Adjunctive treatment for pediatric focal epilepsy: a systematic review

PURPOSE

We aim to use a network meta-analysis to evaluate the efficacy and safety of antiseizure medications and provide a theoretical basis for rational drug use for children and adolescents in adjunctive treatment.

METHODS

The databases of PubMed, Embase, Cochrane Library, and Web of Science were systematically searched for random clinical trials about perampanel, valproic acid, carbamazepine, lacosamide, lamotrigine, levetiracetam, oxcarbazepine, topiramate, zonisamide, brivaracetam, cenobamate, eslicarbazepine acetate, and pregabalin from their inception until December 10, 2023. The included studies' risk of bias was evaluated by the Cochrane Collaboration's tool (RoB2). The network meta-analysis was performed using Stata 15 on the included studies.

RESULTS

Seventeen studies were identified and of these 19 randomized controlled trials evaluating 9 different antiepileptic drugs were included. In total, 2959 patients were covered in the analysis of the outcomes. For efficacy, lacosamide (OR = 1.91, 95%CI 1.14-3.20), lamotrigine (OR = 3.82, 95%CI 1.86-7.83), levetiracetam (OR = 3.01, 95%CI 1.89-4.80), oxcarbazepine (OR = 2.75, 95%CI 1.52-4.96), perampanel (OR = 2.05, 95%CI 1.15-3.65), and zonisamide (OR = 2.27, 95%CI 1.21-4.24) were more effective than placebo in the 50% responder rate. Lamotrigine ranked first on the cumulative probability curve, followed by levetiracetam. Eslicarbazepine acetate (OR = 6.44, 95%CI 1.43-29.00) and levetiracetam (OR = 5.75, 95%CI 2.45-13.50) were better than placebo in seizure freedom. For safety, topiramate (OR = 4.11, 95%CI 1.43-11.76) and oxcarbazepine (OR = 2.72, 1.28-5.76) were more likely to cause adverse effects in children or adolescents compared to placebo.

CONCLUSION

In terms of efficacy and safety, lamotrigine and levetiracetam may be selected preferentially for the adjunctive treatment of focal epilepsy in children and adolescents. However, owing to the limited random clinical trials, our results need to be verified by further studies.

The placebo effect in the treatment of children with epilepsy: A systematic review

PURPOSE

To investigate the placebo effect in the treatment of children and adolescents with epilepsy.

METHODS

We conducted a systematic review of studies comparing anti-seizure medication (ASM) to placebo in children and adolescents with epilepsy. Eligible studies were identified through the database PubMed following PRISMA guidelines resulting in the identification of 1173 articles. Screening and inclusion were assessed by two independent reviewers and 17 studies met inclusion criteria.

RESULTS

Seventeen studies involving children and adolescents with epilepsy were included in this review. Compared to levetiracetam (LEV) and perampanel (PER), the placebo did not show a significant reduction in seizures. However, compared to pregabalin (PGB) the placebo was significant in reducing seizures at lower doses. Results for eslicarbazepine (ESL) were contradictory. Placebo-treated patients generally had lower Child Behavior checklist (CBCL) problem scores than those on LEV, which was associated with higher Total Problem Scores and worse Aggressive Behavior scores. Adverse event (AE) rates in the placebo groups varied widely, from 14 % to 91.8 %.

CONCLUSION

This systematic review examined the effect of placebo treatment compared to ASMs in childhood epilepsy across 17 studies. The effectiveness of placebos was not significant compared to LEV and PER. However, there was a significant placebo effect compared to PGB, which was higher compared to low PGB doses than compared to high PGB doses. AE rates varied widely. Assessing long-term cognitive and behavioral outcomes was challenging due to short study durations and potential biases. Future research could play a critical role in preventing AEs in children undergoing ASM treatment by providing a deeper understanding of the placebo effect associated with these medications.

Time to prerandomization seizure count design sufficiently assessed the safety and tolerability of perampanel for the treatment of primary generalized tonic-clonic seizures

OBJECTIVE

Static assignment of participants in randomized clinical trials to placebo or ineffective treatment confers risk from continued seizures. An alternative trial design of time to exceed prerandomization monthly seizure count (T-PSC) has replicated the efficacy conclusions of traditionally designed trials, with shorter exposure to placebo and ineffective treatment. Trials aim to evaluate efficacy as well as safety and tolerability; therefore, we evaluated whether this T-PSC design also could replicate the trial's safety and tolerability conclusions.

METHODS

We retrospectively applied the T-PSC design to analyze treatment-emergent adverse events (TEAEs) from a blinded, placebo-controlled trial of perampanel for primary generalized tonic-clonic seizures (NCT01393743). The safety analysis set consisted of 81 and 82 participants randomized to perampanel and placebo arms, respectively. We evaluated the incidences of TEAEs, treatment-related TEAEs, serious TEAEs, and TEAEs of special interest that occurred before T-PSC relative to those observed during the full-length trial.

RESULTS

Of the 67 and 59 participants who experienced TEAEs in the perampanel and placebo arms during full-length trial, 66 (99%) and 54 (92%) participants experienced TEAEs with onset occurring before T-PSC, respectively. When limited to treatment-related TEAEs, 55 of 56 (98%) and 32 of 37 (86%) participants reported treatment-related TEAEs that occurred before T-PSC in the perampanel and placebo arms, respectively. There were more TEAEs after T-PSC with placebo as compared to perampanel (Fisher exact odds ratio = 8.6, p = .035), which resulted in overestimation of the difference in TEAE rate. There was a numerical reduction in serious TEAEs (3/13 occurred after T-PSC, one in placebo and two in perampanel).

SIGNIFICANCE

Almost all TEAEs occurred before T-PSC. More treatment-related TEAEs occurred after T-PSC for participants randomized to placebo than perampanel, which may be due to either a shorter T-PSC or delayed time to TEAE for placebo.

Psychiatric and behavioral concerns of perampanel with concomitant levetiracetam in children with epilepsy

PURPOSE

Perampanel (PER) is expanding the therapeutic scope for pediatric epilepsy owing to its efficacy and favorable safety profile. However, concerns about psychiatric and behavioral adverse events (PBAEs) in combination therapy with levetiracetam (LEV) continue to contribute to hesitation in its prescription. We investigated the risk profiles for PBAEs when adding PER to pediatric epilepsy treatment and analyzed the differences according to the presence of concomitant LEV.

METHODS

We retrospectively reviewed the medical records of children aged 4-18 years with epilepsy who were prescribed PER as adjunctive therapy from March 2016 to February 2023. We compared the occurrence and management of PBAEs between the PER without LEV and PER with LEV groups. The risk factors for PBAEs were also analyzed.

RESULTS

Ninety-four patients (53 boys and 41 girls) were included in this study. The median age of total patients at the time of adding PER was 14.9 years (12.3-16.4 years), and 53 patients (56.4 %) had concomitant LEV. Forty-seven PBAEs occurred in 34 patients (36.2 %), with no significant differences depending on whether concomitant LEV is present or not. The most common PBAEs were aggression (14.9 %), irritability (9.6 %), affect lability (7.4 %), and acute psychosis (6.4 %). PBAEs occurred at a lower dosage (2-6 mg/day) in 70.6 % of the patients. In addition, 73.5 % of patients with PBAEs continued PER treatment by follow-up observation or by reducing the PER dosage. No risk factors, such as the presence of concomitant LEV or lamotrigine, any comorbid conditions, higher PER dosage (8-12 mg/day), two or more concomitant anti-seizure medications, and younger age (<13 years) at PER add-on, showed significant associations.

CONCLUSION

When expanding the use of anti-seizure medications in pediatric patients, real-world evidence on safety issues is crucial for pediatric epileptologists. We confirmed that combination therapy with PER and LEV did not increase the risk profile of PBAEs.

Role of Perampanel in the Management of Pediatric Epilepsies in Asia: Expert Opinion

Management of pediatric epilepsies poses unique challenges around diagnosis, treatment options, comorbidities, and the potential for these factors to interact with processes in the developing brain. In pediatric patients, broad-spectrum antiseizure medications (ASMs) with minimal potential for adverse events (AEs) and limited impact on cognition and behavior are preferred. Perampanel is a first-in-class ASM with broad-spectrum efficacy, a tolerable safety profile, minimal negative impact on cognitive function, and other features that make it a viable treatment option in this patient population. However, evidence and experience of its use in pediatric patients are less extensive than in adult patients. Experts in pediatric epilepsy across the region convened at a series of meetings to discuss the use of perampanel in pediatric patients, including dose optimization, AE prevention and management, and considerations in particular groups. This article summarizes key evidence for perampanel in the pediatric population and consolidates the experts' recommendations for using the ASM in managing pediatric epilepsies.

The Cognitive and Behavioural Effects of Perampanel in Children with Neurodevelopmental Disorders: A Systematic Review

In children and adolescents with epilepsy, neurodevelopmental comorbidities can impair the quality of life more than seizures. The aim of this review was to evaluate the cognitive and behavioural effects of perampanel (PER) in the paediatric population. We performed a systematic search of the literature, selecting studies published in English including children and adolescents with epilepsy treated with PER. Cognitive and behavioural outcomes were assessed through validated neuropsychological standardised scales. Eighteen studies involving 3563 paediatric patients were included. Perampanel did not impair general cognitive functions and visuospatial skills, whereas a slight improvement in verbal memory and a decline in attentional power were detected. In adolescents with refractory epilepsies, high doses and/or rapid titration of PER and an underlying psychiatric disorder were risk factors for developing or worsening psychiatric outcomes such as anger, aggressiveness, and irritability. Data on children and adolescents treated with new antiseizure medications are scant, and neuropsychiatric effects are tricky to be detected during developmental age. According to the currently available evidence, PER showed an overall favourable risk-benefit profile. Pharmacodynamics, co-administration of other antiseizure medications, and family and personal history of neuropsychiatric disorders should be considered before PER treatment.

