Phenobarbital in Status epilepticus - Rediscovery of an effective drug

Clinical characteristics and treatment approach of established New-Onset status epilepticus (eNOSE): A Real-World multicenter experience

INTRODUCTION

Status Epilepticus (SE) can occur in patients without a previous epilepsy diagnosis, a condition identified as "new-onset status epilepticus" (NOSE). Treatment with benzodiazepine may fail in NOSE termination, requiring anti-seizure medication (ASM) employment. The term "established NOSE" (eNOSE) is generally employed in this context. This study aims to describe the main clinical characteristics of a large sample of patients suffering from eNOSE, compare the ASM efficacy, and explore the risk factors associated with ASM treatment unresponsiveness and eNOSE-associated mortality.

METHODS

Adult patients diagnosed with eNOSE were retrospectively selected between January 2016 and December 2022. We reviewed demographics, clinical data, diagnostic work-up, and treatment. We considered the last ASM introduced before the eNOSE termination as effective.

RESULTS

123 patients were included (age: 67.9 ± 17.3). eNOSE acute etiology was mostly reported. In the overall cohort, phenytoin showed the highest response rate (p = 0.01). In the pairwise comparisons, valproate was superior to levetiracetam (p = 0.02) but not to lacosamide (p = 0.50). Phenytoin had a significantly higher resolution rate than levetiracetam (p = 0.001) but not lacosamide (p = 0.14). Thirty patients were refractory to ASM treatment. No predictors of refractoriness were identified. Thirty-nine patients died. Age and GCS were identified as eNOSE-related mortality risk factors.

CONCLUSION

eNOSE frequently has an acute etiology with several associated syndromes. Phenytoin is more effective in managing eNOSE, even though lacosamide, valproate, and levetiracetam can represent further therapeutic options. Age and GCS are the main risk factors for eNOSE-associated mortality.

Efficacy of second-line anticonvulsant agents with adult status epilepticus: A systematic review and network meta-analysis

BACKGROUND

Status epilepticus (SE) is potentially life-threatening, however, it is unclear which antiepileptic drugs (AEDs) should be used as second-line AEDs.

OBJECTIVE

We conducted a network meta-analysis (NMA) of randomized controlled trials (RCTs) comparing multiple second-line AEDs for SE to investigate the efficacy of AEDs.

METHODS

We searched MEDLINE, CENTRAL, ClinicalTrials.gov, and World Health Organization International Clinical Trials Platform Search Portal and included RCTs for patients aged ≥15 years with SE on December 31, 2023. We compared multiple second-line AEDs for SE including fosphenytoin (fPHT), lacosamide (LCM), levetiracetam (LEV), phenytoin (PHT), phenobarbital (PHB), and valproate (VPA). The primary and secondly outcomes were termination of seizures integrating the absence of seizure recurrence at 30 min and 60 min, and adverse events associated with AEDs, respectively, with expressing as relative risk (RR) with a 95% confidence interval (CI). We conducted a NMA using frequentist-based approach with multivariate random effects, and assessed the certainty based on the Grading of Recommendations, Assessment, Development, and Evaluations framework.

RESULTS

Seven RCTs (n = 780) were included, and statistically significant difference was detected between VPA vs. PHB (RR, 0.67; 95% CI, 0.53-0.85; very low certainty), fPHT vs. PHB (RR, 0.66; 95% CI, 0.48-0.90; very low certainty), LCM vs. PHB (RR, 0.62; 95% CI, 0.41-0.93; very low certainty), and LEV vs. PHB (RR, 0.69; 95% CI, 0.51-0.94; very low certainty). Moreover, PHB was the highest in the ranking for termination of seizures. For adverse events, no significant reduction was observed owing to the selection of AEDs, although the ranking of PHB was the lowest.

CONCLUSIONS

PHB may have been the most effective for seizure termination as second-line AEDs in adult patients with SE. However, the certainty of almost all comparisons was "very low", and careful interpretation is essential.

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

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.

