induced by midazolam remains unknown. This study aims to clarify the protective effect of dexmedetomidine on midazolam-induced neurogenesis damage and explore its potential mechanism. Postnatal 7-day-old Sprague-Dawley (SD) rats and cultured NSCs were treated with either normal saline, midazolam, or dexmedetomidine combined with midazolam. The rats were sacrificed at 1, 3, and 7 days after treatment. Cell proliferation was assessed by 5-bromodeoxyurdine (BrdU) incorporation. Cell viability was determined using MTT assay. Cell differentiation and apoptosis were detected by immunofluorescent staining and terminal dUTP nick-end labeling (TUNEL), respectively. The protein levels of p-JNK, p-P38, and cleaved caspase-3 were quantified using Western blotting. Midazolam decreased cell proliferation and increased cell apoptosis in the subventricular zone (SVZ), the subgranular zone (SGZ) of the hippocampus, and cultured NSCs. Moreover, midazolam decreased cell viability and increased the expression of p-JNK and p-P38 in cultured NSCs. Co-treatment with dexmedetomidine attenuated midazolam-induced changes in cell proliferation, viability, apoptosis, and protein expression of p-JNK and p-P38 in cultured NSCs. Midazolam and dexmedetomidine did not affect the differentiation of the cultured NSCs. These results indicate that dexmedetomidine alleviated midazolam-induced neurogenesis damage via JNK and P38 MAPK pathways.

Midazolam: an essential palliative care drug

Midazolam is a commonly used benzodiazepine in palliative care and is considered one of the four essential drugs needed for the promotion of quality care in dying patients. Acting on the benzodiazepine receptor, it promotes the action of gamma-aminobutyric acid. Gamma-aminobutyric acid action promotes sedative, anxiolytic, and anticonvulsant properties. Midazolam has a faster onset and shorter duration of action than other benzodiazepines such as diazepam and lorazepam lending itself to greater flexibility in dosing than other benzodiazepines. The kidneys excrete midazolam and its active metabolite. Metabolism occurs in the liver by the P450 system. This article examines the pharmacology, pharmacodynamics, and clinical uses of midazolam in palliative care.

Drug-drug interactions in Neonatal Intensive Care Units: how to overcome a challenge

INTRODUCTION

Critically ill patients in neonatal intensive-care units (NICU) are exposed to a large number of drugs. Clinical trials for safety, dosing and efficacy are lacking although age-dependent alterations of pharmacokinetics (PK), drug-drug-interactions (DDIs), as well as intravenous admixture incompatibilities (IAI) may impact drug efficacy and trigger side-effects in this vulnerable population. Consequently, implementation of a routinely used DDIs checking regimen may help guide in decision making and will assist clinicians to avoid serious and preventable events. Therefore, the goal of the present work is to identify and assess the risk of relevant DDIs of drugs commonly used in the NICU.

EVIDENCE ACQUISITION

A literature review study was performed to identify and further assess the risk of relevant DDIs of 48 drugs frequently used in the tertiary care NICU of the University Hospital of Cologne. DDIs were categorized into five different classes according to their severity (contraindicated, minor, moderate, and major DDI, IAI), based on the classification used in the Micromedex database. In the database a major interaction is defined as any interaction that can be life threatening and/or demands medical intervention to avoid severe adverse effects. Moderate interactions can lead to a degradation of the patient's status and demand an adjustment in the therapy, and minor interactions only have a limited clinical effect. All identified DDIs in the present study are presented as a Visual Interaction Triangle (VIT) and recommendations on the management of clinically significant DDIs are provided.

EVIDENCE SYNTHESIS

According to the classification used in the Micromedex database: a total of 160 (13.2%) possible interactions (DDI, IAI) were found. Fifty-five (4.9%) cases were categorized as serious interactions (DDI-major), 48 (4.2%) were less severe (DDI-moderate/minor) and in 52 (4.6%) cases an intravenous admixture drug interaction was found. Five (0.4%) drug-combinations were contraindicated.

