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.

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.

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.

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.

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.