Levetiracetam: part II, the clinical profile of a novel anticonvulsant drug

Pharmacokinetic and pharmacodynamic data from the NEOLEV1 and NEOLEV2 studies

OBJECTIVES

To confirm that levetiracetam (LEV) demonstrates predictable pharmacokinetics(PK) at higher doses and to study the pharmacodynamics(PD) of LEV.

DESIGN

Pharmacokinetic data from the NEOLEV1 and NEOLEV2 trials were analysed using a non-linear mixed effects modelling approach. A post hoc analysis of the effect of LEV on seizure burden was conducted.

SETTING

Neonatal intensive care unit.

PATIENTS

Term neonates with electrographically confirmed seizures.

INTERVENTIONS

In NEOLEV1, neonates with seizures persisting following phenobarbital (PHB) received LEV 20 or 40 mg/kg bolus followed by 5 or 10 mg/kg maintenance dose(MD) daily. In NEOLEV2, patients received a 40 mg/kg intravenous LEV load, followed by 10 mg/kg doses 8 hourly. If seizures persisted, a further 20 mg/kg intravenous load was given. If seizures persisted, PHB was given. PK data were collected from 16 NEOLEV1 patients and 33 NEOLEV2 patients. cEEG data from 48 NEOLEV2 patients were analysed to investigate onset of action and seizure burden reduction.

MAIN OUTCOME MEASURES

Clearance (CL) and volume of distribution (Vd) were determined. Covariates that significantly affected LEV disposition were identified.

RESULTS

Primary outcome: The median initial LEV level was 57 µg/mL (range 19-107) after the first loading dose and at least 12 µg/mL at 48 hours in all infants. CL and Vd were estimated to be 0.0538 L/hour and 0.832 L, respectively. A direct relationship between postnatal age and CL was observed. The final population pharmacokinetic(PopPK) model described the observed data well without significant biases. CL and Vd were described as CL (L/hour)=0.0538×(weight in kg/3.34)0.75×(postnatal age in days/5.5) 0.402 and Vd (L)=0.832×(weight in kg/3.34).Seizure burden reduced within 30 min of LEV administration. 28% of patients were completely seizure free after LEV. In an additional 25% of patients, seizure burden reduced by 50%.

CONCLUSIONS

LEV pharmacokinetics remained predictable at higher doses. Very high-dose LEV can now be studied in neonates.

TRIAL REGISTRATION NUMBER

NCT01720667.

Development of SV2A Ligands for Epilepsy Treatment: A Review of Levetiracetam, Brivaracetam, and Padsevonil

Epilepsy is a common neurological disorder that is primarily treated with antiseizure medications (ASMs). Although dozens of ASMs are available in the clinic, approximately 30% of epileptic patients have medically refractory seizures; other limitations in most traditional ASMs include poor tolerability and drug-drug interactions. Therefore, there is an urgent need to develop alternative ASMs. Levetiracetam (LEV) is a first-line ASM that is well tolerated, has promising efficacy, and has little drug-drug interaction. Although it is widely accepted that LEV acts through a unique therapeutic target synaptic vesicle protein (SV) 2A, the molecular basis of its action remains unknown. Even so, the next-generation SV2A ligands against epilepsy based on the structure of LEV have achieved clinical success. This review highlights the research and development (R&D) process of LEV and its analogs, brivaracetam and padsevonil, to provide ideas and experience for the R&D of novel ASMs.

Psychiatric assessment prior to and after switch from levetiracetam to brivaracetam

PURPOSE

Brivaracetam is often used as an alternative to levetiracetam in patients with epilepsy (PWE) encountering efficacy issues or adverse events with levetiracetam. This study evaluated the psychological status of PWE who were switched from levetiracetam to brivaracetam due to psychiatric tolerability concerns in comparison to those who remained on levetiracetam.

METHODS

We used various psychological assessments including the Symptom Checklist SCL-90-R, the Beck Depression Inventory-II, and the adverse event profile. Eligible participants completed the questionnaires at baseline and again 8 days later. Psychological changes were assessed using standard statistical methods to show differences between a group that immediately switched from levetiracetam to brivaracetam and another group with unchanged levetiracetam.

RESULTS

Between May 2020 and May 2021, 63 patients participated in the study, of whom 34 switched from levetiracetam to brivaracetam. At baseline, participants who switched to brivaracetam had fewer antiseizure medications but experienced more monthly seizures. Baseline scores for anxiety (p = 0.020) and psychoticism (p = 0.046) on SCL-90-R in PWE switched to brivaracetam were higher than in the remaining group. In the subsequent assessment, all psychological scores were reduced and were no longer significantly different between both groups. Using multiple regression, initial treatment with a single antiseizure medication and male gender emerged as predictors of psychological improvement.

CONCLUSION

Our study found no increased risk of adverse events or psychiatric symptoms after switching from levetiracetam to brivaracetam. Though statistically non-significant, a trend towards improved psychiatric outcomes in the switch group warrants further investigation in future trials with stronger designs for enhanced statistical power.

