Treatment Of Partial-onset Seizures Research Articles

Neuropharmacology of Levetiracetam as Anti-epileptic Medication

United state food and drug administration approved Levetiracetam on 30th November 1999 for the use as adjuanctive therapy in the treatment of partial onset seizures in adults with epilepsy. Therapeutic indications of Levetiracetam includes monotherapy in the treatment of partial onset seizures with or without secondary generalisation in adults and adolescents from 16 years of age with newly diagnosed epilepsy. Levetiracetam is indicated as adjunctive therapy in the treatment of partial onset seizures with or without secondary generalisation in adults, adolescents, children and infants from 1 month of age with epilepsy, in the treatment of myoclonic seizures in adults and adolescents from 12 years of age with juvenile myoclonic epilepsy, in the treatment of primary generalised tonic-clonic seizures in adults and adolescents from 12 years of age with idiopathic generalised epilepsy. This article describes the pharmacological aspects of Levetiracetam that will helful to health professionals.

Extrapolation of Efficacy from Adults to Pediatric Patients of Drugs for Treatment of Partial Onset Seizures: A Regulatory Perspective.

The US Food and Drug Administration (FDA) has concluded that the efficacy of drugs approved for the treatment of partial onset seizures (POS) in adults can be extrapolated to pediatric patients 1 month of age and above and that independent efficacy trials in this pediatric population are no longer needed. This paper focuses on the dosing, pharmacokinetic (PK), exposure-response, and clinical information that were leveraged from the approved drugs for the treatment of POS to conduct analyses that supported extrapolation of efficacy in pediatric patients. Clinical data from trials for eight drugs (levetiracetam, oxcarbazepine, topiramate, lamotrigine, gabapentin, perampanel, tiagabine, and vigabatrin) approved in both adults and pediatric patients for the treatment of POS were analyzed. Comparisons of exposures at approved doses, placebo response, and model-based exposure-response relationships were performed. Based on disease similarity, similar response to intervention, and similar exposure-response relationships in adults and pediatric patients, it was concluded that extrapolation of efficacy in pediatric patients aged 1 month and above is acceptable. PK analysis to determine pediatric dose and regimens that provide drug exposure similar to that known to be effective in adult patients with POS will be required, along with long-term open-label safety data in pediatric patients.

Method Development and Validation of a Novel UHPLC Coupled with MS/MS System for the Estimation of Brivaracetam in Human (K2EDTA) Plasma Samples and its Application to Pharmacokinetic Study

Background: Brivaracetam is a novel antiepileptic drug clinically approved for the treatment of partial onset seizures in adults and adolescents. It has some abuse potential and assigns to Schedule V category under the Controlled Substance Act by the Drug Enforcement Administration. It is essential to develop a faster, simple, and highly sensitive method for the quantification of Brivaracetam in human plasma by employing simple liquid-liquid extraction. Objective: The objective of this study is to develop and validate a novel UHPLC-MS/MS method for the estimation of brivaracetam in human plasma samples and application to pharmacokinetic study. Methods: An ultra-high-pressure liquid chromatography-tandem mass spectrometry method was developed and validated according to current regulatory guidelines for bioanalytical methods. Sample processing (50 μL) involved only a simple liquid-liquid extraction by ethyl acetate as extraction solvent. Brivaracetam-d7 was used as an internal standard. The chromatographic analysis was performed by a Unisol C18 (4.6 X 100 mm, 5μm) column using 0.1% formic acid in water/acetonitrile (20/80 V/V) as an isocratic mobile phase, at a flow rate of 1.0 mL/min with a run time of 2.2 min. Brivaracetam and its internal standard Brivaracetam D7 were detected and quantified in positive ion mode using multiple reaction monitoring transitions at m/z 213.100→168.100 and m/z 220.000→175.100, respectively. The developed method was applied to assess pharmacokinetic parameters like Cmax, Tmax, t1/2 and AUC for Brivaracetam in healthy, male, and adult humans. Results: The method was validated over a concentration range of 20.000 ng/mL to 4000. 000 ng/mL. Both intra- and inter-assay precision and accuracy were <15% for all quality control samples. No matrix effect was observed. Pharmacokinetic results showed that test formulation is bioequivalent with reference formulation. Conclusion: The present assay is faster, highly sensitive and simpler than previously published analytical reports for brivaracetam in human plasma samples and is suitable for pharmacokinetic evaluation of any marketed formulation.

