Additional Antiepileptic Drugs Research Articles

Structural basis for antiepileptic drugs and botulinum neurotoxin recognition of SV2A.

More than one percent of people have epilepsy worldwide. Levetiracetam (LEV) is a successful new-generation antiepileptic drug (AED), and its derivative, brivaracetam (BRV), shows improved efficacy. Synaptic vesicle glycoprotein 2a (SV2A), a putative membrane transporter in the synaptic vesicles (SVs), has been identified as a target of LEV and BRV. SV2A also serves as a receptor for botulinum neurotoxin (BoNT), which is the most toxic protein and has paradoxically emerged as a potent reagent for therapeutic and cosmetic applications. Nevertheless, no structural analysis on AEDs and BoNT recognition by full-length SV2A has been available. Here we describe the cryo-electron microscopy structures of the full-length SV2A in complex with the BoNT receptor-binding domain, BoNT/A2 HC, and either LEV or BRV. The large fourth luminal domain of SV2A binds to BoNT/A2 HC through protein-protein and protein-glycan interactions. LEV and BRV occupy the putative substrate-binding site in an outward-open conformation. A propyl group in BRV creates additional contacts with SV2A, explaining its higher binding affinity than that of LEV, which was further supported by label-free spectral shift assay. Numerous LEV derivatives have been developed as AEDs and positron emission tomography (PET) tracers for neuroimaging. Our work provides a structural framework for AEDs and BoNT recognition of SV2A and a blueprint for the rational design of additional AEDs and PET tracers.

Efficacy and tolerability of rufinamide in the treatment of Lennox–Gastaut syndrome (experience of the Svt. Luka’s Association of Medical Institutions)

Background. Lennox–Gastaut syndrome (LGS) is a classic developmental and epileptic encephalopathy with a debut in childhood, characterized by resistance to therapy, a severe course, and an unfavorable prognosis. Due to the existing difficulties in treatment of LGS, hopes are pinned on development of new antiepileptic drugs with fundamentally different mechanisms of action, aimed specifically at the treatment of this severe form of epilepsy.Rufinamide (Inovelon®) is a new antiepileptic drug registered in the Russian Federation for use in the adjunctive therapy of LGS in patients older than 1 year. The main mechanism of action of rufinamide is the restriction of neuronal discharges associated with the blocking effect on sodium channels (regulation of sodium channels activity by increasing duration of their inactive state), and stabilization of neuronal membranes. The drug has a number of advantages concernung pharmacokinetic parameters and efficacy (including a wide spectrum of antiepileptic activity, good oral absorption, absence of active metabolites, urinary excretion, low affinity for plasma proteins, biotransformation without cytochrome P450 isoenzymes, low risk of drug interactions) and fairly good tolerability. The daily dose of rufinamide varies from 600 mg (with simultaneous administration of valproate) to 1000 mg (if the patient does not take valproate) in children over 4 years of age with a body weight of less than 30 kg and up to 2200–3200 mg in children over 4 years of age with a body weight of more than 30 kg and in adults; in children under 4 years of age, the maximum daily dose in combination with valproate is 30 mg/kg, and without valproic acid – 45 mg/kg.Aim. To analyze the efficacy and tolerability of rufinamide in the treatment of epilepsy based on the long-term experience of using the drug in the Svt. Luka’s Association of Medical Institutions.Materials and methods. We observed 64 patients aged from 1.5 to 26 years (44 men, 20 women) treated with rufinamide (Inovelon®). Among them, the structural etiology LGS was diagnosed in 36 patients, the genetic and presumably genetic etiology LGS – in 28. In all cases, rufinamide was used in accordance with approved indications as an additional antiepileptic drug, more often in combination with valproate, topiramate, levetiracetam or lamotrigine. Titration of the drug was carried out according to the recommendations in the instructions for use, up to a therapeutic dose that ranged from 200 to 1600 mg/day (in most cases from 400 to 1200 mg/day), depending on age and concomitant therapy.Results and conclusion. Remission of all types of seizures was registered in 17 (26.6 %) patients, and a decrease in the incidence of seizures by more than 50 % was recorded in 28 (43.8 %) patients. Of them, 13 patients demonstrated reduction in seizures frequency by more than 75–90 % and remission of one of several types of seizures. In general, the therapeutic effect (reduction of seizures frequency by at least 50 %) was achieved in 45 (70.3 %) of 64 patients. A decrease in seizures frequency of by at least 50 % was observed in 8 (12.5 %) patients; in 10 (15.6 %) patients, rufinamide therapy was not effective; in 1 (1.56 %) case an aggravation of bilateral convulsive seizures was noted when rufinamide was administered.In most cases, rufinamide is well tolerated. Our patients had side effects in 10 (15.6 %) cases. Only in 2 (3.1 %) cases, rufinamide was withdrawn directly due to side effects (the reason for withdrawal in these cases was an allergic reaction and psychosis).The retention rate for therapy lasting 1 year or more is 65.6 % (42 of 64 patients).Thus, our data have demonstrated efficacy and good tolerability of rufinamide in treating epileptic seizures associated with LGS, confirming numerous literature data. However, in our analysis, a higher rate of seizure remission was obtained, although we have included patients with mainly resistant forms of epilepsy in the analysis.