Pharmacokinetic considerations surrounding the use of levetiracetam for seizure prophylaxis in neurocritical care - an overview

INTRODUCTION

Levetiracetam (LEV) is one of the most widely used anti-seizure medications (ASMs) in clinical practice. This is due both to a different mechanism of action when compared to other ASMs and its easy handling. Indeed, because of its interesting pharmacokinetic properties, it is often used outside of the labelled indications, notably in the neurocritical setting as prophylaxis of epileptic seizures.

AREAS COVERED

A literature search was conducted and the most relevant studies on the pharmacokinetic properties of LEV were selected by two independent investigators. Current evidence on the use of ASM prophylaxis in the neurocritical setting was also reviewed, highlighting and discussing the strengths and limits of LEV as drug of choice for anti-epileptic prophylaxis in this scenario.

EXPERT OPINION

LEV has a "near-ideal" pharmacokinetic profile, which makes it an attractive drug for ASM prophylaxis in neurocritical care. However, current recommendations restrict ASMs prophylaxis to very selected circumstances and the role of LEV is marginal. Moreover, studies are generally designed to compare LEV versus phenytoin, whereas studies comparing LEV versus placebo are lacking. Further randomized trials will be needed to better elucidate LEV utility and its neuroprotective role in the neurocritical setting.

Past, present and future of therapeutic strategies against amyloid-β peptides in Alzheimer's disease: a systematic review

Alzheimer's disease (AD) is the most prevalent neurodegenerative disease in ageing, affecting around 46 million people worldwide but few treatments are currently available. The etiology of AD is still puzzling, and new drugs development and clinical trials have high failure rates. Urgent outline of an integral (multi-target) and effective treatment of AD is needed. Accumulation of amyloid-β (Aβ) peptides is considered one of the fundamental neuropathological pillars of the disease, and its dyshomeostasis has shown a crucial role in AD onset. Therefore, many amyloid-targeted therapies have been investigated. Here, we will systematically review recent (from 2014) investigational, follow-up and review studies focused on anti-amyloid strategies to summarize and analyze their current clinical potential. Combination of anti-Aβ therapies with new developing early detection biomarkers and other therapeutic agents acting on early functional AD changes will be highlighted in this review. Near-term approval seems likely for several drugs acting against Aβ, with recent FDA approval of a monoclonal anti-Aβ oligomers antibody -aducanumab- raising hopes and controversies. We conclude that, development of oligomer-epitope specific Aβ treatment and implementation of multiple improved biomarkers and risk prediction methods allowing early detection, together with therapies acting on other factors such as hyperexcitability in early AD, could be the key to slowing this global pandemic.

Levetiracetam treatment leads to functional recovery after thoracic or cervical injuries of the spinal cord

Spinal cord injury (SCI) leads to dramatic impairments of motor, sensory, and autonomic functions of affected individuals. Following the primary injury, there is an increased release of glutamate that leads to excitotoxicity and further neuronal death. Therefore, modulating glutamate excitotoxicity seems to be a promising target to promote neuroprotection during the acute phase of the injury. In this study, we evaluated the therapeutic effect of a FDA approved antiepileptic drug (levetiracetam-LEV), known for binding to the synaptic vesicle protein SV2A in the brain and spinal cord. LEV therapy was tested in two models of SCI-one affecting the cervical and other the thoracic level of the spinal cord. The treatment was effective on both SCI models. Treated animals presented significant improvements on gross and fine motor functions. The histological assessment revealed a significant decrease of cavity size, as well as higher neuronal and oligodendrocyte survival on treated animals. Molecular analysis revealed that LEV acts by stabilizing the astrocytes allowing an effective uptake of the excess glutamate from the extracellular space. Overall, our results demonstrate that Levetiracetam may be a promising drug for acute management of SCI.

Levetiracetam pharmacokinetics in critically ill patients undergoing renal replacement therapy

PURPOSE

To determine clearance of levetiracetam in patients requiring continuous renal replacement therapy (CRRT) or sustained low efficiency dialysis (SLED).

MATERIALS AND METHODS

Adult patients with acute kidney injury or end stage renal disease requiring either CRRT or SLED and levetiracetam were eligible for inclusion. Simultaneous arterial, venous, and effluent samples for analysis of levetiracetam concentrations were collected every two hours for up to 6-8 h. Levetiracetam clearance (CL) and half-life (t_1/2) were calculated for each modality.

RESULTS

Eight CRRT patients and 4 SLED patients completed the study: 67% male, mean age 50 ± 13 years, and 83% had AKI. Seven CRRT patients received continuous venovenous hemodiafiltration (CVVHDF) [median pre-replacement rate 700 mL/h (range 500-1000), post-replacement rate 500 mL/h (range 200-1000), effluent rate 2500 mL/h (range 1700-3650) and delivered CRRT dose 27 mL/kg/h (range 19-54)] and one patient received CVV hemofiltration (CVVH). The mm mean levetiracetam CL during CVVHDF was 31.2 ± 8.5 mL/min, and the and the mean t_1/2 was 10.4 ± 2.2 h. For the patient requiring CVVH, clearance and t_1/2 were 22.5 mL/min and 9.5 h, respectively. Mean levetiracetam CL during SLED performed at a blood flow rate of 250 mL/min and a dialysate flow rate of 100 mL/min was 74.0 ± 25.3 mL/min and t_1/2 was 4.8 ± 2.3 h.

