Phenobarbital as Anticonvulsant Prophylaxis in Patients With Traumatic Brain Injury at Risk for Alcohol Withdrawal Syndrome

Background: Anticonvulsant prophylaxis (ACP) for early post-traumatic seizures (PTS) is recommended in patients with traumatic brain injury (TBI). Phenobarbital (PB) may be used to prevent alcohol withdrawal syndrome (AWS) in at-risk patients. The dual-purpose use of PB in the TBI population would allow for consolidation of pharmacotherapy. Objective: The primary objective of this study was to determine the frequency of early PTS in TBI patients at risk of AWS treated with PB as ACP. Secondary objectives included determining rates of over sedation and endotracheal intubation. Methods: Patients received an intravenous (IV) loading dose of PB at 15-20 mg/kg followed by 1 mg/kg every 12 hours for 7 days with a goal level of 15-20 mcg/mL. Medication data, seizure frequency, and episodes of over sedation and endotracheal intubation were collected. Results: Eighty patients were treated with PB over a 1-year period. Thirty-nine patients were analyzed. Median loading dose was 19.9 (Interquartile Range 19.1-20.0) mg/kg with a median post load level of 21.7 mcg/mL (IQR 18.3-25.8) mcg/mL. One patient (2.6%) had electrographic evidence for early PTS. PB was discontinued in 4 (10.3%) patients out of concern for over sedation. One patient required endotracheal intubation after rapid PB loading. Conclusion: The frequency of early PTS was low when PB was used as primary ACP in patients with TBI at risk for AWS. Over sedation is a potential adverse effect that should be considered in the choice of ACP. No conclusions can be drawn as to the effectiveness of PB in preventing AWS.

Elevated S100B urine levels predict seizures in infants complicated by perinatal asphyxia and undergoing therapeutic hypothermia

OBJECTIVES

Seizures (SZ) are one of the main complications occurring in infants undergoing therapeutic hypothermia (TH) due to perinatal asphyxia (PA) and hypoxic ischemic encephalopathy (HIE). Phenobarbital (PB) is the first-line therapeutic strategy, although data on its potential side-effects need elucidation. We investigated whether: i) PB administration in PA-HIE TH-treated infants affects S100B urine levels, and ii) S100B could be a reliable early predictor of SZ.

METHODS

We performed a prospective case-control study in 88 PA-HIE TH infants, complicated (n=44) or not (n=44) by SZ requiring PB treatment. S100B urine levels were measured at 11 predetermined monitoring time-points from first void up to 96-h from birth. Standard-of-care monitoring parameters were also recorded.

RESULTS

S100B significantly increased in the first 24-h independently from HIE severity in the cases who later developed SZ and requested PB treatment. ROC curve analysis showed that S100B, as SZ predictor, at a cut-off of 2.78 μg/L achieved a sensitivity/specificity of 63 and 84 %, positive/negative predictive values of 83 and 64 %.

CONCLUSIONS

The present results offer additional support to the usefulness of S100B as a trustable diagnostic tool in the clinical daily monitoring of therapeutic and pharmacological procedures in infants complicated by PA-HIE.

Establishing the safety of phenobarbital treatment of alcohol withdrawal syndrome on general medical wards: A retrospective cohort study

INTRODUCTION

Concern about adverse effects from phenobarbital limits its use in treating alcohol withdrawal syndrome (AWS) on general medical wards. Benzodiazepines are the recommended treatment for inpatient management of AWS, yet a subset of patients have an inadequate response or experience complications of AWS despite treatment with benzodiazepines. Data supporting an alternative treatment are needed. We set out to estimate the rate of serious adverse events (SAEs) of phenobarbital treatment for AWS on general medical wards.

METHODS

Retrospective cohort study of all general medical ward patients hospitalized at a single tertiary urban VA Medical Center from October 2018-May 2021 who received phenobarbital for treatment of AWS. Primary outcomes were SAEs attributed to phenobarbital and treatment failure. SAEs were defined as ICU transfer or intubation for over-sedation, pneumonia, and death. Treatment failure was defined as progression of withdrawal resulting in seizure, ICU transfer, behavioral emergencies, or death.

RESULTS

During the study period, phenobarbital was administered in 29% (244) of all AWS hospitalizations. Among them, 93% had a history of AWS hospitalization and 68% had a history of complicated AWS. Fifty-three percent of patients met criteria for moderate, severe, or complicated withdrawal prior to phenobarbital initiation. The mean cumulative dose of phenobarbital per patient was 966.5 mg (13.6 mg/kg). SAEs occurred in 1 of 244 hospitalizations (0.4%): there were no intubations, ICU transfers for oversedation, or deaths due to phenobarbital or AWS. One case of pneumonia was possibly attributable to phenobarbital. Treatment failures (6 ICU transfers, 9 behavioral emergencies) were identified during 12 of 244 hospitalizations (4.9%).

CONCLUSIONS

SAEs and treatment failures were infrequent among 148 patients treated with phenobarbital across 244 hospitalizations with a mean cumulative dose of 966.5 mg per patient. Our findings suggest that phenobarbital is a safe alternative treatment of AWS in general medical ward patients.

Comparative Outcomes of Levetiracetam and Phenobarbital Usage in the Treatment of Neonatal Seizures: A Retrospective Analysis

OBJECTIVES AND AIM

The primary aim of this study was to conduct a comparative analysis of the safety and efficacy of levetiracetam (LEV) and phenobarbital (PB) as first-line treatments for neonatal seizure management. This study was designed to measure and compare the incidence of adverse effects and to determine the discharge and mortality rates associated with the use of these antiseizure medications (ASMs). Through this comparison, this research sought to provide insights to optimise care for neonates experiencing seizures.

MATERIALS AND METHODS

This retrospective cohort study evaluated 104 neonates treated for seizures at Zeynep Kamil Hospital from 2015 to 2020 after excluding those on non-PB/LEV antiseizure medications. Seizures were characterised using electroencephalogram (EEG) and categorised according to aetiology and frequency. Treatment efficacy was gauged by seizure cessation, as confirmed using EEG. Adverse effects and demographic data were recorded. Statistical analyses were conducted using SPSS, employing the Shapiro-Wilk, independent t-test, Mann-Whitney U test, and chi-square test, with a significance threshold of p < 0.05.

RESULTS

Overall, 104 neonates treated with first-line ASM were evaluated for efficacy; PB was administered in 68.26% of the cases, while LEV was utilised in 31.74%. The total complete response rate was 40.38%, with no significant difference between the PB and LEV groups (p = 0.309). The incidence rate ratios (IRRs) demonstrated that seizure frequency profoundly influenced treatment effectiveness, with IRRs of 2.09 for rare seizures, 3.25 for frequent seizures, and 4.01 for status epilepticus, indicating a higher treatment response rate with increasing seizure frequency. For second-line treatment, among a subset of 62 patients, PB had a slight, non-significant advantage over LEV, with an odds ratio of 1.09, suggesting a marginally better response to LEV. Adverse events were significantly more frequent in the PB group, affecting 19 of 67 neonates (28.36%), compared to only 2 of 71 neonates (2.82%) in the LEV group (p < 0.001). No significant difference was observed in the discharge rates between the two groups (PB, 67.61%; LEV, 75.76%; p = 0.674). Interestingly, the mortality rate was significantly higher in the LEV group (45.45%) than that in the PB group (22.54%; p = 0.045).

CONCLUSION

This study underscores LEV's superior safety profile over PB in neonatal seizure management, evidenced by a significantly lower rate of adverse events. PB seems to be more effective in the second-line treatment of neonatal seizures. Despite the lack of significant differences in the discharge rates, the higher mortality rate associated with LEV warrants further investigation. These findings advocate the cautious selection of antiepileptic drugs in neonatal care, with a preference for LEV based on its safety profile.

"Should We Phenobarb-it-All?" A Phenobarbital-Based Protocol for Non-Intensive Care Unit Trauma Patients at High Risk of or Experiencing Alcohol Withdrawal

BACKGROUND

Alcohol use is frequent in trauma patients and alcohol withdrawal syndrome (AWS) is associated with significant morbidity. Benzodiazepines are commonly used for AWS, but may cause neurologic and respiratory adverse events (AEs). The objective was to evaluate the effectiveness and safety of a phenobarbital-based protocol for the treatment of AWS in non-intensive care unit (ICU) trauma patients.

METHODS

Adult non-ICU trauma patients at high risk of or experiencing AWS PRE and POST implementation of a phenobarbital-based protocol were included. Outcomes were AWS-related complications (AWS-RC), benzodiazepine use, adjunctive medication use, hospital length of stay (HLOS), and medication-related AEs. Subgroup analyses were performed on patients with traumatic brain injury (TBI), rib fractures, and at high risk of severe AWS.

RESULTS

Overall, 110 patients were included (51 PRE, 59 POST). AWS-RC developed in 17 PRE patients compared to 10 POST patients (33% vs 17%; P = .05). PRE patients were more likely to receive benzodiazepines (88% vs 42%, P < .0001) and higher total dose (11 vs 4 mg lorazepam equivalent; P = .001). No difference noted in HLOS (8 vs 8 days, P = .27), adjunctive medication use (49% vs 54%, P = .60), or AEs (57% vs 39%, P = .06). There was no difference in AWS-RC in the TBI subgroup (P = .19), less AEs in the rib fracture POST subgroup (P = .04), and less AWS-RC in the high risk of severe AWS POST subgroup (P = .03).

DISCUSSION

A phenobarbital-based protocol in trauma patients is effective in preventing AWS-RC and decreasing benzodiazepine use without increasing AEs.

