Valproate Concentrations Research Articles

A microRNA signature for valproate-induced steatosis in human hepatocytes and its application to predict fatty liver in paediatric epileptic patients on valproate therapy

Valproate (VPA) has been the first-line, most frequently prescribed antiepileptic drug in children over the past 50 years. VPA causes, idiosyncratic hepatotoxicity in some patients, who often presents with hepatic steatosis. Experimental studies also support that VPA has high potential to induce steatosis. However, there is an apparent lack of significant hepatic problems in neuropediatric units, likely because iatrogenic liver steatosis lacks specific biomarkers. Thus, it is possible that a relevant number of children under VPA have asymptomatic fatty liver. Aims1) to demonstrate VPA-induced triglyceride (TG) accumulation in cultured human upcyte hepatocytes, 2) to identify miRNAs that are deregulated by VPA and associated with TG levels in these cells, and 3) to test these miRNAs, as potential non-invasive biomarkers, in plasma of paediatric epileptic patients on VPA, to identify those with a potential risk of liver steatosis.Human upcyte hepatocytes were exposed to subcytotoxic VPA concentrations. Hepatocytes increased intracellular TGs by 27 % and 45 % after 2 and 4 mM VPA for 24 h. The profiling of cellular miRNAs by microarray analysis after 4 mM VPA identified 43 deregulated human miRNAs (fold-change > 1.5 or < −1.5; FDR p<0.05). Some of them (n=11), which were validated by RTqPCR and showed correlation (Pearson r≥ 0.6) with intracellular TG levels, were selected as potential VPA-induced steatosis biomarkers. Next, we investigated the expression of these miRNAs in human plasma and found that 9 of them could be reliably quantified by RTqPCR: miR-485-3p, miR-127-3p, miR-30a-3p, miR-92b-3p, miR-212-3p, miR-182-5p, miR-183-5p, miR-500a-5p and miR-675-5p. Screening of this 9-miRNA signature in 80 paediatric epileptic patients on VPA identified 18 patients (23 %) that clustered separately because of important alterations in the selected plasma miRNAs. These patients were younger and had higher VPA blood concentrations and serum liver enzyme levels.In conclusion, VPA induced both TG accumulation and deregulation of a set of miRNAs in cultured human hepatocytes. Nine of these miRNAs have demonstrated potential as circulating biomarkers to identify VPA-induced steatosis in epileptic patients, which should require closer clinical follow-up.

Effects of sleeve gastrectomy and Roux-en-Y gastric bypass on pharmacokinetics of lamotrigine and valproate: A cohort study

BackgroundBariatric surgeries may affect the pharmacokinetics of medications through alterations of the gastrointestinal physiology. Pharmacokinetic changes of first-line antiseizure medications such as lamotrigine and valproate following bariatric treatment have received little research attention so far. MethodsIn our prospective case study we included lamotrigine- or valproate-treated patients undergoing bariatric surgery at hospitals in Central Norway. Lamotrigine and valproate concentrations were assessed using serial blood samples over a dose interval, before and one, six and twelve months following surgery. Primary outcomes included changes in area under the time-concentration curve (AUC) with secondary outcomes comprising full pharmacokinetic profiling. ResultsSix lamotrigine-treated obese patients undergoing Roux-en-Y gastric bypass (RYGB) (n = 3) and sleeve gastrectomy (SG) (n = 3), as well as two valproate-treated patients (one undergoing RYGB and one SG) were included. Largest changes for dose-adjusted AUC values after surgery were seen in RYGB-treated patients on lamotrigine (average increases of 38 % one month and 32 % 12 months postoperatively). In the patients on valproate, AUC values were decreased by 22 % after 6 months and by 30 % after 12 months. The interindividual variation was high. Formal statistical testing was not done due to few cases. ConclusionPostoperative pharmacokinetic changes for lamotrigine and valproate were modest, but for lamotrigine changes may be larger in patients undergoing RYGB than in those undergoing SG. Given the substantial interindividual variation, therapeutic drug monitoring should be used to capture pharmacokinetic changes and guide dose adjustments after bariatric surgery.

