The efficacy of lacosamide as monotherapy and adjunctive therapy in focal epilepsy and its use in status epilepticus: clinical trial evidence and experience

CYP2C19 genotype and sodium channel blockers in lacosamide-treated children with epilepsy: two major determinants of trough lacosamide concentration or clinical response

Background

The widespread clinical use of lacosamide (LCM) has revealed significant individual differences in clinical response, with various reported influencing factors. However, it remains unclear how genetic factors related to the disposition and clinical response of LCM, as well as drug-drug interactions (DDIs), exert their influence on pediatric patients with epilepsy.

Objectives

To evaluate the impact of genetic variations and DDIs on plasma LCM concentrations and clinical response.

Design

Patients with epilepsy treated with LCM from June 2021 to March 2023 in the Children's Hospital of Nanjing Medical University were included in the analysis.

Methods

The demographic information and laboratory examination data were obtained from the hospital information system. For the pharmacogenetic study, the left-over blood specimens, collected for routine plasma LCM concentration monitoring, were used to perform genotyping analysis for the selected 26 single nucleotide polymorphisms from 14 genes. The trough concentration/daily dose (C 0/D) ratio and efficacy outcomes were compared.

Results

Patients achieved 90.1% and 68.9% responder rates in LCM mono- and add-on therapy, respectively. The genetic variant in the CYP2C19 *2 (rs4244285) was associated with a better responsive treatment outcome (odds ratio: 1.82; 95% confidence interval: 1.05-3.15; p = 0.031). In monotherapy, 36% of patients were CYP2C19 normal metabolizers (NMs), 49% were intermediate metabolizers (IMs), and 15% were poor metabolizers (PMs) carrying CYP2C19 *2 or *3. Of note, the C 0/D ratios of IMs and PMs were 9.1% and 39.6% higher than those of NMs, respectively. Similar results were in the add-on therapy group, and we also observed a substantial decrease in the C 0/D ratio when patients were concomitant with sodium channel blockers (SCBs).

Conclusion

This study was the first to confirm that CYP2C19 *2 or *3 variants impact the disposition and treatment response of LCM in children with epilepsy. Moreover, concomitant with SCBs, particularly oxcarbazepine, also decreased plasma LCM concentration.

The effect of lacosamide on calcitonin gene-related peptide serum level in episodic migraine patients: a randomized, controlled trial

BACKGROUND

Migraine affects 11-15% of people worldwide, and the calcitonin gene-related peptide (CGRP) is released during the migraine attack, producing pulsating pain of migraine. Also, lacosamide reacts with collapsin-response mediator protein 2, preventing its phosphorylation and leading to the inhibition of CGRP release in the trigeminal system.

OBJECTIVE

The primary outcome was the difference in the serum level of CGRP-LI after three months of treatment with either lacosamide and ibuprofen or ibuprofen alone in episodic migraine patients. The secondary outcomes were assessing safety and efficacy of lacosamide in episodic migraine patients.

METHODS

We conducted an open-label randomized controlled trial on episodic migraine patients aged 10-55 years diagnosed according to (ICHD-3) in Kafr El-Sheikh University Hospital, Egypt. We assessed serum levels of CGRP-LI before and three months after treatment in our two groups, the lacosamide, and the control groups. We also assessed the side effects of treatment in each group, the percentage of patients who achieved ≥ 50% reduction in the migraine monthly days (MMD) frequency and the percentage of patients who achieved pain freedom within 2 h in ≥ 4 of 5 attacks in each group.

RESULTS

200 episodic migraine patients completed the study. There was a statistically significantly higher reduction in the serum CGRP-LI level in the lacosamide group compared with the control group. In addition, lacosamide was well tolerated by patients. Also, the lacosamide group had statistically significant higher percentage of patients who achieved ≥ 50% reduction in the migraine monthly days (MMD) frequency and pain freedom within two hours in ≥ 4 of 5 attacks with P-values 0.002, 0.02 respectively.