Efficacy of Vigabatrin as Treatment for Seizures in Children Without Infantile Spasms (P4-9.009)

<h3>Objective:</h3> To assess the efficacy of vigabatrin as treatment for seizures in children with Tuberous Sclerosis (TS) without infantile spasms. <h3>Background:</h3> The literature states that over half of TS patients with epilepsy are intractable, with patients on vigabatrin fairing slightly better. Vigabatrin is first line for epilepsy in TS patient in Europe, but not the US. <h3>Design/Methods:</h3> A retrospective review of TS patients treated with vigabatrin was conducted. All symptoms were reviewed. <h3>Results:</h3> Six children with TS with focal seizures were identified, four of which are positive for TSC 2 mutation, one positive for TSC 1, and one had no mutation identified. For three patients, vigabatrin was the first line anti-epileptic drug (AED), while it was added on to other AED(s) for the rest. Age range for onset of epilepsy is 4 to 33 months, and initiation age of vigabatrin ranged from 4 months to 9 years 9 months (3/6 &lt;1 year and 3/6 &gt; 32 months age). Duration of Vigabatrin treatment ranges from 9 to 43 months. Three cases have been seizure free for over 12 months, two patients improved (&gt;50% reduction), and one patient remains intractable. Side effects do not show visual compromise. However, encephalopathy was appreciated when combined with CBD in one patient. Two patients have autism spectrum disorder, two patients are developmentally normal without autism, and three are developmentally delayed. All but one patient required another AED: either levetiracetam, oxcarbazepine, or some combination of both. <h3>Conclusions:</h3> Observed vigabatrin efficacy in TS children with epilepsy adds to the data and shows that it is safe and effective. Almost all required additional AED(s) to control seizures. In one case, one child developed encephalopathy in combination with CBD. Otherwise, vigabatrin has been safe over the long term. <b>Disclosure:</b> Mr. Alan Rosario has nothing to disclose. Mr. Bolufer has nothing to disclose. Dr. Prakash has nothing to disclose.

512: THE IMPACT OF LEVETIRACETAM LOADING DOSES ON SUCCESSFUL SEIZURE CESSATION

Introduction: Loading doses of 20 mg/kg of levetiracetam are commonly employed for refractory status epilepticus however, recent studies utilizing higher loading doses of 40-60 mg/kg have prompted a change in practice. This study aims to establish whether higher loading doses of levetiracetam lead to more rapid cessation of status epilepticus and reduced need for additional antiepileptic drugs. Methods: This was an IRB-approved, single-center, retrospective cohort study of patients admitted to a tertiary care academic medical center between April and September 2021. Patients were included if they were > 18 years of age and received levetiracetam as a loading-dose for cessation of status epilepticus. Patients were excluded if levetiracetam was administered for seizure prophylaxis. The primary outcome was unsuccessful seizure termination, defined as a requirement of an additional loading dose or an increase in maintenance doses of levetiracetam. Secondary outcomes included ICU and hospital length of stay, mortality, and need for third line treatment. Results: Of 390 patients screened for inclusion, 206 met inclusion criteria and were included in the primary analysis. Amongst patients who received a loading < 20 mg/kg, 50% had a diagnosis of epilepsy prior to admission, compared to 37.3% in the 20-40 mg/kg group and 42% in the ≥ 40 mg/kg group. Rates of ICU admission were 20%, 37.3% and 36.3%, respectively (p = 0.163). There was a statistically significant difference in ICU (3.5, 8.9, 13.5; p = 0.03) and hospital length of stay (13.1, 22.5, 30.7, p = 0) among groups. The primary outcome, unsuccessful seizure termination, was 13.8% in the < 20 mg/kg group, 12% in the 20-40 mg/kg group, and 34% in the > 40 mg/kg group. The rates of third-line therapy administration in each group was 5% vs. 13.3% vs. 22%, respectively. Conclusions: Among patients treated with loading-doses of levetiracetam > 40 mg/kg, there was a statistically significant increase in maintenance dose of levetiracetam and a trend towards more frequent administration of third-line agents. There was a longer ICU length of stay among patients administered >40 mg/kg loading dose which could have led to increased monitoring and increases in maintenance dosing of levetiracetam among that population.