A validated high-performance liquid chromatography-ultraviolet method for the determination of valproic acid derivatives in pharmaceutical formulations with a microbiological suitability evaluation

Valproic acid and its derivatives are common drugs used in the treatment of epilepsy, a result of CNS disorders. Because the molecular structure of valproic acid, as a fatty acid, does not contain any chromophore groups, its peak response demanded special conditions to be detected in HPLC, ensuring the best precision results. Still, the current approach illustrates simple, validated procedures for conduction. The conducted chromatographic system consists of the BDS Hypersil C8, 150 × 4.6 mm, 5 µm column using a mobile phase of acetonitrile: phosphate buffer (4:6) at a detection wavelength of 215 nm at room temperature. A full method validation study was conducted and approved to ensure precise, repeatable, and accurate results by implementing system suitability parameters. In microbiological terms, a suitability test is used to validate microbiological testing methods, ensuring their efficacy despite potential interference from antimicrobial properties in the tested materials. The HPLC-UV developed and validated analytical method was evaluated, and it was found to be sensitive for use in the detection of low concentrations of methylparaben, propylparaben, and valproate with an optimum run time of six minutes. limit of detection (LODs) were statistically estimated and found to be 2.27 µg/mL, 39.77 ng/mL, and 1.84 µg/mL for methylparaben, propylparaben, and valproate, respectively. Additionally, the method demonstrated a high recovery of methylparaben, propylparaben, and valproate with an excellent closed-accuracy range (98.84% - 101.34%). An excellent regression coefficient (r) of 0.99924, 0.99998, and 0.99997 for methylparaben, valproate, and propylparaben, respectively, was achieved. Assay determination of various pharmaceutical dosage forms in the local market was implemented, yielding admirable results.

Utilizing an acute hyperthermia-induced seizure test and pharmacokinetic studies to establish optimal dosing regimens in a mouse model of Dravet syndrome.

The current standard of care for Dravet syndrome (DS) includes polytherapy after inadequate seizure control with one or more monotherapy approaches. Treatment guidelines are often based on expert opinions, and finding an optimal balance between seizure control and adverse drug effects can be challenging. This study utilizes the efficacy and pharmacokinetic assessment of a second-line treatment regimen that combines clobazam and sodium valproate with an add-on drug as a proof-of-principle approach to establish an effective therapeutic regimen in a DS mouse model. We evaluated the efficacy of add-on therapies stiripentol, cannabidiol, lorcaserin, or fenfluramine added to clobazam and sodium valproate against hyperthermia-induced seizures in Scn1aA1783V/WT mice. Clobazam, N-desmethyl clobazam (an active metabolite of clobazam), sodium valproate, stiripentol, and cannabidiol concentrations were quantified in plasma and brain using liquid chromatography-tandem mass spectrometry for the combinations deemed effective against hyperthermia-induced seizures. The concentration data were used to calculate pharmacokinetic parameters via noncompartmental analysis in Phoenix WinNonLin. Higher doses of stiripentol or cannabidiol, in combination with clobazam and sodium valproate, were effective against hyperthermia-induced seizures in Scn1aA1783V/WT mice. In Scn1aWT/WT mice, brain clobazam and N-desmethyl clobazam concentrations were higher in the triple-drug combinations than in the clobazam monotherapy. Stiripentol and cannabidiol brain concentrations were greater in the triple-drug therapy than when given alone. A polypharmacy strategy may be a practical preclinical approach to identifying efficacious compounds for DS. The drug-drug interactions between compounds used in this study may explain the potentiated efficacy of some polytherapies.

