Hepatotoxicity of newer antiseizure medications in children: an overview and disproportionality analysis of VigiBase.

BACKGROUND: We aimed to characterize newer antiseizure medications (ASMs)-induced hepatotoxicity in children and identify signals of disproportionate reporting of hepatotoxicity-related adverse drug events (ADEs). RESEARCH DESIGN AND METHODS: Case reports reported to VigiBase were accessed using Empirica™ Signal software. To summarize characteristics of the retrieved cases, descriptive statistics were used. A disproportionality analysis was conducted using the Multi-item Gamma Poisson Shrinker algorithm, which calculates Empirical Bayesian Geometric Mean value and its lower and upper 95% confidence limits (EB05 and EB95, respectively). EB05 > 2, N > 0 was considered a signal. RESULTS: Based on 870 analyzed cases, a higher proportion of cases was reported in girls than in boys and in patients aged 2-11 years than in other age groups. Most cases were serious. In 25 cases, hepatotoxicity resulted in death. A high proportion of patients (n = 275, 31.61%) experienced hypersensitivity reactions, mostly due to lamotrigine. The disproportionality analysis yielded 17 signals concerning felbamate, lamotrigine, levetiracetam, oxcarbazepine, stiripentol, and topiramate. Four signals were for severe liver injury and concerned felbamate, lamotrigine, levetiracetam, and topiramate. Gender-biased reporting frequency was detected for four ASM-ADE combinations. CONCLUSION: Our results should serve to raise clinicians' awareness about the potential association between several newer ASMs and drug-induced liver injury in children.

Efficacy of felbamate in a cohort of patients with epilepsy with myoclonic atonic seizures (EMAtS).

Epilepsy with myoclonic atonic seizures (EMAtS) is a rare childhood onset developmental and epileptic encephalopathy which is frequently refractory to medical therapy. The optimal antiseizure medication remains unknown. This study reports the efficacy of felbamate in children with EMAtS. Six large pediatric epilepsy centers performed a retrospective chart review on patients diagnosed with EMAtS at their institutions and collected data on felbamate usage and efficacy. Responders were classified as patients who had a 50% or greater reduction in seizures with a given therapy. Out of 259 patients, 37 (14%) were treated with felbamate. The efficacy of felbamate was 62%, which was greater than that of either levetiracetam or valproic acid (15%, p < 0.001% and 32%, p = 0.001 respectively) and similar to that of the ketogenic diet (69%, p = 0.8). Felbamate appears to be an effective treatment for EMAtS and should be strongly considered in the treatment course of this disease.

Felbamate urolithiasis.

Drug-induced nephrolithiasis is an important consideration in recurrent stone formers with polypharmacy. While felbamate nephrolithiasis has previously been published in the paediatric population, we present the oldest published case of a felbamate stone in an adult, a man in his 30s with Lennox-Gastaut syndrome. Even with moderate dosing, high drug serum levels can occur. Performing at least one stone analysis remains a critical component to care in these patients. Urologists should have a high index of suspicion for drug stone when stone analysis returns indeterminate characterisation in the absence of infection. Close communication with neurology is key to preventing recurrent stone disease.

Binding energy analysis and molecular dynamic simulation studies of the designed orally active, non-toxic GABARAP modulators.

Epilepsy is a severe neurological disorder that occurs when the communication between the neurons is disturbed. Gamma-amino butyric acid-associated protein (GABARAP) plays a key role in balancing Gamma-aminobutyric acid-A (GABA(A)) receptor functions of inhibiting the neurotransmission and controlling the seizure. In this study, we introduce the derivatives of the selected anti-epileptic drugs, namely Felbamate and Clobazam, by substituting different hydrophilic and hydrophobic groups at the specified positions. Molecular docking studies between the derivatives and GABARAP were carried out using PyRx software. The interacting residues were identified from LigPlot+. Drug-likeness, drug-related properties, and toxic endpoints of each derivative were analyzed using the SwissADME, Osiris property explorer, and ProTox-II servers. After analyzing the binding energy, drug-properties, and toxicity, the best five derivatives of Felbamate and Clobazam were selected. Molecular Dynamic simulation studies involving the target-ligand interaction were carried out for 100 nanoseconds using GROMACS 2018. The root mean square deviation, root mean square fluctuation, radius of gyration, Solvent accessible area, Energy plots and trajectories of the ten GABARAP complexes of the derivatives, and two GABARAP complexes of parent drugs were compared and critically analyzed. Among the five Felbamate derivatives, F7 formed the most stable complex with GABARAP. Among the five Clobazam derivatives, C27, C33 and C32 showed stable GABARAP interaction. In light of the above systematic computational analysis, we propose F7, C27, C33, and C32 as the potential anti-epileptic drug candidates for developing novel therapeutics. The substitution of hydrophobic groups at para position on benzene ring has promoted strong binding to GABARAP.Communicated by Ramaswamy H. Sarma.