CONCLUSIONS

Levetiracetam clearance was substantial with both modalities under the operating conditions reported. There is the potential for subtherapeutic concentrations with current recommended dosing strategies that account only for kidney function and not these extracorporeal routes of elimination.

Prophylactic levetiracetam-induced pancytopenia with traumatic extra-dural hematoma: Case report

BACKGROUND

Pancytopenia has only rarely been reported with Levetiracetam use. It is a potentially life threatening adverse effect that requires cessation of therapy.

CASE DESCRIPTION

We describe a case of an otherwise well thirty-two-year-old man who underwent an emergent craniotomy for evacuation of a traumatic extra-dural haematoma. Post-operatively, he developed pancytopenia which corrected with cessation of levetiracetam.

CONCLUSION

This report aims to increase awareness of this rare side effect and reiterates the judicious use of prophylactic levetiracetam in brain trauma.

Levetiracetam Induced Behavioral Abnormalities in a Patient with Seizure Disorder: A Diagnostic Challenge

Levetiracetam is a second-generation antiepileptic drug that is chemically unrelated to other antiepileptic drugs. Levetiracetam is a broad-spectrum antiseizure medication that is approved as an adjunctive therapy in the treatment of partial and generalized tonic-clonic seizures in children and adults with epilepsy. The mechanism by which Levetiracetam induces behavioral changes remains unknown. Its proposed mechanism of action involves binding to synaptic vesicle protein 2A (SV2A) and this leads to neuronal inhibition. Though, the drug has a convenient dosing regimen and is relatively well tolerated, neuropsychiatric side effects can emerge beyond the initial titration period and may be the most common reason for drug discontinuation. Levetiracetam has been reported to cause varying degrees of psychiatric adverse effects including behavioral disturbance such as agitation, hostility and psychosis, and mood symptoms and suicidality. It has been shown to induce psychiatric side effects in 13.3% of adults, with only 0.7% presenting with severe symptoms such as depression, agitation, or hostility. The prevalence rate of development of psychosis in these patients is estimated to be about 1.4%. A review of literature has demonstrated a relative correlation between Levetiracetam use and the development of neurobehavioral symptoms which is increased in predisposed individuals. This research describes the case of a 28-year-old woman with seizure disorder and a psychiatric history of schizoaffective disorder who developed aggressive behavior, paranoia, and severe hostility following administration of Levetiracetam 750 mg orally twice daily. She developed acute behavioral symptoms which were reversed with cessation of Levetiracetam. This report emphasizes the need for developing an appropriately high index of suspicion in promoting surveillance and prompt identification of behavioral adverse effects associated with Levetiracetam especially in high-risk patient population.

Sodium valproate combined with levetiracetam in pediatric epilepsy and its influence on NSE, IL-6, hs-CRP and electroencephalogram improvement

Efficacy of sodium valproate combined with levetiracetam (LEV) in pediatric epilepsy and its influence on neuron-specific enolase (NSE), interleukin-6 (IL-6) and high-sensitivity C-reactive protein (hs-CRP) as well as electroencephalogram (EEG) improvement were studied. Patients (n=100) with pediatric epilepsy admitted to and treated in Xiantao First People's Hospital Affiliated to Yangtze University from December 2015 to 2018 were enrolled in this study and randomly divided into observation group (n=50) and control group (n=50). Sodium valproate was administered in the control group, and the treatment with LEV was combined with sodium valproate in the observation group. After 12 weeks the cognitive function of patients was assessed using the Mini-Mental State Examination (MMSE) scale, Montreal cognitive assessment (MoCA) scale and Wechsler Memory Scale-Revised in China (WMS-RC). The quality of life (QOL) of patients was evaluated with the QOL in epilepsy-31 inventory (QOLIE-31) scale and Barthel Index, and blood was drawn from the patients to detect the neurological function indicators [NSE and glial fibrillary acidic protein (GFAP)] and inflammatory indicators (IL-6, IL-2 and hs-CRP). After treatment, the incidence rates of adverse reactions notably declined in the observation group (P<0.05), and the improvement in the cognitive function in the observation group were both superior to those in the control group (P<0.05). Observation group had lowered content of NSE, GFAP, IL-6, hs-CRP and IL-2 (P<0.05), and α wave was markedly decreased, but θ and δ waves were notably increased in the observation group (P<0.05). In the treatment of pediatric epilepsy, sodium valproate combined with LEV produces better efficacy, fewer adverse reactions, significantly improves patients' QOL and notably lowers the content of NSE, IL-6 and hs-CRP with notable EEG improvement, so it is a safe and reliable treatment that is worth popularization.

Levetiracetam induction of theta frequency oscillations in rodent hippocampus in vitro

Levetiracetam (LEV) has been demonstrated to improve cognitive function. Hippocampal theta rhythm (4-12 Hz) is associated with a variety of cognitively related behaviors, such as exploration in both humans and animal models. We investigated the effects of LEV on the theta rhythm in the rat hippocampal CA3 in hippocampal slices in vitro. We found that LEV increased the theta power in a dose-dependent manner. The increase in theta power can be blocked by GABA_A receptor (GABA_AR) or NMDA receptor (NMDAR) antagonists but not by AMPA receptor antagonist, indicating the involvement of GABA_AR and NMDAR in the induction of theta activity. Interestingly, LEV enhancement of theta power can be also blocked by taurine or GABA-A agonist THIP, indicating that LEV induction of theta may be related to the indirect boosting of GABA action via reduction of extrasynaptic GABA_AR activation. Furthermore, the increased theta power can be partially reduced by the mACh receptor (mAChR) antagonist atropine but not by nACh receptor antagonists, suggesting that mAChR activation provides excitatory input into local network responsible for LEV-induced theta. Our study demonstrated that LEV induced a novel theta oscillation in vitro, which may have implications in the treatment of the neuronal disorders with impaired theta oscillation and cognitive function.