Therapeutic drug monitoring for valproate: deriving a novel formula for calculation of free concentration

BackgroundMonitoring free valproate concentrations, as with other highly protein-bound anticonvulsants, is essential in clinical situations where protein binding may be disrupted. Conversion of measured total concentrations to approximate free concentrations offers a cost-effective alternative. This study evaluated the relationship between total and free valproate concentrations for discordance and the impact of key determinants. A novel formula was devised that incorporates significant variables.MethodsA multicentre, cross-sectional observational analytical study included 101 subjects 18 years and older using valproate for 6 months or longer. Participants were recruited from private and public sector healthcare settings from primary to tertiary level in, South Africa, during 2017–2019.ResultsFree valproate concentrations could be measured for 84 subjects. Discordance for concomitant total and free valproate concentrations was 79.1%. Among 19 participants with elevated free concentrations, 15 (78.9%) had total valproate concentrations within the recommended reference range. Calculations based on the study-derived formula were more accurate in predicting free valproate concentration than previously proposed methods.ConclusionThis study proposes that the novel formula for calculating free valproate enables more accurate prediction.

Pharmacogenetic Variants and Plasma Concentrations of Antiseizure Drugs

Precise estimation of a patient's drug metabolism capacity is important for antiseizure dose personalization. To quantify the differences in plasma concentrations for antiseizure drugs associated with variants of genes encoding drug metabolizing enzymes. PubMed, Clinicaltrialsregister.eu, ClinicalTrials.gov, International Clinical Trials Registry Platform, and CENTRAL databases were screened for studies from January 1, 1990, to September 30, 2023, without language restrictions. Two reviewers performed independent study screening and assessed the following inclusion criteria: appropriate genotyping was performed, genotype-based categorization into subgroups was possible, and each subgroup contained at least 3 participants. The Meta-analysis of Observational Studies in Epidemiology (MOOSE) guidelines were followed for data extraction and subsequent quality, validity, and risk-of-bias assessments. The results from the included studies were pooled with random-effect meta-analysis. Plasma concentrations of antiseizure drugs were quantified with the dose-normalized area under the concentration-time curve, the dose-normalized steady state concentration, or the concentrations after a single dose at standardized dose and sampling time. The ratio of the means was calculated by dividing the mean drug plasma concentrations of carriers and noncarriers of the pharmacogenetic variant. Data from 98 studies involving 12 543 adult participants treated with phenytoin, valproate, lamotrigine, or carbamazepine were analyzed. Studies were mainly conducted within East Asian (69 studies) or White or European (15 studies) cohorts. Significant increases of plasma concentrations compared with the reference subgroup were observed for phenytoin, by 46% (95% CI, 33%-61%) in CYP2C9 intermediate metabolizers, 20% (95% CI, 17%-30%) in CYP2C19 intermediate metabolizers, and 39% (95% CI, 24%-56%) in CYP2C19 poor metabolizers; for valproate, by 12% (95% CI, 4%-20%) in CYP2C9 intermediate metabolizers, 12% (95% CI, 2%-24%) in CYP2C19 intermediate metabolizers, and 20% (95% CI, 2%-41%) in CYP2C19 poor metabolizers; and for carbamazepine, by 12% (95% CI, 3%-22%) in CYP3A5 poor metabolizers. This systematic review and meta-analysis found that CYP2C9 and CYP2C19 genotypes encoding low enzymatic capacity were associated with a clinically relevant increase in phenytoin plasma concentrations, several pharmacogenetic variants were associated with statistically significant but only marginally clinically relevant changes in valproate and carbamazepine plasma concentrations, and numerous pharmacogenetic variants were not associated with statistically significant differences in plasma concentrations of antiseizure drugs.

Retrospective Analysis of Steady-State Sodium Valproate Plasma Concentrations in Chinese Patients With Bipolar Disorder: Impact of Demographic and Clinical Characteristics.