Breastfeeding while on treatment with antiseizure medications: a systematic review from the ILAE Women Task Force

We carried out a systematic review of published information on transfer of antiseizure medications (ASMs) into breastmilk, ASM serum concentrations in breastfed infants, and the wellbeing of infants breastfed by mothers on ASM treatment. Information was extracted from 85 relevant articles. No data on ASM levels in breastmilk or in breastfed infants was identified for cannabidiol, cenobamate, clobazam, eslicarbazepine-acetate, everolimus, felbamate, fenfluramine, retigabine, rufinamide, stiripentol, tiagabine, and vigabatrin. For ASMs, with available information on levels in breastfed infants, very low concentrations (in the order of 10% or less of maternal serum concentrations) were reported for carbamazepine, gabapentin, levetiracetam, oxcarbazepine, phenytoin, valproate, and clonazepam. Slightly higher levels (up to approximately 30% of maternal serum concentrations) have been observed with lamotrigine and topiramate, and in single case reports for brivaracetam, lacosamide, and perampanel. High infant levels (30% up to 100% of maternal serum concentrations) have been reported with ethosuximide, phenobarbital and zonisamide. Adverse infant effects during breastfeeding by mothers on ASMs appear to be rare regardless of the type of ASM, but systematic study is limited. Prospective long-term follow-up studies of developmental outcomes among children who have been breastfed by mothers taking ASMs are sparse and have mainly involved children whose mothers were taking carbamazepine, lamotrigine, levetiracetam, phenytoin or valproate as monotherapy while breastfeeding. Although these studies have not indicated poorer outcome among breastfed children compared with those who were not breastfed, further data on long-term outcomes are needed to draw firm conclusions. It is concluded that breastfeeding should in general be encouraged in women taking ASMs, given the well-established benefits of breastfeeding with regard to both short- and long-term infant health in the general population. Counselling needs to be individualized including information on the current knowledge regarding the woman's specific ASM treatment.

Psychobehavioural and Cognitive Adverse Events of Anti-Seizure Medications for the Treatment of Developmental and Epileptic Encephalopathies.

The developmental and epileptic encephalopathies encompass a group of rare syndromes characterised by severe drug-resistant epilepsy with onset in childhood and significant neurodevelopmental comorbidities. The latter include intellectual disability, developmental delay, behavioural problems including attention-deficit hyperactivity disorder and autism spectrum disorder, psychiatric problems including anxiety and depression, speech impairment and sleep problems. Classical examples of developmental and epileptic encephalopathies include Dravet syndrome, Lennox-Gastaut syndrome and tuberous sclerosis complex. The mainstay of treatment is with multiple anti-seizure medications (ASMs); however, the ASMs themselves can be associated with psychobehavioural adverse events, and effects (negative or positive) on cognition and sleep. We have performed a targeted literature review of ASMs commonly used in the treatment of developmental and epileptic encephalopathies to discuss the latest evidence on their effects on behaviour, mood, cognition, sedation and sleep. The ASMs include valproate (VPA), clobazam, topiramate (TPM), cannabidiol (CBD), fenfluramine (FFA), levetiracetam (LEV), brivaracetam (BRV), zonisamide (ZNS), perampanel (PER), ethosuximide, stiripentol, lamotrigine (LTG), rufinamide, vigabatrin, lacosamide (LCM) and everolimus. Bromide, felbamate and other sodium channel ASMs are discussed briefly. Overall, the current evidence suggest that LEV, PER and to a lesser extent BRV are associated with psychobehavioural adverse events including aggressiveness and irritability; TPM and to a lesser extent ZNS are associated with language impairment and cognitive dulling/memory problems. Patients with a history of behavioural and psychiatric comorbidities may be more at risk of developing psychobehavioural adverse events. Topiramate and ZNS may be associated with negative effects in some aspects of cognition; CBD, FFA, LEV, BRV and LTG may have some positive effects, while the remaining ASMs do not appear to have a detrimental effect. All the ASMs are associated with sedation to a certain extent, which is pronounced during uptitration. Cannabidiol, PER and pregabalin may be associated with improvements in sleep, LTG is associated with insomnia, while VPA, TPM, LEV, ZNS and LCM do not appear to have detrimental effects. There was variability in the extent of evidence for each ASM: for many first-generation and some second-generation ASMs, there is scant documented evidence; however, their extensive use suggests favourable tolerability and safety (e.g. VPA); second-generation and some third-generation ASMs tend to have the most robust evidence documented over several years of use (TPM, LEV, PER, ZNS, BRV), while evidence is still being generated for newer ASMs such as CBD and FFA. Finally, we discuss how a variety of factors can affect mood, behaviour and cognition, and untangling the associations between the effects of the underlying syndrome and those of the ASMs can be challenging. In particular, there is enormous heterogeneity in cognitive, behavioural and developmental impairments that is complex and can change naturally over time; there is a lack of standardised instruments for evaluating these outcomes in developmental and epileptic encephalopathies, with a reliance on subjective evaluations by proxy (caregivers); and treatment regimes are complex involving multiple ASMs as well as other drugs.

Felbamate as an oral add-on therapy in six dogs with presumptive idiopathic epilepsy and generalized seizures resistant to drug therapy.