Seizure Prophylaxis in Traumatic Brain Injury: A Comparative Study of Levetiracetam and Phenytoin Cerebrospinal Fluid Levels in Trauma Patients with Signs of Increased Intracranial Pressure Requiring Ventriculostomy

Background

One of the most common life-threatening injuries to trauma patients arriving in the emergency department (ED) is traumatic brain injury (TBI). Traditionally, intravenous medications have been given as seizure prophylaxis in patients demonstrating signs of increased intracranial pressure (ICP), as post-traumatic seizures in trauma patients are associated with higher morbidity and mortality. Medications traditionally given for this indication such as phenytoin have been established to reach therapeutic levels in the cerebrospinal fluid (CSF) quickly and are effective in preventing post-traumatic seizures but often have a large side-effect profile. A newer medication that is being used for seizure prophylaxis in patients with epilepsy is levetiracetam. Levetiracetam typically has a better side effect profile, but it has not been demonstrated that the drug reaches therapeutic levels in the CSF as quickly as phenytoin. Studies have shown levetiracetam and phenytoin to be equivocal in the prevention of post-TBI seizure prophylaxis.

Methods

This was a prospective, randomized, case-control study at a Level II trauma center of adult patients (age >/= 18 years) who suffered severe TBI (sTBI) requiring the placement of an external ventricular drain (EVD) from May 2017 to June 2018. Twelve patients were randomly placed into one of two groups for the administration of antiepileptic medication (either levetiracetam or phenytoin), allowing for the subsequent serial collection of CSF for the analysis of therapeutic levels of antiepileptic medications. Levetiracetam or phenytoin was administered at standardized fixed doses per our neurosurgical center standard protocol. CSF was collected before either drug was administered, 60 minutes after completion of administration and 360 minutes after completion of drug administration. Data analysis was performed to compare the time frame for which therapeutic levels of the medications were achieved in the CSF. The published steady-state and therapeutic CSF level of levetiracetam is 32 mcg/ml and phenytoin is 2 mcg/ml.

Results

A trend was observed in which the closer the fixed dosage approximated the weight-based dosing of phenytoin, the more their CSF phenytoin level increased (and approximated the therapeutic range) with an associated R-squared value of 0.6274. This trend was not found in patients receiving levetiracetam.

Conclusions

Levetiracetam does not reach levels needed for seizure prophylaxis in human CSF when loaded at standard dosing regimens in the acute setting. Phenytoin does reach levels needed for seizure prophylaxis in human CSF with standardized regimen dosing when dosages approximate weight-based dosing. If needed, in the acute setting phenytoin should have additional doses given prior to six hours after the loading dose to achieve therapeutic CSF levels. 

Levetiracetam and brivaracetam: a review of evidence from clinical trials and clinical experience

Until the early 1990s, a limited number of antiepileptic drugs (AEDs) were available. Since then, a large variety of new AEDs have been developed and introduced, several of them offering new modes of action. One of these new AED families is described and reviewed in this article. Levetiracetam (LEV) and brivaracetam (BRV) are pyrrolidone derivate compounds binding at the presynaptic SV2A receptor site and are thus representative of AEDs with a unique mode of action. LEV was extensively investigated in randomized controlled trials and has a very promising efficacy both in focal and generalized epilepsies. Its pharmacokinetic profile is favorable and LEV does not undergo clinically relevant interactions. Adverse reactions comprise mainly asthenia, somnolence, and behavioral symptoms. It has now been established as a first-line antiepileptic drug. BRV has been recently introduced as an adjunct antiepileptic drug in focal epilepsy with a similarly promising pharmacokinetic profile and possibly increased tolerability concerning psychiatric adverse events. This review summarizes the essential preclinical and clinical data of LEV and BRV that is currently available and includes the experiences at a large tertiary referral epilepsy center.

Neuroprotective effect of levetiracetam in mouse diabetic retinopathy: Effect on glucose transporter-1 and GAP43 expression

AIMS

Retinopathy is a neurodegenerative complication associating diabetes mellitus. Diabetic retinopathy (DR) is the primary reason of visual loss during early adulthood. DR has a complicated multifactorial pathophysiology initiated by hyperglycaemia-induced ischaemic neurodegenerative retinal changes, followed by vision-threatening consequences. The main therapeutic modalities for DR involve invasive delivery of intravitreal antiangiogenic agents as well as surgical interventions. The current work aimed to explore the potential anti-inflammatory and retinal neuroprotective effects of levetiracetam.