CONCLUSION

The daily use of lacosamide 50 mg Bid for three months in episodic migraine patients was associated with a significant reduction in serum CGRP-LI, better clinical outcomes regarding frequency and duration of migraine attacks, and was well tolerated by patients. These results were derived from an open-label pilot study that needed to be thoroughly investigated by a large-scale, randomized, double-blinded, placebo-controlled study.

TRIAL REGISTRATION

 We registered our trial on ClinicalTrials.gov, named after "The Lacosamide's Effect on Calcitonin Gene-related Peptide in Migraine Patients," and with a clinical trial number (NCT05632133)-August 8, 2023.

The JAK-STAT Signaling Pathway in Epilepsy

Epilepsy is defined as spontaneous recurrent seizures in the brain. There is increasing evidence that inflammatory mediators and immune cells are involved in epileptic seizures. As more research is done on inflammatory factors and immune cells in epilepsy, new targets for the treatment of epilepsy will be revealed. The Janus kinase-signal transducer and transcriptional activator (JAKSTAT) signaling pathway is strongly associated with many immune and inflammatory diseases, At present, more and more studies have found that the JAK-STAT pathway is involved in the development and development of epilepsy, indicating the JAK-STAT pathway's potential promise as a target in epilepsy treatment. In this review, we discuss the composition, activation, and regulation of the JAK-STAT pathway and the relationship between the JAK-STAT pathway and epilepsy. In addition, we summarize the common clinical inhibitors of JAK and STAT that we would expect to be used in epilepsy treatment in the future.

Cytochrome P450-mediated antiseizure medication interactions influence apoptosis, modulate the brain BAX/Bcl-XL ratio and aggravate mitochondrial stressors in human pharmacoresistant epilepsy

Polytherapy with antiseizure medications (ASMs) is often used to control seizures in patients suffering from epilepsy, where about 30% of patients are pharmacoresistant. While drug combinations are intended to be beneficial, the consequence of CYP-dependent drug interactions on apoptotic protein levels and mitochondrial function in the epileptic brain remains unclear. We examined the interactions of ASMs given prior to surgery in surgically resected brain tissues and of three ASMs (lacosamide, LCM; oxcarbazepine, OXC; levetiracetam LEV) in isolated brain cells from patients with drug-resistant epilepsy (n = 23). We divided the patients into groups-those who took combinations of NON-CYP + CYP substrate ASMs, NON-CYP + CYP inducer ASMs, CYP substrate + CYP substrate or CYP substrate + CYP inducer ASMs-to study the 1) pro- and anti-apoptotic protein levels and other apoptotic signaling proteins and levels of reactive oxygen species (reduced glutathione and lipid peroxidation) in brain tissues; 2) cytotoxicity at blood-brain barrier epileptic endothelial cells (EPI-ECs) and subsequent changes in mitochondrial membrane potential in normal neuronal cells, following treatment with LCM + OXC (CYP substrate + CYP inducer) or LCM + LEV (CYP substrate + NON-CYP-substrate) after blood-brain barrier penetration, and 3) apoptotic and mitochondrial protein targets in the cells, pre-and post-CYP3A4 inhibition by ketoconazole and drug treatments. We found an increased BAX (pro-apoptotic)/Bcl-XL (anti-apoptotic) protein ratio in epileptic brain tissue after treatment with CYP substrate + CYP substrate or inducer compared to NON-CYP + CYP substrate or inducer, and subsequently decreased glutathione and elevated lipid peroxidation levels. Further, increased cytotoxicity and Mito-ID levels, indicative of compromised mitochondrial membrane potential, were observed after treatment of LCM + OXC in combination compared to LCM + LEV or these ASMs alone in EPI-ECs, which was attenuated by pre-treatment of CYP inhibitor, ketoconazole. A combination of two CYP-mediated ASMs on EPI-ECs resulted in elevated caspase-3 and cytochrome c with decreased SIRT3 levels and activity, which was rescued by CYP inhibition. Together, the study highlights for the first time that pro- and anti-apoptotic proteins levels are dependent on ASM combinations in epilepsy, modulated via a CYP-mediated mechanism that controls free radicals, cytotoxicity and mitochondrial activity. These findings lead to a better understanding of future drug selection choices offsetting pharmacodynamic CYP-mediated interactions.