Efficacy and safety of perampanel for the treatment of epilepsy in adolescents: a meta-analysis

BACKGROUND

In the present meta-analysis, the efficacy and safety of perampanel (PER) for the treatment of adolescents with epilepsy were assessed.

METHODS

Keyword searches were performed in Embase, PubMed, Cochrane Library, Web of Science, EBSCO and CNKI from 1 January 2020 to 10 October 2020. The randomized controlled trials (RCTs) and case-control studies in which PER was compared with other Anti-seizure drugs (ASDs) and/or placebo in children with epilepsy, were considered eligible studies. Odds ratio (OR) with 95% confidence interval (95% CI) for the dichotomous outcome statistic was calculated using a fixed-effects or random-effects model.

RESULTS

Three RCTs with a total of 372 adolescents' patients were included in this meta-analysis. Placebo was used as a control in these studies. Compared with placebo, PER showed better efficacy in median seizure frequency reduction from baseline per 28 days (OR = 2.49, 95% CI: 1.25-4.96, p = 0.009) and in responder rate (OR = 1.87, 95% CI: 1.15-3.05, p = 0.01); both were considered statistically increased in PER group. Regarding adverse effects (AEs), significant differences between PER and placebo (OR = 1.47, 95% CI: 0.92-2.41, p = 0.11) were not found, and the most common AEs of PER were dizziness (24.0%), somnolence (15.9%), headache (11.2%), nasopharyngitis (9.7%), upper respiratory tract infection (7.0%) and aggression (7.0%).

CONCLUSION

Based on the results in this study, PER showed better efficacy than placebo therapy in children with epilepsy and the AEs were similar in PER group and placebo group. PER showed good efficacy and a low risk of AEs, and might be a promising medication for the treatment of pediatric epilepsy. In the future, well-designed and large-scale RCTs are necessary to validate the present findings.

Quantifying and controlling the impact of regression to the mean on randomized controlled trials in epilepsy

OBJECTIVE

Randomized controlled trials (RCTs) in epilepsy for drug treatments are plagued by high costs. One potential remedy is to reduce placebo response via better control over regression to the mean (RTM). Here, RTM represents an initial observed seizure rate higher than the long-term average, which gradually settles closer to the average, resulting in apparent response to treatment. This study used simulation to clarify the relationship between eligibility criteria and RTM.

METHODS

Using a statistically realistic seizure diary simulator, the impact of RTM on placebo response and trial efficacy was explored by varying eligibility criteria for a traditional treatment phase II/III RCT for drug-resistant epilepsy.

RESULTS

When the baseline period was included in the eligibility criteria, increasingly larger fractions of RTM were observed (25%-47% vs. 23%-25%). Higher fractions of RTM corresponded with higher expected placebo responses (50% responder rate [RR50]: 2%-9% vs. 0%-8%) and lower statistical efficacy (RR50: 47%-67% vs. 47%-81%). The exclusion of baseline from eligibility criteria was shown to decrease the number of patients needed by roughly 30%.

SIGNIFICANCE

The manipulation of eligibility criteria for RCTs has a predictable and important impact on RTM, and therefore on placebo response; the difference between drug and placebo was more easily detected. This in turn impacts trial efficacy and therefore cost. This study found dramatic improvements in efficacy and cost when baseline was not included in eligibility.

Efficacy and Safety of Five Broad-Spectrum Antiseizure Medications for Adjunctive Treatment of Refractory Epilepsy: A Systematic Review and Network Meta-analysis

BACKGROUND

Overall, up to one-third of epilepsy patients have drug-resistant epilepsy. However, there was previously no meta-analysis to support the guidelines for broad-spectrum antiseizure medication selection for the adjunctive treatment of refractory epilepsy. In the present meta-analysis, we assessed the efficacy and safety of three second-generation broad-spectrum antiseizure medications, lamotrigine (LTG), levetiracetam (LEV), and topiramate (TPM), and two third-generation broad-spectrum antiseizure medications, perampanel (PER) and lacosamide (LCM), for the adjunctive treatment of refractory epilepsy.

METHODS

We systematically searched PubMed, Embase, and CENTRAL from inception to July 15, 2022. The studies included in the meta-analysis were required to meet the following criteria: (1) be randomized, double-blind clinical trials; (2) include patients aged >2 years with a clinical diagnosis of drug-resistant epilepsy; (3) have at least 8 weeks for the treatment period excluding the titration phase; and (4) report the outcomes of seizure response, seizure freedom and the withdrawal rate due to treatment-emergent adverse effects. Data were extracted, and the risk of bias for each study was assessed by two authors independently using RoB2 tools. We performed the network meta-analysis for each outcome through a group of programs in the mvmeta and network packages in Stata. Relative odds ratios with 95% confidence intervals were calculated as the result of the analyses. The surface under the cumulative ranking curve (SUCRA) and mean ranks were used to rank these treatments.

RESULTS

Forty-two randomized controlled trials (RCTs) (LTG-placebo: n = 6, LEV-placebo: n = 13, TPM-placebo: n = 9, PER-placebo: n = 6, LCM-placebo: n = 7, LEV-TPM: n = 1) with 10257 participants (LTG = 569, LEV = 1626, TPM = 701, PER = 1734, LCM = 1908, placebo = 3719) were included. Levetiracetam had subequal efficacy in 50 % seizure frequency reduction to TPM [odds ratio (OR) 1.00, 95% confidence interval (CI) 0.73-1.38], and LEV had a higher rate of ≥ 50% seizure frequency reduction than LCM (OR 1.49, 95% CI 1.11-2.01) and PER (OR 1.68, 95% CI 1.24-2.29). Levetiracetam was also related to a higher proportion of seizure freedom participants than TPM (OR 1.87, 95% CI 1.20-2.89), PER (OR 2.23, 95% CI 1.12-4.43), and LCM (OR 2.97, 95% CI 1.46-6.05). In addition, LEV was associated with a lower risk of experiencing at least one treatment-emergent adverse event (TEAE) than PER (OR 0.63, 95% CI 0.46-0.85) and TPM (OR 0.51, 95 % CI 0.36-0.72) and a lower proportion of patients experiencing TEAEs leading to discontinuation than PER (OR 0.51, 95% CI 0.27-0.97) and TPM (OR 0.50, 95 % CI 0.27-0.93).

CONCLUSIONS

Third-generation drugs (PER and LCM) had no advantages in terms of efficacy and safety for adjunctive treatment of refractory epilepsy compared with several second-generation drugs (LEV and LTG). Levetiracetam was the priority choice for adjunctive treatment of refractory epilepsy. Perampanel and LCM had no advantages in terms of efficacy and safety among the five drugs.

REGISTRATION

PROSPERO registration number, CRD42022344153; last edited on December 23, 2022.

Perampanel and lacosamide monotherapy in pediatric patients with newly diagnosed focal epilepsy: A prospective study evaluating efficacy, tolerability, and behavior

PURPOSE

Perampanel (PER) and lacosamide (LCM) are the new third-generation anti-seizure medications (ASMs) that were approved for the monotherapy of focal epilepsy in children over four years of age in China, in 2021. Very few studies have analyzed the application of PER monotherapy among pediatric patients aged ≥four years, and no study compared the efficacy and tolerability of PER monotherapy with LCM monotherapy in pediatric patients with focal epilepsy. The present study aimed to investigate the efficacy, tolerability, and effect on behavior and emotion of PER and LCM as monotherapy in pediatric patients with newly diagnosed focal epilepsy, which is beneficial for clinicians to have more choices to treat pediatric patients with focal epilepsy.

METHODS

This was a prospective, single-center, observational study that involved pediatric patients (disease onset age ≥four years) with newly diagnosed focal epilepsy treated with PER or LCM as primary monotherapy. Outcomes included retention, being responders, and seizure-free rates after 3, 6, and 12 months. Adverse events (AEs) were noticed throughout the follow-up period. Behavioral outcomes were evaluated with Achenbach Child Behavior Checklist (CBCL/4-16) at baseline and after three and six months.

RESULTS

Using randomization, 60 patients receiving PER (31 females, 29 males, median age: 7.79 [5.34, 10.16] years, median dose: 3.0 [2.0, 4.0] mg/day) and 60 patients receiving LCM (25 females, 35 males, median age: 7.72 [5.91, 10.72] years, median dose: 150.0 [100.0, 200.0] mg/day) were enrolled in the study. At the 12-month follow-up, the retention rates in the PER and LCM groups, both were 90.4%, and the responder rates were 65.4% and 71.2%, while seizure-free rates were 57.7% and 67.3%, respectively. There were no significant differences in the retention, responder and seizure-free rates between the two groups (P > 0.05). There were no significant differences in the responder rates between patients with BECTS, abnormal brain magnetic resonance imaging (MRI), or types of seizure in the two groups (P > 0.05). In the PER group, 28.8% (15/52) of patients experienced AEs, of which the most frequently reported were irritability (n = 7; 13.5%), dizziness (n = 5; 9.6%), somnolence (n = 3; 5.8%), ataxia (n = 1; 1.9%), headache (n = 1; 1.9%), and rash (n = 1; 1.9%). In the LCM group, 15.4% (8/52) of the patients had AEs, including headache (n = 4; 7.5%), dizziness (n = 4; 7.5%), nausea (n = 2; 3.8%), somnolence (n = 2; 3.8%), irritability (n = 1; 1.9%), stomach ache (n = 1; 1.9%), and vomiting (n = 1; 1.9%). The incidence of irritability was significantly higher in the PER group than in the LCM group (13.5% vs. 1.9%, P = 0.031), which occurred mainly within eight weeks after drug administration. Patients with irritability were not dangerous to surrounding people by the assessment of parental observation in the life. And the symptoms were relieved spontaneously within a few months. The outcomes of total scores, internalizing scores, and externalizing scores of the CBCL did not show statistically significant differences in the PER and LCM groups between baseline and three and six months. Characteristics of behavior and emotion did not have substantial changes in patients treated with PER and LCM monotherapy.