Intranasal delivery of topiramate nanoemulsion: Pharmacodynamic, pharmacokinetic and brain uptake studies

Epilepsy is the noncommunicable and chronic central nervous system disorder characterized by frequent, unprovoked seizures, or electrical disturbances in the brain. Topiramate is used as an antiepileptic drug for the treatment of partial onset seizures, generalized seizures and Lennox-Gastaut Syndrome. Topiramate, a BCS class II drug, has a relatively low bioavailability. It is also a substrate of P-glycoprotein and Blood Brain Barrier restricts its entry into the brain. This investigation was aimed to prepare O/W nanoemulsion delivery system of topiramate to improve its brain bioavailability. Topiramate loaded nanoemulsion was prepared by phase titration method. It was consisting of 2% w/w Capmul MCM C8, 32% w/w Tween 20:Carbitol (2:1) and 66% w/w water. It was characterized for globule size, viscosity, polydispersibility index, zeta potential, pH, conductivity values, transmittance and TEM. Pharmacodynamic, pharmacokinetic and brain drug uptake study was carried out using wistar albino rats post intranasal and oral administration. Topiramate loaded nanoemulsion was having a globule size of 4.73±0.52nm. It was stable for six months. Brain uptake of topiramate post intranasal administration of topiramate loaded nanoemulsion was significantly (P<1.86×10-8) higher when it was compared with oral administration of topiramate loaded nanoemulsion. This study indicates that intranasal administration of topiramate containing nanoemulsion could be an encouraging approach for the treatment of epilepsy to minimize the dose of topiramate in direction to avoid dose related adverse events.

New Treatment for Partial-Onset Seizures in Adults.

Cenobamate (Xcopri) is now approved to treat partial-onset seizures in adults.Serious adverse effects include drug reaction with eosinophilia and systemic symptoms (also called multiorgan hypersensitivity) and a shortened QT interval.

Cenobamate: First Approval

Cenobamate (XCOPRI®) is an oral, small molecule neurotherapeutic azole compound that is being developed by SK Life Science Inc. and Arvelle Therapeutics for the treatment of epilepsy. Based on results of two pivotal phase 2 trials, cenobamate was recently approved in the USA for use in the treatment of partial-onset seizures in adult patients. This article summarizes the milestones in the development of cenobamate leading to this first approval.

Neural Networks in Generalized Epilepsy and Novel Antiepileptic Drugs.

In previous works, alterations of neurotransmitters and neuropeptides in the brain areas involved in generalized epilepsy have been reported. We reviewed the alterations of these neurotransmitters and neuropeptides in the following brain areas involved in generalized epilepsy: hippocampus, hypothalamus, thalamus and cerebral cortex. In these brain areas, the neural networks are also actualized. The mechanisms of action of newer antiepileptic drugs in the treatment of generalized epilepsy are also discussed. Up-dating the neurotransmitter and neuropeptide alterations, we found that hippocampal GABAergic neurons presynaptically inhibit epileptogenic neurons via GABAB receptors. Epilepsy modulating neuropeptides (galanin, neuropeptide Y, dynorphin) are also involved. GABA deficiency, serotonin hyperactivity, dopamine hyperactivity and glutamate excitotoxicity can enhance ictogenesis: neurons containing these neurotransmitters form the main neural circuit. An increased excitability occurs when the alteration of these neurotransmitters is permanent. In preclinical studies, the GABAB receptor agonist GS 39,783 exerted a good antiepileptic effect. Perampanel, an AMPA receptor antagonist, showed good clinical effects in the treatment of partial-onset seizures and primary generalized tonic-clonic seizures. In this treatment, perampanel can be combined with other antiepileptic drugs. Brivaracetam, which shows a high affinity for the synaptic vesicle 2A, exerted a good efficacy in the treatment of adult focal seizures and secondarily generalized tonic-clonic seizures.

Pharmacokinetic and pharmacodynamic considerations for the clinical efficacy of perampanel in focal onset seizures