CONCLUSIONS

In this web-based study, a total of 160 DDIs were identified. Although only 4.9% were classified as clinically relevant, practitioners can use the presented VIT as a unique clinical reference to avoid possible predictable adverse effects and to uncover possible drug-interaction potential.

Maturation of midazolam clearance in critically ill children with severe bronchiolitis: A population pharmacokinetic analysis

PURPOSE

The aim of the present study was to develop a population pharmacokinetic model of midazolam, and to evaluate the influence of maturation process and other variability factors in critically ill children with severe acute bronchiolitis, who received a long-term intravenous infusion of midazolam.

METHODS

In the study were included 49 critically ill children of both genders (from 0 to 130 weeks of age) with severe acute bronchiolitis hospitalised in intensive care units. Nonlinear mixed effects modelling approach was applied for data analyses and simulations.

RESULTS

The final model is a two-compartment model that includes the effects of body weight using allometric scaling with fixed exponents and maturation of clearance. For a typical subject, scaled to the adult body weight of 70 kg, population pharmacokinetic values were estimated at 8.52 L/h for clearance (when maturation function was 1), 25.5 L/h for intercompartmental clearance, and 5.71 L and 39.8 L for the volume of the central and peripheral compartment, respectively. Based on the final model, maturation reaches 50% of the adult clearance in 45.9 weeks of postmenstrual age. The influence of gender, ABCB1 genotype and biochemical parameters on midazolam clearance was not detected. Results of simulations indicate the need for reduced dosing in certain groups of patients in order to maintain plasma concentrations of midazolam within recommended values.

CONCLUSIONS

The developed population pharmacokinetic model can contribute to the dosing optimisation of midazolam, especially in critically ill children as it includes the influence of size and maturation of clearance, which are important parameters for achieving the desired plasma concentrations of midazolam.

Recently Registered Midazolam Doses for Preterm Neonates Do Not Lead to Equal Exposure: A Population Pharmacokinetic Model

Although midazolam is a frequently used sedative in neonatal intensive care units, its use in preterm neonates has been off-label. Recently, a new dosing advice for midazolam for sedation on intensive care units has been included in the label (0.03 mg/[kg·h] for preterm neonates <32 weeks and 0.06 mg/[kg·h] for neonates >32 weeks). Concentration-time data of a prospective multicenter study (29 patients, median gestational age 26.7 [range 24.0-31.1 weeks]) were combined with previously published data (26 patients, median gestational age 28.1 [range 26.3-33.6 weeks]), and a population pharmacokinetic model describing the maturation of midazolam pharmacokinetics was developed in NONMEM 7.3. Clearance was 73.7 mL/h for a neonate weighing 1.1 kg and changed nonlinearly with body weight (exponent 1.69). Volume of distribution increased linearly with body weight and was 1.03 L for a neonate weighing 1.1 kg. Simulations of the newly registered dosing show considerable differences in steady-state concentrations in preterm neonates. To reach similar steady-state concentrations of 400 µg/mL (±100 µg/mL), a dose of 0.03 mg/(kg·h) is adequate for neonates ≥1 kg and ≤2 kg but would have to be reduced to 0.02 mg/(kg·h) (-33%) in neonates <1 kg and increased to 0.04 mg/(kg·h) (+33%) in neonates weighing >2 kg and ≤2.5 kg. The impact of the observed differences in exposure is difficult to assess because no target concentrations have yet been defined for midazolam, but the current analysis shows that one should be cautious in giving dosage advice based on historical data with a lack of reliable pharmacokinetic and effect data.

Postsurgery analgesic and sedative drug use in a French neonatal intensive care unit: A single-center retrospective cohort study

OBJECTIVE

To describe pain assessment, the pattern of analgesic and sedative drug use, and adverse drug reactions in a neonatal intensive care unit (NICU) during the postsurgery phase.

METHOD

Demographic characteristics, pain scores, and drug use were extracted and analyzed from electronic patient medical files for infants after surgery, admitted consecutively between January 2012 and June 2013.