Effect of Lacosamide and Ethosuximide Chronic Treatment on Neural Precursor Cells and Cognitive Functions after Pilocarpine Induced Status Epilepticus in Mice

Seizures in about 40% of patients with epilepsy fail to respond to anti-seizure medication (ASM) and may lead to uncontrolled and prolonged seizures often inducing status epilepticus (SE). The aim of the study was to evaluate the impact of a long-term treatment with two different generation ASMs: ethosuximide (ETS, a classic ASM) and lacosamide (LCM, a 3rd generation ASM) on neural stem cells’ (NSCs’) proliferation and learning and memory functions after pilocarpine (PILO)-induced SE in mice. The following drugs were used: LCM (10 mg/kg), ETS (20 mg/kg), and PILO (300 mg/kg). Cell counting was done using confocal microscope and ImageJ software. Cognitive functions were evaluated with the Morris water maze (MWM) test. The level of several selected neurometabolites was measured with magnetic resonance spectroscopy (MRS). Obtained results indicated no significant impact of ETS treatment on the neurogenesis process in PILO mice. Interestingly, LCM significantly decreased the total amount of newborn neurons. The MWM test indicated no significant changes in the time and distance traveled by the ETS and LCM groups compared to PILO control mice, although all measured parameters were more favorable for the PILO mice treated with ASM. Conclusions: The presented results show that long term treatment with LCM and ETS seems to be safe for the cognitive functions and the proper course of neurogenesis in the mouse PILO-induced SE model, although one should remember that LCM administered chronically may act to reduce new neurons’ formation.

Efficacy and safety of lacosamide in the treatment of status epilepticus in a patient with comorbidities

Efficacy, safety and tolerability of lacosamide in the treatment of status epilepticus are well described. However, other evidence of its pharmacologic profile in elderly patients with other comorbidities seems warranted. We describe the case of an 80 year-old woman with an history of arterial hypertension, ischemic cardiomyopathy, COPD, CKD, previous laryngeal cancer, a stoma positioning for diverticular disease and previous surgery for a left frontal meningioma. Since then, the patient developed focal epilepsy and she was on levetiracetam and valproic acid therapy. The patient was admitted to our department for a focal status epilepticus characterized by non-fluent aphasia and right facio-brachial clonic movements. She also presented with aspiration pneumonia and started intravenous antibiotic treatment. After failure of a first-line antiepileptic drug, lacosamide intravenous treatment was started, with complete reversal of the clinical picture. EEG then showed focal slow waves mixed to interictal epileptiform discharges over the left fronto-temporal regions. The patient was then discharged home with an oral lacosamide treatment and at 3 months she was seizure-free. Our case report confirms the efficacy of lacosamide in status epilepticus, highlighting its safety and tolerability in an elderly and fragile patient with multiple comorbidities and drug therapy.

A prospective, real-world, clinical pharmacokinetic study to inform lacosamide dosing in critically ill patients undergoing continuous venovenous haemofiltration (PADRE-02)

AIMS

Although the use of continuous renal replacement therapy (CRRT) has increased, limited dosing information exists on the effect of CRRT on antiepileptic drug pharmacokinetics. The objectives of this practice-based study are to evaluate the pharmacokinetics of lacosamide and recommend individualized dosing recommendations in critically ill patients receiving continuous venovenous haemofiltration (CVVH).