MAIN METHODS

This study was performed on alloxan-induced diabetes in mice (n: 21). After 10 weeks, a group of diabetic animals (n: 7) was treated with levetiracetam (25 mg/kg) for six weeks. Retinal tissues were dissected and paraffin-fixed for examination using (1) morphometric analysis with haematoxylin and eosin (HE), (2) immunohistochemistry (GLUT1, GFAP and GAP43), and (3) RT-PCR-detected expression of retinal inflammatory and apoptotic mediators (TNF-α, IL6, iNOS, NF-κB and Tp53).

KEY FINDINGS

Diabetic mice developed disorganized and debilitated retinal layers with upregulation of the gliosis marker GFAP and downregulation of the neuronal plasticity marker GAP43. Additionally, diabetic retinae showed increased transcription of NF-κB, TNF-α, IL6, iNOS and Tp53. Levetiracetam-treated mice showed downregulation of retinal GLUT1 with relief and regression of retinal inflammation and improved retinal structural organization.

SIGNIFICANCE

Levetiracetam may represent a potential neuroprotective agent in DR. The data presented herein supported an anti-inflammatory role of levetiracetam. However, further clinical studies may be warranted to confirm the effectiveness and safety of levetiracetam in DR patients.

A meta-analysis of levetiracetam for randomized placebo-controlled trials in patients with refractory epilepsy

OBJECTIVE

The objective of this study was to investigate the efficacy and safety profile of levetiracetam as add-on therapy in patients with refractory epilepsy.

METHODS

Web of Science, MEDLINE (Ovid and PubMed), Cochrane Library, EMBASE, and Google Scholar were systematically searched to identify potential eligible randomized controlled trials by two reviewers independently. Pooled estimates of risk ratios (RRs) for 50%, 75%, and 100% reduction from baseline were calculated using the fixed-effect model or random-effect model. Quality of included studies was assessed with the Cochrane Collaboration's Risk of Bias tool. Serious adverse events and withdrawals induced by interventions and the most common side effects were analyzed.

RESULTS

Seventeen trials with a total of 3,205 participants were included in this meta-analysis, including 14 trials for adulthood and three trials for children. Pooled estimates suggested that levetiracetam was an effective anti-epileptic drug at 1,000-3,000 mg/day (RR =2.00 for 1,000 mg/day, RR =2.68 for 2,000 mg/day, RR =2.18 for 3,000 mg/day) for adults and 60 mg/kg/day (RR =2.00) for children compared to placebo in terms of 50% reduction from baseline. Likewise, as for seizure freedom rate, levetiracetam had an advantage over placebo at 1,000-3,000 mg/day (RR =5.84 for 1,000 mg/day, RR =4.55 for 2,000 mg/day, RR =4.57 for 3,000 mg/day, respectively) for adults and 60 mg/kg/day (RR =4.52) for children. Regarding safety profile, patients treated with levetiracetam had significantly higher occurrence than placebo for somnolence, asthenia, dizziness, infection, nasopharyngitis, anxiety, and irritability; however, most studies reported that these adverse events were mild and transient.

CONCLUSION

Levetiracetam is an effective anti-epileptic drug for both adults and children with generalized or partial-onset refractory seizures at 1,000-3,000 or 60 mg/kg/day, with a favorable adverse event profile.

Effects of levetiracetam on astroglial release of kynurenine-pathway metabolites

BACKGROUND AND PURPOSE

Several preclinical studies have demonstrated the unique profiles of levetiracetam (LEV), inhibits spontaneous absence epilepsy models but does not affect traditional convulsion models; however, the detailed pharmacological mechanisms of action of LEV remain to be clarified.

EXPERIMENTAL APPROACH

We determined the interaction between LEV and IFNγ regarding astroglial release of anti-convulsive (kynurenic acid and xanthurenic acid), pro-convulsive (quinolinic acid) and anti-convulsive but pro-absence (cinnabarinic acid) kynurenine-pathway metabolites from rat cortical primary cultured astrocytes using ultra-HPLC equipped with MS.

KEY RESULTS

IFNγ increased basal astroglial release of cinnabarinic acid and quinolinic acid but decreased that of kynurenic acid and xanthurenic acid. IFNγ enhanced inositol 1,4,5-trisphosphate (IP₃ ) receptor agonist (adenophostin A, AdA)-induced astroglial release of kynurenine-pathway metabolites, without affecting AMPA-induced release. LEV increased basal astroglial release of kynurenic acid and xanthurenic acid without affecting cinnabarinic acid or quinolinic acid. Chronic and acute LEV administration inhibited AMPA- and AdA-induced kynurenine-pathway metabolite release. Upon chronic administration, LEV enhanced stimulatory effects of IFNγ on kynurenic acid and xanthurenic acid, and reduced its stimulatory effects on cinnabarinic acid and quinolinic acid. Furthermore, LEV inhibited stimulatory effects of chronic IFNγ on AdA-induced release of kynurenine-pathway metabolites.

CONCLUSIONS AND IMPLICATIONS

This study demonstrated several mechanisms of LEV: (i) inhibition of AMPA- and AdA-induced astroglial release, (ii) inhibition of IFNγ-induced IP₃ receptor activation and (iii) inhibition of release of cinnabarinic acid and quinolinic acid with activation of that of kynurenic acid induced by IFNγ. These combined actions of LEV may contribute to its unique profile.