RESULT

One hundred and sixty-eight infants were included. Acute (DAN score) and prolonged (EDIN score) pain assessment scores were used in 79% and 64% of infants, respectively, on the 1st day. This percentage decreased over the 7 days following surgery. The weekly average scores postsurgery were 2/15 (±2.2) for the EDIN score and 1.6/10 (±2.0) for the DAN score. The rates of pain control were 88% for the EDIN and 72% for the DAN. The most prescribed opiate drug was fentanyl (98 patients; 58%) with an average dose of 1.8 (±0.6) μg/kg/h. Midazolam was used in 95 patients (56%), with an average dose of 35 (±14) μg/kg/h. A bolus was administered in 7% (±7.4) of the total dose for fentanyl and 8% (±9.3) for midazolam. Similar doses were used in term and preterm neonates. Of 118 patients receiving fentanyl and/or midazolam, 40% presented urinary retention, 28% a weaning syndrome. Paracetamol (155 patients; 92%) and nalbuphine (55 patients; 33%) were the other medications most often prescribed.

CONCLUSION

The off-label use of fentanyl and midazolam was necessary to treat pain after surgery. Pain assessment should be conducted for all neonates in order to optimize their treatment. Research on analgesic and sedative medicine in vulnerable neonates seems necessary to standardize practices and reduce adverse drug reactions.

Intranasal midazolam and fentanyl for procedural sedation and analgesia in infants in the neonatal intensive care unit

BACKGROUND

The intranasal route is a minimally invasive method for rapidly delivering midazolam and fentanyl to provide short-term analgesia and sedation in infants. However, intranasal use of midazolam and fentanyl is not labeled for infants and safety data are sparse. The objective of this study is to evaluate the safety of intranasal midazolam and intranasal fentanyl in infants admitted to the Neonatal Intensive Care Unit (NICU).

METHODS

We retrospectively identified all infants receiving intranasal midazolam or fentanyl in the NICU from 2009 to 2015. We recorded indication for use and vital signs and determined the proportion of infants experiencing the following adverse events: death within 24 hours, hypotension, bradycardia, worsening respiratory status, and chest wall rigidity. Vital signs 4 hours before and after each dose were compared using the Wilcoxon signed-rank test.

RESULTS

We identified 17 infants (gestational ages 23- 41 weeks) receiving 25 intranasal doses. None of the infants died or developed hypotension, bradycardia, or chest wall rigidity. Intranasal delivery was most commonly used for sedation during magnetic resonance imaging studies. Other indications include analgesia or sedation for retinopathy of prematurity surgery, intubation, and peripherally inserted central catheter placement. One infant receiving intranasal midazolam experienced worsening respiratory status. Vital signs before and after dosing were not significantly different.

CONCLUSIONS

Intranasal midazolam and fentanyl use in term and preterm infants appeared safe and well-tolerated in this small cohort of infants. Larger, prospective studies evaluating the safety and efficacy of intranasal midazolam and fentanyl use in infants are warranted.

Dexmedetomidine versus Midazolam-Fentanyl in Procedural Analgesia Sedation for Reduction of Anterior Shoulder Dislocation: A Randomized Clinical Trial

BACKGROUND

Shoulder joint dislocation is the most common dislocation of joints in the body. To reduce the anterior shoulder dislocation, it is necessary to have analgesia and sedation.

METHODS

In this randomized clinical trial, patients were divided into two equal groups. Group I received midazolam-fentanyl (0.05 mg/kg fentanyl at a dose of 1 µg/kg) for 10 minutes and group II received dexmedetomidine (1 µg/kg in the initial dose and then 0.2 µg/kg/h) for 10 minutes. The levels of analgesia according to VAS criteria and the time to reach desired sedation were compared between the two groups.