Analysis of Adverse Events Following Phenobarbital Administration for Pediatric Patients Categorized by One-Year Age Increments Using the U.S. Food and Drug Administration Adverse Event Reporting System

Background Organ and body development greatly varies in pediatric patients from year to year. Therefore, the incidence of each adverse event following phenobarbital (PB) administration would vary with age. However, in clinical trials, increasing the sample size of pediatric patients in each age group has been challenging. Therefore, previous studies were conducted by dividing pediatric patients into three or four age groups based on the development stage. Although these results were useful in clinical settings, information on adverse events that occurred at one-year age increments in pediatric patients could further enhance treatment and care. Objectives This study investigated in one-year age increments the occurrence tendency of each adverse event following PB administration in pediatric patients. Methods This study used data obtained from the U.S. Food and Drug Administration Adverse Event Reporting System (FAERS). Two inclusion criteria were set: (1) treatment with PB between January 2004 and June 2023 and (2) age 0-15 years. Using the cutoff value obtained using the Wilcoxon-Mann-Whitney test by the minimum p-value approach, this study explored changes in the occurrence tendency of each adverse event in one-year age increments. At the minimum p-value of <0.05, the age corresponding to this p-value was determined as the cutoff value. Conversely, at the minimum p-value of ≥0.05, the cutoff value was considered nonexistent. Results This study investigated all types of adverse events and explored the cutoff value for each adverse event. We identified 34, 16, 15, nine, five, five, eight, three, and eight types of adverse events for the cutoff values of ≤3/>3, ≤4/>4, ≤5/>5, ≤6/>6, ≤7/>7, ≤8/>8, ≤9/>9, ≤10/>10, and ≤11/>11 years, respectively. Conclusions This study demonstrated that adverse events requiring attention in pediatric patients varied with age. The findings help in the improvement of treatment and care in the pediatric clinical settings.

Clinical and Genetic Features of Dravet Syndrome: A Prime Example of the Role of Precision Medicine in Genetic Epilepsy

Dravet syndrome (DS), also known as severe myoclonic epilepsy of infancy, is a rare and drug-resistant form of developmental and epileptic encephalopathies, which is both debilitating and challenging to manage, typically arising during the first year of life, with seizures often triggered by fever, infections, or vaccinations. It is characterized by frequent and prolonged seizures, developmental delays, and various other neurological and behavioral impairments. Most cases result from pathogenic mutations in the sodium voltage-gated channel alpha subunit 1 (SCN1A) gene, which encodes a critical voltage-gated sodium channel subunit involved in neuronal excitability. Precision medicine offers significant potential for improving DS diagnosis and treatment. Early genetic testing enables timely and accurate diagnosis. Advances in our understanding of DS's underlying genetic mechanisms and neurobiology have enabled the development of targeted therapies, such as gene therapy, offering more effective and less invasive treatment options for patients with DS. Targeted and gene therapies provide hope for more effective and personalized treatments. However, research into novel approaches remains in its early stages, and their clinical application remains to be seen. This review addresses the current understanding of clinical DS features, genetic involvement in DS development, and outcomes of novel DS therapies.

Differentiated and non-differentiated HepaRG™ cells: A possible in-vitro model system for early hepatocarcinogenesis and non-genotoxic carcinogens

Many xenobiotics are non-genotoxic carcinogens (NGC) in rodent liver. Their mode of action (MoA) and health risks for humans are unclear and no in-vitro tests are available to predict NGC. Human HepaRG™ cells in the differentiated (d-HepaRG) and non-differentiated state (nd-HepaRG) were studied as new approach methodology (NAM) for NGC. Cell-biological assays were performed with d-/nd-HepaRG and human hepatoma/hepatocarcinoma cell lines to characterize the benign/malignant phenotype. Reaction of d-/nd-HepaRG to several liver growth factors and NGC (phenobarbital, PB; cyproterone acetate, CPA; WY-14643) was compared to unaltered and premalignant rat hepatocytes in ex-vivo culture. Enzyme induction by NGC was checked by RT-qPCR/oligo-arrays. Growth, anchorage-independency, migration, clonogenicity, and in-vivo tumorigenicity of nd-HepaRG ranged between benign d-HepaRG and malignant hepatoma/hepatocarcinoma cells. All growth factors elevated DNA replication of d-/nd-HepaRG cells, similarly to unaltered/premalignant rat hepatocytes. NGC induced their prototypical enzymes in the rat and human cells, but elicited a growth response only in the unaltered/premalignant rat hepatocytes and not in human d-/nd-HepaRG cells. To conclude, a benign/premalignant phenotype of d-/nd-HepaRG cells and a reactivity towards several hepatic growth factors and NGC, as known from human hepatocytes, are essential components for an in-vitro model for early stage human hepatocarcinogenesis.The potential value as new approach methodology (NAM) for NGC is discussed.