CONCLUSIONS

The present study documented similar good effectiveness and good tolerance of PER and LCM as monotherapy in pediatric patients with newly diagnosed focal epilepsy and showed no behavioral or emotional impact, as assessed by the CBCL. Though the incidence of irritability with PER monotherapy may be higher than that with LCM monotherapy soon after medication initiation, this side effect appears to resolve spontaneously within a few months. At present, this study was the first research about PER and LCM monotherapy in pediatric patients with newly diagnosed focal epilepsy evaluating efficacy, tolerability, and behavior in China.

Efficacy of perampanel in pediatric epilepsy with known and presumed genetic etiology

OBJECTIVE

The efficacy of perampanel (PER) in pediatric epilepsy with specific etiologies has not been well established. Here, we investigated outcome and predictors of PER treatment in a pediatric cohort with known and presumed genetic etiology.

METHODS

We included pediatric patients with potential genetic epilepsy who received PER treatment and underwent whole-exome sequencing (WES) from January 2020 to September 2021. All patients were followed up for >12 months.

RESULTS

A total of 124 patients were included. Overall response rates were 51.6% and 49.6% at 6 months and 12 months, respectively. Pathogenic or likely pathogenic variants in 27 multiple genes were detected among 58 patients (46.8%) by WES. On performing multivariate logistic regression analysis, only developmental delay (OR = 0.406, P = 0.042) was a negative predictor of treatment response. However, the seizure onset age, positive WES results, and number of ASMs before PER administration were not significantly. Thirteen carriers with variants in the SCN1A gene showed a better response compared to eight patients with other sodium channels (P = 0.007), and to the other 45 patients with positive WES results (OR = 7.124, 95% CI = 1.306-38.860, P = 0.023). Adverse events were only reported in 23 patients, the most common being emotional problems.

INTERPRETATION

PER is safe and efficacious in pediatric patients with known and presumed genetic etiology. The response rate is comparable to that reported in other pediatric populations, and lower among those with developmental delay. A gene-specific response to PER is found along with better efficacy links to pathogenic variants in the SCN1A gene.

The broad-spectrum activity of perampanel: state of the art and future perspective of AMPA antagonism beyond epilepsy

Glutamate is the brain's main excitatory neurotransmitter. Glutamatergic neurons primarily compose basic neuronal networks, especially in the cortex. An imbalance of excitatory and inhibitory activities may result in epilepsy or other neurological and psychiatric conditions. Among glutamate receptors, AMPA receptors are the predominant mediator of glutamate-induced excitatory neurotransmission and dictate synaptic efficiency and plasticity by their numbers and/or properties. Therefore, they appear to be a major drug target for modulating several brain functions. Perampanel (PER) is a highly selective, noncompetitive AMPA antagonist approved in several countries worldwide for treating different types of seizures in various epileptic conditions. However, recent data show that PER can potentially address many other conditions within epilepsy and beyond. From this perspective, this review aims to examine the new preclinical and clinical studies-especially those produced from 2017 onwards-on AMPA antagonism and PER in conditions such as mesial temporal lobe epilepsy, idiopathic and genetic generalized epilepsy, brain tumor-related epilepsy, status epilepticus, rare epileptic syndromes, stroke, sleep, epilepsy-related migraine, cognitive impairment, autism, dementia, and other neurodegenerative diseases, as well as provide suggestions on future research agenda aimed at probing the possibility of treating these conditions with PER and/or other AMPA receptor antagonists.

Efficacy and Safety of Perampanel in Children with Drug-Resistant Focal-Onset Seizures: A Retrospective Review

BACKGROUND

Epilepsy is one of the most common neurological disorders. Existing antiseizure medications (ASMs) are still unable to control seizures in one-third of these patients, making the discovery of antiseizure therapies with novel mechanisms of action a necessity.

AIM OF THE STUDY

This study aimed to determine the safety and efficacy of perampanel (PER) as an adjuvant treatment for children with drug-resistant focal-onset seizures with or without focal to bilateral tonic-clonic seizures.

PATIENTS AND METHODS

This is a single-center retrospective study of 38 epileptic pediatric patients, aged 2 to 14, at King Faisal Specialist Hospital and Research Center whose seizures were pharmaco-resistant to more than two antiseizure medications and followed for at least three months after PER adjuvant therapy initiation. Efficacy was assessed by the PER response rate at 3-, 6-, and 12-month follow-up evaluations, and side effects were also reported.

RESULTS

Multiple seizure types were reported. Myoclonic seizures were the predominant type of epilepsy in 17 children (44.7%). At 3 months, 6 months, and 12 months of follow-up, approximately 23.4%, 23.4%, and 18.4% of the patients were seizure-free at these time points, respectively. Adverse events were documented in 14 patients (35.7%) and led to the discontinuation of PER in 26.3%, 31.6%, and 36.8% of the studied group at the 3-, 6-, and 12-month follow-ups, respectively. The most common adverse events included dizziness or drowsiness, irritability, gait disturbance, and confusion; however, all were transient, and no serious adverse effects occurred.

CONCLUSION

Our findings confirm the therapeutic efficacy of adjunctive PER in the treatment of drug-resistant epilepsy in children. As an adjunctive treatment for epilepsy, perampanel demonstrated sufficient effectiveness and tolerability.

Perampanel add-on for drug-resistant focal epilepsy

BACKGROUND

Epilepsy is one of the most common neurological disorders. Approximately 30% of people with epilepsy are considered to be drug-resistant, and usually need treatment with a combination of other antiepileptic drugs. Perampanel is a newer antiepileptic drug that has been investigated as add-on therapy for drug-resistant focal epilepsy.

OBJECTIVES

To evaluate the benefits and harms of perampanel as add-on therapy for people with drug-resistant focal epilepsy.

SEARCH METHODS

We used standard, extensive Cochrane search methods. The latest search date was 20 October 2022.

SELECTION CRITERIA

We included randomised controlled trials comparing add-on perampanel with placebo.

DATA COLLECTION AND ANALYSIS

We used standard Cochrane methods. Our primary outcome was 1. 50% or greater reduction in seizure frequency. Our secondary outcomes were 2. seizure freedom, 3. treatment withdrawal due to any reason, 4. treatment withdrawal due to adverse effects, and 5.

ADVERSE EFFECTS

We used an intention-to-treat population for all primary analyses. We presented the results as risk ratios (RR) with 95% confidence intervals (CIs), except for individual adverse effects, which we reported with 99% CIs to compensate for multiple testing. We used GRADE to assess certainty of evidence for each outcome.

MAIN RESULTS

We included seven trials involving 2524 participants, all aged over 12 years. The trials were double-blind, randomised, placebo-controlled trials with treatment duration of 12 to 19 weeks. We assessed four trials at overall low risk of bias, and three trials at overall unclear risk of bias, due to risk of detection, reporting, and other biases. Compared with placebo, participants receiving perampanel were more likely to achieve a 50% or greater reduction in seizure frequency (RR 1.67, 95% CI 1.43 to 1.95; 7 trials, 2524 participants; high-certainty evidence). Compared to placebo, perampanel increased seizure freedom (RR 2.50, 95% CI 1.38 to 4.54; 5 trials, 2323 participants; low-certainty evidence) and treatment withdrawal (RR 1.30, 95% CI 1.03 to 1.63; 7 trials, 2524 participants; low-certainty evidence). Participants treated with perampanel were more likely to withdraw from treatment due to adverse effects compared to those receiving placebo (RR 2.36, 95% CI 1.59 to 3.51; 7 trials, 2524 participants; low-certainty evidence). A higher proportion of participants receiving perampanel reported one or more adverse effects when compared to participants who received placebo (RR 1.17, 95% CI 1.10 to 1.24; 7 trials, 2524 participants; high-certainty evidence). Compared with placebo, participants receiving perampanel were more likely to experience ataxia (RR 14.32, 99% CI 1.09 to 188.31; 2 trials, 1098 participants; low-certainty evidence), dizziness (RR 2.87, 99% CI 1.45 to 5.70; 7 trials, 2524 participants; low-certainty evidence), and somnolence (RR 1.76, 99% CI 1.02 to 3.04; 7 trials, 2524 participants). Subgroup analysis indicated that a larger proportion of participants who received perampanel at a dose of 4 mg/day (RR 1.38, 95% CI 1.05 to 1.83; 2 trials, 710 participants), 8 mg/day (RR 1.83, 95% CI 1.51 to 2.22; 4 trials, 1227 participants), or 12 mg/day (RR 2.38, 95% CI 1.86 to 3.04; 3 trials, 869 participants) achieved a 50% or greater reduction in seizure frequency compared to placebo; however, treatment with perampanel 12 mg/day also increased treatment withdrawal (RR 1.77, 95% CI 1.31 to 2.40; 3 trials, 869 participants).