RESULTS

A total of 60 patients participated in this study. The time to reach the desired sedation was 8.60 ± 2.3 minutes in the dexmedetomidine group and 11.27 ± 3.57 minutes in the midazolamfentanyl group (p= 0.001). Also, the VAS score in both midazolam-fentanyl and dexmedetomidine groups was 3.3 ± 1.24 and 2.57 ± 0.9, respectively. The differences were statistically significant (p=0.015). There was significant relationship between the time to reach desired sedation and the level of analgesia. Moreover, there was no significant difference between patient age and the time to reach the desired level of analgesia. During this study, no side effect was observed.

CONCLUSION

The findings of this study show that dexmedetomidine provides a higher level of analgesia than midazolam-fentanyl. Moreover, it was also shown that dexmedetomidine causes quicker procedural sedation than midazolam-fentanyl.

Evaluation of intranasal delivery route of drug administration for brain targeting

The acute or chronic drug treatments for different neurodegenerative and psychiatric disorders are challenging from several aspects. The low bioavailability and limited brain exposure of oral drugs, the rapid metabolism, elimination, the unwanted side effects and also the high dose to be added mean both inconvenience for the patients and high costs for the patients, their family and the society. The reason of low brain penetration of the compounds is that they have to overcome the blood-brain barrier which protects the brain against xenobiotics. Intranasal drug administration is one of the promising options to bypass blood-brain barrier, to reduce the systemic adverse effects of the drugs and to lower the doses to be administered. Furthermore, the drugs administered using nasal route have usually higher bioavailability, less side effects and result in higher brain exposure at similar dosage than the oral drugs. In this review the focus is on giving an overview on the anatomical and cellular structure of nasal cavity and absorption surface. It presents some possibilities to enhance the drug penetration through the nasal barrier and summarizes some in vitro, ex vivo and in vivo technologies to test the drug delivery across the nasal epithelium into the brain. Finally, the authors give a critical evaluation of the nasal route of administration showing its main advantages and limitations of this delivery route for CNS drug targeting.

Paradoxical Reaction to Midazolam in Preterm Neonates: A Case Series

Midazolam is a drug belonging to the benzodiazepine group and is used commonly for seizure control as well as preoperative and procedure-related sedation in neonates. Many adverse effects of midazolam have been reported in the past. Paradoxical stimulation of the central nervous system such as restlessness, nightmare, and hallucinations as well as hypomanic behavior has been reported in adults and children. Seizure is a rare adverse effect of midazolam. Cases of myoclonic movements associated with midazolam have been published worldwide; however, none so far have been reported from India. We report two newborns in our Neonatal Unit, who developed myoclonic seizure after the administration of midazolam. Both of these neonates were preterm, require multiple invasive and noninvasive investigations also leads to parent and clinician stress.

Midazolam as a first-line treatment for neonatal seizures: Retrospective study

Midazolam is commonly used to treat refractory seizures in newborns and as a first-line anti-epileptic drug in children. Its use as first-line treatment of neonatal seizures has not been investigated so far. We retrospectively studied the tolerability of midazolam in 72 newborn infants who received i.v. or i.n. midazolam as first-line treatment for seizures. No major side-effect exclusively due to midazolam was reported. The i.n. route was used for 20 patients (27.8%). Effectiveness could not be formally evaluated due to the absence of systematic electroencephalogram recording while midazolam was administered. In conclusion, midazolam was well-tolerated as a first-line abortive emergency treatment of neonatal seizure. The i.n. route offers a useful alternative to i.v. phenobarbital or phenytoin in emergency settings.

Pharmacotherapy for Seizures in Neonates with Hypoxic Ischemic Encephalopathy

Seizures are common in neonates with moderate and severe hypoxic ischemic encephalopathy (HIE) and are associated with worse outcomes, independent of HIE severity. In contrast to adults and older children, no new drugs have been licensed for treatment of neonatal seizures over the last 50 years, because of a lack of controlled clinical trials. Hence, many antiseizure medications licensed in older children and adults are used off-label for neonatal seizure, which is associated with potential risks of adverse effects during a period when the brain is particularly vulnerable. Phenobarbital is worldwide the first-line drug and is considered standard of care, although there is a limited evidence base for its efficacy. Second-line agents include phenytoin, benzodiazepines, levetiracetam, and lidocaine. These drugs are discussed in more detail along with two emerging drugs (bumetanide and topiramate). More safety, pharmacokinetic, and efficacy data are needed from well-designed clinical trials to develop safe and effective antiseizure regimes for the treatment of neonatal seizures in HIE.