The initial treatment in convulsive status epilepticus in China: A multi-center observational study

OBJECTIVE

To investigate the initial treatment of patients with convulsive status epilepticus (CSE) in a resource-limited region of China, and to discuss the difference of in-hospital outcomes and economic costs between those with guideline-recommended initial treatment and those without.

METHODS

In this retrospective study, we screened adult patients discharged with the diagnosis of CSE in four centers in west China. Individuals with different exposure to the initial drug were divided into benzodiazepine (BDZ) and non-BDZ group for outcome comparison. The primary outcomes were seizure control, and the ratio of patients who developed refractory SE. The secondary outcomes included in-hospital mortality, the modified Rankin Scale (mRS) score at discharge, in-hospital respiratory support rate, length, and cost of the stay.

RESULTS

Three-hundred and thirteen patients (127, 40.6% were women) with CSE were included. The median age was 43 (range 16-92). There were 152 (48.6%) patients initially treated with BDZ. Among the 36 who received midazolam as initial treatment, twenty-six received an insufficient dose. The other 116 (76.3%) patients in the BDZ group chose diazepam as initial treatment. Fifteen of them (12.9%) were treated underdose. In the non-BDZ group (161, 51.4%), antiseizure medications (ASMs) and/or coma-induced drugs were used as initial treatment. Among those initially administrated ASMs, intramuscular phenobarbital (38,37.6%) and valproate (46, 52.3%) were most frequently seen. There was a significant difference in the time latency to initial treatment and etiology between BDZ and non-BDZ group. The non-BDZ group reported a higher cessation rate after initial treatment compared to the BDZ group (P = 0.012). No significant difference in other primary and secondary outcomes.

SIGNIFICANCE

Non-adherence and underdosing of the initial treatment of SE were common in China. However, the non-BDZ group showed a better seizure control rate. The effect came from early aggressive medication, that is, the combination of ASMs and anesthesia. Non-BDZ group was not inferior to BDZs in terms of seizure control, the occurrence of in-hospital death, and poor outcome at discharge. More robust evidence is needed in developing settings when choosing the initial treatment.

Epilepsy: Mitochondrial connections to the 'Sacred' disease

Over 65 million people suffer from recurrent, unprovoked seizures. The lack of validated biomarkers specific for myriad forms of epilepsy makes diagnosis challenging. Diagnosis and monitoring of childhood epilepsy add to the need for non-invasive biomarkers, especially when evaluating antiseizure medications. Although underlying mechanisms of epileptogenesis are not fully understood, evidence for mitochondrial involvement is substantial. Seizures affect 35%-60% of patients diagnosed with mitochondrial diseases. Mitochondrial dysfunction is pathophysiological in various epilepsies, including those of non-mitochondrial origin. Decreased ATP production caused by malfunctioning brain cell mitochondria leads to altered neuronal bioenergetics, metabolism and neurological complications, including seizures. Iron-dependent lipid peroxidation initiates ferroptosis, a cell death pathway that aligns with altered mitochondrial bioenergetics, metabolism and morphology found in neurodegenerative diseases (NDDs). Studies in mouse genetic models with seizure phenotypes where the function of an essential selenoprotein (GPX4) is targeted suggest roles for ferroptosis in epilepsy. GPX4 is pivotal in NDDs, where selenium protects interneurons from ferroptosis. Selenium is an essential central nervous system micronutrient and trace element. Low serum concentrations of selenium and other trace elements and minerals, including iron, are noted in diagnosing childhood epilepsy. Selenium supplements alleviate intractable seizures in children with reduced GPX activity. Copper and cuproptosis, like iron and ferroptosis, link to mitochondria and NDDs. Connecting these mechanistic pathways to selenoproteins provides new insights into treating seizures, pointing to using medicines including prodrugs of lipoic acid to treat epilepsy and to potential alternative therapeutic approaches including transcranial magnetic stimulation (transcranial), photobiomodulation and vagus nerve stimulation.

