Pharmacological and therapeutic properties of valproate: a summary after 35 years of clinical experience

Model-Based Bioequivalence Analysis to Assess and Predict the Relative Bioavailability of Valproic Acid Formulations

BACKGROUND AND OBJECTIVE

Model-based bioequivalence (MBBE) encompasses the use of nonlinear mixed effect models supporting the estimation of pharmacokinetic endpoints to assess the relative bioavailability between multi-source drug products. This application emerges as a valuable alternative to the standard non-compartmental analysis (NCA) in bioequivalence (BE) studies in which dense sampling is not possible. In this work, we aimed to assess the application of MBBE compared to traditional methods in evaluating the relative bioavailability of two formulations with different drug release properties. Additionally, we sought to predict the performance of a modified-release formulation in a multiple-dose scenario, leveraging data from a single-dose study.

METHODS

MBBE analysis was implemented to estimate the BE endpoints (90% CI for the Test/Reference geometric mean ratio, T/R GMR) in area under the concentration-time curve (AUC) and maximum concentration (Cmax) using data from a single-dose, 2-period, 2-sequence BE study performed in 14 healthy subjects between a locally developed valproic acid extended-release formulation (Test) and the brand-name delayed-release formulation (Reference).

RESULTS

Results were compared with the standard approach, revealing that MBBE analysis achieved higher discrimination between formulations for Cmax, addressing limitations of the experimental sampling design and highlighting an advantage for this model-based analysis even when rich data are available. Additionally, the bioequivalence outcome under the multiple-dose scenario was predicted through a simulation-based study for both total and unbound valproic acid concentrations, considering the impact of valproic acid saturable binding on BE conclusions.

CONCLUSIONS

The MBBE analysis was superior to the NCA approach in detecting product-related differences, overcoming limitations in the study experimental design. Predictions for the multiple-dose scenario preclude that the extended-release properties of the Test formulation would persist at steady state, resulting in lower peak-to-trough fluctuation and bioequivalent performance in terms of the extent of drug absorption. Overall, these results should discourage unnecessary experimentation in healthy subjects.

New valproate regulations, informed choice and seizure risk

Valproate is the most effective medication for generalised epilepsies, and several specific epilepsy syndromes. For some people, it will be the only medication to establish seizure remission, and withdrawing it carries risks of seizure recurrence and Sudden Unexpected Death in Epilepsy (SUDEP). It is also of proven efficacy for bipolar disorder and migraine prevention. Guidelines based on observational and epidemiological studies stress that maternal valproate related teratogenicity and neurodevelopmental effects are significantly higher than for other antiseizure medications (ASMs). It should, therefore, only be used if other medications are ineffective and after balancing the teratogenicity risk. Regulatory restrictions have changed prescribing practices and reduced valproate use. The number of other medications that must be trialled in the different conditions for which valproate has effectiveness and the consequences of the lack of efficacy of those drugs leading to significant harm including death remains unexplored. Risk minimisation measures (RMMs) for valproate, chiefly Pregnancy Prevention practices (PPP), consider foetal risk and not risk to people living with epilepsy. In the United Kingdom (UK), limitations relating to valproate use in all people < 55 years commenced in January 2024. While the evidence in child-bearing women is not disputed, the data in males are based on animal models, case reports, and one commissioned, unpublished, non-peer reviewed report unavailable to the UK public, stakeholder charities or professionals. Evidence suggests that 30-40% of people switching from valproate have breakthrough seizures. Thus, an estimated 21,000-28000 people in the UK will imminently be exposed to the potential hazards of breakthrough seizures, including death. There is little government investment in monitoring the effects of these changes to valproate prescribing on patient health and quality of life. This review summarises the history of valproate regulation, evidence underpinning it and argues how the latest regulations in the UK do not align with the country's medical regulatory bodies ethical principles nor with the Montgomery principles of informed patient choice and autonomy. It dissects how such regulations infringe Common Law principles, nor give due regard for patient outcomes beyond reproduction. The paper looks to provide recommendations to redress these concerns while appreciating the core need for such governance to emerge in the first place.

Targeting m6A mRNA demethylase FTO alleviates manganese-induced cognitive memory deficits in mice

Manganese (Mn) induced learning and memory deficits through mechanisms that are not fully understood. In this study, we discovered that the demethylase FTO was significantly downregulated in hippocampal neurons in an experimental a mouse model of Mn exposure. This decreased expression of FTO was associated with Mn-induced learning and memory impairments, as well as the dysfunction in synaptic plasticity and damage to regional neurons. The overexpression of FTO, or its positive modulation with agonists, provides protection against neurological damage and cognitive impairments. Mechanistically, FTO interacts synergistically with the reader YTHDF3 to facilitate the degradation of GRIN1 and GRIN3B through the m6A modification pathway. Additionally, Mn decreases the phosphorylation of SOX2, which specifically impairs the transcriptional regulation of FTO activity. Additionally, we found that the natural compounds artemisinin and apigenin that can bind molecularly with SOX2 and reduce Mn-induced cognitive dysfunction in mice. Our findings suggest that the SOX2-FTO-Grins axis represents a viable target for addressing Mn-induced neurotoxicity and cognitive impairments.

CoQ10 targeted hippocampal ferroptosis in a status epilepticus rat model

Status epilepticus (SE), the most severe form of epilepsy, leads to brain damage. Uncertainty persists about the mechanisms that lead to the pathophysiology of epilepsy and the death of neurons. Overloading of intracellular iron ions has recently been identified as the cause of a newly recognized form of controlled cell death called ferroptosis. Inhibiting ferroptosis has shown promise as a treatment for epilepsy, according to recent studies. So, the current study aimed to assess the possible antiepileptic impact of CoQ10 either alone or with the standard antiepileptic drug sodium valproate (SVP) and to evaluate the targeted effect of COQ10 on hippocampal oxidative stress and ferroptosis in a SE rat model. Using a lithium-pilocarpine rat model of epilepsy, we evaluated the effect of SVP, CoQ10, or both on seizure severity, histological, and immunohistochemical of the hippocampus. Furthermore, due to the essential role of oxidative stress and lipid peroxidation in inducing ferroptosis, we evaluated malonaldehyde (MDA), reduced glutathione (GSH), glutathione peroxidase 4 (GPX4), and ferritin in tissue homogenate. Our work illustrated that ferroptosis occurs in murine models of lithium-pilocarpine-induced seizures (epileptic group). Nissl staining revealed significant neurodegeneration. A significant increase in the number of astrocytes stained with an astrocyte-specific marker was observed in the hippocampus. Effective seizure relief can be achieved in the seizure model by administering CoQ10 alone compared to SVP. This was accomplished by lowering ferritin levels and increasing GPX4, reducing MDA, and increasing GSH in the hippocampus tissue homogenate. In addition, the benefits of SVP therapy for regulating iron stores, GPX4, and oxidative stress markers were amplified by incorporating CoQ10 as compared to SVP alone. It was concluded that CoQ10 alone has a more beneficial effect than SVP alone in restoring histological structures and has a targeted effect on hippocampal oxidative stress and ferroptosis. In addition, COQ10 could be useful as an adjuvant to SVP in protecting against oxidative damage and ferroptosis-related damage that result from epileptic seizures.

Early versus late switch over of antiseizure medications from intravenous to the oral route in children with seizures: Single-blinded, randomized controlled trial (ELAIO trial)

INTRODUCTION

Early switch-over of anti-seizure medications (ASMs) from intravenous to oral route may reduce the duration of hospitalization, drug acquisition costs, and behavioral upset in hospitalized children with seizures.

OBJECTIVE

The primary objective was to compare short-term seizure recurrence within 1 week in hospitalized children aged 1 month to 18 years with new-onset/breakthrough seizures after an early versus late switch-over from intravenous to the oral route of ASMs. Secondary objectives were to compare the incidence of status epilepticus, duration of hospital stay, drug acquisition costs, and caregiver-reported satisfaction scores in both groups.

METHODS

In this single-blind randomized controlled trial, patients with seizures were categorized based on the number of ASMs required and the history of status epilepticus. Patients in each category were randomized in a 1:1 ratio into either early or late switch-over (ES or LS) groups. In the ES groups, ASMs were tapered one-by-one between 0 and 24 hours of seizure freedom, while in the LS groups, they were tapered one-by-one between 24 and 48 hours of seizure freedom.