Predicting CYP3A-mediated midazolam metabolism in critically ill neonates, infants, children and adults with inflammation and organ failure

AIMS

Inflammation and organ failure have been reported to have an impact on cytochrome P450 (CYP) 3A-mediated clearance of midazolam in critically ill children. Our aim was to evaluate a previously developed population pharmacokinetic model both in critically ill children and other populations, in order to allow the model to be used to guide dosing in clinical practice.

METHODS

The model was evaluated externally in 136 individuals, including (pre)term neonates, infants, children and adults (body weight 0.77-90 kg, C-reactive protein level 0.1-341 mg l^-1 and 0-4 failing organs) using graphical and numerical diagnostics.

RESULTS

The pharmacokinetic model predicted midazolam clearance and plasma concentrations without bias in postoperative or critically ill paediatric patients and term neonates [median prediction error (MPE) <30%]. Using the model for extrapolation resulted in well-predicted clearance values in critically ill and healthy adults (MPE <30%), while clearance in preterm neonates was over predicted (MPE >180%).

CONCLUSION

The recently published pharmacokinetic model for midazolam, quantifying the influence of maturation, inflammation and organ failure in children, yields unbiased clearance predictions and can therefore be used for dosing instructions in term neonates, children and adults with varying levels of critical illness, including healthy adults, but not for extrapolation to preterm neonates.

Intramuscular Lorazepam for Status Epilepticus in Children With Complex Medical and Physical Disabilities

Background: A protocol was developed to achieve status epilepticus (SE) resolution: step 1, intramuscular (IM) lorazepam; step 2, repeat IM lorazepam; step 3, rectal diazepam. Objective: The primary objective was to identify the number of patients with SE resolution after step 1. Secondary objectives included categorization of mean number of IM doses per episode and patient factors associated with SE resolution. Methods: This was a retrospective study of patients <21 years old with complex medical and physical disabilities admitted over 5 years. For analysis, IM dosing was categorized as high dose (>0.05 mg/kg/dose) and low dose (≤0.05 mg/kg/dose). A generalized linear mixed-model regression was used to assess the relationship with SE resolution at step 1 and patient characteristics. Results: A total of 44 patients were included (n = 162 episodes). SE resolution was noted in 68.5% of episodes after step 1. Models were stratified by gender to present odds of SE resolution at step 1 versus step 2/3. For women, no covariate was significant. For men, the odds of SE resolution at step 1 were 14.9 times higher in those receiving 2 versus 4 maintenance antiepileptics, adjusting for covariates. Additionally, odds of resolution at step 1 was 3.1 times higher for high-dose versus low-dose lorazepam in males, adjusting for covariates, but was not statistically significant. Conclusions: SE resolution was noted in 68.5% after step 1. Unadjusted, females had a higher odds of SE resolution at step 1 than males. In males, high-dose lorazepam had higher odds of SE resolution at step 1 than low-dose lorazepam, though not significantly different.

Comparison of ease of administration of intranasal midazolam spray and oral midazolam syrup by parents as premedication to children undergoing elective surgery

BACKGROUND

The efficacy of midazolam as premedication in children for providing pre-operative sedation and reducing parental separation anxiety has been well established. Many studies have compared the effectiveness and medication acceptance of midazolam via oral and intranasal routes. In this study, we have compared the ease of administration of oral midazolam syrup and intranasal midazolam spray as premedication, administered by parents to children.

METHODS

Ninety children were randomly allocated into one of the two groups: group N received nasal midazolam spray 0.2 mg/kg and group O received oral midazolam syrup 0.5 mg/kg administered by the parent. The parent recorded ease of administration score and facial hedonic score. The observer recorded modified medication acceptance score. Vitals and sedation scores were assessed at specific intervals. Thirty minutes after drug administration the child was separated from the parent, and parental separation anxiety score was recorded. Mask acceptance score was recorded after application of mask upon arrival in the OT.