HLA-A*11:01 is associated with levetiracetam-induced psychiatric adverse events

Levetiracetam (LEV) is effective for focal and generalized epilepsy and is used worldwide because of its relatively few drug interactions and favorable tolerability. However, some psychiatric adverse events (PAEs) have been reported, resulting in drug withdrawal. The pathophysiology of LEV-induced PAE has not yet been elucidated. In this study, we investigated the relationship between PAEs and human leukocyte antigen (HLA) genes. Eleven epilepsy patients, who developed PAEs after the administration of LEV and spontaneously improved after drug withdrawal, were enrolled retrospectively. Genomic DNA from the peripheral blood was extracted, and four-digit allele genotyping of HLA genes was performed. The genotype frequencies of HLA genes were compared to those of 80 patients in which LEV was well tolerated, as well as to 485 individuals from the general Korean population. The frequency of the HLA-A*1101 allele was significantly higher in the LEV-induced PAEs group compared to both the LEV-tolerant group (p = 0.021, OR 4.80, 95% CI 1.30-17.74) and the general Korean population (p = 0.015, OR 4.62, 95% CI 1.38-15.45). This study is the first attempt at investigating the relationship between the HLA system and LEV-induced PAE. The results of this study suggest that the HLA-A*1101 allele could be a risk factor for the development of PAEs.

Newer Antiepileptic Drugs for Status Epilepticus in Adults: What's the Evidence?

Status epilepticus (SE) is one of the most frequent neurological emergencies. Despite this, understanding of its pathophysiology and evidence regarding its management is limited. Rapid, effective, and well-tolerated treatment to achieve seizure cessation is advocated to prevent brain damage or potentially lethal outcomes. The last two decades have witnessed an exponential increase in the number of available antiepileptic drugs (AEDs). These compounds, especially lacosamide and levetiracetam, in view of their intravenous formulation, have been increasingly prescribed in SE. These and other newer AEDs present a promising profile in terms of tolerability, with few centrally depressive effects, favorable pharmacokinetic properties, and fewer drug interactions than classical AEDs; conversely, they are more expensive. There is still no clear evidence to suggest a specific beneficial impact of newer AEDs on SE outcome, preventing any strong recommendation regarding their prescription in SE. Further comparative studies are urgently required to clarify their place and optimal use in the armamentarium of SE treatment.

B cell aplasia and hypogammaglobulinemia associated with levetiracetam

Levetiracetam (LEV) is a second-generation antiepileptic drug approved for the treatment of several types of epilepsy. We report a 45-year-old female who developed hypogammaglobulinemia and B cell aplasia during LEV treatment. The Naranjo probability score for an adverse drug reaction was 6. After LEV discontinuation, the number of B cells gradually increased and reached normal levels within two months. This case suggests that monitoring of immunoglobulin levels and lymphocyte subsets analysis is important in patients treated with LEV, especially in cases of prolonged infections.

SIMILAR CASES PUBLISHED

1.

A meta-analysis of randomized controlled trials on levetiracetam in the treatment of pediatric patients with epilepsy

OBJECTIVE

To evaluate clinical efficacy, safety, and tolerability of levetiracetam as mono- or adjunctive therapy in the treatment of children and adolescents with epilepsy.

MATERIALS AND METHODS

We performed a meta-analysis of randomized controlled trials published from January 2007 to December 2016 in the databases Web of Science, Medline, Embase, Cochrane Library, and PubMed, Bing, Baidu, Google Scholar, Chinese National Knowledge Infrastructure (CNKI), and Wanfang Data. All of the studies eligible were compared for the efficacy, safety, and tolerability of levetiracetam with other antiepileptic drugs (AEDs) in epilepsy.

RESULTS

Thirteen randomized controlled trials on a total of 1,013 patients met the inclusion criteria in present study. Compared with other AEDs (oxcarbazepine, valproate, sulthiame, carbamazepine, and placebo), we found that levetiracetam had a comparable seizure-free rate (RR 1.16, 95% CI 1.03-1.31; P=0.30). Regarding seizure-frequency reduction ≥50% from baseline, levetiracetam also seemed equivalent to other AEDs (RR 1.08, 95% CI 1.01-1.16; P=0.35). In spite of patients treated with levetiracetam having a lower incidence of side effects compared with patients treated with other AEDs (RR 0.90, 95% CI 0.77-1.06), the difference between them was minute and not statistically significant (P=0.22).

CONCLUSION

Based on this meta-analysis, it seemed that levetiracetam had comparable effects concerning efficacy, tolerability, and adverse events. Nevertheless, 13 studies were insufficient to draw a conclusion that levetiracetam is effective as mono- and adjunctive therapy for all types of epilepsy syndromes and seizures. Larger-sample and more well-designed trials are needed to justify the widespread use of levetiracetam in the treatment of children and adolescents.