Facial dysmorphology in children exposed in pregnancy to anticonvulsant medications correlates with deficits in IQ

Some children exposed at conception to the antiepileptic drugs (AEDs) phenytoin (PHT), phenobarbital (PB), and carbamazepine (CBZ) have changes in their midface and fingers. It has been suggested that the anticonvulsant-exposed child with these subtle changes in facial features (the "anticonvulsant face") has a greater likelihood of having deficits in IQ in comparison with children exposed to the same anticonvulsants who do not have these features. 115 AED-exposed children (40, PHT; 34, PB; and 41, CBZ) between 6.5 and 16 years of age and 111 unexposed children matched by sex, race, and year in school were evaluated. The evaluations were (WISC-III), physical examination with measurements of facial features and digits and photographs. The AED-exposed children had cephalometric radiographs, but not the unexposed. Each parent had a similar examination of face and hands plus tests of intelligence. These AED-exposed children showed an increased frequency of a short nose and anteverted nares, features of the "anticonvulsant face." Lateral skull radiographs showed a decrease in the angle between the anterior cranial base and nasal bone, which produces anteverted nares. Mean IQs were significantly lower on one or more IQ measures for the children with these facial features. Shortening of the distal phalanges and small fingernails correlated with the presence of a short nose in that child. The findings in 115 children exposed at conception to either phenytoin, phenobarbital, or carbamazepine, as monotherapy, confirmed the hypothesis that those with a short nose and anteverted nares had a lower IQ than exposed children without those features.

Evaluation of Phenobarbital Adsorption Efficiency on Biosorbents or Activated Carbon Obtained from Adansonia Digitata Shells

The removal of pharmaceutically active compounds present in relatively low concentration in wastewater is critical. This is because they have a severe, negative impact on life and the environment. To address this issue, adsorption was used, which is an effective wastewater treatment method for removing substances found in low concentrations in water. This study compared the adsorption performance of active carbon to three biosorbents derived from Adansonia digitata shells. The adsorbents were prepared and characterized using TGA, SEM, EDX, and FTIR analyses and pHPZC. To better understand the adsorption process, equilibrium and reaction kinetics studies were conducted. The effect of contact time, initial phenobarbital concentration, adsorbent mass, and pH was investigated in static conditions. The adsorption results revealed that the biosorbent B3 has a higher affinity for the eliminated compound, with an equilibrium time of 60 min and an adsorption capacity of 47.08 mg/g at an initial concentration of 50 mg/L. The experimental data are consistent with Langmuir and Sips adsorption isotherm models, and with the pseudo-second order and Elovich models for kinetics description. This indicates strong interactions between the adsorbent materials and the pharmaceutical micropollutant. Based on these findings, it appears that, among the tested materials, B3 biosorbent is the most efficient for removing phenobarbital present in low concentrations in water.

Early life phenobarbital exposure dysregulates the hippocampal transcriptome

Introduction: Phenobarbital (PB) and levetiracetam (LEV) are the first-line therapies for neonates with diagnosed seizures, however, a growing body of evidence shows that these drugs given during critical developmental windows trigger lasting molecular changes in the brain. While the targets and mechanism of action of these drugs are well understood-what is not known is how these drugs alter the transcriptomic landscape, and therefore molecular profile/gene expression during these critical windows of neurodevelopment. PB is associated with a range of neurotoxic effects in developing animals, from cell death to altered synaptic development to lasting behavioral impairment. LEV does not produce these effects. Methods: Here we evaluated the effects of PB and Lev on the hippocampal transcriptome by RNA sequencing. Neonatal rat pups were given a single dose of PB, Lev or vehicle and sacrificed 72 h later-at time at which drug is expected to be cleared. Results: We found PB induces broad changes in the transcriptomic profile (124 differentially expressed transcripts), as compared to relatively small changes in LEV-treated animals (15 transcripts). PB exposure decreased GABAergic and oligodendrocyte markers pvalb and opalin, and increased the marker of activated microglia, cd68 and the astrocyte- associated gene vegfa. These data are consistent with the existing literature showing developmental neurotoxicity associated with PB, but not LEV. Discussion: The widespread change in gene expression after PB, which affected transcripts reflective of multiple cell types, may provide a link between acute drug administration and lasting drug toxicity.

An isotope dilution-liquid chromatography-tandem mass spectrometry (ID-LC-MS/MS)-based candidate reference measurement procedure (RMP) for the quantification of phenobarbital in human serum and plasma

OBJECTIVES

Phenobarbital serves as an antiepileptic drug (AED) and finds application in the treatment of epilepsy either as monotherapy or adjunctive therapy. This drug exhibits various pharmacodynamic properties that account for its beneficial effects as well as potential side effects. Accurate measurement of its concentration is critical for optimizing AED therapy through appropriate dose adjustments. Therefore, our objective was to develop and validate a new reference measurement procedure (RMP) for the accurate quantification of phenobarbital levels in human serum and plasma.

METHODS

A sample preparation protocol based on protein precipitation followed by a high dilution step was established in combination with a liquid chromatography-tandem mass spectrometry (LC-MS/MS) method using a C8 column to separate target analytes from known and unknown interferences. Assay validation and determination of measurement uncertainty were performed based on current guidelines. Selectivity and Specificity were assessed using spiked serum and plasma samples; to investigate possible matrix effects (MEs) a post-column infusion experiment and a comparison of standard line slopes was performed. Precision and accuracy were determined within a multiday precision experiment.

RESULTS

The RMP was shown to be highly selective and specific, with no evidence of matrix interferences. It can be used to quantify phenobarbital in the range of 1.92 to 72.0 μg/mL. Intermediate precision was less than 3.2 %, and repeatability coefficient of variation (CV) ranged from 1.3 to 2.0 % across all concentration levels. The relative mean bias ranged from -3.0 to -0.7 % for native serum levels, and from -2.8 to 0.8 % for Li-heparin plasma levels. The measurement uncertainties (k=1) for single measurements and target value assignment were 1.9 to 3.3 % and 0.9 to 1.6 %, respectively.

CONCLUSIONS

A novel LC-MS/MS-based candidate RMP for the quantification of phenobarbital in human serum and plasma is presented which can be used for the standardization of routine assays and the evaluation of clinically relevant samples.

Phenibut: Review and Pharmacologic Approaches to Treating Withdrawal

β-Phenyl-γ-aminobutyric acid (phenibut) is an analog of the inhibitory neurotransmitter γ-aminobutyric acid (GABA) that was first synthesized in Russia in the early 1960s. It is marketed as a nootropic (smart drug) to improve cognitive performance, and to treat generalized and social anxiety, insomnia, and alcohol withdrawal. The use of phenibut is legal in the USA and it is widely available online without a prescription. Increased public awareness of phenibut has led to a growing number of reports of acute intoxication and withdrawal. In this review, we describe the pharmacology of phenibut, the presentation and management of acute intoxication, and regulatory issues, placing particular emphasis on the treatment of acute withdrawal, for which there are no comparative studies. Among 29 cases of phenibut withdrawal, patients were successfully treated with baclofen, benzodiazepines, and phenobarbital, as individual agents or in various combinations. Ancillary medications included antipsychotics, dexmedetomidine, gabapentin, and pregabalin. After stabilization, a number of patients did well on baclofen tapers, whereas others were weaned off benzodiazepines or phenobarbital. Phenobarbital may be preferred over baclofen, or used as an added agent, in patients at risk for seizures. As long as phenibut remains legal, cases of phenibut intoxication and withdrawal are likely to increase. As urine or plasma drug screening for phenibut is not widely available, it is vital that clinicians obtain a detailed medication history in patients presenting to the emergency department with nonspecific symptoms that may represent phenibut intoxication or withdrawal. Further, clinicians may wish to consult an addiction specialist or toxicologist in these situations.

Fecal supernatants from dogs with idiopathic epilepsy activate enteric neurons

Introduction

Alterations in the composition and function of the gut microbiome have been reported in idiopathic epilepsy (IE), however, interactions of gut microbes with the enteric nervous system (ENS) in this context require further study. This pilot study examined how gastrointestinal microbiota (GIM), their metabolites, and nutrients contained in intestinal contents communicate with the ENS.

Methods

Fecal supernatants (FS) from healthy dogs and dogs with IE, including drug-naïve, phenobarbital (PB) responsive, and PB non-responsive dogs, were applied to cultured myenteric neurons to test their activation using voltage-sensitive dye neuroimaging. Additionally, the concentrations of short-chain fatty acids (SCFAs) in the FS were quantified.

Results

Our findings indicate that FS from all examined groups elicited neuronal activation. Notably, FS from PB non-responsive dogs with IE induced action potential discharge in a higher proportion of enteric neurons compared to healthy controls, which exhibited the lowest burst frequency overall. Furthermore, the highest burst frequency in enteric neurons was observed upon exposure to FS from drug-naïve dogs with IE. This frequency was significantly higher compared to that observed in PB non-responsive dogs with IE and showed a tendency to surpass that of healthy controls.

Discussion

Although observed disparities in SCFA concentrations across the various FS samples might be associated with the induced neuronal activity, a direct correlation remains elusive at this point. The obtained results hint at an involvement of the ENS in canine IE and set the basis for future studies.

High Doses of ANA12 Improve Phenobarbital Efficacy in a Model of Neonatal Post-Ischemic Seizures

Phenobarbital (PB) remains the first-line medication for neonatal seizures. Yet, seizures in many newborns, particularly those associated with perinatal ischemia, are resistant to PB. Previous animal studies have shown that in postnatal day P7 mice pups with ischemic stroke induced by unilateral carotid ligation, the tyrosine receptor kinase B (TrkB) antagonist ANA12 (N-[2-[[(hexahydro-2-oxo-1H-azepin-3-yl)amino]carbonyl]phenyl]-benzo[b]thiophene-2-carboxamide, 5 mg/kg) improved the efficacy of PB in reducing seizure occurrence. To meet optimal standards of effectiveness, a wider range of ANA12 doses must be tested. Here, using the unilateral carotid ligation model, we tested the effectiveness of higher doses of ANA12 (10 and 20 mg/kg) on the ability of PB to reduce seizure burden, ameliorate cell death (assessed by Fluoro-Jade staining), and affect neurodevelopment (righting reflex, negative geotaxis test, open field test). We found that a single dose of ANA12 (10 or 20 mg/kg) given 1 h after unilateral carotid ligation in P7 pups reduced seizure burden and neocortical and striatal neuron death without impairing developmental reflexes. In conclusion, ANA12 at a range of doses (10-20 mg/kg) enhanced PB effectiveness for the treatment of perinatal ischemia-related seizures, suggesting that this agent might be a clinically safe and effective adjunctive agent for the treatment of pharmacoresistant neonatal seizures.