Background: Idiopathic or genetic epilepsy commonly affects dogs; affected dogs are often refractory to anti-seizure drug therapy. Felbamate is an anti-seizure drug with established pharmacokinetic and safety data for dogs, but little published evidence of efficacy for managing generalized seizures in this species. Aim: The purpose of this retrospective case series was to evaluate the clinical efficacy and tolerability of oral felbamate in six presumptive epileptic dogs experiencing generalized seizures. Methods: Medical records from six dogs with presumptive idiopathic/genetic epilepsy manifesting as generalized seizure activity, for which oral felbamate was used as an add-on treatment, were reviewed. The number of seizures recorded for the 3-month period immediately before instituting felbamate was recorded for each dog. Short-term (3 months) and long-term (6 months or greater) seizure frequency post-felbamate therapy was recorded for each dog and compared with baseline. Results: Overall, dogs experienced a reduction (82%) in seizures after adding felbamate in the short term, with 5/6 dogs (83%) classified as responders (50% or greater reduction in seizures) and 3/6 dogs (50%) attaining seizure-free status. Mean and median long-term follow-up times were 13 and 11 months, respectively (range: 6 to 23 months). Four of the 6 dogs (67%) remained drug responders at final follow-up, with an average seizure reduction of 98%, 2 of which remained seizure-free at 8 and 21 months. Two dogs (33%) experienced increased seizure activity during long-term follow-up (12 and 23 months) and were considered non-responders. The non-responder dogs had an average long-term seizure reduction of 33%. No dog experienced any obvious adverse effects associated with felbamate administration. However, one dog not included in the analysis because of insufficient (<3 month) post-felbamate follow-up, was weaned off felbamate because of suspected hepatotoxicity. Conclusion: Our small case series suggests that oral felbamate might show promise as an add-on drug for epileptic dogs experiencing generalized seizures resistant to drug therapy. These results warrant a more controlled, prospective investigation into felbamate as a therapeutic agent for canine epilepsy.

Felbamate add-on therapy for drug-resistant focal epilepsy.

BACKGROUND: This is an updated version of the Cochrane Review first published in 2011, and most recently updated in 2019. Epilepsy is a chronic and disabling neurological disorder, affecting approximately 1% of the population. Up to 30% of people with epilepsy have seizures that are resistant to currently available antiepileptic drugs and require treatment with multiple antiepileptic drugs in combination. Felbamate is a second-generation antiepileptic drug that can be used as add-on therapy to standard antiepileptic drugs. OBJECTIVES: To evaluate the efficacy and tolerability of felbamate versus placebo when used as an add-on treatment for people with drug-resistant focal-onset epilepsy. SEARCH METHODS: For the latest update, we searched the Cochrane Register of Studies (CRS Web) and MEDLINE (Ovid, 1946 to 13 July 2021) on 15 July 2021. There were no language or time restrictions. We reviewed the reference lists of retrieved studies to search for additional reports of relevant studies. We also contacted the manufacturers of felbamate and experts in the field for information about any unpublished or ongoing studies. SELECTION CRITERIA: We searched for randomised placebo-controlled add-on studies of people of any age with drug-resistant focal seizures. The studies could be double-blind, single-blind or unblinded and could be of parallel-group or cross-over design. DATA COLLECTION AND ANALYSIS: Two review authors independently selected studies for inclusion and extracted information. In the case of disagreements, a third review author arbitrated. Review authors assessed the following outcomes: 50% or greater reduction in seizure frequency; absolute or percentage reduction in seizure frequency; treatment withdrawal; adverse effects; quality of life. MAIN RESULTS: We included four randomised controlled trials, representing a total of 236 participants, in the review. Two trials had parallel-group design, the third had a two-period cross-over design, and the fourth had a three-period cross-over design. We judged all four studies to be at an unclear risk of bias overall. Bias arose from the incomplete reporting of methodological details, the incomplete and selective reporting of outcome data, and from participants having unstable drug regimens during experimental treatment in one trial. Due to significant methodological heterogeneity, clinical heterogeneity and differences in outcome measures, it was not possible to perform a meta-analysis of the extracted data. Only one study reported the outcome of 50% or greater reduction in seizure frequency, whilst three studies reported percentage reduction in seizure frequency compared to placebo. One study claimed an average seizure reduction of 35.8% with add-on felbamate whilst another study claimed a more modest reduction of 4.2%. Both studies reported that seizure frequency increased with add-on placebo and that there was a significant difference in seizure reduction between felbamate and placebo (P = 0.0005 and P = 0.018, respectively). The third study reported a 14% reduction in seizure frequency with add-on felbamate but stated that the difference between treatments was not significant. There were conflicting results regarding treatment withdrawal. One study reported a higher treatment withdrawal for placebo-randomised participants, whereas the other three studies reported higher treatment withdrawal rates for felbamate-randomised participants. Notably, the treatment withdrawal rates for felbamate treatment groups across all four studies remained reasonably low (less than 10%), suggesting that felbamate may be well tolerated. Felbamate-randomised participants most commonly withdrew from treatment due to adverse effects. The adverse effects consistently reported by all four studies were headache, dizziness and nausea. All three adverse effects were reported by 23% to 40% of felbamate-treated participants versus 3% to 15% of placebo-treated participants. We assessed the evidence for all outcomes using GRADE and rated the evidence as very low certainty, meaning that we have little confidence in the findings reported. We mainly downgraded evidence for imprecision due to the narrative synthesis conducted and the low number of events. We stress that the true effect of felbamate could likely be significantly different from that reported in this current review update. AUTHORS' CONCLUSIONS: In view of the methodological deficiencies, the limited number of included studies and the differences in outcome measures, we have found no reliable evidence to support the use of felbamate as an add-on therapy in people with drug-resistant focal-onset epilepsy. A large-scale, randomised controlled trial conducted over a longer period of time is required to inform clinical practice.