METHODS

Seven patients receiving lacosamide and CVVH in a neurocritical care unit were enrolled. Pre-filter, post-filter and ultrafiltrate samples were obtained at baseline, right after the completion of the infusion, and up to six additional sampling time points post-administration. Patient-specific flow rates and clinical measures were also collected simultaneously at the time of sampling. Plasma concentrations were measured using a validated high-performance liquid chromatography with ultraviolet radiation detection (HPLC-UV) bioanalytical method. Non-compartmental analysis was utilized to characterize the pharmacokinetics of lacosamide.

RESULTS

The observed mean sieving coefficient for lacosamide was 0.80 ± 0.10, suggesting high removal of lacosamide. Concentrations measured in six out of seven patients were observed to be outside the therapeutic range (5-12 mg/L). The estimated average volume of distribution was found to be similar to healthy patients (0.58 L/kg). The mean bias and precision of the estimated total clearance was -2.53% and 14.9%, respectively. Simulations of various doses suggest that effluent flow rate-based dosing regimens could be used to individualize lacosamide therapeutics.

CONCLUSIONS

CVVH clearance contributed a major fraction of the total lacosamide clearance in neurocritically ill patients. Given that drug clearance increases with higher effluent flow rates, lacosamide dosing regimens should be increased to match exposures observed in patients with normal renal function.

Safety, tolerability, and pharmacokinetics of weight-based IV loading dose of lacosamide in the ICU

Among the newer antiseizure medications, lacosamide (LCM) has been increasingly used for acute seizures and status epilepticus in intensive care unit (ICU). We reviewed retrospectively weight-based dosing of IV LCM in patients admitted to ICU with acute seizures and status epilepticus. We have analyzed 354/382 patient treated with IV LCM in ICU during the years 2013-2016. Data collected were age, total body weight, body mass index (BMI), loading dose, post-IV infusion LCM blood level, duration of infusion, blood pressure, heart rate, oxygen saturation, mean arterial pressures, and documented initiation of pressor agents during or within in 30 min of infusion. Larger doses >8 mg/kg of IV LCM that can be safely administered in ICU patients produce effective plasma levels of 15-20 μg/ml with relatively constant volume of distribution.

Therapeutic Options for Patients with Refractory Status Epilepticus in Palliative Settings or with a Limitation of Life-Sustaining Therapies: A Systematic Review

BACKGROUND

Refractory status epilepticus (RSE) represents a serious medical condition requiring early and targeted therapy. Given the increasing number of elderly or multimorbid patients with a limitation of life-sustaining therapy (LOT) or within a palliative care setting (PCS), guidelines-oriented therapy escalation options for RSE have to be omitted frequently.

OBJECTIVES

This systematic review sought to summarize the evidence for fourth-line antiseizure drugs (ASDs) and other minimally or non-invasive therapeutic options beyond guideline recommendations in patients with RSE to elaborate on possible treatment options for patients undergoing LOT or in a PCS.

METHODS

A systematic review of the literature in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines, focusing on fourth-line ASDs or other minimally or non-invasive therapeutic options was performed in February and June 2020 using the MEDLINE, EMBASE and Cochrane databases. The search terminology was constructed using the name of the specific ASD or therapy option and the term 'status epilepticus' with the use of Boolean operators, e.g. "(brivaracetam) AND (status epilepticus)". The respective Medical Subject Headings (MeSH) and Emtree terms were used, if available.

RESULTS

There is currently no level 1, grade A evidence for the use of ASDs in RSE. The best evidence was found for the use of lacosamide and topiramate (level 3, grade C), followed by brivaracetam, perampanel (each level 4, grade D) and stiripentol, oxcarbazepine and zonisamide (each level 5, grade D). Regarding non-medicinal options, there is little evidence for the use of the ketogenic diet (level 4, grade D) and magnesium sulfate (level 5, grade D) in RSE. The broad use of immunomodulatory or immunosuppressive treatment options in the absence of a presumed autoimmune etiology cannot be recommended; however, if an autoimmune etiology is assumed, steroid pulse, intravenous immunoglobulins and plasma exchange/plasmapheresis should be considered (level 4, grade D). Even if several studies suggested that the use of neurosteroids (level 5, grade D) is beneficial in RSE, the current data situation indicates that there is formal evidence against it.