RESULTS

A total of 112 children were enrolled in the study, with 56 in each arm. Seizure recurrence at 1 week and 12 weeks was comparable in ES and LS groups (3/55 vs. 1/54 at 1 week, p=0.61; 7/49 vs. 6/49 at 12 weeks, p=0.98). Drug acquisition costs were significantly lower in the ES group (393±274 vs. 658±568 INR, p=0.002). Thrombophlebitis and dysphoria were significantly more common in the LS group (p=0.008 and 0.03, respectively).

CONCLUSION

The early switch-over of ASMs from intravenous to oral route is safe without any significant increased risk of short-term seizure recurrence and also associated with a reduction in the incidence of thrombophlebitis and ASM acquisition costs.

TRIAL REGISTRATION NO

CTRI/2021/03/032145.

Non-apoptotic role of EGL-1 in exopher production and neuronal health in Caenorhabditis elegans

While traditionally studied for their pro-apoptotic functions, recent research suggests BH3-only proteins also have non-apoptotic roles. Here, we find that EGL-1, the BH3-only protein in Caenorhabditis elegans , promotes the cell-autonomous production of exophers in adult neurons. Exophers are large, micron-scale vesicles that are ejected from the cell and contain cellular components such as mitochondria. EGL-1 facilitates exopher production potentially through regulation of mitochondrial dynamics. Moreover, an endogenous, low level of EGL-1 expression appears to benefit dendritic health. Our findings provide insights into the mechanistic role of BH3-only protein in mitochondrial dynamics, downstream exopher production, and ultimately neuronal health.

Significance statement

BH3-only proteins were known for their function in inducing cell death. Their presence in healthy adult neurons, however, suggests additional roles. Our study focused on the BH3-only protein EGL-1 in the nematode Caenorhabditis elegans , where its apoptotic role was discovered. We reveal a new role in cell-autonomously promoting exopher production - a process where neurons extrude large vesicles containing potentially harmful cell contents. EGL-1 appears to promote this by regulating mitochondrial dynamics. We also report that low levels of EGL-1 benefit neuronal health and function. These findings expand our understanding of BH3-only proteins, mitochondrial dynamics, and exopher production in neurons and provide insights for neurodegenerative diseases.

A comprehensive assessment of palmatine as anticonvulsant agent - In vivo and in silico studies

Previously, we demonstrated that palmatine (PALM) - an isoquinoline alkaloid from Berberis sibrica radix, exerted antiseizure activity in the pentylenetetrazole (PTZ)-induced seizure assay in larval zebrafish. The aim of the present study was to more precisely characterize PALM as a potential anticonvulsant drug candidate. A range of zebrafish and mouse seizure/epilepsy models were applied in the investigation. Immunostaining analysis was conducted to assess the changes in mouse brains, while in silico molecular modelling was performed to determine potential targets for PALM. Accordingly, PALM had anticonvulsant effect in ethyl 2-ketopent-4-enoate (EKP)-induced seizure assay in zebrafish larvae as well as in the 6 Hz-induced psychomotor seizure threshold and timed infusion PTZ tests in mice. The protective effect in the EKP-induced seizure assay was confirmed in the local field potential recordings. PALM did not affect seizures in the gabra1a knockout line of zebrafish larvae. In the scn1Lab-/- zebrafish line, pretreatment with PALM potentiated seizure-like behaviour of larvae. Repetitive treatment with PALM, however, did not reduce development of PTZ-induced seizure activity nor prevent the loss of parvalbumin-interneurons in the hippocampus of the PTZ kindled mice. In silico molecular modelling revealed that the noted anticonvulsant effect of PALM in EKP-induced seizure assay might result from its interactions with glutamic acid decarboxylase and/or via AMPA receptor non-competitive antagonism. Our study has demonstrated the anticonvulsant activity of PALM in some experimental models of seizures, including a model of pharmacoresistant seizures induced by EKP. These results indicate that PALM might be a suitable new drug candidate but the precise mechanism of its anticonvulsant activity has to be determined.

Associations between one-carbon metabolism and valproic acid-induced liver dysfunction in epileptic patients

Valproic acid (VPA) has been widely used as an antiepileptic drug for decades. Although VPA is effective and well-tolerated, long-term VPA treatment is usually associated with hepatotoxicity. However, the underlying mechanisms of VPA-caused hepatotoxicity remain unclear. In this study, a total of 157 pediatric patients with epilepsy were recruited and divided into normal liver function (NLF, 112 subjects) group and abnormal liver function (ABLF, 45 subjects) group. We observed that MTHFR A1298C and MTHFR C677T variants may be linked to VPA-induced liver dysfunction (p = 0.001; p = 0.023, respectively). We also found that the MTHFR A1298C polymorphism was associated with a higher serum Hcy level (p = 0.001) and a lower FA level (p = 0.001). Moreover, the serum Hcy levels was strongly correlated with the GSH and TBARS concentrations (r = -0.6065, P < 0.001; r = 0.6564, P < 0.001, respectively). Furthermore, logistic analysis indicated that MTHFR A1298C/C677T polymorphisms and increased Hcy concentrations may be risk factors for VPA-induced liver dysfunction. These results suggested that individual susceptibility to VPA-induced liver dysfunction may result from MTHFR A1298C/C677T polymorphisms and increased Hcy levels. This study may be helpful for the prevention and guidance of VPA-induced liver dysfunction.

Valproate use associated with frontal and cerebellar gray matter volume reductions: A voxel-based morphometry study

Recent morphometric magnetic resonance imaging (MRI) studies suggested the possibility that valproate (VPA) use is associated with parieto-occipital cortical thinning in patients with heterogeneous epilepsy syndromes. In this study, we examined the effect of VPA on the brain volume using a large number of homogenous patients with idiopathic generalized epilepsy. Voxel-based morphometry was used to compare regional gray matter (GM) volume between 112 patients currently taking VPA (VPA+ group), 81 patients not currently taking VPA (VPA- group), and 120 healthy subjects (control group). The VPA+ group showed a significant GM volume reduction in the bilateral cerebellum, hippocampus, insula, caudate nucleus, medial frontal cortex/anterior cingulate cortex, primary motor/premotor cortex, medial occipital cortex, and anteromedial thalamus, as compared to the control group. The VPA- group showed a significant GM volume reduction in the anteromedial thalamus and right hippocampus/temporal cortex, as compared to the control group. Compared to the VPA- group, the VPA+ group had a significant GM volume reduction in the bilateral cerebellum, primary motor/premotor cortex, and medial frontal cortex/anterior cingulate cortex. We have provided evidence that VPA use could result in GM volume reductions in the frontal cortex and cerebellum. Our findings should be acknowledged as a potential confounding factor in morphometric MRI studies that include subjects taking VPA.

Phenytoin-induced cerebellar atrophy: A case for reversibility of neurological decline

This case serves as a reminder of the infrequent, yet consequential occurrence of cerebellar degeneration linked to phenytoin usage. Whilst emphasizes the importance of monitoring patients on long-term phenytoin therapy, and it further suggests considering employing bedside imaging tools such as Ultrasound fusion imaging for follow-up of patients at risk of this type of disorder. We present a case study involving a 23-year-old woman who experienced significant neurological impairment resulting in severe cerebellar atrophy while undergoing phenytoin treatment. On cessation of phenytoin, the patient exhibited improvement with enhanced cerebellar function.

Preclinical Study in Mouse Thymus and Thymocytes: Effects of Treatment with a Combination of Sodium Dichloroacetate and Sodium Valproate on Infectious Inflammation Pathways

The research presents data from a preclinical study on the anti-inflammatory effects of a sodium dichloroacetate and sodium valproate combination (DCA-VPA). The 2-week treatment with a DCA 100 mg/kg/day and VPA 150 mg/kg/day combination solution in drinking water's effects on the thymus weight, its cortex/medulla ratio, Hassall's corpuscles (HCs) number in the thymus medulla, and the expression of inflammatory and immune-response-related genes in thymocytes of male Balb/c mice were studied. Two groups of mice aged 6-7 weeks were investigated: a control (n = 12) and a DCA-VPA-treated group (n = 12). The treatment did not affect the body weight gain (p > 0.05), the thymus weight (p > 0.05), the cortical/medulla ratio (p > 0.05), or the number of HCs (p > 0.05). Treatment significantly increased the Slc5a8 gene expression by 2.1-fold (p < 0.05). Gene sequence analysis revealed a significant effect on the expression of inflammation-related genes in thymocytes by significantly altering the expression of several genes related to the cytokine activity pathway, the inflammatory response pathway, and the Il17 signaling pathway in thymocytes. Data suggest that DCA-VPA exerts an anti-inflammatory effect by inhibiting the inflammatory mechanisms in the mouse thymocytes.