Assessment of metabolic activation of felbamate in chimeric mice with humanized liver in combination with in vitro metabolic assays.

Felbamate (FBM) is an antiepileptic drug that has minimal toxicity in preclinical toxicological species but has a serious idiosyncratic drug toxicity (IDT) in humans. The formation of reactive metabolites is common among most drugs associated with IDT, and 2-phenylpropenal (2-PP) is believed to be the cause of IDT by FBM. It is important to consider the species difference in susceptibility to IDT between experimental animals and humans. In the present study, we used an in vitro and in vivo model system to reveal species difference in IDT of FBM. Human cytochrome P450 (CYP) and carboxylesterase (CES) expressing microsomes were used to clarify the isozymes involved in the metabolism of FBM. The remaining amount of FBM was significantly reduced in incubation with microsomes expressing human CYP2C8, 2C9, 2E1, and CES1c isozymes. Chimeric mice with humanized liver are expected to predict IDT in humans. Therefore, metabolite profiles in chimeric mice with humanized liver were investigated after administration of FBM. Metabolites after glutathione (GSH) conjugation of 2-phenylpropenal (2-PP), which is the reactive metabolite responsible for FBM-induced IDT, were detected in chimeric mice plasma and liver homogenate. Mass spectrometry imaging (MSI) visualizes distribution of FBM and endogenous GSH, and GSH levels in human hepatocyte were decreased after administration of FBM. In this study, we identified CYP and CES isozymes involved in the metabolism of FBM and confirmed reactive metabolite formation and subsequent decrease in GSH using humanized animal model. These results would provide useful information for the susceptibility to IDT between experimental animals and humans.

The interplay of epilepsy with impaired mitophagy and autophagy linked dementia (MAD): A review of therapeutic approaches.

The duration and, age of dementia have been linked to a higher risk of seizures. The exact mechanism that drives epileptogenesis in impaired mitophagy and autophagy linked dementia (MAD) is fully defined after reviewing the Scopus, Publon, and Pubmed databases. The epileptogenesis in patients with Alzheimer's disease dementia (ADD) and Parkinson's disease dementia (PDD) is due to involvement of amyloid plaques (Aß), phosphorylated tau (pTau), Parkin, NF-kB and NLRP3 inflammasome. Microglia, the prime protective and inflammatory cells in the brain exert crosstalk between mitophagy and inflammation. Several researchers believed that the inflammatory brain cells microglia could be a therapeutic target for the treatment of a MAD associated epilepsy. There are conventional antiepileptic drugs such as gabapentin, lamotrigine, phenytoin sodium, carbamazepine, oxcarbazepine, felbamate, lamotrigine, valproate sodium, and topiramate are prescribed by a psychiatrist to suppress seizure frequency. Also, the conventional drugs generate serious adverse effects and synergises dementia characteristics. The adverse effect of carbamazepine is neurotoxic and also, damages haemopoietic system and respiratory tract. The phenytoin treatment causes cerebellar defect and anemia. Dementia and epilepsy have a complicated relationship, thus targeting mitophagy for cure of epileptic dementia makes sense. Complementary and alternative medicine (CAM) is one of the rising strategies by many patients of the world, not only to suppress seizure frequency but also to mitigate dementia characteristics of patients. Therefore our present review focus on the interplay between epilepsy and MAD and their treatment with CAM approaches.

Effects of new antiseizure drugs on seizure activity and anxiety-like behavior in adult zebrafish.