ABSTRACTIntroduction: Medical therapy is the mainstay of management of epilepsy. Despite the increasing number of available antiepileptic drugs (AEDs), approximately one-third of epileptic patients do not have adequate control of seizures. There is still a need for the development of new AEDs with enhanced effectiveness and tolerability.Areas covered: The present manuscript is based on an Internet and PubMed search (January 2005 to August 2018). It is focused on pharmacokinetic and clinical data of perampanel (PER) for the treatment of epilepsy.Expert opinion: PER has a novel mechanism of action, which opens up new options for a rational combination therapy. Phase III trials have demonstrated the efficacy and safety of PER as adjunctive therapy for the treatment of partial-onset seizures (POS) and primary generalized tonic–clonic seizures in patients aged ≥12 years. PER is also approved by FDA as monotherapy for the treatment of POS. A clinical trial is ongoing to verify the efficacy and safety of PER monotherapy in untreated patients with POS. In the future, head-to-head comparisons are needed to determine the exact position of PER relative to other AEDs. Moreover, further studies are needed to evaluate the efficacy and safety of PER in patients aged <12 years.Abbreviations: 4βOHC: 4β-hydroxycholesterol; AUC: area under the curve; CBZ: Carbamazepine; CLCr: creatinine clearance; Cmax: maximum plasma concentration; CYP: cytochrome P; EIAED: enzyme-inducing antiepileptic drug; EMA: European Medicines Agency; FDA: Food and Drug Administration; GI: gastrointestinal; OXC: oxcarbazepine; PER: perampanel; PGTC: primary generalized tonic-clonic; PHT: phenytoin; POS: partial-onset seizures; QD: once-daily; TEAE: treatment-emergent adverse event; Tmax: median time to reach peak concentration; UGT: uridine diphosphoglucose-glucuronosyltransferase; VPA: valproic acid

PD70 Cost-Effectiveness Of Deep Brain Stimulation For Epilepsy In Australia

Introduction:Deep brain stimulation (DBS), which uses an implantable device to modulate brain activity, is an adjunctive treatment for partial-onset seizures in patients with medically refractory epilepsy. Our objective was to perform an exploratory cost-utility analysis of DBS in conjunction with medical therapy, compared with medical therapy alone, using the latest clinical data and costs for the Australian healthcare system.Methods:A deterministic five-state Markov model was used to project treatment response and outcomes over the patients’ lifetimes, based on 5-year data from the recent Stimulation of the Anterior Nucleus of the Thalamus for Epilepsy (SANTE) DBS trial and drug outcome data identified through a literature search. Costs were based on 2017 data for the Australian healthcare system, and response-specific utilities were derived from published literature. We estimated the lifetime discounted incremental cost-effectiveness ratio (ICER) in Australian dollars per quality-adjusted life-year (QALY) for patients 36 years of age, fifty-five percent of whom were men. Costs and effects were discounted at five percent per annum. The robustness of projections was evaluated through scenario and sensitivity analyses.Results:Under assumed continued treatment benefit, DBS was projected to add 3.48 QALYs over the patients’ lifetimes, at an increased cost of AUD 142,304 (USD 105,960), resulting in an ICER of AUD 40,951 (USD 30,492) per QALY gained. Reducing the analysis horizon to 20 years increased the ICER to AUD 49,803 (USD 37,083). Increasing the DBS generator life from 3 to 6 years decreased the ICER to AUD 23,956 (USD 17,838) per QALY. Longer follow-up periods and younger age at treatment were associated with greater cost effectiveness. Results were sensitive to assumptions about health state-specific utility estimates and long-term treatment effects.Conclusions:Our exploratory findings suggest that DBS is a cost-effective treatment strategy in the Australian healthcare system for patients with medically refractory epilepsy. DBS therapy might meaningfully improve patient outcome at a health economic profile that compares favorably to other well accepted therapies. Consideration of indirect costs would further add to this value proposition.

Antiepileptic drug monotherapy for epilepsy: a network meta-analysis of individual participant data.

Antiepileptic drug monotherapy for epilepsy: a network meta-analysis of individual participant data.

Euro-Esli: a European audit of real-world use of eslicarbazepine acetate as a treatment for partial-onset seizures

The Euro-Esli study was an exploratory pooled analysis of data from 14 European clinical practice studies, which was conducted to audit the real-world effectiveness, safety, and tolerability of eslicarbazepine acetate (ESL) as an adjunctive treatment for partial-onset seizures. Retention and effectiveness were assessed after 3, 6, and 12 months of ESL treatment, and at the final visit. Safety and tolerability were assessed throughout ESL treatment by evaluating adverse events (AEs) and ESL discontinuation due to AEs. Data from 2058 patients (52.1% male; mean age 44.0 years) were included. All 2058 patients were assessed for safety and 1975 (96.0%) patients were assessed for effectiveness. After 12 months, retention, responder (≥50% seizure frequency reduction), and seizure freedom rates were 73.4, 75.6, and 41.3%, respectively. AEs were reported for 34.0% of patients and led to discontinuation in 13.6% of patients. The most frequently reported AEs were dizziness (6.7% of patients), fatigue (5.4%), and somnolence (5.1%). No unexpected safety signals emerged over a median duration of follow-up of >5 years. Subgroup analyses revealed that ESL was significantly more effective in patients aged ≥65 versus <65 years, in patients who were not receiving treatment with other sodium channel blockers versus those who were receiving treatment with other sodium channel blockers, and in patients who were receiving <2 versus ≥2 concomitant antiepileptic drugs at baseline. Euro-Esli is the largest ESL clinical practice study conducted to date. This study provides strong and reassuring evidence of ESL’s safety profile, and complements the data from clinical trials.