Long-lasting antiseizure effects of chronic intrasubthalamic convection-enhanced delivery of valproate

Intracerebral drug delivery is an experimental approach for the treatment of drug-resistant epilepsies that allows for pharmacological intervention in targeted brain regions. Previous studies have shown that targeted pharmacological inhibition of the subthalamic nucleus (STN) via modulators of the GABAergic system produces antiseizure effects. However, with chronic treatment, antiseizure effects are lost as tolerance develops. Here, we report that chronic intrasubthalamic microinfusion of valproate (VPA), an antiseizure medication known for its wide range of mechanisms of action, can produce long-lasting antiseizure effects over three weeks in rats. In the intravenous pentylenetetrazole seizure-threshold test, seizure thresholds were determined before and during chronic VPA application (480 μg/d, 720 μg/d, 960 μg/d) to the bilateral STN. Results indicate a dose-dependent variation in VPA-induced antiseizure effects with mean increases in seizure threshold of up to 33%, and individual increases of up to 150%. The lowest VPA dose showed a complete lack of tolerance development with long-lasting antiseizure effects. Behavioral testing with all doses revealed few, acceptable adverse effects. VPA concentrations were high in STN and low in plasma and liver. In vitro electrophysiology with bath applied VPA revealed a reduction in spontaneous firing rate, increased background membrane potential, decreased input resistance and a significant reduction in peak NMDA, but not AMPA, receptor currents in STN neurons. Our results suggest an advantage of VPA over purely GABAergic modulators in preventing tolerance development with chronic intrasubthalamic drug delivery and provide first mechanistic insights in intracerebral pharmacotherapy targeting the STN.

Design and evaluation of gastro-swelling/gastro-floating sustained-release tablets of brivaracetam for epilepsy therapy

To prolong the absorption of the drug and achieve the effect of gastric retention, new brivaracetam tablets together with the characteristics of rapid swelling and sustained floating have been developed here. The tablets were optimized and prepared by direct compression techniques using Kollidon® SR and cross-linked polyvinylpyrrolidone (PVPP) XL as the matrix and disintegrant respectively, and carbomer 71G NF and polyethylene oxide (PEO) N60K as the gel materials to achieve sustained release effect. The characteristics of static expansion, floating time, drug release and dynamic swelling performance in vitro of the tablets were evaluated. The optimized formulations (F5 and F10) exhibited satisfactory swelling and floating properties, mechanical strength, and in vitro sustained-release characteristic with diffusion and matrix erosion mechanisms. X-ray images of beagle dogs showed that the tablet F5 could be retained in the stomach for more than 6 h. Furthermore, the pharmacokinetic studies in volunteers exhibited that the bioavailability of F5 and F10 was 95.70% (90% CI, 83.80%-109.28%) and 103.39% (90% CI, 87.61%-122.01%), respectively, relative to commercial tablets, with Tmax prolonged, demonstrating an excellent sustained-release effect. Therefore, the present system can reduce dosing frequency and improve patient compliance, which is expected to be a promising treatment option for epilepsy patients.

Dysregulation of the Wnt/β-catenin signaling pathway via Rnf146 upregulation in a VPA-induced mouse model of autism spectrum disorder

Autism spectrum disorder (ASD) is a neurodevelopmental disorder associated with impaired social behavior and communication, repetitive behaviors, and restricted interests. In addition to genetic factors, environmental factors such as prenatal drug exposure contribute to the development of ASD. However, how those prenatal factors induce behavioral deficits in the adult stage is not clear. To elucidate ASD pathogenesis at the molecular level, we performed a high-resolution mass spectrometry-based quantitative proteomic analysis on the prefrontal cortex (PFC) of mice exposed to valproic acid (VPA) in utero, a widely used animal model of ASD. Differentially expressed proteins (DEPs) in VPA-exposed mice showed significant overlap with ASD risk genes, including differentially expressed genes from the postmortem cortex of ASD patients. Functional annotations of the DEPs revealed significant enrichment in the Wnt/β-catenin signaling pathway, which is dysregulated by the upregulation of Rnf146 in VPA-exposed mice. Consistently, overexpressing Rnf146 in the PFC impaired social behaviors and altered the Wnt signaling pathway in adult mice. Furthermore, Rnf146-overexpressing PFC neurons showed increased excitatory synaptic transmission, which may underlie impaired social behavior. These results demonstrate that Rnf146 is critical for social behavior and that dysregulation of Rnf146 underlies social deficits in VPA-exposed mice.

Effect of valproic acid upon skeletal muscle subjected to prolonged tourniquet application

Background

Valproic acid (VPA), a histone deacetylase inhibitor, has shown improved outcomes when used as a pharmaceutical intervention in animal studies of hemorrhage, septic shock, and combined injuries. This study was designed to investigate the ability of VPA to mitigate ischemia-reperfusion injury produced by prolonged tourniquet application to an extremity.

Methods

The ischemia-reperfusion model in anesthetized rats was established using hemorrhage and a 3-hour tourniquet application. VPA was administered intravenously prior to tourniquet wear and removal. Ischemia-reperfusion injury was evaluated by investigating pathway signaling, immune modulation of cytokine release, remote organ injury, and skeletal muscle function during convalescence.

Results

We found that VPA sustained Protein kinase B (Akt) phosphorylation and Insulin-like growth factor signaling and modulated the systemic release of interleukin (IL)-1β, tumor necrosis factor alpha, and IL-6 after 2 hours of limb reperfusion. Additionally, VPA attenuated a loss in glomerular filtration rate at 3 days after injury. Histological and functional evaluation of extremity skeletal muscle at 3, 7, and 21 days after injury, however, demonstrated no significant differences in myocytic degeneration, necrotic formation, and maximal isometric tetanic torque.

Conclusions

Our results demonstrate that VPA sustains early prosurvival cell signaling, reduces the inflammatory response, and improves renal function in a hemorrhage with prolonged ischemia and reperfusion model. However, these do not translate into meaningful preservation in limb function when applied as a pharmaceutical augmentation to tourniquet wear.

Level of evidence

IV.

Intraamygdaloid Oxytocin Increases Time Spent on Social Interaction in Valproate-Induced Autism Animal Model

Autism spectrum disorder (ASD) is a pervasive neurodevelopmental disorder that affects about 1.5% of children worldwide. One of the core symptoms is impaired social interaction. Since proper treatment has not been found yet, an investigation of the exact pathophysiology of autism is essential. The valproate (VPA)-induced rat model can be an appropriate way to study autism. Oxytocin (OT) may amend some symptoms of ASD since it plays a key role in developing social relationships. In the present study, we investigated the effect of the intraamygdaloid OT on sham and intrauterine VPA-treated rats' social interaction using Crawley's social interaction test. Bilateral guide cannulae were implanted above the central nucleus of the amygdala (CeA), and intraamygdaloid microinjections were carried out before the test. Our results show that male Wistar rats prenatally exposed to VPA spent significantly less time on social interaction. Bilateral OT microinjection increased the time spent in the social zone; it also reached the level of sham-control animals. OT receptor antagonist blocked this effect of the OT but in itself did not significantly influence the behavior of the rats. Based on our results, we can establish that intraamygdaloid OT has significantly increased time spent on social interaction in the VPA-induced autism model, and its effect is receptor-specific.

Current and emerging pharmacotherapy for the treatment of Lennox-Gastaut syndrome

INTRODUCTION

Lennox-Gastaut syndrome (LGS) is a severe childhood-onset epileptic encephalopathy, characterized by multiple seizure types, generalized slow spike-and-wave complexes in the EEG, and cognitive impairment. Seizures in LGS are typically resistant to treatment with antiseizure medications (ASMs). Tonic/atonic ('drop') seizures are of particular concern, due to their liability to cause physical injury.

AREAS COVERED

We summarize evidence for current and emerging ASMs for the treatment of seizures in LGS. The review focuses on findings from randomized, double-blind, placebo-controlled trials (RDBCTs). For ASMs for which no double-blind trials were identified, lower quality evidence was considered. Novel pharmacological agents currently undergoing investigation for the treatment of LGS are also briefly discussed.

EXPERT OPINION

Evidence from RDBCTs supports the use of cannabidiol, clobazam, felbamate, fenfluramine, lamotrigine, rufinamide, and topiramate as adjunct treatments for drop seizures. Percentage decreases in drop seizure frequency ranged from 68.3% with high-dose clobazam to 14.8% with topiramate. Valproate continues to be considered the first-line treatment, despite the absence of RDBCTs specifically in LGS. Most individuals with LGS will require treatment with multiple ASMs. Treatment decisions should be individualized and take into account adverse effects, comorbidities, general quality of life, and drug interactions, as well as individual efficacy.