This study comprehensively examined the demographic and clinical characteristics of patients undergoing valproic acid therapy and explored their potential impact on plasma valproic acid concentrations. All enrolled patients were administered the extended-release formulation. An in-depth investigation of factors, including dose, age, sex, body mass index, co-administered medications, and laboratory test findings, was conducted to evaluate their potential influence on study outcomes. In total, 164 patients met the inclusion criteria and were included in the analysis. The patient age ranged from 13 to 60 years, with a median age of 25.71 years. Most patients (89%) received a daily dose of 1 g valproic acid. Co-administered psychiatric medications included aripiprazole, quetiapine, and lorazepam. Laboratory test results, such as hemoglobin and transaminase levels, were also collected as part of the study. The average plasma valproic acid plasma concentration was 79.8 mg/L. The dose significantly affected valproic acid concentrations, as a higher percentage of measurements exceeded the therapeutic range at a daily dose of 1 g. Furthermore, females exhibited significantly higher valproic acid concentrations compared with males at the same dose ( P < 0.05). However, different age groups showed no statistically significant differences in valproic acid concentrations ( P > 0.05). The co-administered antipsychotic and antidepressant medications significantly affected valproate concentrations, as reflected in the multiple regression model ( P < 0.01). This study offers valuable insights into the demographic and clinical characteristics of patients undergoing valproic acid therapy. It highlights the influence of dose, sex, and concomitant medications on plasma valproic acid concentrations. Overall, these findings can help guide dose adjustments and implement personalized treatment strategies in valproic acid therapy.

Total valproate versus free valproate in therapeutic drug monitoring for bipolar disorder: A cross-sectional study.

The debate about observing total versus free serum valproate levels for therapeutic drug monitoring (TDM) has been unresolved for decades. This study was planned to assess the agreement between the total versus free valproate levels and the advantage of one method over the other in TDM. The present cross-sectional study was done on 93 patients with bipolar disorder. The intraclass correlation coefficient, Bland Altman analysis, and Lin's concordance analysis were done to assess the agreement between the total and free valproate concentrations. Linear and polynomial models were constructed to evaluate the relation between the two measurements. Receiver operating characteristics analysis was done to compare the accuracy for differentiating remission from non-remission on Young's mania rating scale (YMRS). The intraclass correlation coefficient and Lin's concordance correlation coefficient were 0.491 (p = .002) and 0.055 (95% CI:0.037, 0.073), respectively. Bland Altman's analysis showed proportional bias. A polynomial model of second order was found to be the best fit for the prediction of free valproate from the data for total valproate, and 81.4% of the variability in free valproate could be explained when adjusted for albumin levels. The area under the curve for total valproate was 0.60 when compared to free valproate 0.56 for differentiating between remission and non-remission, but the comparison between the two ROC analyses was not statistically significant. Free valproate does not provide any added advantage over the total valproate levels; hence, total valproate levels may continue to be used as the marker for drug monitoring.

Population Pharmacokinetics of Valproate in Children: The Importance of Total Daily Dose, Compliance and Co-Treatment

Abstract Valproate represents one of the most commonly used anticonvulsants worldwide, whose narrow therapeutic range and high potential for drug-drug interactions leads to pronounced intra- and inter-individual variability in plasma concentration and response. The aim of our study was to apply population pharmacokinetics analysis to comprehensively investigate and detect the most important factors affecting pharmacokinetics of valproate in Serbian children with epilepsy. This retrospective observational study was based on demographic and medical data retrieved from the medical records on epileptic patients treated with valproate at the pediatric department of the Clinical Centre, Kragujevac, Serbia. Valproate serum concentrations were obtained as a part of routine medical practice. Population pharmacokinetics analysis was performed by MonolixSuite 2019R1 (Lixoft, Antony, France) software, using one-compartment model with first order absorption and linear elimination. The study included 1642 valproate concentrations obtained from 232 patients, of which 201 (1420 concentrations) were included in the index set used for the modelling, while the other 31 (222 concentrations) were the validation set used for external validation of the final model. Covariate testing based on the whole index set revealed that only total daily valproate dose significanly affected the clearance of valproate: Cl (l/h)= 0.135×1.002DD. When only compliant patients were included, co-treatment with carbamazepine was shown to be of significance as well: Cl(l/h)=0.121×1.002DD×1.2CBZ. Our study demonstrated that valproate clearance correlates with total valproate daily dose. The influence of co-treatment with carbamazepine on valproate pharmacokinetics can be observed and used for clearance estimation only in compliant patients.