A Systematic Appraisal of Neurosurgical Seizure Prophylaxis: Guidance for Critical Care Management

Clinical decisions are often made in the presence of some uncertainty. Health care should be based on a combination of scientific evidence, clinical experience, economics, patient value judgments, and preferences. Seizures are not uncommon following brain injury, surgical trauma, hemorrhage, altered brain metabolism, hypoxia, or ischemic events. The impact of seizures in the immediate aftermath of injury may be a prolonged intensive care stay or compounding of the primary injury. The aim of brain injury management is to limit the consequences of the secondary damage. The original intention of seizure prophylaxis was to limit the incidence of early-onset seizures. However, clinical trials have been equivocal on this point, and there is concern about the adverse effects of antiepileptic drug therapy. This review of the literature raises concerns regarding the arbitrary division of seizures into early onset (7 d) and late onset (8 d and beyond). In many cases it would appear that seizures present within 24 hours of the injury or after 7 days, which would be outside of the scope of current seizure prophylaxis guidance. There also does not appear to be a pathophysiological reason to divide brain injury-related seizures into these timeframes. Therefore, a solution to the conundrum is to reevaluate current practice. Prophylaxis could be offered to those receiving intensive care for the primary brain injury, where the impact of seizure would be detrimental to the management of the brain injury, or other clinical judgments where prophylaxis is prudent. Neurosurgical seizure management can then focus attention on which agent has the best adverse effect profile and the duration of therapy. The evidence seems to support levetiracetam as the most appropriate agent. Although previous reviews have identified an increase cost associated with the use of levetiracetam, current cost comparisons with phenytoin demonstrate a marginal price differential. The aim of this review is to assimilate the applicable literature regarding seizure prophylaxis. The final guidance is a forum upon which further clinical research could evaluate a new seizure prophylaxis paradigm.

Levetiracetam-induced leukocytoclastic vasculitis

Drug-induced leukocytoclastic vasculitis is a small-vessel vasculitis that most commonly manifests with palpable purpuric lesions on gravity-dependent areas. Vasculitis occurs within weeks after initial administration of medication and demonstrates clearance upon withdrawal of medication. Levetiracetam, a pyrrolidone derivative, is used as an adjunctive therapy in patients with refractory focal epilepsy, myoclonic epilepsy, and primary generalized tonic–clonic seizures. We present a case of a 14-year-old female, who developed cutaneous small-vessel vasculitis within 8 days of initiation of levetiracetam. Vasculitis was successfully managed by discontinuation of medication and systemic corticosteroids. This adverse reaction, to the best of our knowledge, has not been previously reported in literature.

Levetiracetam Versus Phenytoin for Seizure Prophylaxis Following Traumatic Brain Injury: A Systematic Review and Meta-Analysis

BACKGROUND

Seizure following traumatic brain injury (TBI) constitutes a common complication that requires effective prevention to improve the outcome of TBI. Phenytoin has been the only recommended antiepileptic drug (AED) for seizure prophylaxis; however, several shortcomings have affected its use. Intravenous levetiracetam has been available since 2006 and has been increasingly accepted as a seizure prophylaxis for brain injury, mainly due to its favorable pharmacokinetic features and minimal adverse events profile. However, the efficacy and safety of levetiracetam versus phenytoin for seizure prophylaxis following TBI are not well clarified.

OBJECTIVE

The aim of this study was to assess the efficacy and safety of levetiracetam versus phenytoin for seizure prophylaxis following TBI.

METHODS

We conducted a search of the MEDLINE, EMBASE, and Cochrane library databases to March 2016, and screened original research that included patients with TBI who received levetiracetam. We included randomized controlled trials (RCTs) or controlled observational cohort studies that compared levetiracetam and phenytoin, as well as uncontrolled case series regarding prophylactic levetiracetam following TBI. The outcomes included early or late seizure prophylaxis and safety. The estimates of seizure prophylaxis were pooled using a meta-analysis, and the estimates for the case series were pooled using descriptive statistics.

RESULTS

A total of 1614 patients from 11 studies were included in this review, of whom 1285 patients from eight controlled studies (one RCT and seven cohort studies) were included in the meta-analysis. Levetiracetam was not superior to phenytoin with regard to early seizure prophylaxis (risk ratio [RR] 1.10, 95 % confidence interval [CI] 0.64-1.88); the estimate of early seizure incidence was 0.05 (95 % CI 0.02-0.08). Three studies that assessed late seizure did not indicate the superiority of levetiracetam to phenytoin. There were no differences in mortality during hospitalization or after 6 months, or in the number of patients with adverse reactions between levetiracetam and phenytoin.

CONCLUSIONS

Levetiracetam does not appear to be superior to phenytoin in efficacy or safety with regard to early or late seizure prophylaxis following TBI; however, no class I evidence was identified. Additional evidence from high-quality studies is required.

Abbreviated levetiracetam treatment effects on behavioural and histological outcomes after experimental TBI

OBJECTIVE

Long-term prophylactic treatment with levetiracetam (LEV) has multiple neuroprotective effects in a traumatic brain injury (TBI) rat model. Although a rational time-frame of seizure prophylactic treatment with LEV for after TBI is not well established, clinical prophylaxis with LEV often includes treatment duration similar to clinical treatment guidelines with Phenytoin. Thus, this study investigated the effects of abbreviated LEV treatment on behavioural function and histological evidence of neuroprotection.

RESEARCH DESIGN

Pre-clinical trial of abbreviated LEV dosing in an experimental model of TBI Methods: After either controlled cortical impact (CCI) injury or sham surgery, rats received three 50 mg kg(-1) doses over 24 hours or vehicle. After injury/sham surgery, beam performance, spatial learning, contusion volume size and hippocampal neuron survival were assessed.