AUTHORS' CONCLUSIONS

Add-on perampanel is effective at reducing seizure frequency and may be effective at maintaining seizure freedom for people with drug-resistant focal epilepsy. Although perampanel was well-tolerated, there was a higher proportion of treatment withdrawals with perampanel compared with placebo. Subgroup analysis suggested that 8 mg/day and 12 mg/day are the most efficacious perampanel doses; however, the use of 12 mg/day would likely increase the number of treatment withdrawals. Future research should focus on investigating the efficacy and tolerability of perampanel with longer-term follow-up, as well as exploring an optimal dose.

Efficacy, tolerability and safety of perampanel in children and adolescents with epilepsy: Systematic review and meta-analysis

OBJECTIVE

Perampanel (PER) is a novel antiepileptic drug. The efficacy, tolerability and safety of PER in children and adolescents with epilepsy are still unclear. We aimed to study the efficacy and safety of PER in children and adolescents with epilepsy.

METHODS

We searched PubMed, Embase and Cochrane Library for relevant literature up to November 2022. Then we extracted the relevant data from eligible literature for systematic review and meta-analysis.

RESULT

Twenty-one studies involving 1968 children and adolescent patients were included. A reduction in seizure frequency of at least 50 percent occurred in 51.5% (95% confidence interval [CI] [47.1%, 55.9%]) of patients. Complete seizure cessation occurred in 20.6% (95%CI [16.7%, 25.4%]). The incidence of adverse events was 40.8% (95%CI [33.8%, 48.2%]). The most common adverse events were drowsiness 15.3% (95% CI [13.7%, 16.9%]), irritability 9.3% (95%CI [8.0%, 10.6%]), dizziness 8.4% (95% CI [7.2%, 9.7%]). The incidence of drug discontinuation due to adverse events was 9.2% (95% CI [7.0%, 11.5%]).

CONCLUSION

PER is generally well tolerated and effective in the treatment of epilepsy in children and adolescents. Larger studies are still needed to explore the application of PER in children and adolescents.

RISK OF BIAS AND LIMITATION

The funnel plot suggests that there may be publication bias in our meta-analysis, and most of the included studies were Asian, so there may be some racial differences.

The safety of perampanel in different disorders and doses: A meta-analysis

PURPOSE

To investigate the safety of perampanel in different disorders and doses.

METHODS

Embase, the Cochrane Library, Medline, and ClinicalTrials.gov were searched from inception to July 2022 for randomized controlled trials (RCTs). The meta-analysis was performed by using Review Manager 5.3 and R 4.2.1 software.

RESULTS

A total of 17 RCTs with 5711 subjects were included in the final analysis. The double-blind treatment phase was from 12 weeks to 48 weeks. Our results showed that 11 adverse events (aggression, ataxia, balance disorder, dizziness, fall, fatigue, irritability, rash, somnolence, vertigo, and weight increase) were statistically significantly associated with perampanel, and 4 of them (ataxia, dizziness, fatigue, and somnolence) showed a clear dose-response relationship. Psychiatric adverse events occurred most frequently among serious treatment-emergent adverse events (TEAEs). At 8 mg/day, seven adverse events (aggression, balance disorder, dizziness, fatigue, irritability, vertigo, and weight increase) occurred more frequently in patients with epilepsy than in patients with other disorders, whereas dose discontinuation rates due to adverse events were lower in patients with epilepsy than in patients with other disorders.

CONCLUSION

The safety profile of perampanel is dependent on diseases and dose. The risk of adverse events was statistically significantly higher, with doses exceeding 4 mg/day. Despite a higher risk of adverse events, patients with epilepsy had a lower perampanel discontinuation rate than patients with other disorders.

Comparative antiseizure medications of adjunctive treatment for children with drug-resistant focal-onset seizures: A systematic review and network meta-analysis

Purpose: In this study, we intended to compare and rank the efficacy and acceptability of antiseizure medications (ASMs) for adjunctive treatment of children with drug-resistant focal-onset seizures. Method: We conducted a computerized search of PubMed, EMBASE, Cochrane Library, Web of Science, and Google Scholar to identify eligible randomized controlled trials (RCTs) published before 31 May 2022. We included studies evaluating the efficacy and tolerability of antiseizure medications for children with drug-resistant focal-onset seizures. The efficacy and safety were reported in terms of responder and dropout rate along with serious adverse events, the outcomes were ranked with the surface under the cumulative ranking curve (SUCRA). Results: A total of 14 studies (16 trials) with 2,464 patients were included, involving 10 active antiseizure medications. For the primary endpoint of at least 50% reduction in focal-onset seizures, the surface under the cumulative ranking curve ranking suggested that lamotrigine and levetiracetam were more effective as compared with other antiseizure medications; moreover, levetiracetam had the highest probability of rank first for achieving seizure freedom. Concerning tolerability, oxcarbazepine and eslicarbazepine acetate were associated with higher dropout rates relative to other antiseizure medications and placebo, and topiramate was associated with higher occurrence of side effects. No significant differences were found between active antiseizure medications concerning dropout for side effects. Conclusion: According to the surface under the cumulative ranking curve ranking, lamotrigine, levetiracetam, and oxcarbazepine were more efficacious than other active antiseizure medications in terms of responder rate. Concerning tolerability, oxcarbazepine was more likely to lead to dropout and topiramate was associated with higher occurrence of side effects.

Effectiveness and tolerability of adjunctive perampanel in the treatment of pediatric patients with uncontrolled epilepsy: A retrospective, single-center, real-world study

OBJECTIVE

The main aim of this study was to assess the efficacy, safety, and tolerability of adjunctive perampanel (PER) in the treatment of children and adolescents with epilepsy.

METHODS

Pediatric patients who visited the pediatric epilepsy clinic of Henan Provincial People's Hospital between May 2020 and December 2021 were recruited. All participants were treated with PER as adjunctive therapy and were seen routinely (minimum: a baseline and 12-week visit). The efficacy and tolerability of adjunctive PER for the treatment of epilepsy were investigated.

RESULTS

One hundred and fourteen patients were enrolled, among whom 7 (6.1%) were lost to follow-up. At 12 weeks, the responder rate and the seizure-free rate were 56.1% (60/107) and 32.7% (35/107), respectively. The responder rate increased with the duration of PER administration and was significantly higher when PER was used as an early add-on (after ≤2 prior antiseizure medications (ASMs)) than a late add-on (after >2 prior ASMs). However, there was no significant difference in the treatment efficacy of adjunctive PER in patients with different epilepsy etiologies or types. Adverse events, including irritability, dizziness, somnolence, ataxic gait, weight gain, and tinnitus, were reported in thirty-two patients (29.9%).

CONCLUSIONS

In a routine clinical setting of pediatric patients with epilepsy, good effectiveness and tolerability of adjunctive PER were demonstrated. Notably, patients initiating PER as an early add-on showed a better seizure outcome than those initiating PER as a late add-on.

Effectiveness and tolerability of adjunctive perampanel in pediatric patients (aged 4-12 years) with refractory epilepsy: An observational study

Information on the effects of perampanel in Chinese children ≤12 years of age with refractory epilepsy is limited; thus, we conducted an observational study to assess the effectiveness, safety, and tolerability of adjunctive perampanel in this pediatric population. In this study, we reviewed the medical records of pediatric patients aged 4 to 12 years with refractory epilepsy who were admitted to Children's Hospital of Soochow University and prescribed perampanel between January 2020 and January 2021. Effectiveness of perampanel was measured by 50% responder rates, seizure-freedom rates, and retention rates for up to 48 weeks. Adverse events were monitored and recorded throughout the study. A total of 34 patients (male, n = 15) who exhibited refractory epilepsy were included in this study, and 64.71% of patients had focal-onset seizures combined with generalized epilepsy. The mean (± standard deviation) age of patients was 7.21 (± 2.12) years, with a mean (± standard deviation) age at seizure onset of 4.57 (± 2.59) years. After the addition of perampanel, the 50% responder rates at 4, 8, 12, 24, 36, and 48 weeks were 37.50% (12/32), 43.75% (14/32), 53.13% (17/32), 59.38% (19/32), 59.38% (19/32), and 62.07% (18/29). Two patients withdrew from perampanel treatment due to adverse events in the first 2 weeks. Adverse events were reported by 44.12% (15/34) of patients, and the retention rates at 36 and 48 weeks were 94.12% (32/34) and 85.29% (29/34), respectively. Overall, perampanel exhibited good effectiveness, safety, and tolerability in the treatment of pediatric patients (aged 4-12 years) with refractory epilepsy. These findings suggest that personalized treatment and better baseline seizure control may increase the responder rate and retention rate of perampanel.

Perampanel and childhood absence epilepsy: A real life experience

Objectives

The aim of our study was to evaluate the effectiveness and tolerability of perampanel (PER) as first add-on and as second line monotherapy in subjects with childhood absence epilepsy.

Methods

Our sample consisted of 20 patients with childhood absence epilepsy, aged between 8 and 10, already in therapy with a first antiseizure medication with incomplete seizure control. PER was added as first add-on in a dose ranging from 3 to 8 mg/die with 1- 2 mg/week increments. The patients that were seizure-free were shifted to a PER monotherapy. All patients underwent a standardized neuropsychological evaluation in order to assess non-verbal intelligence and executive functions before adding PER and after 6 months of drug therapy. All parents completed two questionnaires, in order to assess the emotional-behavioral problems and parental stress.