Evaluating Clinical Sequelae of the Carbapenem-Valproate Interaction: A Retrospective Analysis.

Previous studies identified a rapid decrease in valproate serum concentrations when coadministered with a carbapenem; however, the specific consequences and subsequent therapy adjustments are not well described. We aimed to investigate the clinical and therapeutic implications of the carbapenem-valproate drug-drug interaction. This retrospective analysis included data from 2 large academic medical centers during January 2017 to June 2022. The primary outcome was incidence of seizures or behavioral events stratified by valproate indication. All adult patient encounters with concomitant administration of any carbapenem antimicrobial and valproate were included. Patients without prolonged exposure to valproate prior to hospitalization, without valproate levels pre- and post-carbapenem administration, with an admitting diagnosis of seizure, with exposure to other agents that decrease valproate concentrations, or who had a seizure during the hospitalization prior to carbapenem exposure were excluded. Two hundred fifty-eight episodes of concomitant use among 78 unique adult patients were included. Valproate was used for seizure control in 41 patients (52.6%) and for mood-related disorders in 37 (47.4%). In those prescribed valproate for its antiepileptic properties, seizures occurred following carbapenem administration in 46.3% of encounters. In those taking valproate for mood-related disorders, 50.8% met the primary endpoint of behavioral disturbance. Our study demonstrates significant clinical implications of the carbapenem-valproate interaction. Clinicians should be aware of this interaction and consider alternative antimicrobial and/or antiepileptic agents whenever possible. Adding or increasing doses of antiepileptic agents and/or consultation with a neurologist prior to concomitant use should be considered when this combination cannot be avoided.

Effect of dietary supplementation with Lactobacillus helveticus R0052 on seizure thresholds and antiseizure potency of sodium valproate in mice

ObjectiveBoth animal and human studies, though limited, showed that multi-strain probiotic supplementation may reduce the number of seizures and/or seizure severity. Here, we evaluated the effect of a single strain probiotic supplementation on seizure susceptibility, antiseizure efficacy of sodium valproate, and several behavioral parameters in mice.MethodsLactobacillus helveticus R0052 was given orally for 28 days. Its influence on seizure thresholds was evaluated in the ivPTZ- and electrically-induced seizure tests. The effect on the antiseizure potency of valproate was assessed in the scPTZ test. We also investigated the effects of probiotic supplementation on anxiety-related behavior (in the elevated plus maze and light/dark box tests), motor coordination (in the accelerating rotarod test), neuromuscular strength (in the grip-strength test), and spontaneous locomotor activity. Serum and brain concentrations of valproate as well as cecal contents of SCFAs and lactate were determined using HPLC method.ResultsL. helveticus R0052 significantly increased the threshold for the 6 Hz-induced psychomotor seizure. There was also a slight increase in the threshold for myoclonic and clonic seizure in the ivPTZ test. L. helveticus R0052 did not affect the threshold for tonic seizures both in the maximal electroshock- and ivPTZ-induced seizure tests. No changes in the antiseizure potency of valproate against the PTZ-induced seizures were reported. Interestingly, L. helveticus R0052 increased valproate concentration in serum, but not in the brain. Moreover, L. helveticus R0052 did not produce any significant effects on anxiety-related behavior, motor coordination, neuromuscular strength, and locomotor activity. L. helveticus R0052 supplementation resulted in increased concentrations of total SCFAs, acetate, and butyrate.ConclusionsAltogether, this study shows that a single-strain probiotic – L. helveticus R0052 may decrease seizure susceptibility and this effect can be mediated, at least in part, by increased production of SCFAs. In addition, L. helveticus R0052 may affect bioavailability of valproate, which warrants further investigations.

Derivation and Validation of a New Equation for Estimating Free Valproate Concentration in Critically Ill Adult Patients.