From HDAC to Voltage-Gated Ion Channels: What's Next? The Long Road of Antiepileptic Drugs Repositioning in Cancer.

Simple SummaryAlthough in the last decades the clinical outcome of cancer patients considerably improved, the major drawbacks still associated with chemotherapy are the unwanted side effects and the development of drug resistance. Therefore, a continuous effort in trying to discover new tumor markers, possibly of diagnostic, prognostic and therapeutic value, is being made. This review is aimed at highlighting the anti-tumor activity that several antiepileptic drugs (AEDs) exert in breast, prostate and other types of cancers, mainly focusing on their ability to block the voltage-gated Na+ and Ca++ channels, as well as to inhibit the activity of histone deacetylases (HDACs), all well-documented tumor markers and/or molecular targets. The existence of additional AEDs molecular targets is highly suspected. Therefore, the repurposing of already available drugs as adjuvants in cancer treatment would have several advantages, such as reductions in dose-related toxicity CVs will be sent in a separate mail to the indicated address of combined treatments, lower production costs, and faster approval for clinical use.Cancer is a major health burden worldwide. Although the plethora of molecular targets identified in the last decades and the deriving developed treatments, which significantly improved patients’ outcome, the occurrence of resistance to therapies remains the major cause of relapse and mortality. Thus, efforts in identifying new markers to be exploited as molecular targets in cancer therapy are needed. This review will first give a glance on the diagnostic and therapeutic significance of histone deacetylase (HDAC) and voltage gated ion channels (VGICs) in cancer. Nevertheless, HDAC and VGICs have also been reported as molecular targets through which antiepileptic drugs (AEDs) seem to exert their anticancer activity. This should be claimed as a great advantage. Indeed, due to the slowness of drug approval procedures, the attempt to turn to off-label use of already approved medicines would be highly preferable. Therefore, an updated and accurate overview of both preclinical and clinical data of commonly prescribed AEDs (mainly valproic acid, lamotrigine, carbamazepine, phenytoin and gabapentin) in breast, prostate, brain and other cancers will follow. Finally, a glance at the emerging attempt to administer AEDs by means of opportunely designed drug delivery systems (DDSs), so to limit toxicity and improve bioavailability, is also given.

508 Comparing effectiveness and safety of levetiracetam loading doses among patients with status epilepticus.

OBJECTIVES/GOALS: Our long-term goal is to improve the clinical outcomes of patients with status epilepticus through increasing the level of evidence surrounding guidelines. The specific objective of our proposed work is to compare the outcomes and adverse drug events between the Neurocritical Care and American Epilepsy Society levetiracetam dose recommendations. METHODS/STUDY POPULATION: This is a retrospective, single site, cohort study comparing outcomes of hospitalized patients with status epilepticus treated with levetiracetam bolus at the University of Kansas Health System. Patients outcomes will be compared based on levetiracetam bolus dose received. The primary outcome will be seizure reoccurrence within 24 hours. Secondary outcomes include number of additional anti-epileptic drugs administered, cumulative dose of benzodiazepines administered within 24 hours of levetiracetam bolus administration and incidence of adverse drug reactions. All study data will be extracted retrospectively from the EPIC chart review following patient list generation through the HERON i2b2 database query. RESULTS/ANTICIPATED RESULTS: Aim 1 will characterize levetiracetam dosing among patients admitted to the University of Kansas Medical Center for status epilepticus during routine clinical care. We hypothesize that given the inconsistency in dosing recommendations from various professional societies and drug references, we will observe inconsistent dosing of levetiracetam among those hospitalized due to status epilepticus.Aim 2 will evaluate effectiveness and safety across the various levetiracetam doses. We estimate that adherence to the higher weight-based dosing recommendations of the 2016 American Epilepsy Society guideline may result in improved outcomes with a similar frequency and severity of adverse drug events compared to lower/fixed-dose levetiracetam dose recommendation of the 2012 Neurocritical Care guideline. DISCUSSION/SIGNIFICANCE: Notable inconsistencies across the dosing recommendations for levetiracetam exist between the guidelines for treatment of status epilepticus and commonly used tertiary drug information databases. This variation in guidance may lead to differences in dosing and warrants further exploration to better support the management of status epilepticus.