Several studies with larvae and adult zebrafish have shown that old and new antiseizure drugs (ASDs) produce discrepant results in seizure tests, locomotor activity or anxiety models. In this study, the pentylenetetrazole seizure test (PTZ) was performed to assess the effectiveness of four new ASDs: lamotrigine (LTG), topiramate (TPM), felbamate (FBM), and levetiracetam (LEV) in the subsequent stages of seizures in adult fish. All ASDs were administered intraperitoneally (i.p.). The time of maximal anticonvulsant effect and the dose-response relationship of the drugs were assessed. The effects of studied ASDs on the locomotor activity and the anxiety-like behavior in the color preference test were also investigated. Furthermore, drug concentrations in zebrafish homogenates were determined. LTG, TPM, and LEV significantly increased the seizure latency at three subsequent stages of seizures (SI-SIII), while FBM was effective only at SI. Locomotor activity decreased after TPM treatment. TPM and FBM exhibited a strong anxiolytic-like effect in the color preference test. LEV at the highest dose tested had a weak anxiolytic-like effect. The HPLC analysis showed average concentrations of the studied ASDs in the fish body during their maximum anticonvulsant activity. The present study shows that FBM cannot inhibit all subsequent PTZ seizure stages in the adult fish. Except for LTG, the studied drugs affected the anxiety-like behavior of treated animals. Furthermore, only TPM significantly changed locomotion parameters. Our findings support the need to accurately characterize the efficacy of new ASDs at different stages of the PTZ-induced seizures in adult zebrafish.

Anti-seizure medications for Lennox-Gastaut syndrome.

BACKGROUND: Lennox-Gastaut syndrome (LGS) is an age-specific epilepsy syndrome characterised by multiple seizure types, including drop seizures. LGS has a characteristic electroencephalogram, an onset before age eight years and an association with drug resistance. This is an updated version of the Cochrane Review published in 2013. OBJECTIVES: To assess the efficacy and tolerability of anti-seizure medications (ASMs) for LGS. SEARCH METHODS: We searched the Cochrane Register of Studies (CRS Web) and MEDLINE (Ovid, 1946 to 28 February 2020) on 2 March 2020. CRS Web includes randomised controlled trials (RCTs) or quasi-RCTs from the Cochrane Central Register of Controlled Trials (CENTRAL); the Specialised Registers of Cochrane Review Groups, including Cochrane Epilepsy; PubMed; Embase; ClinicalTrials.gov; and the World Health Organization's International Clinical Trials Registry Platform (ICTRP). We imposed no language restrictions. We contacted pharmaceutical companies and colleagues in the field to seek any unpublished or ongoing studies. SELECTION CRITERIA: We considered RCTs, including cross-over trials, of ASMs for LGS in children and adults. We included studies of ASMs used as either monotherapy or as an add-on (adjunctive) therapy. We excluded studies comparing different doses of the same ASM. DATA COLLECTION AND ANALYSIS: We used standard Cochrane methodological procedures, including independent, dual assessment for risk of bias and application of the GRADE approach to rate the evidence certainty for outcomes. MAIN RESULTS: We found no trials of ASM monotherapy. The review included 11 trials (1277 participants; approximately 11 weeks to 112 weeks follow-up after randomisation) using add-on ASMs for LGS in children, adolescents and adults. Two studies compared add-on cannabidiol (two doses) with add-on placebo in children and adolescents only. Neither study reported overall seizure cessation or reduction. We found high-certainty evidence that 72 more people per 1000 (confidence interval (CI) 4 more to 351 more) had adverse events (AE) leading to study discontinuation with add-on cannabidiol, compared to add-on placebo (two studies; 396 participants; risk ratio (RR) 4.90, 95% CI 1.21 to 19.87). One study compared add-on cinromide with add-on placebo in children and adolescents only. We found very low-certainty evidence that 35 more people per 1000 (CI 123 fewer to 434 more) had 50% or greater average reduction of overall seizures with add-on cinromide compared to add-on placebo (one study; 56 participants; RR 1.15, 95% CI 0.47 to 2.86). This study did not report participants with AE leading to study discontinuation. One study compared add-on clobazam (three doses) with add-on placebo. This study did not report overall seizure cessation or reduction. We found high-certainty evidence that 106 more people per 1000 (CI 0 more to 538 more) had AE leading to study discontinuation with add-on clobazam compared to add-on placebo (one study; 238 participants; RR 4.12, 95% CI 1.01 to 16.87). One study compared add-on felbamate with add-on placebo. No cases of seizure cessation occurred in either regimen during the treatment phase (one study; 73 participants; low-certainty evidence). There was low-certainty evidence that 53 more people per 1000 (CI 19 fewer to 716 more) with add-on felbamate were seizure-free during an EEG recording at the end of the treatment phase, compared to add-on placebo (RR 2.92, 95% CI 0.32 to 26.77). The study did not report overall seizure reduction. We found low-certainty evidence that one fewer person per 1000 (CI 26 fewer to 388 more) with add-on felbamate had AE leading to study discontinuation compared to add-on placebo (one study, 73 participants; RR 0.97, 95% CI 0.06 to 14.97). Two studies compared add-on lamotrigine with add-on placebo. Neither study reported overall seizure cessation. We found high-certainty evidence that 176 more people per 1000 (CI 30 more to 434 more) had ≥ 50% average seizure reduction with add-on lamotrigine compared to add-on placebo (one study; 167 participants; RR 2.12, 95% CI 1.19 to 3.76). We found low-certainty evidence that 40 fewer people per 1000 (CI 68 fewer to 64 more) had AE leading to study-discontinuation with add-on lamotrigine compared to add-on placebo (one study; 169 participants; RR 0.49, 95% CI 0.13 to 1.82). Two studies compared add-on rufinamide with add-on placebo. Neither study reported seizure cessation. We found high-certainty evidence that 202 more people per 1000 (CI 34 to 567 more) had ≥ 50% average seizure reduction (one study; 138 participants; RR 2.84, 95% CI 1.31 to 6.18). We found low-certainty evidence that 105 more people per 1000 (CI 17 fewer to 967 more) had AE leading to study discontinuation with add-on rufinamide compared to add-on placebo (one study; 59 participants; RR 4.14, 95% CI 0.49 to 34.86). One study compared add-on rufinamide with another add-on ASM. This study did not report overall seizure cessation or reduction. We found low-certainty evidence that three fewer people per 1000 (CI 75 fewer to 715 more) had AE leading to study discontinuation with add-on rufinamide compared to another add-on ASM (one study; 37 participants; RR 0.96, 95% CI 0.10 to 9.57). One study compared add-on topiramate with add-on placebo. This study did not report overall seizure cessation. We found low-certainty evidence for ≥ 75% average seizure reduction with add-on topiramate (one study; 98 participants; Peto odds ratio (Peto OR) 8.22, 99% CI 0.60 to 112.62) and little or no difference to AE leading to study discontinuation compared to add-on placebo; no participants experienced AE leading to study discontinuation (one study; 98 participants; low-certainty evidence). AUTHORS' CONCLUSIONS: RCTs of monotherapy and head-to-head comparison of add-on ASMs are currently lacking. However, we found high-certainty evidence for overall seizure reduction with add-on lamotrigine and rufinamide, with low-certainty evidence for AE leading to study discontinuation compared with add-on placebo or another add-on ASM. The evidence for other add-on ASMs for overall seizure cessation or reduction was low to very low with high- to low-certainty evidence for AE leading to study discontinuation. Future research should consider outcome reporting of overall seizure reduction (applying automated seizure detection devices), impact on development, cognition and behaviour; future research should also investigate age-specific efficacy of ASMs and target underlying aetiologies.