Results

15/20 patients responded to add-on PER and were seizure-free, in 3/20 patients we observed a reduction of seizure frequency <50%, and in the 2 remaining patients the add-on therapy with PER did not lead to a reduction in seizures frequency from baseline. The patients who were seizure-free were switched to PER monotherapy. 9/15 patients remained seizure-free in monotherapy with PER. In the first month of therapy with PER 2/20 patients (10%) reported mild, transient side effects of irritability, headache and dizziness, which did not lead to discontinuation of therapy. Adjunctive treatment with PER did not negatively affect non-verbal intelligence, executive functions, emotional/behavioral symptoms of children and parental stress levels.

Significance

Our clinical experience in real life showed that PER appears to be effective in the control of absence seizures in childhood absence epilepsy, with a favorable tolerability profile. PER would seem effective on absence seizures even in monotherapy. Further studies with larger samples, longer follow-up and controlled vs. placebo (or other first choice antiseizure medications) are needed to confirm our data.

Impact of Antiseizure Medications on Appetite and Weight in Children

There are numerous potential factors that may affect growth in children with epilepsy, and these must be evaluated in any child with appetite and weight concerns. Antiseizure medications (ASMs) have potential adverse effects, and many may affect appetite, thus impacting normal growth and weight gain. The aim of this review is to focus on the impact of both epilepsy and ASMs on appetite and weight in children. We systematically reviewed studies using Medline assessing the impact of ASMs on appetite and weight in children. Eligible studies included randomized controlled trials and open-label studies (open-label extension and interventional) that targeted or included the pediatric population (0-18 years of age). Each study was classified using the American Academy of Neurology (AAN) Classification of Evidence for Therapeutic Studies, and the level of evidence for impact on appetite and weight in children was graded. ASMs associated with decreased appetite and/or weight loss include fenfluramine, topiramate, zonisamide, felbamate, rufinamide, stiripentol, cannabidiol, brivaracetam and ethosuximide; ASMs with minimal impact on weight and appetite in children include oxcarbazepine, eslicarbazepine, lamotrigine, levetiracetam, lacosamide, carbamazepine, vigabatrin and clobazam. The ASM most robustly associated with increased appetite and/or weight gain is valproic acid; however, both pregabalin and perampanel may also lead to modest weight gain or increased appetite in children. Certain ASMs may impact both appetite and weight, which may lead to increased morbidity of the underlying disease and impaired adherence to the treatment regimen.

Movement Disorders Secondary to Novel Antiseizure Medications in Pediatric Populations: A Systematic Review and Meta-analysis of Risk

Novel antiseizure medications are thought to be safer than their conventional counterparts, though no dedicated analysis of movement disorder risk among pediatric populations using novel antiseizure medications has been completed. We report a systematic review with meta-analysis describing the relationship between novel antiseizure medications and movement disorders in pediatrics.MEDLINE, EMBASE, and the World Health Organization's International Clinical Trials Registry Platform were searched up to October 2020 for randomized controlled trials investigating novel antiseizure medications in pediatric populations. Antiseizure medications included lacosamide, perampanel, eslicarbazepine, rufinamide, fenfluramine, cannabidiol, and brivaracetam. Outcomes were pooled using random effects models; risk difference (RD) and 95% confidence intervals (CIs) were calculated.Twenty-three studies were selected from 1690 nonredundant manuscripts (n = 1912 total). There was a significantly increased risk of movement disorders associated with perampanel (RD 0.07, 95% CI 0.01-0.13; n = 133), though only 1 relevant trial was found. No increased risk of movement disorders was found with other antiseizure medications.Our findings indicate most novel antiseizure medications are safe to use in pediatric populations with respect to movement disorders. However, findings were limited by quality of adverse event reporting.

The bee venom active compound melittin protects against bicuculline-induced seizures and hippocampal astrocyte activation in rats

Epilepsy is a chronic neuropathology characterized by an abnormal hyperactivity of neurons that generate recurrent, spontaneous, paradoxical and synchronized nerve impulses, leading or not to seizures. This neurological disorder affects around 70 million individuals worldwide. Pharmacoresistance is observed in about 30% of the patients and long-term use of antiepileptics may induce serious side effects. Thus, there is an interest in the study of the therapeutic potential of bioactive substances isolated from natural products in the treatment of epilepsy. Arthropod venoms contain neurotoxins that have high affinity for molecular structures in the neural tissue such as receptors, transporters and ion channels both in glial and neuronal membranes. This study evaluated the potential neuroprotective effect of melittin (MEL), an active compound of bee venom, in the bicuculline-induced seizure model (BIC) in rats. Male Wistar rats (3 months, 250-300 g) were submitted to surgery for the implantation of a unilateral cannula in the lateral ventricle. After the recovery period, rats received a microinjection of saline solution or MEL (0.1 mg per animal). Firstly, rats were evaluated in the open field (20 min) and in the elevated plus maze (5 min) tests after received microinjection of saline or MEL. After, 30 min later animals received BIC (100 mg/ml) or saline, and their behaviors were analyzed for 20 min in the open field according to a seizure scale. At the end, rats were euthanized, brains collected and processed to glial fibrillary acidic protein (GFAP) immunohistochemistry evaluation. No changes were observed in MEL-treated rats in the open field and elevated plus maze. However, 90% of MEL-treated animals were protected against seizures induced by BIC. There was an increase in the latency for the onset of seizures, accompanied by a reduction of GFAP-immunoreactivity cells in the dentate gyrus and CA1. Thus, our study suggests that MEL has an anticonvulsant potential, and further studies are needed to elucidate the mechanisms involved in this action.

Does a psychiatric history play a role in the development of psychiatric adverse events to perampanel… and to placebo?

OBJECTIVE

The purpose of this study was to establish whether a past psychiatric history could play a role in the development of psychiatric treatment-emergent adverse events (PTEAEs) in patients randomized to perampanel (PER) or placebo.

METHODS

The development of PTEAEs was compared between patients with/without a psychiatric history in a post hoc analysis from four randomized placebo-controlled trials (RPCTs) of PER (304/305/306/335) in patients with treatment-resistant focal epilepsy.

RESULTS

Among the 2,187 patients enrolled in the RPCTs, 352 (16.1%) had a psychiatric history (PER n = 244; placebo n = 108), while 1835 patients (83.9%) did not (PER n = 1325; placebo n = 510). Compared to patients without a psychiatric history, those with a positive history reported more PTEAEs for both patients randomized to PER (11.8% vs. 29.9%, p < 0.01) or to placebo (9.2% vs. 19.4%, p < 0.01). The prevalence of PTEAEs was not higher among patients randomized to 2 mg and 4 mg/day doses than placebo in both those with and without psychiatric history. Rather, the higher prevalence rates were among subjects randomized to 8 mg (29.8%) and 12 mg (36.4%) PER doses in patients with a past psychiatric history.

SIGNIFICANCE

A psychiatric history appears to increase the risk of PTEAEs in patients randomized to placebo and to PER at doses of 8 and 12 mg/day. It should be identified in all patients considered for treatment with PER, particularly when prescribed at doses above 4 mg/day.

Psychiatric disorders of the combination of levetiracetam either with lacosamide or perampanel: a retrospective cohort study

Background The number of patients with epilepsy receiving perampanel or lacosamide as an add-on treatment following levetiracetam treatment has increased. Although levetiracetam causes psychiatric disorders, it is unclear whether they occur with the combined use of these antiepileptic drugs. Objective To determine the frequency of psychiatric disorders in patients received lacosamide or perampanel in combination with levetiracetam. Setting A single-center retrospective cohort study. Method Patients who received levetiracetam + lacosamide or levetiracetam + perampanel were selected. Medical records from the start of combination therapy contained characteristics of patients and the incidence of psychiatric disorders. Main outcome measure The frequency of psychiatric disorders, the time to onset, dose reduction or discontinuation following psychiatric disorders, and the clinical course following disorder onset. Results Forty-four patients used levetiracetam + lacosamide and 50 used levetiracetam + perampanel. The incidence of psychiatric disorders was significantly lower (p < 0.001) with levetiracetam + lacosamide (6.8%) than with levetiracetam + perampanel (44%). The incidence of affect lability was significantly higher with levetiracetam + perampanel than with levetiracetam + lacosamide (p = 0.018). The time to the onset of psychiatric disorders was within 1 month of dose initiation or increase in one case (33.3%) with levetiracetam + lacosamide and 16 cases (72.7%) with levetiracetam + perampanel. There was no significant difference in clinical characteristics and antiepileptic drug dosages owing to the presence or absence of psychiatric disorders. Conclusion As the frequency of psychiatric disorders was higher with levetiracetam + perampanel therapy, levetiracetam + lacosamide may be preferable. These disorders tended to develop within 1 month of therapy and were not dose-dependent. Antiepileptic drugs should be cautiously prescribed to avoid psychiatric disorders.

Clinical experience on the use of perampanel in epilepsy among child neurologists in the Philippines

BACKGROUND

Perampanel is the latest anti-seizure medication introduced in the Philippines in 2015. This was initially approved as an adjunctive treatment for focal seizures and those with secondary generalization among individuals 12 years old and above. By March 2020, it has been approved also for generalized seizures and in children 4 years and above. The general objective of this research is to describe the clinical experience of Filipino child neurologists on the use of perampanel in children.

METHODS

This is a cross-sectional descriptive study that surveyed child neurologists with review of medical records of children who have received perampanel as either an adjunctive therapy or monotherapy for epilepsy.