CONCLUSIONS

RSE in patients undergoing LOT or in a PCS represents a challenge for modern clinicians and epileptologists. The evidence for the use of ASDs in RSE beyond that in current guidelines is low, but several effective and well-tolerated options are available that should be considered in this patient population. More so than in any other population, advance care planning, advance directives, and medical ethical aspects have to be considered carefully before and during therapy.

Lacosamide-associated second-degree atrioventricular block in a healthy, young athlete

Lacosamide enhances slow inactivation of voltage-gated sodium channels and can lead to dose-dependent PR interval prolongation. Previously, lacosamide has been associated with second-degree atrioventricular (AV) heart block in the context of multiple medical comorbidities and/or in the elderly with multimorbidity on other dromotropic agents. We report a case of second-degree AV block occurring in a healthy, athletic young adult. The patient had baseline bradycardia with no known cardiac comorbidities. He was exquisitely sensitive to lacosamide with EKG and telemetry changes developing on the order of hours after receiving intravenous lacosamide. Lacosamide was subsequently stopped, the second-degree AV block was no longer present and EKG returned to baseline. We hypothesize that his sensitivity to lacosamide-induced AV block was possibly secondary to his baseline bradycardia with early repolarization changes. The case underscores the importance of surveillance cardiac monitoring. While medical comorbidities and an older age may portend a greater risk of PR prolongation, routine EKGs should be considered in all patients receiving lacosamide.

•

This is a case of second-degree AV block with lacosamide in a healthy, young adult.

•

PR prolongation can be seen with lacosamide irrespective of medical comorbidities.

•

Surveillance cardiac monitoring should be considered in patients taking lacosamide.

Postmarketing experience with brivaracetam in the treatment of focal epilepsy in children and adolescents

INTRODUCTION

This multicenter, retrospective study aimed to evaluate the efficiency, retention, safety, and tolerability of brivaracetam (BRV) in children and adolescents with focal epilepsy.

METHODS

All patients aged ≤17 years with focal epilepsy who started BRV in 2016 and 2017 were analyzed.

RESULTS

Thirty-four patients (mean age: 12.2 years, range: 3-17 years, 56% female) were treated with BRV for 25 days to 24 months, with a total exposure time of 19.7 years. Overnight switch from levetiracetam (LEV) to BRV was performed in 20 patients at a median ratio of 10:1. Retention rate was 97% at three months, with only one patient reporting a discontinuation of BRV treatment. Further dropouts were reported in one patient after seven months and in two patients after one year of treatment, respectively. The median length of exposure to BRV was 180 days. Efficacy at three months was 47% (50% responder rate), with 10 patients (29%) reporting seizure freedom. A long-term 50% responder rate was present in 12 patients [35%; four patients seizure-free (12%)] for more than six months and in seven patients (21%; no seizure-free patients) for more than 12 months. Treatment-emergent adverse events were observed in 12% of patients, with the most common being sedation, somnolence, loss or gain of appetite, and psychobehavioral adverse events.

CONCLUSIONS

Use of BRV in children and adolescents seems to be safe and well-tolerated. The results with 50% responder rate of 47% are consistent with those from randomized controlled trials and postmarketing studies in adults. An immediate switch from LEV to BRV at a ratio of 10:1 is feasible. The occurrence of psychobehavioral adverse events seems less prominent than under LEV and a switch to BRV can be considered in patients with LEV-induced adverse events.

Pharmacology of new and developing intravenous therapies for the management of seizures and epilepsy

INTRODUCTION

Antiepileptic drugs (AEDs) are administered orally for chronic use. Parenteral formulations might be necessary when the oral route is not feasible (e.g. an impairment of consciousness, trauma, dysphagia, gastrointestinal illness) or for treatment of seizure emergencies. At present, few intravenous (IV) formulations are available on the market.