Impact of a Divided Phenobarbital Load and Taper Compared With Lorazepam Symptom Triggered Therapy in Hospitalized Patients

BACKGROUND

Benzodiazepines are the preferred treatment for alcohol withdrawal. Phenobarbital is an alternative in the setting of prescriber expertise or benzodiazepine contraindication.

OBJECTIVE

To evaluate the efficacy and safety of a phenobarbital dosing strategy aimed at treating a spectrum of alcohol withdrawal symptoms across various patient populations.

METHODS

Retrospective review of patients admitted with concerns of alcohol withdrawal between May 2018 and November 2022. Patients were separated into a before-after cohort of lorazepam or phenobarbital. The primary outcome was hospital length of stay (LOS). Secondary outcomes were intensive care unit (ICU) LOS, escalation of respiratory support, increased level of care (LOC), and incidence of delirium tremens and/or seizures.

RESULTS

Two hundred and seventy-seven patients received lorazepam and 198 received phenobarbital. Hospital LOS was longer in the phenobarbital cohort compared with the lorazepam cohort (6.9 vs 9.3 days). There was no difference in ICU LOS. Level of care increases were fewer in the phenobarbital cohort (4 events vs 19 events). There were higher rates of non-invasive respiratory interventions in the lorazepam cohort and higher rates of mechanical ventilation in the phenobarbital cohort. Utilization of phenobarbital was attributed to a reduction in delirium tremens and seizures.

CONCLUSION AND RELEVANCE

This study is novel because of the broad application of a phenobarbital order set across multiple levels of care and patient admission diagnoses. A risk targeted split load intravenous phenobarbital order set can safely be administered to patients with fewer escalations of care, seizures, delirium tremens, and respiratory care escalation.

Pharmacokinetics and tolerability of a veterinary phenobarbital product in healthy dogs

Introduction

Phenobarbital has been used for many decades in both human and veterinary epileptic patients. Many formulations for a particular drug exist, most of which are marketed for humans. Recently a veterinary specific phenobarbital product has been introduced to the market in the United States. Utilizing a specific formulation to treat patients may help decrease the issue of bioequivalence between one pharmaceutical product to another. Therefore, the goal of this study was to determine single and multiple dosing pharmacokinetics and tolerability of a veterinary specific phenobarbital product over a 4-week time period.

Materials and methods

8 Healthy dogs from a canine research colony were used in the study.

Results

Overall, this phenobarbital formulation was well tolerated in the dogs in this study. Cmax, Tmax, half-life, and AUC after single 12 mg/kg oral dose were 23.5 μg/mL, 4.2 h, 94 h, and 2,758 h*μg/mL. Following chronic dosing, these parameters were 29.1 μg/mL, 3.4 h, 70 h, and 2,971 h*μg/mL, respectively.

Discussion

This formulation demonstrated a mean absolute bioavailability of 100%, with similar pharmacokinetic properties to previously published data.

A retrospective evaluation of phenobarbital-induced hematologic changes in 69 cats

BACKGROUND

Phenobarbital (PB) is used as a first-line treatment for recurrent epileptic seizures in cats. While hematologic abnormalities are well-known side effects of antiepileptic therapy with PB in humans and dogs, little is known about such alterations in cats.

OBJECTIVES

The aim of this retrospective study was to investigate the prevalence and clinical relevance of cytopenia during PB treatment in cats.

METHODS

In this single-center, retrospective clinical study, 69 cats-with suspected idiopathic epilepsy admitted to the Small Animal Clinic of the University of Veterinary Medicine in Vienna (VMU)-were included. A complete blood count for each patient was performed, and changes in hematocrit, leukocytes, neutrophils, and thrombocytes were documented and graded.

RESULTS

Fifty-three out of 69 cats (76.8%) showed cytopenias with a reduction of at least one cell fraction during PB treatment. The most frequent change was neutropenia (60%), followed by leukopenia (49.3%), thrombocytopenia (24.1%), and anemia (20.3%). Most of the changes were mild or moderate; only one patient (1.5%) showed severe leukopenia and neutropenia, and one was a life-threatening neutropenia (1.5%) with a serum PB concentration within or even below the therapeutic range. These patients did not present with clinical symptoms other than those related to epileptic episodes. Cats who received combination therapy showed lower hematocrits than those who received monotherapy. A tendency for leukocytes and neutrophils to decrease during PB treatment was also seen.

CONCLUSIONS

Blood cytopenias may frequently occur in cats on chronic PB therapy, even when serum drug levels are within the therapeutic range. However, clinical signs are typically mild to moderate and rarely severe.

Successful management of severe generalized tetanus in a 23-year man with phenobarbital adjuvant: A case report

Generalized tetanus is still a global concern with a mortality rate of up to 50%, especially in low and middle-income countries. We reported a 23-year-old man from Afghanistan admitted to emergency department, with the chief complaint of generalized severe spasms and lockjaw. The patient had skin lesions and had never been vaccinated against tetanus. He intubated and admitted to the intensive care unit (ICU) with diagnose of severe generalized tetanus. After receiving tetanus immunoglobulin and intravenous metronidazole, a combination therapy of midazolam, propofol, atracurium, and morphine was administered. Due to the refractory muscular spasms intravenous phenobarbital started and little by little recovery was achieved. The patient receiving the first two doses of the Td vaccine, and discharged on Day 42 of hospitalization with no symptom recurrence. This case management showed adding phenobarbital to severe tetanus treatment regimen could significantly reduce refractory spasm caused by tetanus, also decrease other medication requirement.

Phenobarbital versus benzodiazepines in alcohol withdrawal syndrome

AIM

Phenobarbital, a long-acting barbiturate, presents an alternative to conventional benzodiazepine treatment for alcohol withdrawal syndrome (AWS). Currently, existing research offers only modest guidance on the safety and effectiveness of phenobarbital in managing AWS in hospital settings. The study objective was to assess if a phenobarbital protocol for the treatment of AWS reduces respiratory complications when compared to a more traditionally used benzodiazepine protocol.

METHODS

A retrospective cohort study analyzing adults who received either phenobarbital or benzodiazepine-based treatment for AWS over a 4-year period, 2015-2019, in a community teaching hospital in a large academic medical system.

RESULTS

A total of 147 patient encounters were included (76 phenobarbital and 71 benzodiazepine). Phenobarbital was associated with a significantly decreased risk of respiratory complications, defined by the occurrence of intubation (15/76 phenobarbital [20%] vs. 36/71 benzodiazepine [51%]) and decreased incidence of the requirement of six or greater liters of oxygen when compared with benzodiazepines (10/76 [13%] vs. 28/71 [39%]). There was a significantly higher incidence of pneumonia in benzodiazepine patients (15/76 [20%] vs. 33/71 [47%]). Mode Richmond Agitation Sedation Scale (RASS) scores were more frequently at goal (0 to -1) between 9 and 48 h after the loading dose of study medication for phenobarbital patients. Median hospital and ICU length of stay were significantly shorter for phenobarbital patients when compared with benzodiazepine patients (5 vs. 10 days and 2 vs. 4 days, respectively).

CONCLUSION

Parenteral phenobarbital loading doses with an oral phenobarbital tapered protocol for AWS resulted in decreased risk of respiratory complications when compared to standard treatment with benzodiazepines.

Anti-seizure medications for neonates with seizures

BACKGROUND

Newborn infants are more prone to seizures than older children and adults. The neuronal injury caused by seizures in neonates often results in long-term neurodevelopmental sequelae. There are several options for anti-seizure medications (ASMs) in neonates. However, the ideal choice of first-, second- and third-line ASM is still unclear. Further, many other aspects of seizure management such as whether ASMs should be initiated for only-electrographic seizures and how long to continue the ASM once seizure control is achieved are elusive.

OBJECTIVES

1. To assess whether any ASM is more or less effective than an alternative ASM (both ASMs used as first-, second- or third-line treatment) in achieving seizure control and improving neurodevelopmental outcomes in neonates with seizures. We analysed EEG-confirmed seizures and clinically-diagnosed seizures separately. 2. To assess maintenance therapy with ASM versus no maintenance therapy after achieving seizure control. We analysed EEG-confirmed seizures and clinically-diagnosed seizures separately. 3. To assess treatment of both clinical and electrographic seizures versus treatment of clinical seizures alone in neonates.

SEARCH METHODS

We searched MEDLINE, Embase, CENTRAL, Epistemonikos and three databases in May 2022 and June 2023. These searches were not limited other than by study design to trials.

SELECTION CRITERIA

We included randomised controlled trials (RCTs) that included neonates with EEG-confirmed or clinically diagnosed seizures and compared (1) any ASM versus an alternative ASM, (2) maintenance therapy with ASM versus no maintenance therapy, and (3) treatment of clinical or EEG seizures versus treatment of clinical seizures alone.

DATA COLLECTION AND ANALYSIS

Two review authors assessed trial eligibility, risk of bias and independently extracted data. We analysed treatment effects in individual trials and reported risk ratio (RR) for dichotomous data, and mean difference (MD) for continuous data, with respective 95% confidence interval (CI). We used GRADE to assess the certainty of evidence.