RESULTS

There were 65 patients included in the study aged 1 to 18 years with a mean age of 10.0 ± 5.2 years and a median of 10 years. Follow-up duration were between 2 weeks to more than a year. Perampanel was started in 98.5% as an add-on treatment between 5 months and 18 years of age. The responder rate is 69.2% (45/65), seizure-free rate is 29.2% (19/65), seizure-aggravation rate is 9.2% (6/65), and perampanel retention rate is 83.1% (54/65). Treatment emergent adverse events were noted in 53.8% of the children with somnolence (20.0%), gait problems (12.3%), weight gain (10.8%) and dizziness (9.2%) as the most common events experienced. Dizziness was experienced significantly more among children 12 to 18 years of age.

CONCLUSION

Perampanel is seen to be effective and relatively safe to use among Filipino children.

Efficacy and safety of adjunctive perampanel in adolescent patients with epilepsy: Post hoc analysis of six randomized studies

OBJECTIVE

This post hoc analysis of six randomized, double-blind, Phase II and III studies evaluated efficacy and safety of adjunctive perampanel (2-12 mg/day) in adolescent patients (aged ≥12 to ≤17 years) with uncontrolled partial-onset seizures, with or without secondarily generalized (SG) seizures, or primary generalized tonic-clonic (PGTC) seizures.

METHODS

Adolescent patients from Studies 304 (NCT00699972), 305 (NCT00699582), 306 (NCT00700310), 335 (NCT01618695), 235 (NCT01161524), and 332 (NCT01393743) were included. Efficacy assessments (split by seizure type) included median percent change in seizure frequency per 28 days from baseline and seizure-freedom rates. Safety assessments (all seizure types combined) included monitoring of treatment-emergent adverse events (TEAEs).

RESULTS

The Safety Analysis Set included 372 adolescent patients (placebo, n = 114; perampanel, n = 258); the Full Analysis Set included 346 patients with partial-onset seizures (placebo, n = 103; perampanel, n = 243), of whom 125 experienced SG seizures during baseline (placebo, n = 37; perampanel, n = 88), and 22 with PGTC seizures (placebo, n = 9; perampanel, n = 13). Compared with placebo, perampanel 8 and 12 mg/day conferred greater median percent reductions in seizure frequency per 28 days for partial-onset seizures (18.0% vs 35.9% and 53.8% [both P < 0.01]) and SG seizures (24.4% vs 72.8% [P < 0.001] and 57.8% [P < 0.01]), and greater seizure-freedom rates (partial-onset: 7.8% vs 13.2% and 11.8% [not statistically significant]; SG: 8.1% vs 40.7% [P < 0.001] and 41.7% [P < 0.01]). For PGTC seizures, and compared with placebo, perampanel 8 mg/day was also associated with greater median percent reductions in seizure frequency per 28 days (29.8% vs 88.0%) and greater seizure-freedom rates (11.1% vs 23.1%). Treatment-emergent adverse events were reported in 76 (66.7%) placebo- and 192 (74.4%) perampanel-treated patients (most common: dizziness, somnolence, headache, and nasopharyngitis). Serious TEAEs occurred in 5 (4.4%) placebo- and 11 (4.3%) perampanel-treated patients.

CONCLUSIONS

Adjunctive perampanel was efficacious and generally well tolerated in adolescent patients with partial-onset, SG, or PGTC seizures and represents a potentially beneficial treatment option for adolescents with uncontrolled epilepsy.

Perampanel tolerability in children and adolescents with focal epilepsy: Effects on behavior and executive functions

OBJECTIVES

Perampanel (PER) is a noncompetitive α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA) glutamate receptor antagonist recently approved for focal and generalized epilepsies as an add-on therapy. It is well tolerated and effective as treatment of various pediatric epilepsy syndromes; PER does not seem to negatively affect the cognitive profile of children and adolescents, but its influence on executive functions is still to be assessed.

METHODS

Our sample included 37 children aged 12-18 years, with focal pharmacoresistant epilepsy already in therapy with 2 or 3 antiepileptic drug (AED); PER was added with 1 mg/week increments up to a dose of 2-4 mg/day. Changes in executive functions were assessed by the EpiTrack Junior test. Emotional and behavioral aspects were evaluated through the interview for parents Child Behavior Checklist (CBCL). Both tests were performed before taking PER and after 6 and 12 months of treatment.

RESULTS

After 12 months of PER in 22/30 patients, global score of the EpiTrack Junior test remained almost unchanged; in 7/30 patients, this score improved. The CBCL did not show significant changes in emotional or behavioral problems.

CONCLUSIONS

Adjunctive treatment with PER did not negatively affect executive functions that could also be improved. No emotional/behavioral negative effects have been reported, and this suggests a good tolerability in the middle/long term.

Real-Life Effectiveness and Tolerability of Perampanel in Pediatric Patients Aged 4 Years or Older with Epilepsy: A Korean National Multicenter Study

Background and Purpose

The US Food and Drug Administration approval for perampanel has only recently been expanded to patients as young as 4 years, and so there have been few real-life studies of the effects of perampanel in pediatric patients. The aim of this study was to determine the long-term efficacy, factors affecting treatment response, and tolerability of perampanel as an add-on therapy in pediatric patients aged 4 years or older with epilepsy.

Methods

This multicenter retrospective observational study collected data from pediatric epilepsy centers of four Korean national universities. Changes in the seizure frequency from baseline, adverse events, and retention rates were obtained at 3, 6, and 12 months. Adverse events and discontinuation profiles were obtained to assess tolerability.

Results

This study included 220 children and adolescents (117 males and 103 females) aged 4 to 20 years. The overall response rate was 43.6%, and the seizure-freedom rate was 17.7%. Factors affecting a good treatment response were the absence of intellectual disability, small number of concomitant antiepileptic drugs, and low baseline seizure frequency. Eighty-eight patients (40%) experienced adverse events, but they mostly were of mild severity and resolved after the dose reduction or discontinuation of perampanel. The retention rates at 3, 6, and 12 months were 85.0%, 71.8%, and 50.5%, respectively.

Conclusions

Adjunctive treatment with perampanel was efficacious and tolerated in pediatric patients aged 4 years or older with epilepsy. Early perampanel treatment may help to reduce the burden of their seizures and improve their quality of life.

An Evidence-Based Review On The Use Of Perampanel For The Treatment Of Focal-Onset Seizures In Pediatric Patients

Perampanel, a non-competitive AMPA receptor antagonist, is a once-daily oral antiepileptic drug approved for the treatment of focal seizures and primary generalized tonic-clonic seizures in children 12 years of age and over. We conducted a systematic review of the data on perampanel in children and adolescents with focal-onset seizures. We found 21 published papers on the pediatric use of perampanel for focal-onset seizures, including 9 papers on clinical trials and ancillary studies of these trials, of which 2 focused on pharmacokinetics, 1 was a meta-analysis, and 9 were real-life studies (1 was prospective). Perampanel, as an adjunctive treatment for uncontrolled focal-onset seizures, results in an improvement of seizure control with a generally good safety profile. Evidence-based data are currently available for children 12 years of age and over. Higher amounts of perampanel might be required in patients taking enzyme-inducing antiepileptic drugs. The most common adverse events are somnolence, dizziness and behavioral adverse events. The latter seems more frequent in adolescents than in adults and in adolescents with preexisting behavioral comorbidities. Current studies did not identify any short-term impact of perampanel on cognitive functions. Its long half-life allows once-daily administration. Real-life studies further established that a decrease of the dose frequently resolves adverse events, as demonstrated in pivotal studies. Pharmacokinetic and safety studies are still ongoing in the younger population, down to 4 years of age, in order to apply for approval in this age group.

Mechanisms Underlying Aggressive Behavior Induced by Antiepileptic Drugs: Focus on Topiramate, Levetiracetam, and Perampanel

Antiepileptic drugs (AEDs) are effective against seizures, but their use is often limited by adverse effects, among them psychiatric and behavioral ones including aggressive behavior (AB). Knowledge of the incidence, risk factors, and the underlying mechanisms of AB induced by AEDs may help to facilitate management and reduce the risk of such side effects. The exact incidence of AB as an adverse effect of AEDs is difficult to estimate, but frequencies up to 16% have been reported. Primarily, levetiracetam (LEV), perampanel (PER), and topiramate (TPM), which have diverse mechanisms of action, have been associated with AB. Currently, there is no evidence for a specific pharmacological mechanism solely explaining the increased incidence of AB with LEV, PER, and TPM. Serotonin (5-HT) and GABA, and particularly glutamate (via the AMPA receptor), seem to play key roles. Other mechanisms involve hormones, epigenetics, and “alternative psychosis” and related phenomena. Increased individual susceptibility due to an underlying neurological and/or a mental health disorder may further explain why people with epilepsy are at an increased risk of AB when using AEDs. Remarkably, AB may occur with a delay of weeks or months after start of treatment. Information to patients, relatives, and caregivers, as well as sufficient clinical follow-up, is crucial, and there is a need for further research to understand the complex relationship between AED mechanisms of action and the induction/worsening of AB.

Safety and tolerability profile of new antiepileptic drug treatment in children with epilepsy

INTRODUCTION

Treatment of pediatric epilepsy requires a careful evaluation of the safety and tolerability profile of antiepileptic drugs (AEDs) to avoid or minimize as much as possible adverse events (AEs) on various organs, hematological parameters, and growth, pubertal, motor, cognitive and behavioral development.

AREAS COVERED

Treatment-emergent AEs (TEAEs) reported in the literature 2000-2018 regarding second- and third-generation AEDs used in the pediatric age, with exclusion of the neonatal period that exhibits specific peculiarities, have been described on the basis of their frequency, severity/tolerability, and particular association with a given AED.