AREAS COVERED

The purpose of this review is to summarize the pharmacological characteristics and clinical applications of IV medications that have been recently introduced to the armamentarium of epilepsy therapy or are currently being developed. Apart from AEDs, other compounds belonging to different pharmacological classes (e.g. diuretics, anesthetics), which have shown potential effectiveness in seizure control, are taken into consideration, and the pathophysiological premises supporting their use for epilepsy treatment are illustrated. The authors give particular focus to immunomodulatory and immunosuppressive agents, which have become the therapeutic cornerstones for immune-mediated epilepsies, despite regulatory obstacles.

EXPERT OPINION

In several circumstances, especially in the case of seizure-related emergencies, clinical practice seems not match literature-based evidence, and several IV AEDs are still used off-label. Strong evidence derived from randomized clinical trials (RCTs) is needed to support the effectiveness and tolerability of any therapeutic approach, however common and "accepted' it may be, in order to guarantee patient safety and well-being.

Antiepileptic Drugs and Liver Disease

Acute, symptomatic seizures or epilepsy may complicate the course of hepatic disease. Choosing the most appropriate antiepileptic drug in this setting represents a difficult challenge, as most medications are metabolized by the liver. This article focuses on the acute and chronic treatment of seizures in patients with advanced liver disease and reviews the hepatotoxic potential of specific antiepileptic drugs. Newer antiepileptic drugs without, or with minimal, hepatic metabolism, such as levetiracetam, lacosamide, topiramate, gabapentin, and pregabalin should be used as first-line therapy. Medications undergoing extensive hepatic metabolism, such as valproic acid, phenytoin, and felbamate should be used as drugs of last resort. In special circumstances, as in patients affected by acute intermittent porphyria, exposure to most antiepileptic drugs could precipitate attacks. In this clinical scenario, bromides, levetiracetam, gabapentin, and vigabatrin constitute safe choices. For the treatment of status epilepticus, levetiracetam and lacosamide, available in intravenous preparations, are good second-line therapies after benzodiazepines fail to control seizures. Hepatotoxicity is also a rare and unexpected side effect of some antiepileptic drugs. Drugs such as valproic acid, phenytoin, and felbamate, have a well-recognized association with liver toxicity. Other antiepileptic drugs, including phenobarbital, benzodiazepines, ethosuximide, and the newer generations of antiepileptic drugs, have only rarely been linked to hepatotoxicity. Thus physicians should be mindful of the pharmacokinetic profile and the hepatotoxic potential of the different antiepileptic drugs available to treat patients affected by liver disease.

Lacosamide in status epilepticus: Systematic review of current evidence

OBJECTIVE

The intravenous formulation of lacosamide (LCM) and its good overall tolerability and safety favor the use in status epilepticus (SE). The aim of this systematic review was to identify and evaluate studies reporting on the use of LCM in SE.

METHODS

We performed a systematic literature search of electronic databases using a combined search strategy from 2008 until October 2016. Using a standardized assessment form, information on the study design, methodologic framework, data sources, efficacy, and adverse events attributed to LCM were extracted from each publication and systematically reported.

RESULTS

In total, 522 SE episodes (51.7% female) in 486 adults and 36 children and adolescents were evaluated with an overall LCM efficacy of 57%. Efficacy was comparable between use in nonconvulsive (57%; 82/145) and generalized-convulsive (61%; 30/49; p = 0.68) SE, whereas overall success rate was better in focal motor SE (92%; 34/39, p = 0.013; p < 0.001). The efficacy with later positioning of LCM decreased from 100% to 20%. The main adverse events during treatment of SE are dizziness, abnormal vision, diplopia, and ataxia. Overall, lacosamide is well tolerated and has no clinically relevant drug-drug interactions.

SIGNIFICANCE

The available data regarding the use of LCM in SE are promising, with a success rate of 57%. The strength of LCM is the lack of interaction potential and the option for intravenous use in emergency situations requiring rapid uptitration.