Anti-ictogenic and antiepileptogenic properties of perampanel in mature and immature rats.

Perampanel (PER) is a selective noncompetitive antagonist at α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid receptors, the first of its class approved for the adjunctive treatment of partial onset seizures and generalized seizures. This study explored anti-ictogenic and antiepileptogenic effects of PER in rats at different stages of development. Using a rapid kindling model in postnatal day 14 (P14), P21, P28, and P60 rats, we studied two doses of PER: 1 and 2mg/kg injected intraperitoneally 30min before afterdischarge assessment. We also assessed blood and brain concentrations of PER 30min after the injection. PER 2mg/kg significantly increased the afterdischarge threshold (ADT) at all ages, whereas PER at 1mg/kg increased ADT only in P21 rats. PER 2mg/kg also shortened the afterdischarge duration in P14 and P28 rats. PER increased the number of stimulations required to achieve a stage 4-5 seizure in a dose-dependent manner in P14 and P21 rats, with almost complete elimination of stage 4-5 seizures. At P28, only PER 2mg/kg increased the number of stimulations required to develop a stage 4-5 seizure. In contrast, PER had no effect on the number of stage 4-5 seizures at P60. We did not observed any age-dependent significant difference in the serum and brain levels of PER 30min after the injection. PER exerted anti-ictogenic effects from P14 to P60 independent of brain maturation. PER also exhibited antiepileptogenic effects with a stronger effect in the younger animals.

Pharmacokinetic drug evaluation of lacosamide for the treatment of partial-onset seizures

ABSTRACTIntroduction: The goal of pharmacologic therapy with antiepileptic drugs (AEDs) is to reduce the frequency of seizures and achieve a seizure-free state with minimal side effects. However 30% of patients treated with available AEDs continue to experience uncontrolled seizures. There is still need for new AEDs with enhanced effectiveness and tolerability.Areas covered: The present manuscript is based on an extensive Internet and PubMed search from 1992 to 2017. It is focused on the pharmacokinetic properties of lacosamide (LCM) for the treatment of partial-onset seizures.Expert opinion: LCM is an anticonvulsant approved as add-on treatment or monotherapy of partial-onset seizures with or without secondary generalization. LCM shares many of the pharmacokinetic characteristics of an ideal AED. LCM displays linear and dose-proportional pharmacokinetics, rapid and complete absorption from the gastrointestinal tract, low plasma-protein binding, renal excretion and a terminal half-life that supports twice-daily dosing. Because the bioavailability and tolerability of oral and intravenous LCM are comparable, LCM offers the advantage of direct conversion from oral to intravenous administration, and vice versa, without the need for titration or dose adjustment. Further studies are needed to determine optimal timing, dosing, as well as the safety and efficacy of LCM in status epilepticus.

Antiepileptic drug monotherapy for epilepsy: a network meta-analysis of individual participant data.

Antiepileptic drug monotherapy for epilepsy: a network meta-analysis of individual participant data.

UPLC-MS/MS assay for identification and quantification of brivaracetam in plasma sample: Application to pharmacokinetic study in rats.

Brivaracetam (BVR) is a novel antiepileptic drug (AED), approved clinically for the treatment of partial onset seizures in adults and adolescents. It has some abuse potential and assigned to Schedule V category under the Controlled Substance Act by the Drug Enforcement Administration. Being an AED and drug of abuse, a sensitive and robust assay is necessary for determination of BVR in biological fluids. Herein, we report a sensitive and validated UPLC-MS/MS assay for identification and quantification of BVR in plasma samples. The samples were prepared by one step liquid liquid extraction method using tert-Butyl methyl ether as extracting solvent. BVR and internal standard (carbamazepine) were separated on Aquity BEH™ C-18 column and eluted by using gradient mobile phase combination of acetonitrile and 0.1% formic acid in water. The precursor to product ion transition of m/z 213.12→54.95 (qualifier), 213.12→168.10 (quantifier) for BVR, and m/z 237.06→193.25 for IS were used for MRM detection and quantification. The assay was validated according to USFDA and SWGTOX guidelines for method validation and all parameter results were within the acceptable limits. The calibration curves were found to be linear in concentration range of 1.98-2000ng/mL (r2≥0.995) having LOD and LLOQ of 0.80 and 1.98ng/mL, respectively. The assay was successfully employed in BVR pharmacokinetic study in rats and can be suitable for therapeutic drug monitoring, pharmacokinetic study and forensic analysis.