Effectiveness and tolerability of perampanel in сhildren and adolescents (own experience of Svt. Luka’s Institute of Child Neurology and Epilepsy)

Effectiveness and tolerability of perampanel in сhildren and adolescents (own experience of Svt. Luka’s Institute of Child Neurology and Epilepsy)

Survey on Antiepileptic Drug Therapy in Patients with Drug Resistant Epilepsy.

Background and PurposeIndividualized anti-epileptic drug (AED) selection in patient with epilepsy is crucial. However, there is no unified opinion in treating patients with drug resistant epilepsy (DRE). This survey aimed to make a consolidate consensus with epileptologists’ perspectives of the treatment for Korean DRE patients by survey responses.MethodsThe survey was conducted with Korean epilepsy experts who have experience prescribing AEDs via e-mail. Survey questionnaires consisted of six items regarding prescription patterns and practical questions in treating patients with DRE in Korea. The research period was from February 2021 to March 2021.ResultsThe survey response rate was 83.3% (90/108). Most (77.8%) of the responders are neurologists. The proportion of patients whose seizures were not controlled by the second AED was 26.9%. The proportion of patients who had taken five or more AEDs is 13.9%, and those who are currently taking five or more AEDs are 7.3%, of which 54.5% and 37.9% reported positive effects on additional AED, respectively. The majority (91.1%) of respondents answered that the mechanism of action was the top priority factor when adding AED. Regarding data priority, responders considered that expert opinion should have the top priority, followed by clinical experiences, reimbursement guidelines and clinical evidence. Responders gave 64.9 points (range from 0 to 100) about overall satisfaction on reimbursement system of Health Insurance Review and Assessment Service for AED.ConclusionsThis study on AED therapy for DRE patients is the first nationwide trial in Korean epilepsy experts. In five drug failure, the top priorities on AED selection are mechanism of action and expert opinion. These findings might help to achieve consensus and recognize the insight on optimal therapy of AED in DRE.

Abstracts of the 30th Annual Pediatric Pharmacy Association (PPA) Meeting April 21 to 25, 2021

Abstracts of the 30th Annual Pediatric Pharmacy Association (PPA) Meeting April 21 to 25, 2021

The use of perampanel in drug-resistant focal epilepsy: its effect on sleep

Perampanel (PER) is an antiepileptic drug (AED), the effects of which on sleep have not been studied in Russia.Objective: to assess changes in the quality of sleep, the level of daytime sleepiness, and the polysomnographic (PSG) characteristics of nocturnal sleep in patients with drug-resistant focal epilepsy when PER is incorporated into the therapy regimen as an additional AED.Patients and methods. The investigation enrolled 12 patients (4 men and 8 women) aged 21 to 49 years with drug-resistant epilepsy treated with several AEDs, who had initiated therapy with PER as an additional AED. PSG study and questioning survey were done before and 1 month after initiation of PER therapy.Results and discussion. After one month of PER therapy, there was an increase in the quality of night sleep in 5 cases and a reduction in daytime sleepiness in 6 cases. The PSG pattern was stable in 3 patients, worsened in 1, and improved in 8.Conclusion. The preliminary results suggest that PER therapy improves night sleep quality and reduces daytime sleepiness in about half of the cases, as evidenced by the improved PSG pattern in 67% of patients.

The prognosis of brain magnetic resonance imaging injury pattern for outcomes of hypothermia-treated infants.

Magnetic resonance imaging (MRI) can be a tool that allows the observation of structural injury patterns after cooling. The aim of this study was to determine the early pattern of brain injury in the MRIs of infants with hypoxic ischemic encephalopathy (HIE) after cooling and to search for any clinical factors related to abnormal MRI findings.The study retrospectively recruited 118 infants who were treated with therapeutic hypothermia (TH) between 2013 and 2016.Forty-three patients had normal brain MRI, and 75 had abnormal brain MRI findings. The TH-treated infants with abnormal brain MRI readings showed significantly more clinical seizures and the use of additional antiepileptic drugs (AEDs) than the normal MRI group. As a long-term outcome, more lesions in the basal ganglia and thalamus, posterior limb of internal capsule, or severe white matter lesions were associated with abnormal neurodevelopmental outcomes at 18 to 24 months of age.A higher frequency of clinical seizures and AED use were related to abnormal brain injury on MRI. A significant risk for poor long-term outcomes was found in the abnormal brain MRI group.