Maternal treatment with aripiprazole prevents the development of a valproic acid-induced autism-like phenotype in juvenile male mice

Autism spectrum disorder (ASD) describes a heterogeneous group of neurodevelopmental conditions characterized by deficits in social communication and repetitive behaviors. Aripiprazole (APZ) is an atypical antipsychotic that can safeguard mice against autism-like behavior induced by valproic acid (VPA). In the present study, we examined the effects of maternal treatment with APZ (10 mg/kg) in juvenile mice prenatally exposed to VPA on neurodevelopmental behaviors, social interactions, communication, and working memory, as well as synaptophysin (SYP), synaptosomal-associated protein, 25 kDa (SNAP-25) and microtubule-associated protein 2 (MAP-2) expression in the medial prefrontal cortex (mPFC) and cell viability in the hippocampus. In addition, to evaluate possible APZ interference with the anticonvulsant properties of VPA on pentylenetetrazole (PTZ)-induced seizures were evaluated. Maternal treatment with APZ significantly prevented body weight loss, self-righting, eye-opening, social interactions, social communication, and working memory deficits in mice prenatally exposed to VPA. Additionally, the decrease in the SYP, SNAP-25, and MAP-2 expressions in the mPFC and cell death in the hippocampus was prevented by APZ. Furthermore, APZ (10 mg/kg) did not interfere with the anticonvulsant effect of VPA (15 mg/kg) in animals with PTZ-induced seizures. These findings indicate that maternal treatment with APZ in pregnant mice exposed to VPA protects animals against the ASD-like behavioral phenotype, and this effect may be related, at least in part, to synaptic plasticity and neuronal protection in the PFC and hippocampus. APZ may serve as an effective pharmacological therapeutic target against autistic behaviors in the VPA animal model of ASD, which should be further investigated to verify its clinical relevance.

A Rapid Review of "Low-Threshold" Psychiatric Medication Prescribing: Considerations for Street Medicine and Beyond

OBJECTIVE

No widely accepted clinical guidelines, and scant directly applicable pragmatic research, are available to guide the prescription of psychiatric medications in "low-threshold" outpatient settings, such as street outreach, urgent care, and crisis care, as well as walk-in, shelter, and bridge and transition clinics. Providers frequently prescribe medications in these settings without patients' having firm psychiatric diagnoses and without medical records to guide clinical decision making. Persons who receive medications in these settings often seek help voluntarily and intermittently for mental illness symptoms. However, because of structural and individual factors, such patients may not engage in longitudinal outpatient psychiatric care. The authors reviewed the literature on psychiatric medication prescribing in low-threshold settings and offer clinical considerations for such prescribing.

METHODS

The authors conducted a rapid literature review (N=2,215 abstracts), which was augmented with up-to-date clinical prescribing literature, the authors' collective clinical experience, and DSM-5 section II diagnostic criteria to provide considerations for prescribing medications in low-threshold settings.

RESULTS

For individuals for whom diagnostic uncertainty is prominent, a symptom-based diagnostic and treatment approach may be best suited to weigh the risks and benefits of medication use in low-threshold settings. Practical considerations for treating patients with clinical presentations of psychosis and trauma, as well as mood, anxiety, and substance use disorders, in low-threshold settings are discussed.

CONCLUSIONS

An urgent need exists to invest in pragmatic research and guideline development to delineate best-practice prescribing in low-threshold settings.

Valproic Acid-Induced Upregulation of Multidrug Efflux Transporter ABCG2/BCRP via PPARα-Dependent Mechanism in Human Brain Endothelial Cells

Despite the progress made in the development of new antiepileptic drugs (AEDs), poor response to them is a rising concern in epilepsy treatment. Of several hypotheses explaining AED treatment failure, the most promising theory is the overexpression of multidrug transporters belonging to ATP-binding cassette (ABC) transporter family at blood-brain barrier. Previous data show that AEDs themselves can induce these transporters, in turn affecting their own brain bioavailability. Presently, this induction and the underlying regulatory mechanism involved at human blood-brain barrier is not well elucidated. Herein, we sought to explore the effect of most prescribed first- and second-line AEDs on multidrug transporters in human cerebral microvascular endothelial cells, hCMEC/D3. Our work demonstrated that exposure of these cells to valproic acid (VPA) induced mRNA, protein, and functional activity of breast cancer resistance protein (BCRP/ABCG2). On examining the substrate interaction status of AEDs with BCRP, VPA, phenytoin, and lamotrigine were found to be potential BCRP substrates. Furthermore, we observed that siRNA-mediated knockdown of peroxisome proliferator-activated receptor alpha (PPARα) or use of PPARα antagonist, resulted in attenuation of VPA-induced BCRP expression and transporter activity. VPA was found to increase PPARα expression and trigger its translocation from cytoplasm to nucleus. Findings from chromatin immunoprecipitation and luciferase assays showed that VPA enhances the binding of PPARα to its response element in the ABCG2 promoter, resulting in elevated ABCG2 transcriptional activity. Taken together, these in vitro findings highlight PPARα as the potential molecular target to prevent VPA-mediated BCRP induction, which may have important implications in VPA pharmacoresistance. SIGNIFICANCE STATEMENT: Induction of multidrug transporters at blood-brain barrier can largely affect the bioavailability of the substrate antiepileptic drugs in the brains of patients with epilepsy, thus affecting their therapeutic efficacy. The present study reports a mechanistic pathway of breast cancer resistance protein (BCRP/ABCG2) upregulation by valproic acid in human brain endothelial cells via peroxisome proliferator-activated receptor alpha involvement, thereby providing a potential strategy to prevent valproic acid pharmacoresistance in epilepsy.

The Impact of Levetiracetam and Valproate on Platelet Functions-A Double-Blind, Placebo-Controlled Crossover Study

It is known that valproate inhibits platelet functions; however, the exact mechanisms are not clearly identified. We studied 12 healthy adult volunteers (1 female, 11 male; age range 31.7 ± 7.8 years) before and after valproate 500 mg and compared the results to levetiracetam 1000 mg as a control substance and placebo. The study had a crossover and double-blind design. A blood sample was taken before and 90 min after medication intake, because the times to maximum serum concentration (T_max) are 1.5 h for levetiracetam and 1 to 3 h for valproate. We analysed changes in platelet, erythrocyte, and leukocyte cell count and in platelet functions (CD62 expression (P selectin), thrombin binding, and fibrinogen binding). We found no significant differences in all cell counts before and after different study drugs. After valproate intake, but not after placebo or levetiracetam intake, the fibrinogen binding significantly decreased and the CD62 expression significantly increased resulting in decreased platelet aggregation. Our data suggest that the platelet dysfunctions reported for valproate result from decreased fibrinogen binding and from increased CD62 expression. This phenomenon might be one reason for the increased bleeding risk under valproate and cannot be observed for levetiracetam.

Therapeutic and Toxic Effects of Valproic Acid Metabolites

Valproic acid (VPA) and its salts are psychotropic drugs that are widely used in neurological diseases (epilepsy, neuropathic pain, migraine, etc.) and psychiatric disorders (schizophrenia, bipolar affective disorder, addiction diseases, etc.). In addition, the indications for the appointment of valproate have been expanding in recent years in connection with the study of new mechanisms of action of therapeutic and toxic metabolites of VPA in the human body. Thus, VPA is considered a component of disease-modifying therapy for multiple tumors, neurodegenerative diseases (Huntington's disease, Parkinson's disease, Duchenne progressive dystrophy, etc.), and human immunodeficiency syndrome. The metabolism of VPA is complex and continues to be studied. Known pathways of VPA metabolism include: β-oxidation in the tricarboxylic acid cycle (acetylation); oxidation with the participation of cytochrome P-450 isoenzymes (P-oxidation); and glucuronidation. The complex metabolism of VPA explains the diversity of its active and inactive metabolites, which have therapeutic, neutral, or toxic effects. It is known that some active metabolites of VPA may have a stronger clinical effect than VPA itself. These reasons explain the relevance of this narrative review, which summarizes the results of studies of blood (serum, plasma) and urinary metabolites of VPA from the standpoint of the pharmacogenomics and pharmacometabolomics. In addition, a new personalized approach to assessing the cumulative risk of developing VPA-induced adverse reactions is presented and ways for their correction are proposed depending on the patient's pharmacogenetic profile and the level of therapeutic and toxic VPA metabolites in the human body fluids (blood, urine).