Modeling and Simulation Strategy to Support Eslicarbazepine Acetate (ESL) Pediatric Dose Selection in the Treatment of Partial Onset Seizures Based on Matching Adult Exposures (P3.246)

Modeling and Simulation Strategy to Support Eslicarbazepine Acetate (ESL) Pediatric Dose Selection in the Treatment of Partial Onset Seizures Based on Matching Adult Exposures (P3.246)

New developments in the management of partial-onset epilepsy: role of brivaracetam.

Currently, a number of novel anticonvulsant drugs, the so-called third generation, are in various stages of development. Several of them are already available or in ongoing clinical trials. These new compounds should take advantage of new insights into the basic pathophysiology of epileptogenesis, drug metabolism and drug interactions. Many of them still need to be further evaluated mainly in real-world observational trials and registries. Among newer anticonvulsant drugs for partial-onset seizures (POSs), rufinamide, lacosamide, eslicarbazepine and perampanel are those new treatment options for which more substantial clinical evidence is currently available, both in adults and, to some extent, in children. Among the newest anticonvulsant drugs, brivaracetam, a high-affinity synaptic vesicle protein 2A ligand, reported to be 10- to 30-fold more potent than levetiracetam, is highly effective in a broad range of experimental models of focal and generalized seizures. Unlike levetiracetam, brivaracetam does not inhibit high-voltage Ca2+ channels and AMPA receptors and appears to inhibit neuronal voltage-gated sodium channels playing a role as a partial antagonist. Brivaracetam has a linear pharmacokinetic profile, is extensively metabolized and is excreted by urine (only 8%–11% unchanged). It does not seem to influence the pharmacokinetics of other antiepileptic drugs. It was approved in the European Union in January 2016 and in the US in February 2016 as an adjunctive therapy for the treatment of POS in patients older than 16 years of age. To date, its clinical efficacy as adjunctive antiepileptic treatment in adults with refractory POS at doses between 50 and 200 mg daily has been extensively assessed in two Phase IIb and four Phase III randomized controlled studies. Long-term extension studies show sustained efficacy of brivaracetam. Overall, the drug is generally well tolerated with only mild-to-moderate side effects. This is true also by intravenous route. Brivaracetam has not yet been evaluated as monotherapy or in comparison with other new anticonvulsant drugs.

Carbamazepine versus phenytoin monotherapy for epilepsy: an individual participant data review.

Carbamazepine versus phenytoin monotherapy for epilepsy: an individual participant data review.

Eslicarbazepine acetate: A therapeutic agent of paramount importance in acute anticonvulsant therapy

Eslicarbazepine acetate (ESL) is a new, once daily, orally administered, third generation antiepileptic drug which is indicated in the treatment of partial-onset seizures. ESL is known to exert it’s anticonvulsant effect by blocking the voltage-gated sodium channels. Several clinical trials and pharmacological studies have revealed that seizure control was better with ESL monotherapy (1 200 or 1 600 mg once daily) following a switch from other antiepileptic drugs in comparison with pseudo-placebo patients. The studies have indicated the ESL to be well tolerated and produced only mild to moderate emergent adverse events with the therapy. Being a dibenzazepine family member, structure and chemistry of ESL resembles more or less to carbamazepine and oxcarbazepine. ESL differs structurally from carbamazepine and oxcarbazepine at the 10, 11 position of dibenazepine nucleus. This molecular variation results in differences in metabolism and thus helps to prevent the formation of toxic epoxide metabolites. ESL following oral administration is rapidly metabolised to active metabolite namely S-licarbazepine which is responsible for its pharmacological activity. ESL exhibits acceptable pharmacokinetic profile and shows insignificant drug-drug interactions. In phase III clinical program, ESL was found to be efficacious and well tolerated in adult patients with partial onset seizures previously not controlled with treatment with one or two other antiepileptic drugs.

Carbamazepine versus phenobarbitone monotherapy for epilepsy: an individual participant data review.

Carbamazepine versus phenobarbitone monotherapy for epilepsy: an individual participant data review.