RESULTS

Oral midazolam syrup was found to have better ease of administration than intranasal midazolam spray as felt by the parent. Medication acceptance was better for oral midazolam. Both the groups had similar sedation scores at 15 and 30 min. Children in the oral group had a better reduction in parental separation anxiety at 30 min after drug administration and better mask acceptance than the nasal group.

CONCLUSION

Oral midazolam syrup is easier for parents to administer and has better medication acceptance in children when compared to intranasal midazolam spray.

The efficacy of dexmedetomidine-remifentanil versus dexmedetomidine-propofol in children undergoing flexible bronchoscopy: A retrospective trial

Flexible bronchoscopy has been more and more used for diagnosis and management diseases of respiratory system in pediatrics. Previous studies have reported that remifentanil (RF) and propofol are safe and effective for flexible bronchoscopy in adults, however, there have no trials evaluate the efficacy of DEX-RF versus dexmedetomidine-propofol in children undergoing flexible bronchoscopy.We divided 123 children undergoing flexible bronchoscopy with DEX-RF or dexmedetomidine-propofol into 2 groups: Group DR (n = 63, DEX infusion at 1.0 μg kg for 10 minutes, then adjusted to 0.5-0.7 μg kg h; RF infusion at 1.0 μg kg for 5 minutes, then adjusted to 0.05-0.2 μg kg min), Group DP (n = 60, DEX infusion at 1.0 μg kg for 10 minutes, then adjusted to 0.5-0.7 μg kg h; propofol infusion at 10 μg kg for 5 minutes, then adjusted to 0.05-0.1 μg kg min). Ramsay sedation scale of the 2 groups was maintained at 3. Anesthesia onset time; total number of intraoperative patient movements; hemodynamics; total cumulative dose of DEX; amount of and time to first-dose rescue midazolam and lidocaine; postoperative recovery time; adverse events; and bronchoscopist satisfaction score were recorded.Anesthesia onset time was significantly shorter in DP (8.22 ± 2.48 vs 12.25 ± 6.43 minutes, respectively, for DP, DR, P = 0.015). The perioperative hemodynamic profile was more stable in DR than DP group. More children moved during flexible bronchoscopy in DP group (P = 0.009). Total dose of rescue midazolam and lidocaine was significantly higher in DR than in DP (P < 0.001). Similarly, the time to first dose of rescue midazolam and lidocaine was significantly longer in DP than in DR (P < 0.001). Total cumulative dose of DEX was more in DR than DP group (P < 0.001). The time to recovery for discharge from the postanesthesia care unit (PACU) was significantly shorter in DP than in DR group (P < 0.001). The bronchoscopist-satisfaction scores were higher for DR than DP (P = 0.036). There were significant differences between the 2 groups in terms of the overall incidence of hypertension, tachycardia, and hypoxemia (P < 0.05).Although underwent longer recovery time and more incidence of rescue scheme, DEX-RF resulted in more stable hemodynamic profiles and bronchoscopist-satisfaction scores, lesser patient movements, and can hence be more effectively used in children undergoing flexible bronchoscopy than dexmedetomidine-propofol.

Dexmedetomidine is Associated with an Increased Incidence of Bradycardia in Patients with Trisomy 21 After Surgery for Congenital Heart Disease