Comparison of immunological, histological and oxidative effects of felbamate and levetiracetam in traumatic brain injury.

OBJECTIVE: We aimed to compare immunological, histological and oxidative effects of antiepileptic agents; felbamate and levetiracetam on head trauma in rats. MATERIALS AND METHODS: In this study, 32 Sprague-Dawley genus male rats were used. A closed head trauma mechanism was constituted in order to perform head trauma in rats. Rats were divided into 4 groups, and each group had 8 rats. Following head trauma, Group 1 (Control); normal saline was administered, Group 2; levetiracetam 50 mg/kg was administered, Group 3; felbamate 100 mg/kg was administered, and Group 4; levetiracetam 50 mg/kg and felbamate 100 mg/kg were administered with a combination. Injections were administered intraperitoneally once a day for 20 days. The rats were decapitated at the end of the 20th day. Blood and tissue samples were collected and analyzed for biochemical, immunohistochemical and histological parameters. RESULTS: Serum cytokine levels in Group 2, 3 and 4 were lower when compared to the control group. In Group 4, in which combined therapy was performed, cytokine levels were found to be the lowest. In Groups 2 and 3, a significant decrease in vascular congestion, mononuclear cell infiltration, hemorrhage, and neural degeneration was noticed in the pia mater. In Group 2, a decrease in vascular congestion and Purkinje cell degeneration was obtained in the cerebellum. However, the best outcomes were determined in Group 4. CONCLUSIONS: We determined that levetiracetam and felbamate alone are useful with respect to immunological, oxidative and histological alterations. However, their utility is better when used in a combination.

Felbamate in the treatment of refractory epileptic spasms.

Several small case series provide conflicting impressions of the efficacy of felbamate for treatment of epileptic spasms. Using a large single-center cohort of children with epileptic spasms, we retrospectively evaluated the efficacy and safety of felbamate. We identified all patients with video-EEG confirmed epileptic spasms who were treated with felbamate at our center. We quantified felbamate exposure by calculating peak and weighted-average weight-based dose. Clinical response was defined as resolution of epileptic spasms for at least 28 days, beginning not more than 3 months after felbamate initiation. Electroclinical response was defined as clinical response accompanied by overnight video-EEG demonstrating freedom from epileptic spasms and hypsarrhythmia. Among a cohort of 476 infants, we identified 62 children who were treated with felbamate, of whom 58 had previously failed treatment with hormonal therapy or vigabatrin. Median peak and weighted-average felbamate dosages were 47 and 40 mg/kg/day, respectively. Five (8%) children were classified as clinical responders and two (3%) children were classified as electroclinical responders. Among 17 patients with latency from epileptic spasms onset to felbamate initiation of less than 12 months, we observed 4 (24%) clinical responders. This study suggests that felbamate may be efficacious for treatment of epileptic spasms and that further rigorous study is warranted.

Felbamate for infantile spasms syndrome resistant to first-line treatments.