Profile of Drug Utilization in Patients with Rare Diseases in Tuscany, Italy: A Population-Based Study

Patients with rare diseases (RDs) generally have delayed diagnosis and misdiagnosis, which lead to inappropriate care or the need to modify treatment during the course of the disease. The medical care of RD patients can be further complicated by the presence of comorbidities. In this population-based study, we evaluated the prevalence, intensity of use, and consumption of drugs prescribed to RD patients residing in Tuscany (Italy) in the years 2008-2018. Data from the Registry of Rare Diseases of Tuscany were integrated with information retrieved from regional pharmaceutical prescription databases. The overall prevalence of drug use in the RD patients was 85.4%. Drugs for the alimentary tract and metabolism and antiinfectives for systemic use showed the highest prevalence of use, while drugs for the nervous system had the highest intensity of use only in the pediatric patients. The adults exhibited a female preponderance in terms of the prevalence of use and drug consumption in almost all the age groups and therapeutic categories. Conversely, a higher prevalence of use was observed in the male children. These results provide relevant insights into drug profiles in RD patients, representing a first step for future analyses to monitor changes in drug utilization in patients with RDs over time.

Compliance with Prescribing and Dispensing Conditions for Valproate and Related Substances in Girls and Women of Childbearing Potential: A Survey of Community Pharmacists in France

INTRODUCTION

Prenatal exposure to valproate and related substances is associated with a risk of malformations and/or neurodevelopmental disorders. In France, prescription and dispensing conditions of oral valproate forms are subject to risk minimization measures for girls and women of childbearing potential with the aim to limit pregnancy under this treatment. These risk minimization measures were issued in 2015 and were strengthened in 2018.

OBJECTIVE

We aimed to evaluate compliance with prescription and dispensing conditions of valproate for oral administration: an annual prescription from a specialist and a signed risk acknowledgment form.

METHODS

Two prospective observational surveys were carried out between 2018 and 2020 on a representative sample of French community pharmacies. Data were collected from female patients aged 2-49 years presenting to one of the participating pharmacies with a valproate prescription.

RESULTS

In total, 1067 and 824 valproate prescriptions were analyzed in 2018 and 2020, respectively, the majority of which were for girls and women of childbearing potential (≥ 92%). The prescription and dispensing conditions for valproate were met in 42% of cases (95% confidence interval 39-45) in 2018 and in 47% of cases (95% confidence interval 43-50) in 2020. Compliance levels were higher for prescriptions from neurologists (≥ 60%) than from other prescribers (≤ 45%).

CONCLUSIONS

In France, the implementation of specific risk minimization measures for girls and women of childbearing potential with respect to oral valproate forms and related substances requires a stronger involvement of stakeholders. Increased awareness and compliance among healthcare professionals regarding risk minimization measures could limit prenatal exposure to valproate.

Testicular histone hyperacetylation in mice by valproic acid administration affects the next generation by changes in sperm DNA methylation

Various studies have described epigenetic inheritance through sperms. However, the detailed mechanisms remain unclear. In this study, we focused on DNA methylation in mice treated with valproic acid (VPA), an inducer of epigenomic changes, and analyzed the treatment effects on the sperm from the next generation of mice. The administration of 200 mg/kg/day VPA to mice for 4 weeks caused transient histone hyperacetylation in the testes and DNA methylation changes in the sperm, including promoter CpGs of genes related to brain function. Oocytes fertilized with VPA-treated mouse sperm showed methylation fluctuations at the morula stage. Pups that were fathered by these mice also showed behavioral changes in the light/dark transition test after maturation. Brain RNA-seq of these mice showed that the expression of genes related to neural functions were altered. Comparison of the sperm DNA methylation status of the next generation of mice with that of the parental generation revealed the disappearance of methylation changes observed in the sperm of the parental generation. These findings suggest that VPA-induced histone hyperacetylation may have brain function-related effects on the next generation through changes in sperm DNA methylation.

Risk factors and outcome of hyperammonaemia in people with epilepsy

BACKGROUND

Hyperammonaemia is a recognised complication of antiseizure treatment but risk factors leading to individual patient susceptibility and outcome remain unclear.

OBJECTIVE

To identify risk factors for hyperammonaemia and investigate the impact of its management on clinical outcomes.

METHODS

We carried out a retrospective observational study of adults with epilepsy who had ammonia tested over a 3-year period. Hyperammonaemia was defined as ammonia level > 35 μmol/L. Patients were classified into two groups: hyperammonaemic and non-hyperammonaemic. Association analyses and linear regression analysis were used to identify risk factors for hyperammonaemia.

RESULTS

We reviewed 1002 ammonia requests in total and identified 76 people with epilepsy who had ammonia concentration measured, including 26 with repeated measurements. 59/76 (78%) were found to have hyperammonaemia. There was borderline statistical significance of hyperammonaemia being less common in patients with an established monogenic/metabolic condition than in those with structural or cryptogenic epilepsy (P = 0.05). Drug resistance, exposure to stiripentol and oxcarbazepine were identified as risk factors for hyperammonaemia. We found a dose-dependent association between valproate and hyperammonaemia (P = 0.033). Clinical symptoms were reported in 22/59 (37%) of the hyperammonaemic group. Improved clinical outcomes with concurrent decrease in ammonia concentration were seen in 60% of patients following treatment adjustment.

CONCLUSIONS

Drug resistance and exposure to stiripentol, oxcarbazepine or high-dose valproate are associated with an increased risk of hyperammonaemia. Clinicians should consider symptoms related to hyperammonaemia in patients on high-dose valproate or multiple antiseizure treatments. Prompt identification of hyperammonaemia and subsequent treatment adjustments can lead to improved clinical outcomes.

Pharmacogenetics-based population pharmacokinetic analysis and dose optimization of valproic acid in Chinese southern children with epilepsy: Effect of ABCB1 gene polymorphism

Objective: The aim of this study was to establish a population pharmacokinetic (PPK) model of valproic acid (VPA) in pediatric patients with epilepsy in southern China, and provide guidance for individualized medication of VPA therapy. Methods: A total of 376 VPA steady-state trough concentrations were collected from 103 epileptic pediatric patients. The PPK parameter values for VPA were calculated by using the nonlinear mixed-effects modeling (NONMEM) method, and a one-compartment model with first-order absorption and elimination processes was applied. Covariates included demographic information, concomitant medications and selected gene polymorphisms. Goodness-of-fit (GOF), bootstrap analysis, and visual predictive check (VPC) were used for model evaluation. In addition, we used Monte Carlo simulations to propose dose recommendations for different subgroup patients. Results: A significant effect of the patient age and ABCB1 genotypes was observed on the VPA oral clearance (CL/F) in the final PPK model. Compared with patients with the ABCB1 rs3789243 AA genotype, CL/F in patients with GG and AG genotypes was increased by 8% and reduced by 4.7%, respectively. The GOF plots indicated the satisfactory predictive performance of the final model, and the evaluation by bootstrap and VPC showed that a stable model had been developed. A table of individualized dosing regimens involving age and ABCB1 genotype was constructed based on the final PPK model. Conclusion: This study quantitatively investigated the effects of patient age and ABCB1 rs3789243 variants on the pharmacokinetic variability of VPA. The PPK models could be beneficial to individual dose optimization in epileptic children on VPA therapy.

Synergistic association of resveratrol and histone deacetylase inhibitors as treatment in amyotrophic lateral sclerosis

Amyotrophic lateral sclerosis (ALS) is a fatal neurodegenerative disease associated with motor neuron degeneration, progressive paralysis and finally death. Despite the research efforts, currently there is no cure for ALS. In recent years, multiple epigenetic mechanisms have been associated with neurodegenerative diseases. A pathological role for histone hypoacetylation and the abnormal NF-κB/RelA activation involving deacetylation of lysines, with the exclusion of lysine 310, has been established in ALS. Recent findings indicate that the pathological acetylation state of NF-κB/RelA and histone 3 (H3) occurring in the SOD1(G93A) murine model of ALS can be corrected by the synergistic combination of low doses of the AMP-activated kinase (AMPK)-sirtuin 1 pathway activator resveratrol and the histone deacetylase (HDAC) inhibitors MS-275 (entinostat) or valproate. The combination of the epigenetic drugs, by rescuing RelA and the H3 acetylation state, promotes a beneficial and sexually dimorphic effect on disease onset, survival and motor neurons degeneration. In this mini review, we discuss the potential of the epigenetic combination of resveratrol with HDAC inhibitors in the ALS treatment.