MAIN RESULTS

We included 18 trials (1342 infants) in this review. Phenobarbital versus levetiracetam as first-line ASM in EEG-confirmed neonatal seizures (one trial) Phenobarbital is probably more effective than levetiracetam in achieving seizure control after first loading dose (RR 2.32, 95% CI 1.63 to 3.30; 106 participants; moderate-certainty evidence), and after maximal loading dose (RR 2.83, 95% CI 1.78 to 4.50; 106 participants; moderate-certainty evidence). However, we are uncertain about the effect of phenobarbital when compared to levetiracetam on mortality before discharge (RR 0.30, 95% CI 0.04 to 2.52; 106 participants; very low-certainty evidence), requirement of mechanical ventilation (RR 1.21, 95% CI 0.76 to 1.91; 106 participants; very low-certainty evidence), sedation/drowsiness (RR 1.74, 95% CI 0.68 to 4.44; 106 participants; very low-certainty evidence) and epilepsy post-discharge (RR 0.92, 95% CI 0.48 to 1.76; 106 participants; very low-certainty evidence). The trial did not report on mortality or neurodevelopmental disability at 18 to 24 months. Phenobarbital versus phenytoin as first-line ASM in EEG-confirmed neonatal seizures (one trial) We are uncertain about the effect of phenobarbital versus phenytoin on achieving seizure control after maximal loading dose of ASM (RR 0.97, 95% CI 0.54 to 1.72; 59 participants; very low-certainty evidence). The trial did not report on mortality or neurodevelopmental disability at 18 to 24 months. Maintenance therapy with ASM versus no maintenance therapy in clinically diagnosed neonatal seizures (two trials) We are uncertain about the effect of short-term maintenance therapy with ASM versus no maintenance therapy during the hospital stay (but discontinued before discharge) on the risk of repeat seizures before hospital discharge (RR 0.76, 95% CI 0.56 to 1.01; 373 participants; very low-certainty evidence). Maintenance therapy with ASM compared to no maintenance therapy may have little or no effect on mortality before discharge (RR 0.69, 95% CI 0.39 to 1.22; 373 participants; low-certainty evidence), mortality at 18 to 24 months (RR 0.94, 95% CI 0.34 to 2.61; 111 participants; low-certainty evidence), neurodevelopmental disability at 18 to 24 months (RR 0.89, 95% CI 0.13 to 6.12; 108 participants; low-certainty evidence) and epilepsy post-discharge (RR 3.18, 95% CI 0.69 to 14.72; 126 participants; low-certainty evidence). Treatment of both clinical and electrographic seizures versus treatment of clinical seizures alone in neonates (two trials) Treatment of both clinical and electrographic seizures when compared to treating clinical seizures alone may have little or no effect on seizure burden during hospitalisation (MD -1871.16, 95% CI -4525.05 to 782.73; 68 participants; low-certainty evidence), mortality before discharge (RR 0.59, 95% CI 0.28 to 1.27; 68 participants; low-certainty evidence) and epilepsy post-discharge (RR 0.75, 95% CI 0.12 to 4.73; 35 participants; low-certainty evidence). The trials did not report on mortality or neurodevelopmental disability at 18 to 24 months. We report data from the most important comparisons here; readers are directed to Results and Summary of Findings tables for all comparisons.

AUTHORS' CONCLUSIONS

Phenobarbital as a first-line ASM is probably more effective than levetiracetam in achieving seizure control after the first loading dose and after the maximal loading dose of ASM (moderate-certainty evidence). Phenobarbital + bumetanide may have little or no difference in achieving seizure control when compared to phenobarbital alone (low-certainty evidence). Limited data and very low-certainty evidence preclude us from drawing any reasonable conclusion on the effect of using one ASM versus another on other short- and long-term outcomes. In neonates who achieve seizure control after the first loading dose of phenobarbital, maintenance therapy compared to no maintenance ASM may have little or no effect on all-cause mortality before discharge, mortality by 18 to 24 months, neurodevelopmental disability by 18 to 24 months and epilepsy post-discharge (low-certainty evidence). In neonates with hypoxic-ischaemic encephalopathy, treatment of both clinical and electrographic seizures when compared to treating clinical seizures alone may have little or no effect on seizure burden during hospitalisation, all-cause mortality before discharge and epilepsy post-discharge (low-certainty evidence). All findings of this review apply only to term and late preterm neonates. We need well-designed RCTs for each of the three objectives of this review to improve the precision of the results. These RCTs should use EEG to diagnose seizures and should be adequately powered to assess long-term neurodevelopmental outcomes. We need separate RCTs evaluating the choice of ASM in preterm infants.

Attenuation of phenobarbital-induced cytochrome P450 expression in carbon tetrachloride-induced hepatitis in mice models

Certain pathological conditions, such as inflammation, are known to affect basal cytochrome P450 (CYP) expression by modulating transcriptional regulation, and the pharmacokinetics of drugs can vary among patients. However, changes in drug-induced CYP expression under pathological conditions have not been elucidated in detail. Here, we investigated the effects of hepatic inflammation and injury on phenobarbital-induced expression of CYP isoforms in mice. Phenobarbital was administered once as a CYP inducer in the carbon tetrachloride-induced hepatitis model mice. The mRNA expression levels of Cyp3a11 and Cyp2b10 in the liver and small intestine were measured using reverse transcription polymerase chain reaction. The enzymatic activity of CYP3A in liver S9 was evaluated using midazolam as the substrate. Phenobarbital increased the mRNA expression of Cyp3a11 and Cyp2b10 in the liver of healthy mice, but not in the small intestine. Increased mRNA expression of hepatic Cyp3a11 and Cyp2b10 by phenobarbital was significantly suppressed in the hepatitis model mice. Hepatitis also suppressed the increased CYP3A enzymatic activity induced by phenobarbital in liver S9, consistent with the results of Cyp3a11 mRNA expression. These results suggest that the inducibility of CYP by phenobarbital may vary in patients with hepatitis, indicating that pharmacokinetic drug-drug interactions can be altered under certain pathological conditions.

Successful management of suspected propofol dependence with phenobarbital in an adult patient with COVID-19

PURPOSE

In critically ill patients, high sedation requirements for prolonged durations are often needed to achieve ventilator synchrony, a practice that was particularly common during the early stages of the coronavirus disease 2019 (COVID-19) pandemic. We report the successful use of phenobarbital to facilitate propofol weaning after prolonged medication exposure.

SUMMARY

A 64-year-old male with hypertension was admitted for the management of acute respiratory distress syndrome due to COVID-19 pneumonia. The patient received high doses of fentanyl and propofol with periods of concomitant midazolam and dexmedetomidine throughout his prolonged time on mechanical ventilation. Total days of exposure were 19 for fentanyl, 17 for propofol, 12 for midazolam, and 15 for dexmedetomidine. Upon improvement in lung function, attempts to wean the patient from propofol all failed due to symptoms such as tachypnea, tachycardia, and hypertension, with symptom resolution only upon return to the previous dose. Phenobarbital was trialed for possible propofol withdrawal syndrome, allowing for a dose reduction of 10 μg/kg/min within 2 hours of the first dose without any corresponding symptoms. The patient continued to receive intermittent doses of phenobarbital for another 36 hours until propofol was discontinued. He underwent tracheostomy shortly after weaning off all sedation and was discharged to rehab 34 days after his initial admission.

CONCLUSION

Information concerning propofol withdrawal syndrome in the literature is limited. Our experience demonstrates the successful use of phenobarbital to facilitate propofol weaning after prolonged exposure.

CAR requires Gadd45β to promote phenobarbital-induced mouse liver tumors in early stage

Phenobarbital (PB) is an archetypal substance used as a mouse hepatocellular carcinoma (HCC) promotor in established experimental protocols. Our previous results showed CAR is the essential factor for PB induced HCC promotion. Subsequent studies suggested Gadd45β, which is induced by PB through CAR activation, is collaborating with CAR to repress TNF-α induced cell death. Here, we used Gadd45β null mice (Gadd45β KO) treated with N-diethylnitrosamine (DEN) at 5 weeks of age and kept the mice with PB supplemented drinking water from 7 to 57 weeks old. Compared with wild type mice, Gadd45β KO mice developed no HCC in the PB treated group. Increases in liver weight were more prominent in wild type mice than KO mice. Microarray analysis of mRNA derived from mouse livers found multiple genes specifically up or down regulated in wild type mice but not null mice in DEN + PB groups. Further qPCR analysis confirmed two genes, Tgfbr2 and irisin/Fndc5, were up-regulated in PB treated wild type mice but no significant increase was observed in Gadd45β KO mice. We focused on these two genes because previous reports showed that hepatic Irisin/Fndc5 expression was significantly higher in HCC patients and that irisin binds to TGF-β receptor complex that includes TGFBR2 subunit. Our results revealed irisin peptide in cell culture media increased the growth rate of mouse hepatocyte-derived AML12 cells. Microarray analysis revealed that irisin-regulated genes in AML12 cells showed a significant association with the genes in the TGF-β pathway. Expression of irisin/Fndc5 and Tgfbr2 induced growth of human HCC cell line HepG2. Thus, Gadd45β plays an indispensable role in mouse HCC development regulating the irisin/Fndc5 and Tgfbr2 genes.

Influence of medications on thyroid function in dogs: An update

Erroneous thyroid function test results can occur because of drugs that alter thyroid hormone physiology in one or more aspects, including synthesis, secretion, distribution, and metabolism. Research since publication of the last review in the Journal of Veterinary Internal Medicine (JVIM) 20 years ago has evaluated the effects of amiodarone, zonisamide, inhalant anesthetics, clomipramine, trilostane, and toceranib on thyroid function tests in the dog. In addition, recent work on the effects of glucocorticoids, sulfonamides, phenobarbital, and nonsteroidal anti-inflammatory drugs will be reviewed. Awareness of these effects is necessary to avoid misdiagnosis of hypothyroidism and unnecessary treatment.

Mild Crigler-Najjar Syndrome with Progressive Liver Disease-A Multicenter Retrospective Cohort Study

Crigler-Najjar Syndrome (CNS) with residual activity of UDP-glucuronosyltransferase 1A1 (UGT1A1) and no need for daily phototherapy is called mild Crigler-Najjar Syndrome. Most of these patients need medical treatment for enzyme induction (phenobarbital) to lower blood levels of unconjugated bilirubin (UCB). Apart from this, no long-term problems have been described so far. The phenotype of patients with the homozygous pathogenic variant c.115C>G p.(His39Asp) in UGT1A1 is described as variable. Clinical observations of our patients led to the assumption that patients with variant c.115C>G have a mild CNS phenotype while having a high risk of developing progressive liver disease. For mild CNS disease, progressive liver disease has not been described so far. Therefore, we conducted a retrospective multicenter analysis of 14 patients with this particular variant, aiming for better characterization of this variant. We could confirm that patients with variant c.115C>G have a high risk of progressive liver disease (seven of fourteen), which increases with age despite having a very mild CNS phenotype. Earlier predictors and causes for an unfavorable disease course are not detectable, but close follow-up could identify patients with progressive liver disease at the beginning. In conclusion, these patients need close and specialized follow-up. Our study questions whether fibrosis in the CNS is really driven by high amounts of UCB or phototherapy.