AIM: To analyse the effects of felbamate in refractory infantile spasms/West syndrome. METHOD: We conducted a 10-year retrospective study of infants (including all infants younger than 18mo) treated with felbamate for electroencephalography-recorded epileptic spasms persisting after first-line treatment. RESULTS: In total, 29 infants (17 males, 12 females) were included in the study. Felbamate was initiated at a mean age of 13.8 months (range 4.5-66mo) after sequential administration or combination of vigabatrin and oral steroids; a ketogenic diet was implemented in 23 infants. Eight infants became spasm-free at a mean dose of 34.6mg/kg/day felbamate (range 26-45mg/kg/day). Mean duration of felbamate use was 19 months (range 1-67mo) for the 19 infants whose treatment was terminated. No severe side effects were observed. Reversible neutropenia led to withdrawal of felbamate in six patients. One spasm-free patient demonstrated recurrence when felbamate was withdrawn. INTERPRETATION: N-methyl-d-aspartate receptors with felbamate controlled epileptic spasms in eight infants resistant to first-line treatment should be targeted.

Felbamate add-on therapy for drug-resistant focal epilepsy.

BACKGROUND: This is an updated version of the Cochrane Review previously published in 2017.Epilepsy is a chronic and disabling neurological disorder, affecting approximately 1% of the population. Up to 30% of people with epilepsy have seizures that are resistant to currently available antiepileptic drugs and require treatment with multiple antiepileptic drugs in combination. Felbamate is a second-generation antiepileptic drug that can be used as add-on therapy to standard antiepileptic drugs. OBJECTIVES: To evaluate the efficacy and tolerability of felbamate versus placebo when used as an add-on treatment for people with drug-resistant focal-onset epilepsy. SEARCH METHODS: For the latest update we searched the Cochrane Register of Studies (CRS Web), MEDLINE, ClinicalTrials.gov and the WHO International Clinical Trials Registry Platform (ICTRP), on 18 December 2018. There were no language or time restrictions. We reviewed the reference lists of retrieved studies to search for additional reports of relevant studies. We also contacted the manufacturers of felbamate and experts in the field for information about any unpublished or ongoing studies. SELECTION CRITERIA: We searched for randomised placebo-controlled add-on studies of people of any age with drug-resistant focal seizures. The studies could be double-blind, single-blind or unblinded and could be of parallel-group or cross-over design. DATA COLLECTION AND ANALYSIS: Two review authors independently selected studies for inclusion and extracted information. In the case of disagreements, the third review author arbitrated. Review authors assessed the following outcomes: 50% or greater reduction in seizure frequency; absolute or percentage reduction in seizure frequency; treatment withdrawal; adverse effects; quality of life. MAIN RESULTS: We included four randomised controlled trials, representing a total of 236 participants, in the review. Two trials had parallel-group design, the third had a two-period cross-over design, and the fourth had a three-period cross-over design. We judged all four studies to be at an unclear risk of bias overall. Bias arose from the incomplete reporting of methodological details, the incomplete and selective reporting of outcome data, and from participants having unstable drug regimens during experimental treatment in one trial. Due to significant methodological heterogeneity, clinical heterogeneity and differences in outcome measures, it was not possible to perform a meta-analysis of the extracted data.Only one study reported the outcome, 50% or greater reduction in seizure frequency, whilst three studies reported percentage reduction in seizure frequency compared to placebo. One study claimed an average seizure reduction of 35.8% with add-on felbamate while another study claimed a more modest reduction of 4.2%. Both studies reported that seizure frequency increased with add-on placebo and that there was a significant difference in seizure reduction between felbamate and placebo (P = 0.0005 and P = 0.018, respectively). The third study reported a 14% reduction in seizure frequency with add-on felbamate but stated that the difference between treatments was not significant. There were conflicting results regarding treatment withdrawal. One study reported a higher treatment withdrawal for placebo-randomised participants, whereas the other three studies reported higher treatment withdrawal rates for felbamate-randomised participants. Notably, the treatment withdrawal rates for felbamate treatment groups across all four studies remained reasonably low (less than 10%), suggesting that felbamate may be well tolerated. Felbamate-randomised participants most commonly withdrew from treatment due to adverse effects. The adverse effects consistently reported by all four studies were: headache, dizziness and nausea. All three adverse effects were reported by 23% to 40% of felbamate-treated participants versus 3% to 15% of placebo-treated participants.We assessed the evidence for all outcomes using GRADE and found it as being very-low certainty, meaning that we have little confidence in the findings reported. We mainly downgraded evidence for imprecision due to the narrative synthesis conducted and the low number of events. We stress that the true effect of felbamate could likely be significantly different from that reported in this current review update. AUTHORS' CONCLUSIONS: In view of the methodological deficiencies, the limited number of included studies and the differences in outcome measures, we have found no reliable evidence to support the use of felbamate as an add-on therapy in people with drug-resistant focal-onset epilepsy. A large-scale, randomised controlled trial conducted over a longer period of time is required to inform clinical practice.

Felbamate produces antidepressant-like actions in the chronic unpredictable mild stress and chronic social defeat stress models of depression.