Incidence, Presentation, and Risk Factors for Sodium Valproate–Associated Hyperammonemia in Neurosurgical Patients: A Prospective, Observational Study

Sodium valproate (VPA) is a commonly prescribed antiepileptic drug (AED) in daily neurosurgical practice. However, the incidence of VPA-associated hyperammonemia (VAH) and its life-threatening consequence, VPA-induced hyperammonemic encephalopathy (VHE), in neurosurgical patients is unknown. We determined the incidence, clinical presentation, and risk factors for VAH. This prospective cohort study was performed on adult neurosurgical patients prescribed VPA for at least a week over a 22-month period. Blood tests for ammonia, VPA, and liver function were performed at the time of recruitment. The primary end point was VAH. Secondary end points were VHE and liver dysfunction. In total, 252 patients were recruited. The commonest disease etiology was brain tumors (27%, 69), followed by aneurysmal subarachnoid hemorrhage (SAH; 26%, 65). VPA was prescribed for primary seizure prophylaxis in 110 patients (44%). The mean daily dose was 1148 mg for a mean duration of 48 months. The mean serum VPA level was 417 μmol/L. In total, 92 patients (37%) were prescribed an additional AED, the most common being phenytoin (65%, 60/92). The mean serum ammonia level was 47 μmol/L. In total, 28% (71/252) of patients had VAH and only 0.7% had VHE. Independent factors were aneurysmal SAH (adjusted odds ratio [aOR] 2.1; 95% confidence interval [CI] 1.1-4.2), concomitant phenytoin (aOR 1.9; 95% CI 1.0-3.5), and phenobarbital (aOR 4.6; 95% CI 1.1-20.0). No associations with VPA dose, duration, serum levels, and liver function were observed. Although VAH is common among neurosurgical patients, VHE is rare. Patients with aneurysmal SAH or on concomitant enzyme-inducing AEDs are at risk. Clinicians should be vigilant for VHE symptoms in these patients.

Barriers in accessing medical cannabis for children with drug-resistant epilepsy in Canada: A qualitative study

IntroductionThe use of medical cannabis to treat drug-resistant epilepsy in children is increasing; however, there has been limited study of the experiences of parents with the current system of accessing medical cannabis for their children. MethodsIn this qualitative study, we used a patient-centered access to care framework to explore the barriers faced by parents of children with drug-resistant epilepsy when trying to access medical cannabis in Canada. We conducted semistructured interviews with 19 parents to elicit their experiences with medical cannabis. We analyzed the data according to five dimensions of access, namely approachability, acceptability, availability, affordability, and appropriateness. ResultsParents sought medical cannabis as a treatment because of a perceived unmet need stemming from the failure of antiepileptic drugs to control their children's seizures. Medical cannabis was viewed as an acceptable treatment, especially compared with adding additional antiepileptic drugs. After learning about medical cannabis from the media, friends and family, or other parents, participants sought authorization for medical use. However, most encountered resistance from their child's neurologist to discuss and/or authorize medical cannabis, and many parents experienced difficulty in obtaining authorization from a member of the child's existing care team, leading them to seek authorization from a cannabis clinic. Participants described spending up to $2000 per month on medical cannabis, and most were frustrated that it was not eligible for reimbursement through public or private insurance programs. ConclusionsParents pursue medical cannabis as a treatment for their children's drug-resistant epilepsy because of a perceived unmet need. However, parents encounter barriers in accessing medical cannabis in Canada, and strategies are needed to ensure that children using medical cannabis receive proper care from healthcare professionals with training in epilepsy care, antiepileptic drugs, and medical cannabis.

Clinical Effectiveness of Levetiracetam Compared to Fosphenytoin in the Treatment of Benzodiazepine Refractory Convulsive Status Epilepticus.

To determine whether levetiracetam is an alternative to fosphenytoin to control Benzodiazepine Refractory Status Epilepticus (BRSE) in pediatric population and also to compare the acute drug related side-effects and ventilation requirement among the both arms of anti-epileptic drug therapy. All consecutive children admitted with BRSE were randomized to group A, who received fosphenytoin at 20mg/kg phenytoin equivalents (PE) dose and group B who received levetiracetam at 40mg/kg over 10min. Time to terminate seizure (response latency) was measured. If seizure remained refractory after 20min of test drug administration, appropriate drug escalation was made according to pediatrician's discretion. All primary and secondary outcome measures were compared between the two therapeutic groups. Of 61 children enrolled over 18 mo period, 29 (47.5%) were randomized to group A and 32 (52.5%) were randomized to Group B. Baseline characteristics were comparable between the two groups. Among 61 children, 58(98%) required Pediatric Intensive Care Unit (PICU) admission and among those 5(8.2%) children required mechanical ventilation. Duration of PICU stay, hospital stay, the response latency and seizure recurrence were compared between both groups. Significant number of children received additional anti-epileptic drugs (AEDs) in fosphenytoin group [9/29(31%)] compared to levetiracetam group [2/32(7%)] to control seizure. Levetiracetam may be an effective alternative to fosphenytoin in management of BRSE in children but multicentric trials with large sample size are needed to substantiate this observation.