An individualized medication model of sodium valproate for patients with bipolar disorder based on machine learning and deep learning techniques

Valproic acid/sodium valproate (VPA) is a widely used anticonvulsant drug for maintenance treatment of bipolar disorders. In order to balance the efficacy and adverse events of VPA treatment, an individualized dose regimen is necessary. This study aimed to establish an individualized medication model of VPA for patients with bipolar disorder based on machine learning and deep learning techniques. The sequential forward selection (SFS) algorithm was applied for selecting a feature subset, and random forest was used for interpolating missing values. Then, we compared nine models using XGBoost, LightGBM, CatBoost, random forest, GBDT, SVM, logistic regression, ANN, and TabNet, and CatBoost was chosen to establish the individualized medication model with the best performance (accuracy = 0.85, AUC = 0.91, sensitivity = 0.85, and specificity = 0.83). Three important variables that correlated with VPA daily dose included VPA TDM value, antipsychotics, and indirect bilirubin. SHapley Additive exPlanations was applied to visually interpret their impacts on VPA daily dose. Last, the confusion matrix presented that predicting a daily dose of 0.5 g VPA had a precision of 55.56% and recall rate of 83.33%, and predicting a daily dose of 1 g VPA had a precision of 95.83% and a recall rate of 85.19%. In conclusion, the individualized medication model of VPA for patients with bipolar disorder based on CatBoost had a good prediction ability, which provides guidance for clinicians to propose the optimal medication regimen.

The Role of Intraamygdaloid Oxytocin and D2 Dopamine Receptors in Reinforcement in the Valproate-Induced Autism Rat Model

Background: autism spectrum disorder (ASD) is a neurodevelopmental disorder affecting around 1 out of 68 children and its incidence shows an increasing tendency. There is currently no effective treatment for ASD. In autism research, the valproate (VPA)-induced autism rodent model is widely accepted. Our previous results showed that intraamygdaloid oxytocin (OT) has anxiolytic effects on rats showing autistic signs under the VPA-induced autism model. Methods: rats were stereotaxically implanted with guide cannulae bilaterally and received intraamygdaloid microinjections. In the present study, we investigated the possible role of intraamygdaloid OT and D2 dopamine (DA) receptors on reinforcement using VPA-treated rats in a conditioned place preference test. OT and/or an OT receptor antagonist or a D2 DA antagonist were microinjected into the central nucleus of the amygdala (CeA). Results: valproate-treated rats receiving 10 ng OT spent significantly longer time in the treatment quadrant during the test session of the conditioned place preference test. Prior treatment with an OT receptor antagonist or with a D2 DA receptor antagonist blocked the positive reinforcing effects of OT. The OT receptor antagonist or D2 DA antagonist in themselves did not influence the time rats spent in the treatment quadrant. Conclusions: Our results show that OT has positive reinforcing effects under the VPA-induced autism rodent model and these effects are OT receptor-specific. Our data also suggest that the DAergic system plays a role in the positive reinforcing effects of OT because the D2 DA receptor antagonist can block these actions.

Integrative genomics reveals pathogenic mediator of valproate-induced neurodevelopmental disability

Prenatal exposure to the anti-seizure medication sodium valproate (VPA) is associated with an increased risk of adverse postnatal neurodevelopmental outcomes, including lowered intellectual ability, autism spectrum disorder and attention-deficit hyperactivity disorder. In this study, we aimed to clarify the molecular mechanisms underpinning the neurodevelopmental consequences of gestational VPA exposure using integrative genomics. We assessed the effect of gestational VPA on foetal brain gene expression using a validated rat model of valproate teratogenicity that mimics the human scenario of chronic oral valproate treatment during pregnancy at doses that are therapeutically relevant to the treatment of epilepsy. Two different rat strains were studied-inbred Genetic Absence Epilepsy Rats from Strasbourg, a model of genetic generalized epilepsy, and inbred non-epileptic control rats. Female rats were fed standard chow or VPA mixed in standard chow for 2 weeks prior to conception and then mated with same-strain males. In the VPA-exposed rats maternal oral treatment was continued throughout pregnancy. Foetuses were extracted via C-section on gestational Day 21 (1 day prior to birth) and foetal brains were snap-frozen and genome-wide gene expression data generated. We found that gestational VPA exposure via chronic maternal oral dosing was associated with substantial drug-induced differential gene expression in the pup brains, including dysregulated splicing, and observed that this occurred in the absence of evidence for significant neuronal gain or loss. The functional consequences of VPA-induced gene expression were explored using pathway analysis and integration with genetic risk data for psychiatric disease and behavioural traits. The set of genes downregulated by VPA in the pup brains were significantly enriched for pathways related to neurodevelopment and synaptic function and significantly enriched for heritability to human intelligence, schizophrenia and bipolar disorder. Our results provide a mechanistic link between chronic foetal VPA exposure and neurodevelopmental disability mediated by VPA-induced transcriptional dysregulation.

The impact of ibuprofen on valproic acid plasma concentration in pediatric patients

The combination of valproic acid (VPA) and ibuprofen is common in children with epilepsy. Three case reports investigated that ibuprofen might decrease plasma concentration of VPA, however, no cohort study was published to evaluate the interaction of ibuprofen on VPA plasma concentration in pediatric patients.Data from patients with measured VPA trough concentrations (C₀) were retrospectively collected in a Chinese teaching and tertiary Children's Hospital from January 2017 to June 2019. The samples measured within 6 weeks of the last ibuprofen administration were considered as ibuprofen combination samples. Patients with paired samples before and after ibuprofen administration were additionally analyzed. The effects of ibuprofen on the VPA trough concentration to dose (C₀/D) ratio were investigated. The proportion of samples with achieved target concentrations of VPA (50-100 mg/L) and the corresponding required dosage were compared. Moreover, subgroup analysis according to the interval between the last ibuprofen dosage and C₀ measurement was performed.A total of 616 samples from 434 patients, of whom 16 had paired samples, were included. VPA C₀/D decreased when ibuprofen was administered by 7.5% and 30.6% of the total samples and paired samples, respectively. The interaction was significant within 1 week of the last ibuprofen dose. No significant differences were observed in the proportion of target concentration achieved and VPA dose requirement when ibuprofen was combined.A moderate effect of ibuprofen on VPA C₀/D was observed within 1 week of ibuprofen administration; the target concentration and required doses of VPA were comparable.

The marmoset as a model for investigating the neural basis of social cognition in health and disease

Social-cognitive processes facilitate the use of environmental cues to understand others, and to be understood by others. Animal models provide vital insights into the neural underpinning of social behaviours. To understand social cognition at even deeper behavioural, cognitive, neural, and molecular levels, we need to develop more representative study models, which allow testing of novel hypotheses using human-relevant cognitive tasks. Due to their cooperative breeding system and relatively small size, common marmosets (Callithrix jacchus) offer a promising translational model for such endeavours. In addition to having social behavioural patterns and group dynamics analogous to those of humans, marmosets have cortical brain areas relevant for the mechanistic analysis of human social cognition, albeit in simplified form. Thus, they are likely suitable animal models for deciphering the physiological processes, connectivity and molecular mechanisms supporting advanced cognitive functions. Here, we review findings emerging from marmoset social and behavioural studies, which have already provided significant insights into executive, motivational, social, and emotional dysfunction associated with neurological and psychiatric disorders.

SARS-CoV-2 Infection, Sex-Related Differences, and a Possible Personalized Treatment Approach with Valproic Acid: A Review

Sex differences identified in the COVID-19 pandemic are necessary to study. It is essential to investigate the efficacy of the drugs in clinical trials for the treatment of COVID-19, and to analyse the sex-related beneficial and adverse effects. The histone deacetylase inhibitor valproic acid (VPA) is a potential drug that could be adapted to prevent the progression and complications of SARS-CoV-2 infection. VPA has a history of research in the treatment of various viral infections. This article reviews the preclinical data, showing that the pharmacological impact of VPA may apply to COVID-19 pathogenetic mechanisms. VPA inhibits SARS-CoV-2 virus entry, suppresses the pro-inflammatory immune cell and cytokine response to infection, and reduces inflammatory tissue and organ damage by mechanisms that may appear to be sex-related. The antithrombotic, antiplatelet, anti-inflammatory, immunomodulatory, glucose- and testosterone-lowering in blood serum effects of VPA suggest that the drug could be promising for therapy of COVID-19. Sex-related differences in the efficacy of VPA treatment may be significant in developing a personalised treatment strategy for COVID-19.