This study aimed to evaluate adverse cardiac events using dexmedetomidine in infants with trisomy 21 and those without (controls) and examined potential risk factors in infants after cardiovascular surgery. We conducted a single-center retrospective cohort study. The medical records of 124 consecutive infants who had undergone cardiovascular surgery between April 1, 2013, and October 31, 2015, were enrolled. Clinical characteristics, usage of dexmedetomidine, and perioperative medications were analyzed. Adverse cardiac events were assessed with the Naranjo score and World Health Organization-The Uppsala Monitoring Centre (WHO-UMC) criteria. In total, 124 consecutive infants (30 patients and 94 controls) met the inclusion criteria. Eight of 30 (26.7 %) patients with trisomy 21 and 12 of 94 (12.8 %) controls experienced adverse cardiac events (i.e., hypotension, transient hypertension, and bradycardia) during dexmedetomidine with median Naranjo score of 6, and causality categories of WHO-UMC criteria were "certain" or "probable." Of those, the incidence of bradycardia occurred at a higher rate in patients with trisomy 21 than in controls (P = 0.011). Multiple logistic regression analysis revealed that the presence of trisomy 21 was an independent risk factor for adverse cardiac events of dexmedetomidine after cardiovascular surgery (odds ratio 4.10, 95 % CI 1.17-11.19, P = 0.006). Dexmedetomidine is associated with an increased incidence of bradycardia in patients with trisomy 21 after surgery for congenital heart disease. Physicians using dexmedetomidine should know a great deal about the characteristics of patients with trisomy 21, and hemodynamic monitoring should be closely observed.

Metabolism and pharmacokinetics of morphine in neonates: A review

Morphine is an agonist of the µ and k receptors, whose activation results in analgesia. Morphine-like agonists act through the µ opioid receptors to cause pain relief, sedation, euphoria and respiratory depression. Morphine is glucuronidated and sulfated at positions 3 and 6; the plasma concentration ratios correlate positively with birth weight, which probably reflects increased liver weight with increasing birth weight. Moreover, morphine clearance correlates positively with gestational age and birth weight. Steady-state morphine plasma concentrations are achieved after 24-48 hours of infusion, but the glucuronide metabolite plasma concentrations do not reach steady state before 60 hours. The morphine-3-glucuronide metabolite has lower clearance, a shorter half-life and a smaller distribution volume compared with the morphine-6 metabolite, which is the most active morphine-like agonist. Ordinary doses cause constipation, urinary retention and respiratory depression. Neonatal pain relief may require a blood level of approximately 120 ng/ml, whereas lower levels (20-40 ng/ml) seem adequate for children. A bibliographic search was performed using the PubMed database and the keywords "morphine metabolism neonate" and "morphine pharmacokinetics neonate". The initial and final cutoff points were January 1990 and September 2015, respectively. The results indicate that morphine is extensively glucuronidated and sulfated at positions 3 and 6, and that the glucuronidation rate is lower in younger neonates compared with older infants. Although much is known about morphine in neonates, further research will be required to ensure that recommended therapeutic doses for analgesia in neonates are evidence based.

Intranasal midazolam for seizure cessation in the community setting

QUESTION

There are times when parents arrive to my clinic after their child has had a seizure and a second seizure takes place in the clinic. While waiting for transport to the hospital, are there ways to stop the seizures without the need to obtain intravenous access in the clinic?

ANSWER

Intravenous diazepam has been a first-line therapy to stop seizures in children for many years. Other routes of drug administration such as intramuscular, rectal, and buccal are available but have several limitations. More evidence suggests that the intranasal route to administer drugs is quick and effective in children, and the use of midazolam has been continuing to show promise in seizure cessation. With its good safety profile, intranasal midazolam can be used in the clinic and prehospital setting for seizure cessation in children.

Pretreatment but not subsequent coincubation with midazolam reduces the cytotoxicity of temozolomide in neuroblastoma cells

Background

Temozolomide (TMZ) induces a G2/M cell cycle arrest and is used for treatment of paediatric tumours, especially neuroblastomas. Patients treated with TMZ frequently receive midazolam for sedation prior to surgery and other interventions. Previous studies suggested both cytoprotective and apoptosis-inducing properties of midazolam. Therefore, the impact of midazolam on TMZ-induced cytotoxicity was investigated in vitro.

Methods

Human neuroblastoma cells were incubated with midazolam alone, as a pretreatment prior to incubation with TMZ or a coincubation of both. Cell viability and proliferation was analysed (XTT and BrdU assay) after 24 h and flowcytometric cell cycle analysis was performed after 24 and 48 h.