Antiepileptic drug effects on subjective and objective cognition

RationaleCognitive impairment is one of the most common complaints for persons with epilepsy (PWE). These impairments are not only associated with seizures, but are also regularly reported as adverse effects of antiepileptic drugs (AEDs). Previous studies have examined cognitive effects of both AED monotherapy and polytherapy, yet there is limited research on these differences with respect to both subjective and objective cognition. The current study uses data from previous research conducted by the Centers for Disease Control and Prevention (CDC)-sponsored Managing Epilepsy Well (MEW) Network collaborative. We used three distinct archival datasets from the following: (1) the HOBSCOTCH efficacy trial at Dartmouth-Hitchcock Medical Center (HOB-1), (2) the multisite replication trial (HOB-2), and (3) epilepsy self-management research conducted at the NYU School of Medicine. MethodsThis retrospective analysis combined baseline data from three datasets to determine how the number of AEDs and the type of AEDs were associated with subjective (patient-reported) and objective (examiner-assessed) cognition. Subjective cognition was captured using the cognitive subscale of the Quality of Life in Epilepsy Inventory (QOLIE-31) in all three datasets (n = 224), while objective cognition was measured using the Repeated Battery for the Assessment of Neuropsychological Status (RBANS) in the HOB-1 dataset (n = 65) and the Brief Test of Adult Cognition by Telephone (BTACT) in the HOB-2 dataset (n = 91). Multivariable linear regression was utilized for our initial assessments, followed by propensity score matching to provide stronger control of covariates. Matching was based on significantly different covariates, such as education, depression, and history of prior epilepsy surgery. Nonparametric statistical tests were utilized to compare these matched subjects. ResultsSubjective cognitive impairment was significantly worse among individuals on polytherapy (2 + AEDs) compared with those on monotherapy (1 AED) (adjusted p = 0.041). These findings were consistent with our propensity score matched comparison of monotherapy and polytherapy, which indicated that polytherapy was associated with worse overall subjective cognition (adjusted p = 0.01), in addition to impairments on the RBANS (Total score p = 0.05) and specific subdomains of the BTACT (Episodic Verbal Memory p < 0.01, Working Memory p < 0.01, Processing Speed p < 0.01). Interestingly, older generation AEDs were associated with better language performance than newer generation and combined generation AED therapy (RBANS Language p = 0.03). These language-specific findings remained significant after controlling for the effects of topiramate and zonisamide (p = 0.04). ConclusionsA greater number of AEDs is significantly and negatively associated with subjective and objective cognition in PWE, and is in line with previous research. Antiepileptic drug type did not, in itself, appear to be associated with subjective cognition. Our findings suggest that ineffective AEDs should be replaced, rather than introducing additional AEDs to a treatment regimen. Further, while subjective and objective cognition assessments were both sensitive at detecting differences based on AED status, the neuropsychological objective subdomains offer additional and specific insights into how cognition is impaired with AEDs.

Phenobarbital, Midazolam Pharmacokinetics, Effectiveness, and Drug-Drug Interaction in Asphyxiated Neonates Undergoing Therapeutic Hypothermia

Background: Phenobarbital and midazolam are commonly used drugs in (near-)term neonates treated with therapeutic hypothermia for hypoxic-ischaemic encephalopathy, for sedation, and/or as anti-epileptic drug. Phenobarbital is an inducer of cytochrome P450 (CYP) 3A, while midazolam is a CYP3A substrate. Therefore, co-treatment with phenobarbital might impact midazolam clearance. Objectives: To assess pharmacokinetics and clinical anti-epileptic effectiveness of phenobarbital and midazolam in asphyxiated neonates and to develop dosing guidelines. Methods: Data were collected in the prospective multicentre PharmaCool study. In the present study, neonates treated with therapeutic hypothermia and receiving midazolam and/or phenobarbital were included. Plasma concentrations of phenobarbital and midazolam including its metabolites were determined in blood samples drawn on days 2–5 after birth. Pharmacokinetic analyses were performed using non-linear mixed effects modelling; clinical effectiveness was defined as no use of additional anti-epileptic drugs. Results: Data were available from 113 (phenobarbital) and 118 (midazolam) neonates; 68 were treated with both medications. Only clearance of 1-hydroxy midazolam was influenced by hypothermia. Phenobarbital co-administration increased midazolam clearance by a factor 2.3 (95% CI 1.9–2.9, p < 0.05). Anticonvulsant effectiveness was 65.5% for phenobarbital and 37.1% for add-on midazolam. Conclusions: Therapeutic hypothermia does not influence clearance of phenobarbital or midazolam in (near-)term neonates with hypoxic-ischaemic encephalopathy. A phenobarbital dose of 30 mg/kg is advised to reach therapeutic concentrations. Phenobarbital co-administration significantly increased midazolam clearance. Should phenobarbital be substituted by non-CYP3A inducers as first-line anticonvulsant, a 50% lower midazolam maintenance dose might be appropriate to avoid excessive exposure during the first days after birth.