Human forebrain organoids reveal connections between valproic acid exposure and autism risk

Valproic acid (VPA) exposure as an environmental factor that confers risk of autism spectrum disorder (ASD), its functional mechanisms in the human brain remain unclear since relevant studies are currently restricted to two-dimensional cell cultures and animal models. To identify mechanisms by which VPA contribute to ASD risk in human, here we used human forebrain organoids (hFOs), in vitro derived three-dimensional cell cultures that recapitulate key human brain developmental features. We identified that VPA exposure in hFOs affected the expression of genes enriched in neural development, synaptic transmission, oxytocin signaling, calcium, and potassium signaling pathways, which have been implicated in ASD. Genes (e.g., CAMK4, CLCN4, DPP10, GABRB3, KCNB1, PRKCB, SCN1A, and SLC24A2) that affected by VPA were significantly overlapped with those dysregulated in brains or organoids derived from ASD patients, and known ASD risk genes, as well as genes in ASD risk-associated gene coexpression modules. Single-cell RNA sequencing analysis showed that VPA exposure affected the expression of genes in choroid plexus, excitatory neuron, immature neuron, and medial ganglionic eminence cells annotated in hFOs. Microelectrode array further identified that VPA exposure in hFOs disrupted synaptic transmission. Taken together, this study connects VPA exposure to ASD pathogenesis using hFOs, which is valuable for illuminating the etiology of ASD and screening for potential therapeutic targets.

Valproic acid decreases vascular smooth muscle cell proliferation via protein phosphatase 2A-mediated p70 S6 kinase inhibition

Valproic acid (VPA) has been used to treat epilepsy and bipolar disorder. Although the abnormal proliferation of vascular smooth muscle cells (VSMCs) is a well-established contributor to the development of various vascular diseases including atherosclerosis, the effect of VPA on VSMC proliferation and its mechanism of action have not been fully revealed. Herein, we investigated the molecular mechanism by which VPA inhibits rat VSMC proliferation. VPA dose-dependently decreased VSMC proliferation, which was accompanied by the dose-dependent decrease in phosphorylation of p70 S6 kinase (p70S6K) at Thr389 (p-p70S6K-Thr³⁸⁹), and overexpression of the p70S6K-T389E mutant gene significantly reversed VPA-inhibited VSMC proliferation. Co-treatment with okadaic acid, a specific protein phosphatase 2A (PP2A) inhibitor, significantly restored p-p70S6K-Thr³⁸⁹. Furthermore, knockdown of PP2Ac gene expression by siRNA significantly reversed VPA-inhibited p-p70S6K-Thr³⁸⁹ and VSMC proliferation. Confocal microscopic analyses and co-immunoprecipitation results clearly showed that the physical binding of p70S6K and PP2Ac was promoted by VPA. Valpromide, a VPA's structural derivative with no histone deacetylase (HDAC) inhibition activity, as well as VPA and sodium butyrate, an HDAC inhibitor similar to VPA, decreased VSMC proliferation and p-p70S6K-Thr³⁸⁹, indicating that HDAC is not involved in VPA-inhibited VSMC proliferation. Finally, the inhibitory effects of VPA on p-p70S6K-Thr³⁸⁹ and VSMC proliferation were reiterated in a platelet-derived growth factor (PDGF)-induced in vitro atherosclerosis model. In conclusion, our results demonstrate that VPA decreased cell proliferation via PP2A-mediated inhibition of p-p70S6K-Thr³⁸⁹ in basal and PDGF-stimulated VSMCs. The results suggest that VPA could be used in the treatment and prevention of atherosclerosis and in-stent restenosis.

Effects of in utero exposure to valproate or levetiracetam on the seizures and newborn histopathology of genetic absence epilepsy rats

Valproate (VPA) and levetiracetam (LEV), the two broad spectrum antiseizure drugs with antiabsence effects were previously tested for their antiepileptogenic effects when administered in the early postnatal period and revealed possible modification of the epileptogenic process though the effect being not persistent. The aim of this study was to investigate the effects of in utero exposure to these drugs on the absence epilepsy seizures of Genetic Absence Epilepsy Rats from Strasbourg (GAERS) rats on electroencephalogram (EEG) which are characterised by bilateral, symmetrical, and synchronized spike-and-wave discharges (SWDs). Considering LEV was proposed as a safer drug of choice in pregnancy, its effects on the newborn histopathology of GAERS was also investigated. Adult female GAERS were randomly grouped as VPA-(400 mg/kg/day), LEV- (100 mg/kg/day), and saline-treated. The drugs were injected into the animals intraperitoneally starting before pregnancy until parturition. The lungs, kidneys, and brains of the LEV-exposed newborns were evaluated histologically to be compared with unexposed naïve Wistar and GAERS newborns. Rest of the VPA-, LEV-, and saline-exposed offsprings were taken for EEG recordings on postnatal day 90. VPA or LEV did not show significant effect on mean cumulative duration and mean number of SWDs on EEG. The lungs of the LEV-exposed offsprings showed thickened alveolar epithelium in most regions, suggesting incomplete development of the alveoli. The renal examination revealed dilated Bowman's spaces in some renal corpuscles, which may be interpreted as a deleterious effect of LEV on the kidney. In addition, brain examination of LEV- and saline-exposed groups revealed irregularities in cortical thickness compared to Wistar control group. Lack of significant difference on SWD parameters may indicate that the mechanism responsible for the antiepileptogenic effects of VPA and LEV may not be operating in the prenatal period. The detrimental effect of LEV exposure observed in our study on the lungs and the kidneys of the newborns should be investigated by further studies with advanced molecular and biochemical techniques.

Postcraniotomy Headache: Etiologies and Treatments

Purpose of Review

Postcraniotomy headache (PCH) is a highly underappreciated and very common adverse event following craniotomy.

Recent Findings

Analgetic medication with opioids often interferes with neurologic evaluation in the acute phase of recovery and should be kept to a minimal, in general, in the treatment of chronic pain as well. We provide an update on the latest evidence for the management of acute and chronic PCH.

Summary

Especially in the neurosurgical setting, enhanced recovery after surgery protocols need to include a special focus on pain control. Patients at risk of developing chronic pain must be identified and treated as early as possible.

Effects of genetic polymorphism of drug-metabolizing enzymes on the plasma concentrations of antiepileptic drugs in Chinese population

As a chronic brain disease, epilepsy affects ~50 million people worldwide. The traditional antiepileptic drugs (AEDs) are widely applied but showing various problems. Although the new AEDs have partially solved the problems of traditional AEDs, the current clinical application of traditional AEDs are not completely replaced by new drugs, particularly due to the large individual differences in drug plasma concentrations and narrow therapeutic windows among patients. Therefore, it is still clinically important to continue to treat patients using traditional AEDs with individualized therapeutic plans. To date, our understanding of the molecular and genetic mechanisms regulating plasma concentrations of AEDs has advanced rapidly, expanding the knowledge on the effects of genetic polymorphisms of genes encoding drug-metabolizing enzymes on the plasma concentrations of AEDs. It is increasingly imperative to summarize and conceptualize the clinical significance of recent studies on individualized therapeutic regimens. In this review, we extensively summarize the critical effects of genetic polymorphisms of genes encoding drug-metabolizing enzymes on the plasma concentrations of several commonly used AEDs as well as the clinical significance of testing genotypes related to drug metabolism on individualized drug dosage. Our review provides solid experimental evidence and clinical guidance for the therapeutic applications of these AEDs.

The effect of erythromycin and clarithromycin versus azithromycin on serum valproate concentration

Introduction

Unlike azithromycin, erythromycin and clarithromycin strongly inhibit CYP450, which metabolizes valproic acid. The aim of this study was to evaluate the impact of macrolide administration on serum valproate trough levels.

Methods

This retrospective cohort study included hospitalized adult patients who concomitantly received valproate with a macrolide. Patients who received a carbapenem, those who do not have a baseline and/or post-levels, and those who received different doses of valproate were excluded. The change in serum valproate trough level from baseline to after the occurrence of co-administration (post-level) was compared in patients who received either erythromycin or clarithromycin versus those who received azithromycin.

Results

A total of thirteen patients were included in the comparison. The mean ± SD for change in serum valproate trough levels was significantly higher in the erythromycin/clarithromycin group than the azithromycin group (209.1 ± 105.9 µmol/L [equivalent to 30.1 ± 15.2 mg/L] vs. 12.7 ± 52.1 µmol/L [equivalent to 1.8 ± 7.5 mg/L]; P = 0.002).

Conclusion

This study found a significantly higher increase in serum trough levels of valproate after co-administration of erythromycin/clarithromycin versus azithromycin. Clinicians should consider avoiding co-administration of erythromycin and clarithromycin with valproate if possible or close monitoring of valproate levels with dose reduction.

Valproate prescription to women of childbearing age in English primary care: repeated cross-sectional analyses and retrospective cohort study

Background

Valproate is a teratogenic drug that should be avoided during the preconception period and pregnancy. The aim was to explore general practitioners’ (GPs) prescription patterns over time, describe trends, and explore inter-practice variation within primary care.