Protein binding of valproate varies among ICU patients, altering the biologically active free valproate concentration (VPAC). Free VPAC is measured at few laboratories and is often discordant with total VPAC. Existing equations to predict free VPAC are either not validated or are inaccurate in ICU patients. We designed this study to derive and validate a novel equation to predict free VPAC using data from ICU patients and to compare its performance to published equations. Retrospective cohort study. Two academic medical centers. Patients older than 18 years old with concomitant free and total VPACs measured in the ICU were included in the derivation cohort if admitted from 2014 to 2018, and the validation cohort if admitted from 2019 to 2022. Multivariable linear regression was used to derive an equation to predict free VPAC. Modified Bland-Altman plots and the rate of therapeutic concordance between the measured and predicted free VPAC were compared. Demographics, median free and total VPACs, and valproate free fractions were similar among 115 patients in the derivation cohort and 147 patients in the validation cohort. The Bland-Altman plots showed the new equation performed better (bias, 0.3 [95% limits of agreement, -13.6 to 14.2]) than the Nasreddine (-9.2 [-26.5 to 8.2]), Kodama (-9.7 [-30.0 to 10.7]), Conde Giner (-7.9 [-24.9 to 9.1]), and Parent (-9.9 [-30.7 to 11.0]) equations, and similar to Doré (-2.0 [-16.0 to 11.9]). The Doré and new equations had the highest therapeutic concordance rate (73%). For patients at risk of altered protein binding such as ICU patients, existing equations to predict free VPAC are discordant with measured free VPAC. A new equation had low bias but was imprecise. External validation should be performed to improve its precision and generalizability. Until then, monitoring free valproate is recommended during critical illness.

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.

Development and Internal Validation of Machine Learning Algorithms for Determining Sodium Valproate Concentrations below the Standard Level Using a Risk Prediction Model of Children with Epilepsy

Background. There is a narrow therapeutic window for sodium valproate, and the blood concentration is too low to control epilepsy, while it is easy to poison the body if the concentration is too high. It is therefore necessary to monitor drug concentration reasonably in order to control epilepsy. The purpose of this study was to establish a model for predicting concentrations of sodium valproate below 50 μg/mL in children with epilepsy. Methods. The clinical data and biochemical examination results of children with epilepsy treated in the pediatric outpatient department of our hospital from June 2019 to March 2022 were retrospectively collected and divided into a development group and a validation group according to a patient ratio of 8 to 2. Five machine learning algorithms were used to identify the key variable factors, and a risk prediction model for sodium valproate blood concentrations lower than the standard concentration was established. The area under the curve (AUC), calibration curve, GiViTi calibration band, and clinical influence curve were used to evaluate the diagnostic efficacy and clinical application value of the model. Results. A total of 525 children with epilepsy were enrolled. In the development group, the random forest algorithm performed best in predicting that the blood concentration of sodium valproate was lower than the standard concentration, showing the highest AUC (1.00). Six factors were determined as a nomogram to predict the incidence of low concentrations. In the validation group and the development group, the calibration curve, GiViTi calibration band, and clinical influence curve all performed well in the evaluation of the diagnostic efficacy and clinical application value of the model. Conclusions. This finding highlights the importance of examining biochemical indices in patients when data regarding the blood concentration of sodium valproate are lacking.

Impact of CYP2C9*2 and *3 polymorphisms on valproate-associated adverse drug reactions in individualsliving with epilepsy: a case-control study.

Epilepsy is characterized by repeated seizure activity. Valproate, acommonly used antiepilepticdrug, shows large inter-individual variation in plasma valproic levels and causes many adverse drug reactions. Aim: To find the influence of CYP2C9*2 and *3 polymorphisms on valproate-associated adverse drug reactions and plasma valproic acid levelsin people with epilepsy. Methods: We recruited 158 peoplewith epilepsy(79 cases and 79 controls) from anepilepsy clinic. Steady-state plasma valproic acid levels were measured using liquid chromatography-mass spectrometryand genotyping of CYP2C9 variantswas carried out with helps of RT-PCR. Results: The presence of a mutantheterozygousgenotype showed an odds ratio (OR) of 2.82 (95% CI: 1.10-7.24) andthe adjusted OR was 5.39 (95% CI: 1.69-17.16). There was no significant difference in steady-state plasma valproate concentration between genotypes. Conclusion: The presence of amutant heterozygous CYP2C9 genotype possesses five-times the risk of developing adverse drug reactions to valproate in people with epilepsy.