Long-term safety and efficacy following conversion to eslicarbazepine acetate monotherapy in adults with focal seizures

ObjectiveTo assess the long-term safety and efficacy of eslicarbazepine acetate (ESL) monotherapy in adults with focal seizures (FS). MethodsStudy 050 was a long-term, multicenter, open-label (OL) safety extension of two conversion-to-ESL monotherapy studies in adults with refractory FS. After participating in Study 045 or 046, patients started on ESL 1600 mg once daily (QD) (or 1200 mg if they previously had a dose reduction), and could adjust the dose 400 mg/week to a dose between 800–2400 mg QD. Patients could add up to two additional antiepileptic drugs (AEDs). This post-hoc analysis focuses on the actual monotherapy subgroup, which included patients in Studies 045/046/050 who did not add additional AEDs. Study endpoints included treatment retention time, time on ESL monotherapy, change in standardized seizure frequency (SSF), change in quality of life (QoL) in epilepsy (QOLIE-31) and Montgomery-Åsberg Depression Rating Scale (MADRS) scores, and incidence of treatment-emergent adverse events (TEAEs); serious adverse events (SAEs), TEAEs leading to discontinuation, and TEAEs related to allergic reaction, hyponatremia and thyroid function were also evaluated. ResultsThere were 274 patients in the Study 050 full intent-to-treat (ITT) population and 140 patients in the actual monotherapy subgroup. Median treatment retention time and time on ESL monotherapy were both >5 years. Median reduction in SSF from baseline was 66.4% in the full ITT population and 78.3% in the actual monotherapy subgroup; responder (≥50% reduction in SSF) rates were 62.4% and 74.3%, respectively. QOLIE-31 scores increased from baseline in the full ITT population and the actual monotherapy subgroup (4.1- and 7.5-point increases, respectively). MADRS scores decreased from baseline in both the full ITT population and the actual monotherapy subgroup (0.7- and 2.9-point decreases, respectively). TEAEs occurred in 85.4% of patients in the full ITT population and 81.4% of patients in the actual monotherapy subgroup. Incidences of SAEs and TEAEs leading to discontinuation, as well as dizziness, depression, fall, partial seizures with secondary generalization, and complex partial seizures, were higher in the full ITT population than in the actual monotherapy subgroup. Allergic reactions, hyponatremia, and hypothyroidism were infrequent, particularly in the actual monotherapy subgroup. ConclusionsThe results of this post-hoc analysis suggest that long-term treatment with ESL was effective and well tolerated, both as a monotherapy and in combination with other AEDs for FS. QoL and tolerability appeared to be better, and incidence of depression lower, in the patient population taking ESL as a monotherapy, compared with the population that included patients taking ESL as an adjunctive therapy.

The effects of topiramate on cognitive functions of patients with focal epilepsy - a follow-up study in a Serbian sample

Introduction/Objective. The aim of this follow-up study was to determine the effects of topiramate therapy on cognitive functions in patients with pharmacoresistant focal epilepsy. Methods. The study sample comprised of 40 topiramate naive patients. The topiramate starting dose was 25 mg, with a fortnightly titration schedule of 25 mg. A wide range of cognitive functions was evaluated through extensive neuropsychological testing at baseline and six months after reaching the target dose (200 mg/day). Results. The most common side effects following the introduction of topiramate were cognitive impairments, reported by 45% of the participants. The neuropsychological scores on attention, executive function, verbal content recall, improved cognitive flexibility, as well as visuospatial ability and speech, obtained at six-month follow-up were significantly lower than at baseline. However, statistically significant correlation between neuropsychological scores and the number of antiepileptic drugs taken alongside topiramate could not be established. Similarly, no statistically significant differences were noted between the percentage of reduced neuropsychological scores at follow-up pertaining to patients with lower and higher baseline cognitive performance. Moreover, regression analysis indicates that the percentage change in the majority of cognitive scores is unrelated to the age at the epilepsy onset, epilepsy duration, presence of brain pathology on magnetic resonance imaging and percentage change in the depression scale score. Conclusion. Despite slow introduction and administration of a relatively small dose, topiramate exhibits adverse effects on a wide range of cognitive functions, which appear unrelated to the number of additional antiepileptic drugs, baseline cognitive functioning, age at the onset of epilepsy and its duration, presence of brain pathology and the extent of depressive symptoms.