Phenobarbital for alcohol withdrawal management in the emergency department: A systematic review of direct evidence for the SAEM GRACE initiative

OBJECTIVES

Alcohol withdrawal syndrome (AWS) is a commonly presenting condition in the emergency department (ED) and can have severe complications, including mortality. Benzodiazepines are first-line medications for treating AWS but may be unavailable or insufficient. This systematic review evaluates the direct evidence assessing the utility of phenobarbital for treating AWS in the ED.

METHODS

A systematic search was conducted and designed according to the patient-intervention-comparator-outcome (PICO) question: (P) adults (≥18 years old) presenting to the ED with alcohol withdrawal; (I) phenobarbital (including adjunctive); (C) benzodiazepines or no intervention; and (O) AWS complications, admission to a monitored setting, control of symptoms, adverse effects, and adjunctive medications. Two reviewers independently assessed articles for inclusion and conducted risk of bias assessments for included studies.

RESULTS

From 70 potentially relevant articles, seven studies met inclusion criteria: three retrospective cohort studies, two retrospective chart reviews, and two randomized controlled trials (RCTs), one examining phenobarbital monotherapy and one examining adjunctive phenobarbital. Across the retrospective cohort studies, treatment of AWS with phenobarbital resulted in lower odds of a subsequent ED visit. The retrospective chart reviews indicated that phenobarbital was associated with higher discharge rate compared to benzodiazepine-only treatments. For the two RCTs, phenobarbital did not differ significantly from benzodiazepine for most outcomes, although concomitant treatment with phenobarbital was associated with lower benzodiazepine use and intensive care unit admission. The heterogeneous designs and small number of studies prevented quantitative synthesis.

CONCLUSIONS

Relatively few studies provide direct evidence on the utility of phenobarbital for AWS in the ED, but the evidence that exists generally suggests that it is a reasonable and appropriate approach. Additional RCTs and other methodologically rigorous investigations are needed for more definitive direct evidence.

Pharmacological pain and sedation interventions for the prevention of intraventricular hemorrhage in preterm infants on assisted ventilation - an overview of systematic reviews

BACKGROUND

Germinal matrix hemorrhage and intraventricular hemorrhage (GMH-IVH) may contribute to neonatal morbidity and mortality and result in long-term neurodevelopmental sequelae. Appropriate pain and sedation management in ventilated preterm infants may decrease the risk of GMH-IVH; however, it might be associated with harms.

OBJECTIVES

To summarize the evidence from systematic reviews regarding the effects and safety of pharmacological interventions related to pain and sedation management in order to prevent GMH-IVH in ventilated preterm infants.

METHODS

We searched the Cochrane Library August 2022 for reviews on pharmacological interventions for pain and sedation management to prevent GMH-IVH in ventilated preterm infants (< 37 weeks' gestation). We included Cochrane Reviews assessing the following interventions administered within the first week of life: benzodiazepines, paracetamol, opioids, ibuprofen, anesthetics, barbiturates, and antiadrenergics. Primary outcomes were any GMH-IVH (aGMH-IVH), severe IVH (sIVH), all-cause neonatal death (ACND), and major neurodevelopmental disability (MND). We assessed the methodological quality of included reviews using the AMSTAR-2 tool. We used GRADE to assess the certainty of evidence.

MAIN RESULTS

We included seven Cochrane Reviews and one Cochrane Review protocol. The reviews on clonidine and paracetamol did not include randomized controlled trials (RCTs) matching our inclusion criteria. We included 40 RCTs (3791 infants) from reviews on paracetamol for patent ductus arteriosus (3), midazolam (3), phenobarbital (9), opioids (20), and ibuprofen (5). The quality of the included reviews was high. The certainty of the evidence was moderate to very low, because of serious imprecision and study limitations. Germinal matrix hemorrhage-intraventricular hemorrhage (any grade) Compared to placebo or no intervention, the evidence is very uncertain about the effects of paracetamol on aGMH-IVH (risk ratio (RR) 0.89, 95% confidence interval (CI) 0.38 to 2.07; 2 RCTs, 82 infants; very low-certainty evidence); midazolam may result in little to no difference in the incidence of aGMH-IVH (RR 1.68, 95% CI 0.87 to 3.24; 3 RCTs, 122 infants; low-certainty evidence); the evidence is very uncertain about the effect of phenobarbital on aGMH-IVH (RR 0.99, 95% CI 0.83 to 1.19; 9 RCTs, 732 infants; very low-certainty evidence); opioids may result in little to no difference in aGMH-IVH (RR 0.85, 95% CI 0.65 to 1.12; 7 RCTs, 469 infants; low-certainty evidence); ibuprofen likely results in little to no difference in aGMH-IVH (RR 0.99, 95% CI 0.81 to 1.21; 4 RCTs, 759 infants; moderate-certainty evidence). Compared to ibuprofen, the evidence is very uncertain about the effects of paracetamol on aGMH-IVH (RR 1.17, 95% CI 0.31 to 4.34; 1 RCT, 30 infants; very low-certainty evidence). Compared to midazolam, morphine may result in a reduction in aGMH-IVH (RR 0.28, 95% CI 0.09 to 0.87; 1 RCT, 46 infants; low-certainty evidence). Compared to diamorphine, the evidence is very uncertain about the effect of morphine on aGMH-IVH (RR 0.65, 95% CI 0.40 to 1.07; 1 RCT, 88 infants; very low-certainty evidence). Severe intraventricular hemorrhage (grade 3 to 4) Compared to placebo or no intervention, the evidence is very uncertain about the effect of paracetamol on sIVH (RR 1.80, 95% CI 0.43 to 7.49; 2 RCTs, 82 infants; very low-certainty evidence) and of phenobarbital (grade 3 to 4) (RR 0.91, 95% CI 0.66 to 1.25; 9 RCTs, 732 infants; very low-certainty evidence); opioids may result in little to no difference in sIVH (grade 3 to 4) (RR 0.98, 95% CI 0.71 to 1.34; 6 RCTs, 1299 infants; low-certainty evidence); ibuprofen may result in little to no difference in sIVH (grade 3 to 4) (RR 0.82, 95% CI 0.54 to 1.26; 4 RCTs, 747 infants; low-certainty evidence). No studies on midazolam reported this outcome. Compared to ibuprofen, the evidence is very uncertain about the effects of paracetamol on sIVH (RR 2.65, 95% CI 0.12 to 60.21; 1 RCT, 30 infants; very low-certainty evidence). Compared to midazolam, the evidence is very uncertain about the effect of morphine on sIVH (grade 3 to 4) (RR 0.08, 95% CI 0.00 to 1.43; 1 RCT, 46 infants; very low-certainty evidence). Compared to fentanyl, the evidence is very uncertain about the effect of morphine on sIVH (grade 3 to 4) (RR 0.59, 95% CI 0.18 to 1.95; 1 RCT, 163 infants; very low-certainty evidence). All-cause neonatal death Compared to placebo or no intervention, the evidence is very uncertain about the effect of phenobarbital on ACND (RR 0.94, 95% CI 0.51 to 1.72; 3 RCTs, 203 infants; very low-certainty evidence); opioids likely result in little to no difference in ACND (RR 1.12, 95% CI 0.80 to 1.55; 5 RCTs, 1189 infants; moderate-certainty evidence); the evidence is very uncertain about the effect of ibuprofen on ACND (RR 1.00, 95% CI 0.38 to 2.64; 2 RCTs, 112 infants; very low-certainty evidence). Compared to midazolam, the evidence is very uncertain about the effect of morphine on ACND (RR 0.31, 95% CI 0.01 to 7.16; 1 RCT, 46 infants; very low-certainty evidence). Compared to diamorphine, the evidence is very uncertain about the effect of morphine on ACND (RR 1.17, 95% CI 0.43 to 3.19; 1 RCT, 88 infants; very low-certainty evidence). Major neurodevelopmental disability Compared to placebo, the evidence is very uncertain about the effect of opioids on MND at 18 to 24 months (RR 2.00, 95% CI 0.39 to 10.29; 1 RCT, 78 infants; very low-certainty evidence) and at five to six years (RR 1.6, 95% CI 0.56 to 4.56; 1 RCT, 95 infants; very low-certainty evidence). No studies on other drugs reported this outcome.

AUTHORS' CONCLUSIONS

None of the reported studies had an impact on aGMH-IVH, sIVH, ACND, or MND. The certainty of the evidence ranged from moderate to very low. Large RCTs of rigorous methodology are needed to achieve an optimal information size to assess the effects of pharmacological interventions for pain and sedation management for the prevention of GMH-IVH and mortality in preterm infants. Studies might compare interventions against either placebo or other drugs. Reporting of the outcome data should include the assessment of GMH-IVH and long-term neurodevelopment.

Neonatal Abstinence Syndrome: A Review of Treatment in the Neonatal Intensive Care Unit

Background

Neonatal abstinence syndrome (NAS) is a collection of symptoms that neonates may experience following antenatal exposure to substances that induce withdrawal. Optimal management remains unknown, and there is variation in management and outcomes.

Objectives

To describe the management, length of hospitalization, and adverse events in near-term and full-term neonates with NAS for whom treatment (pharmacotherapy and/or supportive care) was initiated in the neonatal intensive care unit (NICU).

Methods

A chart review was conducted of neonates admitted to the NICU of Surrey Memorial Hospital, Surrey, British Columbia, who received treatment for NAS between September 1, 2016, and September 1, 2021.

Results

A total of 48 neonates met the inclusion criteria. Opioids represented the most frequent type of antenatal exposure. Polysubstance exposures occurred in 45 (94%) of the neonates. Morphine was given to 29 (60%) of the neonates, and phenobarbital to 6 (13%); 5 of these neonates received both medications. The average duration of morphine treatment was 14 days, and the average length of hospitalization (all patients) was 16 days. All of the neonates experienced adverse events; in particular, 9 (30%) of the 30 who received pharmacotherapy were too sedated to feed, compared with 0% of the 18 with no pharmacotherapy.

Conclusions

The common finding of polysubstance antenatal exposure, involving predominantly opioids, was associated with scheduled morphine pharmacotherapy for the majority of patients, prolonged hospitalization, and frequent adverse events. Pharmacotherapy for NAS was associated with levels of sedation that interfered with feeding in neonates.