Methods

We identified women of childbearing age (12–46 years old) in the Royal College of General Practitioners (RCGP) Research and Surveillance Centre (RSC) sentinel network. We performed repeated cross-sectional analyses from 2004 to 2018 to determine rates of prescription and a retrospective cohort estimated the prevalence of use of valproate during pregnancy.

Results

In 2004, 0.31% (95% Confidence Interval (95%CI):0.18 to 0.44%) women were prescribed valproate, decreasing to 0.16% (95%CI:0.07 to 0.24%) by 2018. Among women with epilepsy, the rate fell from 15.2% (95%CI:14.4 to 16.0%) to 8.8% (95% CI:8.2 to 9.7%) over the same period. In 2018, almost two thirds (62.2%) of women who were prescribed valproate had epilepsy only, whereas bipolar disorder and migraine accounted for 15.8% and 7.4% respectively. Contraceptive prescriptions did not increase over time, and only in 2018 was there greater odds of being prescribed contraception (OR 1.41, 95%CI:1.08 to 1.45). Just under a fifth (19.7%) of women were prescribed valproate during their pregnancy; two out of three of these pregnancies were preceded by folic acid prescription (5 mg). While some practices reduced their rate of valproate prescription, others did not.

Conclusions

Regulatory guidelines have changed GPs' prescription patterns in women of childbearing potential for valproate but not for contraception. Further research is needed to identify the barriers of GPs and women of childbearing potential to undertaking contraception.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12884-021-04351-x.

Investigation of the risk of valproic acid-induced tremor: clinical, neuroimaging, and genetic factors

RATIONALE

Investigation of associated risk factors of valproic acid (VPA)-induced tremor helped in increasing tolerance and optimizing treatment scheme individually.

OBJECTIVES

To determine the risk factors of VPA-induced tremor, with particular attention on identifying tremor-susceptible gene mutations.

METHODS

Epileptic patients taking VPA were divided into a tremor and a non-tremor groups. A mutation of rs9652490 in the leucine-rich repeat and immunoglobulin domain-containing Nogo-receptor-interacting protein 1 (LINGO-1) gene was determined by Sanger sequencing. Cerebellar atrophy was assessed, and various cerebellar dimensions were measured on magnetic resonance imaging (MRI) scans.

RESULTS

One hundred and eighty-one of 200 subjects were included. Multivariate regression analysis indicated several VPA-induced tremor-related factors: females (OR = 2.718, p = 0.014), family history of tremor (OR = 7.595, p = 0.003), treatment duration (> 24 months; OR = 3.294, p = 0.002), and daily dosage (> 1,000 mg/d; OR = 19.801, p = 0.008) of VPA. Chi-square tests revealed that treatment with VPA magnesium-ER (p = 0.030) and carbamazepine combination (p = 0.040) reduced the incidence of tremor. One hundred and seventy-six gene sequencing and 86 MRI results excluded any significant difference between the two groups in the mutation of rs9652490 within LINGO-1, the ratio of cerebellar atrophy or the cerebellar-dimension values (p > 0.05). However, mutation of rs9652490 within LINGO-1 was correlated with increased cerebellar atrophy (p = 0.001), reduced cerebellar hemisphere thickness (p = 0.025), and right cerebellar hemisphere longitudinal diameter (p = 0.047).

CONCLUSIONS

Our cohort indicated risk (female, positive family history of tremor, daily dosage > 1000 mg and treatment duration > 24 months of VPA) and protective factors (VPA magnesium-ER and combination with CBZ) of VPA-induced tremor. Mutation of rs9652490 within LINGO-1 correlated with cerebellar atrophy, neither was correlated with VPA-induced tremor.

The effect of valproic acid on SLC5A8 expression in gonad-intact and gonadectomized rat thymocytes

BACKGROUND

Valproic acid (VPA) pharmacological mechanisms are related to the anti-inflammatory and anti-viral effects. VPA is a histone deacetylases inhibitor and serves a role in its immunomodulatory impacts. VPA has complex effects on immune cell's mitochondrial metabolism. The SLC5A8 transporter of short fatty acids has an active role in regulating mitochondrial metabolism. The study aimed to investigate whether SLC5A8 expresses the sex-related difference and how SLC5A8 expression depends on gonadal hormones, VPA treatment, and NKCC1 expression in rat thymocytes.

METHODS

Control groups and VPA-treated gonad-intact and gonadectomized Wistar male and female rats were investigated (n = 6 in a group). The VPA 300 mg/kg/day in drinking water was given for 4 weeks. The SLC5A8 (Slc5a8 gene) and NKCC1 (Slc12a2 gene) RNA expressions were determined by the RT-PCR method.

RESULTS

The higher Slc5a8 expression was found in the gonad-intact males than respective females (p = 0.004). VPA treatment decreased the Slc5a8 expression in gonad-intact and castrated males (p = 0.02 and p = 0.03, respectively), and increased in gonad-intact female rats compared to their control (p = 0.03). No significant difference in the Slc5a8 expression between the ovariectomized female control and VPA-treated females was determined (p > 0.05). VPA treatment alters the correlation between Slc5a8 and Slc12a2 gene expression in thymocytes of gonad-intact rats.

CONCLUSION

VPA effect on the Slc5a8 expression in rat thymocytes is gender- and gonadal hormone-dependent.

The effects of regular swimming exercise during sodium valproate treatment on seizure behaviors and EEG recordings in pentylenetetrazole-kindled rats

We investigated the effects of alone/combined regular swimming exercise and sodium valproate on epileptic seizure behaviors and EEG recordings, anti-oxidative mechanism, learning, and memory in pentylenetetrazole (PTZ)-kindled rats. Forty-eight healthy rats were randomly divided into eight equal groups as control (CONT), swimming exercise (EX), sodium valproate (SV), SV+EX, PTZ, EX+PTZ, SV+PTZ and SV+EX+PTZ. The rats were forced to regular swimming exercise for 60 min every other day, 13 doses of PTZ (40 mg/kg) were given to induce epileptic seizures and 200 mg/kg SV was given for 28 days. Epileptic seizures were evaluated by visual observation and EEG recordings (total spike numbers and number of epileptiform discharges). Memory and learning skills were assessed with passive avoidance test. According to our visual seizure observations, seizure latency was prolonged only in SV+EX+PTZ (p < 0.001) group, seizure severity score decreased in SV+PTZ (p < 0.05) and SV+EX+PTZ (p < 0.001) groups and seizure frequency was reduced in SV+PTZ (p < 0,001), EX+PTZ (p < 0,001), and SV+EX+PTZ (p < 0,001) groups. Total spike numbers and number of epileptiform discharges highly increased in PTZ group, whereas they decreased in swimming exercise and/or SV treatment groups. The most effective result was seen in the combined therapy group. Memory deficit was observed in PTZ -kindling group, but it didn't change with exercise or SV. Based on our results, regular swimming exercise had positive effects on PTZ-induced seizure frequency, and combined therapy of regular swimming exercise and SV is the most effective way to ameliorate visual seizure behaviors and decrease spike numbers and number of epileptiform discharges according to EEG recordings. Regular swimming exercise could be an alternative option to reduce the dose of SV and the side effects of SV can be avoided in clinical aspects.

Evaluation of micronutrient levels in children with cerebral palsy

BACKGROUND

Many studies evaluating the nutritional status of children with cerebral palsy (CP) have focused on energy requirements and protein intake. The present work aimed to assess nutritional status and micronutrient levels of children with (CP).

METHODS

This multicenter, cross-sectional and observational study was conducted in 10 different cities in Turkey. Data were available for 398 participants. Anthropometric measurements, feeding mode, nutritional status, and micronutrient levels were evaluated.

RESULTS

The study was conducted with 398 participants (303 patients and 95 healthy controls). Statistical analysis showed that according to the Gomez Classification, weight-for-age (WFA) revealed malnutrition in 92.6% of children with CP, based on Centers for Disease Control and Prevention percentiles. Measurements of micronutrient levels showed that zinc levels were low in patients, whereas vitamin A levels were low in controls. Phosphorous and manganese levels were significantly lower in malnourished children than in typical children. The results revealed that children consuming enteral nutrition solutions had higher selenium and lower zinc levels than non-consumers.

CONCLUSIONS

Malnutrition is not only a protein- or calorie-based problem; micronutrient deficiencies might cause severe health problems. Children with chronic neurological disabilities must be carefully evaluated for these issues. Therefore, nutritional interventions should be adapted to nutrition.