An in vitro model of drug-resistant seizures for selecting clinically effective antiseizure medications in Febrile Infection-Related Epilepsy Syndrome.

FIRES is a rare epileptic encephalopathy induced by acute unremitting seizures that occur suddenly in healthy children or young adults after a febrile illness in the preceding 2 weeks. This condition results in high mortality, neurological disability, and drug-resistant epilepsy. The development of new therapeutics is hampered by the lack of validated experimental models. Our goal was to address this unmet need by providing a simple tool for rapid throughput screening of new therapies that target pathological inflammatory mechanisms in FIRES. The model was not intended to mimic the etiopathogenesis of FIRES which is still unknown, but to reproduce salient features of its clinical presentation such as the age, the cytokine storm and the refractoriness of epileptic activity to antiseizure medications (ASMs). We refined an in vitro model of mouse hippocampal/temporal cortex acute slices where drug-resistant epileptic activity is induced by zero Mg2+/100 μM 4-aminopirydine. Clinical evidence suggests that acute unremitting seizures in FIRES are promoted by neuroinflammation triggered in the brain by the preceding infection. We mimicked this inflammatory component by exposing slices for 30 min to 10 μg/ml lipopolysaccharide (LPS). LPS induced a sustained neuroinflammatory response, as shown by increased mRNA levels of IL-1β, CXCL1 (IL-8), TNF, and increased IL-1β/IL-1Ra ratio. Epileptiform activity was exacerbated by neuroinflammation, also displaying increased resistance to maximal therapeutic concentrations of midazolam (100 μM), phenytoin (50 μM), sodium valproate (800 μM), and phenobarbital (100 μM). Treatment of LPS-exposed slices with two immunomodulatory drugs, a mouse anti-IL-6 receptor antibody (100 μM) corresponding to tocilizumab in humans, or anakinra (1.3 μM) which blocks the IL-1 receptor type 1, delayed the onset of epileptiform events and strongly reduced the ASM-resistant epileptiform activity evoked by neuroinflammation. These drugs were shown to reduce ASM-refractory seizures in FIRES patients. The neuroinflammatory component and the pharmacological responsiveness of epileptiform events provide a proof-of-concept validation of this in vitro model for the rapid selection of new treatments for acute ASM-refractory seizures in FIRES.

A New Sensitive Fluorescence Sensor and Photocatalyst for Determination and Degradation of Sodium Valproate Using g-C3N4@Fe3O4@CuWO4 Nanocomposite and FCCD Optimization.

In this research, carbon nitride nanocomposite coupled with Fe3O4 and CuWO4 was thermally synthesized and characterized by different techniques, including SEM, TEM, XRD, EDX, and FTIR. Due to sodium valproate's luminescence quenching of this nanocomposite, a reliable, accurate, sensitive, selective, and fast-acting sodium valproate assay was proposed. Optimization of this fluorescent sensor was carried out by the FCCD approach. In the optimum conditions, the plot of sodium valproate concentration versus nanocomposite fluorescence emission showed a linear response (R2 = 0.9918), with a range of 0-0.55µM, the limit of detection (S/N = 3) equal to 0.85nM and limit of qualification equal to 2.82nM. Photocatalytic activity of g-C3N4@Fe3O4@CuWO4 (40%) nanocomposite exhibited a good potency to sodium valproate degradation. Active species of degradation including superoxide radicals, holes, and hydroxyl radicals were investigated using ammonium oxalate, benzoquinone, and 2-propanol to identify the mechanism of photodegradation action. The activity of benzoquinone in the photocatalytic process led to a reduction in the rate of analyte degradation, which indicates the prominent role of superoxide radicals compared to other species in the degradation process. The degradation rate of the analyte using the Fenton reagent was found to be around two times more than in the Fenton reagent-free process. The possible mechanism for the fluorescence sensor and photocatalytic degradation reaction was also discussed.