Phenobarbital for alcohol withdrawal in the context of the opioid epidemic: a neglected caveat

Phenobarbital interacts with the mortality-reducing opioid agonist therapies buprenorphine and methadone, risking delayed opioid withdrawal and relapse when administered concurrently. With increased adoption of phenobarbital into alcohol withdrawal protocols there should be safeguards in place to—in most cases—avoid phenobarbital for patients with a concurrent opioid use disorder.

Case report: Fatal poisoning caused by additive effects of two barbiturates

A case of fatal poisoning involving multiple psychotropic drugs is presented. Quantitative toxicological analysis showed femoral blood concentrations of pentobarbital, phenobarbital, duloxetine, acetaminophen and tramadol were 10.39, 22.57, 0.22, 0.61 and 0.22 μg/ml, respectively. We concluded that the death was due to the additive effects of two barbiturates. As both pentobarbital and phenobarbital act on gamma-aminobutyric acid (GABA) receptors, central nervous system activity was suppressed, causing respiratory depression. Additive pharmacological effects should be considered in cases of massive ingestion of multiple drugs.

Early diagnosis of neonatal-onset cyclic vomiting syndrome

Cyclic vomiting syndrome (CVS) is characterized by recurrent episodes of severe vomiting with a completely asymptomatic interictal interval. Relatively few patients develop CVS in the neonatal period, and an early diagnosis is difficult. We experienced an infant who was diagnosed with neonatal-onset CVS in early infancy. An 8-day-old girl was admitted to our neonatal intensive care unit because of frequent vomiting beginning 12 h after birth and weight loss reaching 84.2% of her birth weight. Despite extensive examinations, no abnormalities to explain the vomiting were found. She continued to vomit, and a cyclical pattern with a vomiting phase lasting for three days followed by a non-vomiting phase lasting for about one to two weeks became obvious. Based on her clinical course, the family history of migraine and the effectiveness of Phenobarbital, she was diagnosed with CVS at three months old. Although CVS is a diagnosis of exclusion, a family history of migraine can aid its early diagnosis. If the illness is suspected in the neonatal period, diagnostic treatment with Phenobarbital may be considered. The case suggests the need to include CVS in the differential diagnosis of neonates with unexplained repetitive vomiting.

Navigating the Complexities of Intraventricular Hemorrhage in Preterm Infants: An Updated Review

Intraventricular hemorrhage (IVH) is a type of bleeding that occurs in the ventricular cavity of the brain. In this comprehensive study, we provide a summary of the pathogenesis, diagnosis, and treatment of intraventricular hemorrhage in premature infants. Preterm babies are at high risk of developing IVH because their germinal matrix is not fully developed, making their blood vessels more prone to rupture. However, that is not necessarily the case in all preterm babies as the inherent structure of the germinal matrix makes it more susceptible to hemorrhage. Incidences of IVH are discussed based on recent data which states that around 12,000 premature infants in the United States experience IVH each year. Although grades I and II make up the majority of IVH cases and are frequently asymptomatic, IVH remains a significant issue for premature infants in neonatal intensive care facilities worldwide. Grades I and II have been linked to mutations in the type IV procollagen gene, COL4A1, as well as prothrombin G20210A and factor V Leiden mutations. Intraventricular hemorrhage can be detected using brain imaging in the first seven to 14 days following delivery. This review also shines a light on reliable methods for identifying IVH in premature newborns like cranial ultrasound and magnetic resonance imaging along with the treatment of IVH which is primarily supportive and involves the management of intracranial pressure, the correction of coagulation abnormalities, and the prevention of seizures.

Phenobarbital-Based Protocol for Alcohol Withdrawal Syndrome in a Medical ICU: Pre-Post Implementation Study

We assessed the efficacy and safety of PB compared with benzodiazepine (BZD)-based protocols in treating AWS in MICU.

DESIGN

Single-center, pre-post protocol implementation study.

SETTING

The setting is a forty-bed MICU in a tertiary-level academic medical center.

PATIENTS

We included all patients admitted to the MICU with a primary diagnosis of AWS.

INTERVENTIONS

Intravenous PB 260 mg followed by 130-mg doses every 15-30 minutes as needed up to 15 mg/kg of ideal body weight versus escalating doses of BZD, to achieve a Clinical Institute Withdrawal Assessment Alcohol Scale-Revised score less than 10.

MEASUREMENTS AND MAIN RESULTS

ICU and hospital length of stay (LOS), in addition to safety measures were the main outcomes of the study. A total of 102 patients were included, 51 in the PB arm and 51 in the BZD arm. There were no differences in baseline clinical characteristics. Half the patients in each group were admitted with delirium tremens. The use of PB-based protocol was associated with 35% reduction in median ICU LOS (1.5 d [interquartile range, 1.2-2.4 d] vs 2.3 d [1.4-4.8 d]; p = 0.009) and 50% reduction in hospital LOS (3 d [2.7-4 d] vs 6 d [4-10 d]; p < 0.001). After adjustment for comorbidities and clinical factors, PB protocol decreased ICU LOS days by 40% (95% CI; 25.8-53.5%). PB group required fewer adjunctive medications to control symptoms (0.7 [0.5-1] vs 2.5 [2-3]; p < 0.001), less need for intubation (1/51 [2%] vs 10/10 [19.6%]; p = 0.023) and less need for physical restraint (19/51 [37.3%] vs 29/51 [56.9%]; p = 0.047), compared with the BZD group.

CONCLUSIONS

A protocol utilizing rapidly escalating doses of PB over a short period is an effective and safe alternative to BZD in treating AWS in MICU.

Disposable Sensor Chips with Molecularly Imprinted Carbon Paste Electrodes for Monitoring Anti-Epileptic Drugs

Epilepsy is a neurological disorder that affects millions of people worldwide. Anti-epileptic drugs (AEDs) are critical for their management. However, the therapeutic window is narrow, and traditional laboratory-based therapeutic drug monitoring (TDM) methods can be time consuming and unsuitable for point-of-care testing. To address this issue, we developed a disposable sensor chip based on molecularly imprinted polymer-modified carbon paste electrodes (MIP-CPs) for the TDM of AEDs such as phenobarbital (PB), carbamazepine (CBZ), and levetiracetam (LEV). In this work, functional monomers (methacrylic acid) and crosslinking monomers (methylene bisacrylamide and ethylene glycol dimethacrylate) were copolymerized in the presence of the AED template and grafted on the graphite particles by simple radical photopolymerization. The grafted particles were mixed with silicon oil, dissolving ferrocene as a redox marker to make the MIP-carbon paste (CP). Disposable sensor chips were fabricated by packing the MIP-CP into the base made of poly (ethylene glycol terephthalate) (PET) film. The sensor's sensitivity was determined using differential pulse voltammetry (DPV), carried out on a single sensor chip for each operation. Linearity was obtained from 0-60 μg/mL in PB and LEV and 0-12 μg/mL in CBZ, covering their respective therapeutic range. The time taken for each measurement was around 2 min. The experiment using whole bovine blood and bovine plasma indicated that the existence of species that interfered had a negligible effect on the test's sensitivity. This disposable MIP sensor provides a promising approach for point-of-care testing and facilitating the management of epilepsy. Compared with existing tests, this sensor offers a faster and more accurate way to monitor AEDs, which is crucial for optimizing therapy and improving patient outcomes. Overall, the proposed disposable sensor chip based on MIP-CPs represents a significant advancement in AED monitoring, with the potential for rapid, accurate, and convenient point-of-care testing.

Frontline Sodium Channel-Blocking Antiseizure Medicine Use Promotes Future Onset of Drug-Resistant Chronic Seizures

The mechanisms of treatment-resistant epilepsy remain unclear. We have previously shown that frontline administration of therapeutic doses of lamotrigine (LTG), which preferentially inhibits the fast-inactivation state of sodium channels, during corneal kindling of mice promotes cross-resistance to several other antiseizure medicines (ASMs). However, whether this phenomenon extends to monotherapy with ASMs that stabilize the slow inactivation state of sodium channels is unknown. Therefore, this study assessed whether lacosamide (LCM) monotherapy during corneal kindling would promote future development of drug-resistant focal seizures in mice. Male CF-1 mice (n = 40/group; 18-25 g) were administered an anticonvulsant dose of LCM (4.5 mg/kg, i.p.), LTG (8.5 mg/kg, i.p.), or vehicle (0.5% methylcellulose) twice daily for two weeks during kindling. A subset of mice (n = 10/group) were euthanized one day after kindling for immunohistochemical assessment of astrogliosis, neurogenesis, and neuropathology. The dose-related antiseizure efficacy of distinct ASMs, including LTG, LCM, carbamazepine, levetiracetam, gabapentin, perampanel, valproic acid, phenobarbital, and topiramate, was then assessed in the remaining kindled mice. Neither LCM nor LTG administration prevented kindling: 29/39 vehicle-exposed mice were kindled; 33/40 LTG-exposed mice were kindled; and 31/40 LCM-exposed mice were kindled. Mice administered LCM or LTG during kindling became resistant to escalating doses of LCM, LTG, and carbamazepine. Perampanel, valproic acid, and phenobarbital were less potent in LTG- and LCM-kindled mice, whereas levetiracetam and gabapentin retained equivalent potency across groups. Notable differences in reactive gliosis and neurogenesis were also appreciated. This study indicates that early, repeated administration of sodium channel-blocking ASMs, regardless of inactivation state preference, promotes pharmacoresistant chronic seizures. Inappropriate ASM monotherapy in newly diagnosed epilepsy may thus be one driver of future drug resistance, with resistance being highly ASM class specific.

Evaluation of Dexmedetomidine as an Adjunct to Phenobarbital for Alcohol Withdrawal in Critically Ill Patients

INTRODUCTION

Dexmedetomidine (DEX) is commonly used with benzodiazepines for the management of alcohol withdrawal syndrome (AWS), but limited data exist regarding its use with phenobarbital (PHB). This analysis evaluated the utility of DEX in addition to PHB for AWS in adult patients admitted to the intensive care unit (ICU).