Results

Midazolam alone increased cell viability at lower concentrations (2, 4, 8, 16 μM), whereas higher concentrations (128, 256, 512 μM) reduced cell viability. Pretreatment with midazolam 6 h prior to TMZ incubation reduced cytotoxic effects (IC₂₅ 1005 ± 197 μM; IC₅₀ 1676 ± 557 μM; P < 0.05) compared to incubation with TMZ alone (IC₂₅ 449 ± 304 μM; IC₅₀ 925 ± 196 μM) and reduced the antiproliferative effect of TMZ (1000 μM) by 43.9 % (P < 0.05). In contrast, cytotoxic effects of TMZ were increased (IC₇₅ 1175 ± 221 μM vs. 2764 ± 307 μM; P < 0.05) when midazolam pretreatment was followed by coincubation of midazolam and TMZ. Cell cycle analysis revealed increased fractions of cells in G2/M phase after TMZ treatment (100 μM; 48 h), irrespective of midazolam pretreatment.

Conclusion

Midazolam causes a hormetic dose–response relationship in human neuroblastoma cells. Pretreatment with midazolam reduces the cytotoxic and antiproliferative effects of TMZ without interfering with G2/M cell cycle arrest. In contrast, subsequent midazolam coincubation increases overall cytotoxicity.

Intranasal therapies for acute seizures

Most seizure emergencies occur outside of the hospital, and there is a need for treatment interventions that can be administered quickly and safely by nonclinical caregivers. Intranasal benzodiazepine administration does not require intravenous access and offers rapid seizure cessation. Intranasal midazolam is faster at aborting seizure activity than rectal diazepam and quicker to administer than intravenous diazepam. Although time to seizure cessation varies from study to study, intranasal midazolam is efficacious when administered not only by emergency department personnel but also by paramedics and caregivers in out-of-hospital and home settings. Absorption of midazolam intranasal formulations appears to be relatively rapid compared to diazepam formulations. Its shorter elimination half-life may also be beneficial in that patients may more quickly return to normal function because of rapid offset of effect. On the other hand, the faster rate of elimination of midazolam may expose patients to a higher rate of seizure recurrence compared with diazepam. Two diazepam formulations and one midazolam formulation are being currently developed for intranasal use. This article is part of a Special Issue entitled "Status Epilepticus".

Ionization states, cellular toxicity and molecular modeling studies of midazolam complexed with trimethyl-β-cyclodextrin

We investigated the ionization profiles for open-ring (OR) and closed-ring (CR) forms of midazolam and drug-binding modes with heptakis-(2,3,6-tri-O-methyl)-β-cyclodextrin (trimethyl-β-cyclodextrin; TRIMEB) using molecular modeling techniques and quantum mechanics methods. The results indicated that the total net charges for different molecular forms of midazolam tend to be cationic for OR and neutral for CR at physiological pH levels. The thermodynamic calculations demonstrated that CR is less water-soluble than OR, mainly due to the maximal solvation energy ( = −9.98 kcal·mol⁻¹), which has a minimal of −67.01 kcal·mol⁻¹. A cell viability assay did not detect any signs of TRIMEB and OR/CR-TRIMEB complex toxicity on the cEND cells after 24 h of incubation in either Dulbecco’s Modified Eagles Medium or in heat-inactivated human serum. The molecular docking studies identified the more flexible OR form of midazolam as being a better binder to TRIMEB with the fluorophenyl ring introduced inside the amphiphilic cavity of the host molecule. The OR binding affinity was confirmed by a minimal Gibbs free energy of binding (ΔG_bind) value of −5.57 ± 0.02 kcal·mol⁻¹, an equilibrium binding constant (K_b) of 79.89 ± 2.706 μM, and a ligand efficiency index (LE_lig) of −0.21 ± 0.001. Our current data suggest that in order to improve the clinical applications of midazolam via its complexation with trimethyl-β-cyclodextrin to increase drug’s overall aqueous solubility, it is important to concern the different forms and ionization states of this anesthetic. All mean values are indicated with their standard deviations.