Efficacy and tolerability of brivaracetam in the treatment of epilepsy: literature review and own experience

Background. Despite significant advances in epileptology, approximately 30 % of patients suffer from drug-resistant epilepsy. Numerous approaches are currently available to treat epilepsy; however, there are still many patients with treatment-resistant disease, in whom surgery is impossible and alternative methods (vagus nerve stimulation and ketogenic diet) are ineffective. Thus, searching for new effective antiepileptic drugs (AED) for these patients remains highly relevant. In this article, we reviewed available publications and provided own results on the efficacy and tolerability of brivaracetam (Briviact®) in patients with intractable focal epilepsy.Materials and methods. The study included 8 patients aged between 16 and 35 years (mean age 18.3 years; 2 males and 6 females) with intractable focal epilepsy treated at the Svt. Luka’s Institute of Child Neurology and Epilepsy between February 1st, 2017 and September 1st, 2018.All patients received brivaracetam as an additional AED for the treatment of focal and bilateral convulsive seizures. Patients were followed up for 1 to 7.5 months. Brivaracetam was added to 1 or 2 AED (valproate, topiramate, or carbamazepine/oxcarbazepine) at a dose of 100–200 mg/day divided into 2 doses.Results and discussion. Good therapeutic effect (more than 50 % reduction in seizure frequency) was registered in 4 patients (50 %). Two patients (25 %) achieved a 25–50 % reduction in seizure frequency. Minimal clinical efficacy with no effect was observed in one patient (12.5 %). One patient (12.5 %) had aggravation of focal and motor seizures. Brivaracetam significantly reduced the severity (intensity and duration) of epileptic seizures in 70 % of patients. Four patients demonstrated substantial improvements on electroencephalogram (decreased epileptiform activity). One patient had complete suppression of epileptiform activity. Brivaracetam was most effective for bilateral convulsive seizures: 4 out of 5 patients experienced complete relief of these seizures.Brivaracetam demonstrated good tolerability: no side effects were registered in this study. Six out of 8 participants (75 %) currently continue treatment with brivaracetam. It is important that none of the patients had to stop brivaracetam due to poor tolerability. Of note, all of study participants started to receive brivaracetam because they had seizures resistant to multiple (more than 2–3) AED.Conclusion. Our findings suggest high efficacy and good tolerability of brivaracetam in patients with focal epilepsy. Our results are also consistent with the data reported by foreign authors.

Levetiracetam circulating concentrations and response in status epilepticus

IntroductionIntravenous levetiracetam (LEV) is broadly used in the treatment of status epilepticus (SE). A loading dose is usually infused, aiming to reach quickly the range of plasma concentrations considered as therapeutic (12–46 mg/l). The aim of the study was to evaluate the response to LEV in SE, correlated exposure assessed by plasma concentration monitoring, as well as calculated exposure parameters. Materials & methodsWe retrospectively analyzed a SE registry, including patients since 2015 with at least one available LEV plasma level measured less than 36 h after loading. A Bayesian maximum likelihood approach based on a population pharmacokinetic model was used to estimate LEV exposure parameters. We compared plasma levels and pharmacokinetics parameter estimates between responders and nonresponders. Therapeutic response was defined as SE cessation within 24 h following LEV introduction without a need for additional antiepileptic drug (AED). ResultsWe included 29 patients (45 plasma levels). Variability was salient in LEV loading doses (ranging between 17 and 38 mg/kg) and monitoring practice. There was no difference in median plasma concentrations (19.5 versus 21.5 mg/l; p = 0.71), median estimated LEV exposure (25.8 versus 37.0 mg/l; p = 0.61), peak (30.4 versus 41.5 mg/l; p = 0.36), or residual levels after loading dose (14.4 versus 20.5 mg/l; p = 0.07) between responders and nonresponders. ConclusionsLevetiracetam exposure does not seem to differ significantly between responders and nonresponders; greater exposure was not associated with better outcome. Loading doses of 30 mg/kg seem, however, appropriate to quickly reach the target exposure level. The short LEV half-life makes standardized sampling measurement necessary to obtain directly interpretable LEV levels.