METHODS

This was a single-center, retrospective cohort analysis of critically ill adult patients who received PHB plus either DEX or different adjunctive therapies (NO-DEX) for AWS between 2018 and 2021. Patients were excluded if they had underlying altered mental status or seizure disorder unrelated to AWS or received PHB at outside hospitals. Coarsened exact matching (CEM) was performed to match patients on baseline characteristics in a 1:1 ratio. The primary outcome was ICU length of stay (LOS). A multivariate linear regression analysis was performed to assess the effects of DEX on ICU LOS when accounting for confounders. Secondary outcomes included days with delirium and incidence of mechanical ventilation after PHB administration.

RESULTS

Of the 606 encounters evaluated, 197 met criteria for inclusion. After CEM, 56 encounters remained in each group for analysis. The median ICU LOS was 97.2 [50.1:139.5] hours for the DEX group and 47.5 [28.8:88.1] hours for the NO-DEX group (P = .002). The multivariate linear regression analysis showed the use of DEX (P = .008) was independently associated with an increased ICU LOS by 49.8 h. The DEX group had higher rates of total delirium days (208 vs 143 days, P < .001) and a higher incidence of mechanical ventilation after PHB administration (32% vs 9%, P < .001).

CONCLUSION

This analysis suggests the use of adjunctive DEX with PHB for AWS was associated with a prolonged ICU LOS. Additional studies are needed to further understand the role of adjunctive DEX in the treatment of AWS in critically ill patients.

Biochemical Pilot Study on Effects of Pomegranate Seed Oil Extract and Cosmetic Cream on Neurologically Mediated Skin Inflammation in Animals and Humans: A Comparative Observational Study

The presence of phenobarbital and formaldehyde in drugs, food, and beverages can lead to various health issues, including inflammation, oncogenesis, and neurological distress. Psychological stress leads to mood fluctuations and the onset of skin inflammation. Skin inflammation has a range of causes, including chemicals, heavy metals, infection, immune-related disorders, genetics, and stress. The various treatments for skin inflammation include medical and cosmetic creams, diet changes, and herbal therapy. In this study, we investigated the effects of Avocom-M and pomegranate seed oil extract (PSOE) against phenobarbital- and formaldehyde-induced skin biochemical changes in rats. We analyzed the constituents of PSOE using gas chromatography-mass spectrometry and inductively coupled plasma-mass spectrometry. We also observed biochemical changes in the skin of human volunteers with and without TROSYD and PSOE as a skin cream. We compared the biochemical changes in human volunteers' skin before treatment and 21 days after the treatment stopped. The outcomes showed an improvement in the rats' biochemical status, due to PSOE and Avocom-M treatment. The human volunteers treated with TROSYD and PSOE showed substantial amelioration of skin inflammation. PSOE, Avocom-M, and TROSYD produced beneficial effects by reducing the levels of cyclooxygenase-2, lipid peroxidation, tyrosinase, hyaluronidase, elastase, collagenase, and nitric oxide in the animals tested on and in human volunteers.

Altered Pharmacological Efficacy of Phenobarbital with the Treatment of 7,8-Dihydroxyflavone, an Agonist of Tropomyosin Receptor Kinase B, in Rats

From our previous observation that the anesthetic effects of phenobarbital potentiate in rats with a decreased cerebral protein expression of the potassium chloride cotransporter KCC2 (SLC12A5), an in vivo study was conducted to clarify whether the pharmacological effect of phenobarbital alters by stimulating the cerebral tropomyosin receptor kinase B (TrkB) that is known to down-regulate the KCC2 protein expression. The stimulation was performed in rats with repetitious intraperitoneal administration of a TrkB agonist, namely 7,8-dihydroxyflavone (DHF). After that, the rats underwent an intraventricular infusion of phenobarbital using a dwelled cannula, and the onset time of the phenobarbital-induced general anesthesia was determined. In addition, their brain tissues were excised and cerebral cortices were collected. Then, subcellular fractions were prepared and the cerebral expression of various proteins involving the anesthetic effects of phenobarbital was examined. It was demonstrated that phenobarbital induced general anesthesia about 2 times faster in rats receiving the DHF treatment than in control rats, and that the phenobarbital amount in the brain tissue at the onset time of anesthesia was lower in rats with the treatment. Western blotting showed that the cerebral protein expression of KCC2 decreases, and the phosphorylation of the TrkB protein increases with the DHF treatment. These observations indicate that the anesthetic effects of phenobarbital potentiate with the TrkB stimulation and the resultant decrease in the cerebral KCC2 protein expression. The results also suggest that the TrkB protein and its phosphorylation status may be a key modulator of the pharmacological efficacy of phenobarbital.

Barbiturates and pyrazolopyridines for the treatment of postpartum depression-repurposing of two drug classes

Zulresso (brexanolone) is an aqueous formulation of the neurosteroid, allopregnanolone, and the only FDA-approved medication for the treatment of postpartum depression (PPD). While brexanolone is effective for the treatment of PPD, lengthy infusion time and high cost can be prohibitive. Failure of GABA_A receptors to adapt to fluctuating neurosteroid levels is considered to predispose women to mood disorders in the postpartum period. Brexanolone is thought to act via stimulation of δ subunit-containing GABA_A receptors, which are extrasynaptic and localized to particular brain regions. Neurosteroid stimulation of δ subunit-containing GABA_A receptors leads to sustained inhibition (hyperpolarization) of GABAergic neurons, which makes δ subunit-containing GABA_A receptors a potentially important pharmacologic target. Barbiturates and pyrazolopyridines are potent stimulators of δ subunit-containing GABA_A receptors and therefore potentially cost-effective treatments for PPD. Barbiturates are often not prescribed, owing to risk of dependence and respiratory depression. The pyrazolopyridines were tested several decades ago for anxiety and depression but never developed commercially. Herein we use the FDA-approved dosing schedule of brexanolone and GABA_A receptor binding data from various animal models to examine the safety, efficacy, and potential clinical utility of barbiturates and pyrazolopyridines for the treatment of PPD. We suggest consideration of repurposing barbiturates and pyrazolopyridines as safe and readily available treatment alternatives for PPD.

Phenobarbital to manage severe gamma-hydroxybutyrate withdrawal: A case series

INTRODUCTION

Management of a withdrawal syndrome following cessation of regular gamma-hydroxybutyrate (GHB) use, and its precursors, can represent a clinical challenge due to rapid onset delirium and/or seizures. Severe GHB withdrawal can be characterised by persistent or worsening features despite increasing benzodiazepine doses and regular baclofen. Barbiturates, such as phenobarbital, are an appealing option in this context due to their unique GABA-A receptor action.

CASE SERIES

This series describes the use of phenobarbital in 13 cases, 12 patients, across two hospitals in Sydney, Australia, with persistent or progressive GHB withdrawal despite benzodiazepine-based management. A median cumulative dose of oral diazepam prior to commencing phenobarbital was 120 mg (range 80-255 mg). The median time from the last GHB use to the first dose of phenobarbital was 24 h (range 7-57 h). Eight cases received phenobarbital orally on a general ward and 5 intravenously in intensive care units. An improvement in GHB withdrawal symptoms was observed after phenobarbital in all cases and there were no adverse events related to phenobarbital.

DISCUSSION AND CONCLUSION

This case series suggests that phenobarbital for the management of benzodiazepine-resistant GHB withdrawal can be safe, even in general inpatient settings, and may avert the progression of delirium. Most data on the management of GHB withdrawal comes from case reports or series, such as this one. This highlights the need for prospective trials to establish an evidence base for therapeutic approaches, including validated measures of withdrawal severity and more information relating to the safe and effective dosing of phenobarbital.

Radiotherapy of the Hepatocellular Carcinoma in Mice Has a Time-Of-Day-Dependent Impact on the Mouse Hippocampus

Chronic liver diseases including hepatocellular carcinoma (HCC) create a state of chronic inflammation that affects the brain via the liver-brain axis leading to an alteration of neurotransmission and cognition. However, little is known about the effects of HCC on the hippocampus, the key brain region for learning and memory. Moreover, radiotherapy used to treat HCC has severe side effects that impair patients' life quality. Thus, designing optimal strategies, such as chronotherapy, to enhance the efficacy and reduce the side effects of HCC treatment is critically important. We addressed the effects of HCC and the timed administration of radiotherapy in mice on the expression of pro-inflammatory cytokines, clock genes, markers for glial activation, oxidative stress, neuronal activity and proliferation in the hippocampal neurogenic niche. Our data showed that HCC induced the upregulation of genes encoding for pro-inflammatory cytokines, altered clock gene expressions and reduced proliferation in the hippocampus. Radiotherapy, in particular when applied during the light/inactive phase enhanced all these effects in addition to glial activation, increased oxidative stress, decreased neuronal activity and increased levels of phospho(p)-ERK. Our results suggested an interaction of the circadian molecular clockwork and the brain's innate immune system as key players in liver-brain crosstalk in HCC and that radiotherapy when applied during the light/inactive phase induced the most profound alterations in the hippocampus.

The effect of nonadherence on phenobarbital concentrations and recommendations on the replacement dose using Monte Carlo simulation

OBJECTIVES

To determine the impacts of missed phenobarbital (PB) doses on its pharmacokinetics and to investigate the appropriate replacement dosing scheme for various PB missed dose scenarios.

METHODS

Monte Carlo simulations were performed using parameters from the selected population pharmacokinetic study. The impacts of missed PB dose and the proper replacement dosing scheme were assessed based on the percent deviation of simulated concentrations outside the reference range from the full adherence scenario.

RESULTS

The impact of missed PB dose on its concentrations depended on the daily dose. The replacement with a respective regular dose and one and a half regular dose was appropriate for the one and two missed doses scenarios for patients receiving PB monotherapy. For patients receiving PB with valproic acid or phenytoin, the same replacement scheme was still appropriate. The results also indicated that weight did not influence the proper replacement dosing scheme.

CONCLUSIONS

The impacts of missed PB doses on its pharmacokinetics were identified and the proper replacement dosing schemes for different missed dose scenarios were proposed. These schemes should be implemented based on the clinician's justification of the patient's seizure control.