Long-term follow-up of phenobarbital versus valproate for generalized convulsive status epilepticus in adults: A randomized clinical trial

OBJECTIVE

Intravenous phenobarbital is frequently offered to patients with generalized convulsive status epilepticus (GCSE) in China, but its long-term benefits are unclear. We aimed to evaluate the long-term effects of intravenous phenobarbital on adult patients with GCSE.

METHODS

This randomized clinical trial with a 12-month follow-up was performed in Xuanwu Hospital, Capital Medical University (Beijing, China) between February 2011 and December 2021. After the failure of intravenous diazepam treatment, adult patients with GCSE were randomized to receive either intravenous phenobarbital or valproate. Neurological outcome within 12-month was dichotomized as good (modified Rankin scale, mRS 0-2) or poor (mRS 3-6). Cognitive function was measured by mini-mental state examination (MMSE) and Montreal cognitive assessment (MoCA). Hamilton anxiety scale (HAMA) and Hamilton depression scale (HAMD) were tested for mood disorders.

RESULTS

We consecutively recruited 166 patients with GCSE. After excluding individuals with termination after intravenous diazepam (n = 61), and with other exclusion criteria (n = 7), 98 patients were included and 88.0% (66/75) of survivors achieved seizure freedom at 12-month. Forty-five patients (45.92%) had good outcomes at 3-month and 57 patients (58.16%) had good outcomes at 12-month. And 46.67% (35/75) of survivors showed mRS improvement at 12-month (phenobarbital group, n = 17 vs. valproate group, n = 18, P = 0.321). Despite there was no significant difference with respect to good outcomes at 3-month (54.0% vs. 37.5%, P = 0.101), the rate of good outcomes in phenobarbital group was higher than valproate group at 12-month (68.0% vs. 47.92%, P = 0.044). A total of 43 patients successfully participated cognitive and emotional tests. Mild cognitive impairment was found in 7.14% of phenobarbital group and 50.0% in valproate group (P = 0.026). In addition, there were no significant differences with respect to anxiety (36.36% vs. 38.10%) and depression (31.82% vs. 47.62%) between the phenobarbital and valproate groups.

CONCLUSIONS

Combined with long term conventional therapy, intravenous phenobarbital group had more good outcomes than intravenous valproate group in Chinese adult patients with GCSE up to 12-month follow-up. This finding may prompt the option of intravenous phenobarbital especially in patients with limited access to new antiseizure drugs.

Diagnosing nonconvulsive status epilepticus: Defining electroencephalographic and clinical response to diagnostic intravenous antiseizure medication trials

OBJECTIVE

The Salzburg criteria for nonconvulsive status epilepticus (NCSE) and the American Clinical Neurophysiology Society (ACNS) Standardized Critical Care EEG Terminology 2021 include a diagnostic trial with intravenous (IV) antiseizure medications (ASMs) to assess electroencephalographic (EEG) and clinical response as a diagnostic criterion for definite NCSE and possible NCSE. However, how to perform this diagnostic test and assessing the EEG and clinical responses have not been operationally defined.

METHODS

We performed a Delphi process involving six experts to standardize the diagnostic administration of IV ASM and propose operational criteria for EEG and clinical response.

RESULTS

Either benzodiazepines (BZDs) or non-BZD ASMs can be used as first choice for a diagnostic IV ASM trial. However, non-BZDs should be considered in patients who already have impaired alertness or are at risk of respiratory depression. Levetiracetam, valproate, lacosamide, brivaracetam, or (if the only feasible drug) fosphenytoin or phenobarbital were deemed appropriate for a diagnostic IV trial. The starting dose should be approximately two thirds to three quarters of the full loading dose recommended for treatment of status epilepticus, with an additional smaller dose if needed. ASMs should be administered during EEG recording under supervision. A monitoring time of at least 15 min is recommended. If there is no response, a second trial with another non-BDZ or BDZs may be considered. A positive EEG response is defined as the resolution of the ictal-interictal continuum pattern for at least three times the longest previously observed spontaneous interval of resolution (if any), but minimum of one continuous minute. For a clinical response, physicians should use a standardized examination before and after IV ASM administration. We suggest a definite time-locked improvement in a focal deficit or at least one-step improvement on a new dedicated one-domain 10-level NCSE response scale.

SIGNIFICANCE

The proposed standardized approach of a diagnostic IV ASM trial further refines the ACNS and Salzburg diagnostic criteria for NCSE.