Sodium valproate exposure influences the expression of pparg in the zebrafish model.

Valproic acid (VPA) is an anti-epileptic drug used alone or in combination with other medications to treat seizures, mania, and bipolar disorder. VPA recognized as a teratogenic chemical can cause severe birth defects mainly affecting the brain and spinal cord when administered during pregnancy. However, the potential mechanisms of developmental toxicity are still less studied, and in the present study, the influence of VPA exposure was evaluated on zebrafish early-life stages. Zebrafish were exposed to two sublethal concentrations of sodium valproate (SV) (0.06 mM and 0.15 mM) from 24 hours post-fertilization (hpf) to 96 hpf and the SV teratogenic potential was investigated through morphometric analysis of zebrafish larvae combined with the evaluation of cartilage profile. Moreover, the effect of SV on the transcription level of pparg was also performed. The results of the study showed the teratogenic potential of SV, which disrupts the morphometric signature of the head and body. The marked distortion of cartilage structures was paralleled to a malformation of telencephalon and optic tectum in both concentrations suggesting a high teratogen effect of SV on the brain. These data were further confirmed by the increased expression of pparg in the zebrafish head. Overall, the present study confirms the teratogenic activity of SV in the zebrafish model and, for the first time, points out the potential protective role of pparg in the SV dose-dependent toxicity.

Antiseizure Effects of Scoparone, Borneol and Their Impact on the Anticonvulsant Potency of Four Classic Antiseizure Medications in the Mouse MES Model-An Isobolographic Transformation.

Numerous botanical drugs containing coumarins and terpenes are used in ethnomedicine all over the world for their various therapeutic properties, especially those affecting the CNS system. The treatment of epilepsy is based on antiseizure medications (ASMs), although novel strategies using naturally occurring substances with confirmed antiseizure properties are being developed nowadays. The aim of this study was to determine the anticonvulsant profiles of scoparone (a simple coumarin) and borneol (a bicyclic monoterpenoid) when administered separately and in combination, as well as their impact on the antiseizure effects of four classic ASMs (carbamazepine, phenytoin, phenobarbital and valproate) in the mouse model of maximal electroshock-induced (MES) tonic-clonic seizures. MES-induced seizures were evoked in mice receiving the respective doses of the tested natural compounds and classic ASMs (when applied alone or in combinations). Interactions for two-drug and three-drug mixtures were assessed by means of isobolographic transformation of data. Polygonograms were used to illustrate the types of interactions occurring among drugs. The total brain content of ASMs was measured in mice receiving the respective drug treatments with fluorescent polarization immunoassay. Scoparone and borneol, when administered alone, exerted anticonvulsant properties in the mouse MES model. The two-drug mixtures of scoparone with valproate, borneol with phenobarbital and borneol with valproate produced synergistic interactions in the mouse MES model, while the remaining tested two-drug mixtures produced additivity. The three-drug mixtures of scoparone + borneol with valproate and phenobarbital produced synergistic interactions in the mouse MES model. Verification of total brain concentrations of valproate and phenobarbital revealed that borneol elevated the total brain concentrations of both ASMs, while scoparone did not affect the brain content of these ASMs in mice. The synergistic interaction of scoparone with valproate observed in the mouse MES model is pharmacodynamic in nature. Borneol elevated the brain concentrations of the tested ASMs, contributing to the pharmacokinetic nature of the observed synergistic interactions with valproate and phenobarbital in the mouse MES model.

Impact of Intestinal Microbiota Disparities on Sodium Valproate Concentrations in Pediatric Epileptic Patients

Impact of Intestinal Microbiota Disparities on Sodium Valproate Concentrations in Pediatric Epileptic Patients