EXPERT OPINION

Somnolence/sedation and behavioral changes, like irritability and nervousness, are among the most commonly observed TEAEs associated with almost all AEDs. Lamotrigine, Gabapentin, Oxcarbazepine, and Levetiracetam appear to be the best-tolerated AEDs with a ≤2% withdrawal rate, while Tiagabine and Everolimus are discontinued in up to >20% of the patients because of intolerable TEAEs. For some AEDs, literature data are scanty to draw a high-level evidence on their safety and tolerability profile. The reasons are: insufficient population size, short duration of treatments, or lack of controlled trials. A future goal is that of identifying clearer, easier, and more homogeneous methodological strategies to facilitate AED testing in pediatric populations.

Efficacy and tolerability of perampanel in children and adolescents with pharmacoresistant epilepsy: The first real-world evaluation in Asian pediatric neurology clinics

AIM

This study investigated the efficacy and safety of perampanel (PER) adjunctive therapy in pediatric patients with epilepsy whose seizures are pharmacoresistant to existing antiepileptic drugs.

METHODS

A clinical retrospective study was conducted from 2016 to 2017 in the pediatric neurology clinic at a tertiary children's hospital. We reviewed the data obtained from 66 children whose seizures were pharmacoresistant to more than two antiepileptic drugs, and could be followed up for a minimum of 3 months after PER adjunctive therapy initiation. The efficacy was estimated by the PER response rate at 3-, 6-, and 12-month follow-up evaluations, and adverse events were also recorded.

RESULTS

The rate of seizure reduction of >50% was 30.3%, 37.5%, and 34.7% for all seizure types at 3, 6, and 12 months, in which 7.6%, 8.9%, and 14.3% of the patients became seizure-free at these time points, respectively. No significant differences were found between enzyme-inducing and nonenzyme-inducing antiepileptic drugs in combination with PER with regard to the responder rate. Five patients with Dravet syndrome were included in the study. Four of them (80%) exhibited 50% seizure reduction at the last visit, at which point, two patients (40.0%) were seizure-free. The retention rate was 51% at 12 months. Adverse events were documented in 25 patients (35.7%) and led to PER discontinuation in eight patients (12.1%). The most common adverse events comprised irritability, skin rash, dizziness, and somnolence; however, all were transient and successfully managed after PER dose reduction or discontinuation.

CONCLUSION

The current data support the value of adjunctive PER in child and adolescent patients with pharmacoresistant epilepsy in daily clinical practice. Perampanel was efficacious and generally well-tolerated as an add-on treatment for epilepsy.

Perampanel: Does it have broad-spectrum potential?

This article reviews the profile of perampanel, a novel noncompetitive α-amino-3-hydroxyl-5-methyl-4-isoxazole-propionate (AMPA) receptor antagonist, and its role as a potential broad-spectrum antiepileptic drug in the treatment of epilepsy. For this narrative review, data were collected using specified search criteria. Articles reporting the evidence for perampanel's efficacy from preclinical models, phase 3 clinical studies, observational studies, and descriptive evidence were included. AMPA receptors play a key role in mediating the action of glutamate at the excitatory synapse. Preclinical research showed the AMPA receptor blockade to constitute a promising target for antiepileptic drug therapy. In animal models, perampanel proved to be protective against seizures and reduce seizure severity and duration. Four phase-3 randomized controlled trials (3 in patients with focal seizures and one in primary generalized tonic-clonic seizures in idiopathic generalized epilepsy) have been completed. In focal (partial) onset seizures, perampanel (4, 8, and 12 mg) significantly reduced seizure frequency per 28 days (23.3%-28.8% vs 12.8%; P < .01) and responder rates (≥50% reduction in seizures) (28.5%-35.3% vs 19.3%; P < .05) compared with placebo. In primary generalized tonic-clonic seizures, perampanel 8 mg resulted in greater reduction in seizure frequency per 28 days (-76.5% vs -38.4%; P < .0001) and responder rate (64.2% vs 39.5%; P = .0019) than placebo. The efficacy, safety, and tolerability of perampanel have been reproduced in real-world clinical practice, and the agent has been shown to be effective in other epilepsy syndromes. Perampanel is a potentially broad-spectrum antiepileptic drug with a novel mechanism of action that may be a useful addition for patients with epilepsy with various seizure types. The availability of novel antiepileptic drugs for epilepsy treatment enables more individualized treatment for these patients.

The Challenge of Pharmacotherapy in Children and Adolescents with Epilepsy-ADHD Comorbidity

Epilepsy is common in children and adolescents where its prevalence is 3.2-5.5/1000. About one-third of patients also have attention deficit hyperactivity/impulsivity disorder (ADHD). The possible relationship between epilepsy and ADHD is still unclear, and ADHD symptoms (such as inattention, hyperactivity, behavioral disturbances) are frequently considered as adverse effects of antiepileptic drugs (AEDs). The literature was searched for data on the behavioral effects of AEDs. Phenobarbital is the most frequently reported medication to induce symptoms of ADHD, followed by topiramate and valproic acid. Phenytoin seems to exert modest effects, while for levetiracetam there are contrasting data. Lacosamide induces some beneficial effects on behavior; carbamazepine and lamotrigine exert favorable effects on attention and behavior. Gabapentin and vigabatrin have limited adverse effects on cognition. Oxcarbazepine, rufinamide, and eslicarbazepine do not seem to aggravate or induce ADHD symptoms, whereas perampanel can lead to a high incidence of hostile/aggressive behavior, which increases with higher dosages. Information about the behavioral effects of ethosuximide, zonisamide, tiagabine, pregabalin, stiripentol, and retigabine is still limited. Because ADHD significantly affects the quality of life of epilepsy patients, the clinical management of this neuropsychiatric disorder should be a priority. Methylphenidate is effective most children and adolescents with ADHD symptoms and comorbid epilepsy, without a significant increase of seizure risk, although data are still limited with few controlled trials.

Long-term effects of adjunctive perampanel on cognition in adolescents with partial seizures

OBJECTIVE

The aim of this study was to evaluate long-term effects of adjunctive perampanel on cognition, efficacy, growth, safety, and tolerability in adolescents with inadequately controlled partial seizures.

METHODS

Study 235, a multicenter, randomized, double-blind, placebo-controlled, parallel-group, Phase II study with an open-label extension phase (NCT01161524), was primarily designed to assess the effects of adjunctive perampanel on cognition. Patients (aged ≥12 to <18years) had a diagnosis of epilepsy with inadequately controlled partial seizures, with or without secondary generalization, despite receiving 1-3 antiepileptic drugs. During the double-blind phase, adjunctive perampanel or placebo was administered over a 6-week titration period and a 13-week maintenance period up to 12mg/day. During the extension phase, all patients received perampanel. Data from the extension phase are presented here. Study endpoints included change from baseline in Cognitive Drug Research (CDR) measures of cognition, seizure frequency, growth, development, the occurrence of treatment-emergent adverse events (TEAEs), and laboratory values.

RESULTS

A total of 114 patients entered the extension phase (prior double-blind treatment: placebo, n=41; perampanel, n=73). Perampanel had no effect on the CDR system global cognition score, continuity of attention, quality of episodic memory, quality of working memory, or speed of memory but was associated with a significant decline in power of attention at end of treatment compared with baseline (p=0.03). There were no effects on language skills or manual dexterity from baseline to end of treatment. At Weeks 40-52, median reduction in seizure frequency was 74.1%, and 50% responder rate was 66.0%. There were no clinically relevant effects of perampanel on growth or development at end of treatment compared with baseline. Overall, 84.2% of patients experienced at least one TEAE and 70.2% experienced at least one treatment-related TEAE. The most common TEAEs were dizziness (29.8%) and somnolence (19.3%). The TEAEs resulted in the discontinuation of treatment in 6.1% of patients.

CONCLUSIONS

In keeping with the 19-week double-blind phase, long-term adjunctive treatment with perampanel did not have any significant overall effects on the CDR system global cognition score in adolescent patients with inadequately controlled partial seizures. Similar trends were observed across the individual CDR system domains. Adjunctive perampanel showed sustained long-term seizure control and had a safety and tolerability profile similar to that observed in prior clinical studies.

A Review of the New Antiepileptic Drugs for Focal-Onset Seizures in Pediatrics: Role of Extrapolation

Most antiepileptic drugs (AEDs) receive regulatory approval for children years after the drug is available in adults, encouraging off-label use of the drug in children and hindering attempts to obtain quality pediatric data in controlled trials. Extrapolating adult efficacy data to pediatrics can reduce the time between approval in adults and that in children. To extrapolate efficacy from adults to children, several assumptions must be supported, such as (1) a similar disease progression and response to interventions in adults and children, and (2) similar exposure response in adults and children. The Pediatric Epilepsy Academic Consortium for Extrapolation (PEACE) addressed these assumptions in focal-onset seizures (FOS), the most common seizure type in both adults and children. PEACE reviewed the biological and clinical evidence that supported the assumptions that children with FOS have a similar disease progression and response to intervention as adults with FOS. After age 2 years, the pathophysiological underpinnings of FOS and the biological milieu in which seizures are initiated and propagated in children, seizure semiology, electroencephalographic features, etiology and AED response to FOS in children are similar to those in adults with FOS. PEACE concluded that extrapolation of efficacy data in adults to pediatrics in FOS is supported by strong scientific and clinical evidence. However, safety and pharmacokinetic (PK) data cannot be extrapolated from adults to children. Based on extrapolation, eslicarbazepine is now approved for children with FOS, down to age 4 years. Perampanel, lacosamide and brivaracetam are now undergoing PK and safety studies for the purposes of extrapolation down to age 2 or 4 years. When done in conjunction with PK and safety investigations in children, extrapolation of adult data from adults to children can reduce the time delay between approval of effective and safe AEDs in adults and approval in children.