Lacosamide decreases neonatal seizures without increasing apoptosis

OBJECTIVE

Many seizing neonates fail to respond to first-line anticonvulsant medications. Phenobarbital, an allosteric modulator of γ-aminobutyric acid type A (GABA_A ) receptors, has low efficacy in treating neonatal seizures and causes neuronal apoptosis. Nonetheless, it is one of the most used anticonvulsants in this age group. In neonatal mice, phenobarbital's poor effectiveness is due in part to high intraneuronal chloride concentration, which causes GABA to exert depolarizing actions. Therefore, another approach to treat neonatal seizures could be to use anticonvulsants that do not rely on GABAergic modulation. We evaluated whether lacosamide decreases seizures in neonatal mice and whether it increases apoptosis in vitro and in vivo.

METHODS

In vitro, we measured the effect of different lacosamide concentrations on seizure-like activity induced by the pro-convulsant drug 4-aminopyridine in neocortical brain slices (layer IV/V) from neonatal (postnatal day 8-11) and adult (1-1.6 months old) C57BL/6J mice. In vivo, we recorded the effect of different lacosamide concentrations on neonatal behavioral seizures induced by kainic acid. We studied neocortical apoptosis in vitro and in vivo, measuring terminal deoxynucleotidyl transferase (TdT) dUTP nick-end labeling signal and cleaved-caspase 3.

RESULTS

Lacosamide reduced epileptiform activity in neocortical brain slices of neonates and adults in a concentration-dependent manner. In vivo, lacosamide reduced the duration and number of behavioral seizures. Lacosamide did not increase total or neuronal apoptosis in the neocortex in vitro or in vivo.

SIGNIFICANCE

Lacosamide reduces neocortical seizure-like activity in neonatal mice in vitro and in vivo without an acute increase in apoptosis. Our results support the use of lacosamide to treat neonatal seizures, with the advantage of not increasing apoptosis acutely.

Electropolymerization of Metallo-Octaethylporphyrins: A Study to Explore Their Sensing Capabilities

The electropolymerization of metallo-octaethylporphyrins (OEP) containing copper, zinc or nickel metal were performed using cyclic voltammetry at three different potential ranges. The electropolymerized porphyrins were characterized by UV-Vis and Raman spectroscopies and the Soret band (393-445 nm) and Raman bands were used to assess the degree of electropolymerization obtained. The application for an analytical use of the modified electrodes to determine phenobarbital in aqueous solution was evaluated. The electropolymerized CuOEP produced at potentials ranging from 0.0 to 2.2 V was the best performer with a limit of detection (LoD) of 10 mg L^-1 (43.07 µM), a linear range of 10-150 mg L^-1 (43.07 to 646 µM), an average precision of 4.3% (%RSD) and an average % recovery of 101.34%. These results indicate that the CuOEP-modified electrode is suitable for the analysis of phenobarbital in human samples, as the concentration range varies from 10 to 40 mg L^-1 (43.07 to 172.27 µM), typically found in antiepileptic treatments, to those at the toxic level (172-258 µM) or lethal levels (345-650 µM).

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.

A novel 3D printed device with conductive elements for electromembrane extraction combined with HPLC and UV detector

This paper is focused on proposing for a new design and setup for electromembrane extraction. A new cap was designed and conductive vials of different shape were fabricated using three-dimensional printing. The new cap holds three fibers to enhance electromembrane extraction recovery. Conductive vials can simultaneously perform as electrodes therefore, there is no need to include an electrode in sample solutions. Phenobarbital and phenytoin were used as model compounds to assess the setup performance. Under optimal conditions, these analytes were extracted from the sample solution at pH = 9 to the acceptor solution at pH = 13 with a voltage of 40 V for 20 min, while 1-octanol was employed as the supported-liquid-membrane. The influence of conductive vials geometry on the recovery was examined and effects of different shapes were studied by performing numerical simulation to establish electric potential distribution. Of the vials tested with circular, triangular and floral-like cross-sections the latter exhibited the best voltage distribution. The circular vial had the highest recovery attributed to its better hydrodynamic shape, which allows rapid fluid sample transport and therefore enhanced system recovery. The extraction recovery and RSD of circular vial with three fibers was 33.0 and 7.6 for phenobarbital and 42.2 and 10.4 for phenytoin. This article is protected by copyright. All rights reserved.

The effect of nonadherence on phenobarbital concentrations and recommendations on the replacement dose using Monte Carlo simulation

OBJECTIVES

To determine the impacts of missed phenobarbital (PB) doses on its pharmacokinetics and to investigate the appropriate replacement dosing scheme for various PB missed dose scenarios.

METHODS

Monte Carlo simulations were performed using parameters from the selected population pharmacokinetic study. The impacts of missed PB dose and the proper replacement dosing scheme were assessed based on the percent deviation of simulated concentrations outside the reference range from the full adherence scenario.

RESULTS

The impact of missed PB dose on its concentrations depended on the daily dose. The replacement with a respective regular dose and one and a half regular dose was appropriate for the one and two missed doses scenarios for patients receiving PB monotherapy. For patients receiving PB with valproic acid or phenytoin, the same replacement scheme was still appropriate. The results also indicated that weight did not influence the proper replacement dosing scheme.

CONCLUSIONS

The impacts of missed PB doses on its pharmacokinetics were identified and the proper replacement dosing schemes for different missed dose scenarios were proposed. These schemes should be implemented based on the clinician's justification of the patient's seizure control.

Induction by Phenobarbital of Phase I and II Xenobiotic-Metabolizing Enzymes in Bovine Liver: An Overall Catalytic and Immunochemical Characterization

In cattle, phenobarbital (PB) upregulates target drug-metabolizing enzyme (DME) mRNA levels. However, few data about PB's post-transcriptional effects are actually available. This work provides the first, and an almost complete, characterization of PB-dependent changes in DME catalytic activities in bovine liver using common probe substrates and confirmatory immunoblotting investigations. As expected, PB increased the total cytochrome P450 (CYP) content and the extent of metyrapone binding; moreover, an augmentation of protein amounts and related enzyme activities was observed for known PB targets such as CYP2B, 2C, and 3A, but also CYP2E1. However, contradictory results were obtained for CYP1A, while a decreased catalytic activity was observed for flavin-containing monooxygenases 1 and 3. The barbiturate had no effect on the chosen hydrolytic and conjugative DMEs. For the first time, we also measured the 26S proteasome activity, and the increase observed in PB-treated cattle would suggest this post-translational event might contribute to cattle DME regulation. Overall, this study increased the knowledge of cattle hepatic drug metabolism, and further confirmed the presence of species differences in DME expression and activity between cattle, humans, and rodents. This reinforced the need for an extensive characterization and understanding of comparative molecular mechanisms involved in expression, regulation, and function of DMEs.

Impact of neonatal activation of nuclear receptor CAR (Nr1i3) on Cyp2 gene expression in adult mouse liver

Perinatal exposure to environmental chemicals is proposed to reprogram development and alter disease susceptibility later in life. Supporting this, neonatal activation of the nuclear receptor CAR (Nr1i3) by TCPOBOP induces persistent expression of mouse hepatic Cyp2 genes into adulthood, attributed to long-term epigenetic memory of the early life exposure [Hepatology (2012) 56:1499-1509]. Here, we confirm that the same high-dose (15x ED50) neonatal TCPOBOP exposure used in that work induces prolonged (12 weeks) increases in hepatic Cyp2 expression; however, we show that the persistence of expression can be fully explained by the persistence of residual TCPOBOP in liver tissue. When the long-term presence of TCPOBOP in tissue was eliminated by decreasing the neonatal TCPOBOP dose 22-fold (0.67x ED50), strong neonatal increases in hepatic Cyp2 expression were still obtained but did not persist into adulthood. Furthermore, the neonatal ED50-range TCPOBOP exposure did not sensitize mice to a subsequent, low-dose TCPOBOP treatment. In contrast, neonatal treatment with phenobarbital, a short half-life (t1/2=8 h) agonist of CAR and of PXR (Nr1i2), induced high-level neonatal activation of Cyp2 genes and also altered their responsiveness to low-dose phenobarbital exposure at adulthood by either increasing (Cyp2b10) or decreasing (Cyp2c55) expression. Thus, neonatal xenobiotic exposure can reprogram hepatic Cyp2 genes and alter their responsiveness to exposures later in life. These findings highlight the need to carefully consider xenobiotic dose, half-life and persistence in tissue when evaluating the long-term effects of early life environmental chemical exposures.

Efficacy of Phenobarbital and Prognosis Predictors in Women With Epilepsy From Rural Northeast China: A 10-Year Follow-Up Study

Objective

To investigate the efficacy of phenobarbital (PB), factors associated with it, reasons for early treatment termination, and mortality rates in adult women living in rural Northeast China.

Methods

A prospective study was conducted in seven counties of Jilin Province from 2010 to 2020. Adult women diagnosed with convulsive epilepsy were recruited into the study and baseline demographics recorded upon enrollment. Seizure frequency, prescribed drug dose, and adverse reactions were monitored monthly by door-to-door survey or telephone interview.

Results

A total of 1,333 women were included in the study. During the follow-up period, 169 participants (12.7%) were lost to follow-up, and 100 of them (7.5%) died. The percentage of seizure-free participants was 45.3% in the first year, 74.6% in the third year, and 96.6% in the 10th year. A higher baseline seizure frequency (OR = 1.005, 95% CI: 1.002–1.009), more frequent loss-of-consciousness seizures (OR = 1.620, 95% CI: 1.318–1.990), a higher daily dose of PB in the first year (OR = 1.018, 95% CI: 1.014–1.022), a younger age at onset (OR = 0.990, 95% CI: 0.982–0.998), and more severe drowsiness (OR = 1.727, 95% CI: 1.374–2.173) were associated with an increased risk of seizures in the first year, and the higher baseline seizure frequency was still associated with the occurrence of seizures in the third (OR = 1.007, 95% CI: 1.004–1.010) and fifth year (OR = 1.005, 95% CI: 1.002–1.008). Age at enrollment (HR = 0.983, 95% CI: 0.971–0.994) was the only factor that correlated with withdrawal from the study and with the death of the participant during the follow up period, but the correlation in each case was in opposite directions.

Significance

PB has high effectiveness, retention rate, mild side effects, and tolerability when used as a treatment for epilepsy in women from rural areas. Baseline seizure frequency is an important predictor of prognosis regardless of treatment duration. PB is still a valuable tool for the management of epilepsy in adult women from poverty-stricken areas.