Felbamate is an anticonvulsant used in the treatment of epilepsy. In this study, we investigated the antidepressant-like actions of felbamate in mice. The effects of felbamate were first assessed using the forced swimming test (FST) and tail suspension test (TST), and then investigated in the chronic unpredictable mild stress (CUMS) and chronic social defeat stress (CSDS) models of depression. The changes in the hippocampal brain-derived neurotrophic factor (BDNF) signaling cascade after chronic stress and felbamate treatment were also examined. It was found that felbamate exhibited antidepressant-like activities in the FST and TST without affecting the locomotor activity of mice. Felbamate was also effective in both the CUMS and CSDS models of depression. Moreover, felbamate administration fully restored the decreased hippocampal BDNF signaling pathway in both the CUMS-stressed and CSDS-stressed mice. Collectively, felbamate has antidepressant-like actions in mice involving the hippocampal BDNF system.

The effects of felbamate on appetitive and aversive instrumental learning in adult rats.

Antiepileptic medications are the frontline treatment for seizure conditions but are not without cognitive side effects. Previously, our laboratory reported learning deficits in phenytoin-, carbamazepine-, and valproate-treated rats. In the present experiment, the effects of felbamate (FBM) have been compared to water-treated controls (controls) using the same instrumental training tasks employed here. Rats treated with FBM displayed a deficit in acquiring a tone-signaled avoidance response, relative to controls, but this was true only if they had no prior appetitive experience. Terminal avoidance behavior was equivalent to healthy controls. In contrast, the FBM-treated rats showed enhanced acquisition of the avoidance response relative to controls when given the benefit of prior experience in the appetitive condition. Relative to animals treated with phenytoin, carbamazepine, or valproate, FBM-treated rats showed the lowest overall pattern of deficits using these instrumental learning tasks. While FBM treatment has been severely restricted because of rather low risks of serious medical side effects, we suggest that the risks are not substantially higher than those shown to exist for phenytoin, carbamazepine, or valproate. As psychologists, we further suggest that negative cognitive deficits associated with these various drugs, along with their quality-of-life costs, are of relevance in the design of treatment strategies for individuals with seizure disorders.

Felbamate as an add-on therapy for refractory partial epilepsy.

BACKGROUND: This review is an update of a previously published review in the Cochrane Database of Systematic Reviews (Issue 7, 2014) on 'Felbamate as an add-on therapy for refractory epilepsy'. Epilepsy is a chronic and disabling neurologic disorder, affecting approximately 1% of the population. Up to 30% of people with epilepsy have seizures that are resistant to currently available drugs. Felbamate is one of the second-generation antiepileptic drugs and we have assessed its effects as an add-on therapy to standard drugs in this review. OBJECTIVES: To evaluate the efficacy and tolerability of felbamate versus placebo when used as an add-on treatment for people with refractory partial-onset epilepsy. SEARCH METHODS: For the latest update we searched the Cochrane Epilepsy Specialized Register, CENTRAL, MEDLINE, ClinicalTrials.gov and the WHO International Clinical Trials Registry Platform, up to 20 October 2016. There were no language and time restrictions. We reviewed the reference lists of retrieved studies to search for additional reports of relevant studies. We also contacted the manufacturers of felbamate and experts in the field for information about any unpublished or ongoing studies. SELECTION CRITERIA: Randomised placebo-controlled add-on studies of people of any age with refractory partial-onset seizures. The studies could be double-blind, single-blind or unblinded and could be of parallel or cross-over design. DATA COLLECTION AND ANALYSIS: Two review authors independently selected studies for inclusion and extracted information. We resolved disagreements by discussion. If disagreements persisted, the third review author arbitrated. We assessed the following outcomes: 50% or greater reduction in seizure frequency; absolute or percentage reduction in seizure frequency; treatment withdrawal; adverse effects; quality of life. MAIN RESULTS: We included four randomised controlled trials with a total of 236 participants. Two trials were parallel design, the third had a two-period cross-over design, and the fourth had a three-period cross-over design. Two studies were at an unclear risk of bias for random sequence generation and allocation concealment. These two studies did not include any description of their methods for outcome assessment and performance blinding (i.e. participants or doctors). Two studies were at high risk of bias for incomplete outcome data. Due to significant methodological heterogeneity, clinical heterogeneity and differences in outcome measures, it was not possible to perform a meta-analysis of the results. Only one study reported 50% or greater reduction in seizure frequency. One study reported absolute and percentage reduction in seizure frequency compared to placebo, P values were 0.046 and 0.018, respectively. One study reported percentage reduction in seizure frequency compared to placebo, but there were no P values. Adverse effects rates were higher during the felbamate period than the placebo period, particularly headache, nausea and dizziness. AUTHORS' CONCLUSIONS: In view of the methodological deficiencies, limited number of individual studies and differences in outcome measures, we have found no reliable evidence to support the use of felbamate as an add-on therapy in people with refractory partial-onset epilepsy. A large-scale, randomised controlled trial conducted over a longer period of time is required to inform clinical practice.