Perampanel, an AMPA receptor antagonist: From clinical research to practice in clinical settings

Epileptic seizures are refractory to treatment in approximately one-third of patients despite the recent introduction of many newer antiepileptic drugs (AEDs). Development of novel AEDs therefore remains a high priority. Perampanel is a first-in-class non-competitive selective AMPA receptor antagonist with a unique mechanism of action. Clinical efficacy and safety of perampanel as adjunctive treatment for focal seizures with/without secondary generalization (±SG) and primary generalized tonic-clonic (PGTC) seizures have been established in five phase 3 randomized controlled trials (RCTs), and a long-term extension study, and perampanel is approved as monotherapy for focal seizures ±SG in the USA. In patients with focal seizures ±SG, add-on perampanel resulted in median percent reduction in seizure frequency 23.3%-34.5% and ≥50% responder rate 28.5%-37.6%; in PGTC seizures, these results were 76.5% and 64.2%, respectively. Efficacy among adolescents (reduction in seizure frequency 34.8%-35.6%; ≥50% responder rate 40.9%-45.0%) and elderly people (reduction in seizure frequency 12.5%-16.9%; ≥50% responder rate 22.2%-42.9%) is similar to those in adults, and results remain comparable between Asian (reduction in seizure frequency 17.3%-38.0%) and global populations. Perampanel has been extensively studied in real-world clinical practice, with similar efficacy and safety results to the RCTs (≥50% responder rate 12.8%-75.0%; adverse events of somnolence/sedation, dizziness, ataxia, and behavioral changes). Real-world observational studies suggest that perampanel tolerability can be improved by slow titration (2 mg every 2-4 weeks), and bedtime administration can mitigate somnolence and dizziness. Counseling about the potential for behavioral changes and close monitoring are recommended.

Comparative efficacy of antiepileptic drugs in children and adolescents: A network meta-analysis

OBJECTIVE

To estimate the comparative efficacy among antiepileptic drugs in the pediatric population (0-18 years).

METHODS

Using the Embase and MEDLINE databases, we updated to February 2017 the search strategy of the National Institute for Health and Care Excellence guidelines for epilepsy. We only included randomized clinical trials conducted in children and mixed-age populations. According to the PRISMA network meta-analysis guideline, the study-level quality assessment was made with the Cochrane risk-of-bias tool. Three investigators independently selected articles. The efficacy outcome was considered to be seizure freedom or ≥50% seizure reduction.

RESULTS

We selected 46 randomized clinical trials. A total of 5652 individuals were randomized to 22 antiepileptic drugs and placebo. The point estimates of carbamazepine and lamotrigine efficacy showed their superiority with respect to all comparator antiepileptic drugs for the treatment of newly diagnosed focal epilepsy. In refractory focal epilepsy, levetiracetam (odds ratio [OR] = 3.3, 95% credible interval [CrI] = 1.3-7.6) and perampanel (OR = 2.5, 95% CrI = 1.1-5.8) were more effective compared to placebo. Ethosuximide and valproic acid were both superior to lamotrigine against absence seizures. The OR point estimate showed the superiority of adrenocorticotropic hormone over all comparators in infantile spasms. A wide heterogeneity in the length of follow-up was observed among the studies.

SIGNIFICANCE

This network meta-analysis suggests that the quality of studies should be improved through the use of comparative designs, relevant outcomes, appropriate follow-up length, and more reliable inclusion criteria.

Behavioural changes in patients with intellectual disability treated with perampanel

OBJECTIVES

The aim of this cross-sectional retrospective study was to assess the tolerability and efficacy of perampanel in patients with drug-resistant epilepsy who also suffered from intellectual disability (ID).

PATIENTS AND METHODS

We used an industry-independent, non-interventional retrospective evaluation based on standardized, daily seizure records. Twenty-seven patients with ID and drug-resistant epilepsy were started on perampanel between September 2012 and November 2015 after a 3-month observation period without perampanel treatment. Perampanel was given at a maximum dosage of 4-12 mg daily. Evaluation was carried out after 6, 12 and 24 months, including calculation of the retention rate. Mean seizure frequency was compared between the 3-month baseline period and subsequent 3-month treatment periods. The Clinical Global Impression scale was applied to assess qualitative changes in seizure severity, and the Aggressive Behaviour Scale (ABS) gave further insights into challenging behaviour.

RESULTS

Perampanel was efficacious and well tolerated in five of 25 patients. In 18 patients, perampanel treatment was stopped, mainly because of adverse events (n=6), lack of efficacy (n=3) or both (n=9). Behavioural changes were documented in 15 of 27 patients, with aggressive behaviour being the commonest effect; we observed ataxia (n=6) and sedation (n=8) in further patients. The ABS showed worsening of aggressive behaviour in six patients.

CONCLUSIONS

Perampanel was well tolerated and efficacious in one-fifth of our patients. We observed challenging behaviour, ataxia and sedation in a relevant number of patients with ID under perampanel treatment. Further studies are warranted to explore the tolerability of perampanel in patients with ID.

Cognitive and Behavioral Comorbidities: An Unwanted Effect of Antiepileptic Drugs in Children

Epilepsy is one of the most common neurological disorders and, despite optimally chosen and dosed antiepileptic drugs (AEDs), approximately 20%-30% of patients will continue to have seizures. Behavior and cognition are negatively impacted by seizures, but AEDs are also a major contributor to behavioral and cognitive deficits. However, the cognitive and behavioral effect of AEDs in children is insufficiently emphasized in the literature. This review summarizes the cognitive and behavioral effects of AEDs in the pediatric population with the objective of helping pediatricians and pediatric neurologists to select the AEDs with the best profile for their individual patient's needs.

AMPA receptors and perampanel behind selected epilepsies: current evidence and future perspectives

INTRODUCTION

The alpha-amino-3-hydroxy-5-methyl-4-isoxazole propionic acid (AMPA) receptors are the major mediators of glutamate-mediated excitatory neurotransmission, and are critical for synchronization and spread of epileptic activity. Areas covered: AMPA receptor antagonists have been also developed as antiepileptic drugs and perampanel (PER) is the first highly selective, non-competitive AMPA-type glutamate receptor antagonist that is available on the market. It is approved as adjunctive therapy for the treatment of partial-onset seizures with or without secondary generalization, and for primary generalized tonic-clonic seizures in idiopathic generalized epilepsy, in patients aged ≥ 12 years. This article reviews the role of AMPA receptors in the neuronal hyperexcitability underlying epilepsy, the mechanism of action and clinical experience on the anti-seizure activity of PER. Moreover, the rationale for targeting AMPA receptor in specific epileptic disorders, including brain tumor-related epilepsy, mesial temporal lobe epilepsy with/without hippocampal sclerosis, and status epilepticus is evaluated. Finally, the pharmacological rationale for the development of AMPA receptor antagonists in other neurological disorders beyond epilepsy is considered. Expert opinion: Further research aimed at better understanding the pharmacology and blocking mechanism of PER and other AMPA receptor antagonists will drive future development of therapeutic agents that target epilepsy and other neurological diseases.

Spotlight on perampanel in the management of seizures: design, development and an update on place in therapy

Purpose

Perampanel is a first-in-class antiepileptic medication approved for the treatment of partial (focal) seizures, and as adjunctive treatment for primarily generalized tonic–clonic seizures. The pharmacology, efficacy data, adverse-effect profile, pharmacokinetics and place in therapy are reviewed.

Summary

Perampanel is indicated for use in patients with epilepsy who are 12 years of age or older. It is the first medication designed specifically to be a non-competitive antagonist at post-synaptic α-amino-3-hydroxyl-5-methyl-4-isoxazole-propionate receptors. Efficacy in refractory seizures has been established, and ongoing efficacy demonstrated by post-marketing data. The drug is completely absorbed, and exhibits a half-life that allows for once-daily administration in doses up to 12 mg/day. Drug interactions are minimal, but increased doses may be necessary when given with strong inducers of cytochrome P450 enzymes, including when perampanel is co-administered with other antiepileptics that exhibit this property. The most common adverse effects noted in both clinical trials and post-marketing are dizziness and somnolence. Psychiatric and behavioral adverse events have been documented in both adult and pediatric patients, including those with no corresponding diagnostic history.

Conclusion

Perampanel is a novel adjunctive antiepileptic medication that is an effective option for adolescents and adults with partial seizures, and primarily generalized tonic–clonic seizures uncontrolled with other medications.

The Pharmacology and Toxicology of Third-Generation Anticonvulsant Drugs

Epilepsy is a neurologic disorder affecting approximately 50 million people worldwide, or about 0.7% of the population [1]. Thus, the use of anticonvulsant drugs in the treatment of epilepsy is common and widespread. There are three generations of anticonvulsant drugs, categorized by the year in which they were developed and released. The aim of this review is to discuss the pharmacokinetics, drug-drug interactions, and adverse events of the third generation of anticonvulsant drugs. Where available, overdose data will be included. The pharmacokinetic properties of third-generation anticonvulsant drugs include relatively fewer drug-drug interactions, as well as several unique and life-threatening adverse events. Overdose data are limited, so thorough review of adverse events and knowledge of drug mechanism will guide expectant management of future overdose cases. Reporting of these cases as they occur will be necessary to further clarify toxicity of these drugs.