RESULTS

Abbreviated LEV did not improve motor or cognitive performance after TBI. Further, abbreviated LEV did not improve hippocampal neuron sparing or contusion volumes compared with vehicle controls.

CONCLUSIONS

Together with previous work assessing daily LEV treatment, these results suggest that longer-term therapy may be required to confer beneficial effects within these domains. These findings may guide (1) future experimental studies assessing minimal effective dosing for neuroprotection and anti-epileptogenesis and (2) treatment guideline updates for seizure prophylaxis post-TBI.

Levetiracetam-induced pancytopenia

Pancytopenia is a rare side effect of levetiracetam (LEV) that is associated with severe morbidity that requires hospitalization. Here, we report a patient with a right temporoparietal tumor who underwent a temporal craniotomy with resection of the mass and was started on LEV for seizure prophylaxis per the neurosurgery local protocol. The patient developed LEV-induced pancytopenia, which was successfully managed by discontinuation of this medication. Our report aims to increase awareness of this rare cause of pancytopenia among clinicians.

Retention rates of levetiraceram in Chinese children and adolescents with epilepsy

BACKGROUND

Levetiracetam (Lev) is a new antiepileptic drugs, proved to be effective and tolerance in regulatory trials, but these controlled trials do not always predict how useful a drug will be in day to day clinical practice, Retention rates can provide a better indication of efficacy and tolerability in everyday use.

METHODS

Totally 124 patients with more than 3 months disease course were enrolled in the study from June 2007 to December 2007. The LEV dose ranged from 10 to 60 mg/kg per day. Follow up visit were performed at 6 months, 12 months, 24 months and 36 months, and treatment effects, adverse effects were recorded.

RESULTS

The LEV retention rates at 6, 12, 24, and 36 months were 93.5% (116/124), 84.7% (105/124), 65.3% (81/124), and 58.9% (73/124), respectively. The predominant causes of withdrawal were lack of efficacy (62.7%) and serious adverse effects (17.6%). In addition, 48.6% (51/105), 60.5% (49/81) and 72.6% (53/73) patients were seizure-free for 12 months, 24 months and 36 months, respectively. In this study, 75 (60.5%) patients experienced at least one side effect. The most common side effects observed were irritability 38.7% (29/75), somnolence 17.3% (13/75), learning disability 16.0% (12/75), anorexia 17.3% (13/75), somnipathy 13.3% (10/75), and abnormal behavior 13.3% (10/75).

CONCLUSIONS

Our study revealed the high retention rate of LEV in Chinese children and adolescents with epilepsy.

Levetiracetam ameliorates ovarian function in streptozotocin-induced diabetic rats

Diabetes mellitus can adversely affect gonadal function. In the present study, we aimed to investigate the protective effects and mechanism of action of levetiracetam (LEV) on the ovaries in a streptozotocin (STZ)-induced diabetes model in rats. Twenty-one adult female rats were assigned to three groups as control, diabetes group treated with 1 mL/kg/d saline (STZ + SP) and diabetes group treated with 600 mg/kg/d LEV (STZ + LEV). Following 4 weeks treatment, blood samples were collected for biochemical analysis and ovariectomy was performed for histopathological examination. Plasma anti-Mullerian hormone (AMH), glutathione and total anti-oxidant capacity values were significantly lower whereas lipid peroxides and transforming growth factor-β (TGF-β) values were significantly higher in STZ + SP group compared to control. LEV treatment successfully decreased lipid peroxidation and TGF-β levels, and also increased anti-oxidant parameters and AMH levels in diabetic rats. Saline-treated rats significantly displayed ovarian degeneration and decreased counts of follicles. However, treatment of diabetic rats with LEV effectively prevented the degenerative changes and follicle loss. Also, LEV suppressed ovarian nuclear factor-kappa B (NF-kB) immunoexpression in diabetic rats. Taken together, we propose that LEV can ameliorate the adverse effects of diabetes on ovarian function via decreasing NF-kB expression and oxidative stress and increasing anti-oxidant status in rats.

An 11-year review of levetiracetam ingestions in children less than 6 years of age

BACKGROUND

Levetiracetam is a new anticonvulsant, which works to block high-voltage-activated Ca(++) channels in children, for partial-onset seizures. Reports of clinical experience with pediatric ingestions are minimal. The purpose of this study was to characterize the toxicity of accidental levetiracetam exposures in children less than 6 years of age.

METHODS

This was an 11-year retrospective observational case series of pediatric (< 6 years old) levetiracetam ingestions reported to a Poison Control System from 2002 to 2013. Case narratives were individually reviewed to collect desired information on exposure and clinical course. Inclusion criteria were levetiracetam as a single ingested medication, age less than 6 years, treatment in a health care facility, and followed to a known outcome.

RESULTS

Eighty-two cases met inclusion criteria with 55% female patients and overall median age of 2.0 years (range: 1-60 months). The levetiracetam dose ingested was reported in 69 (84.1%) cases, with exact dose (median dose, 45.0 mg/kg; range, 10.5-1429 mg/kg) reported in 33 cases (40.2%). Of these, twenty-nine cases (88%) involved the oral solution formulation and 28 cases (85%) had unintentional therapeutic error as the cause of the exposure. No dose-response relationship was demonstrated; however, the odds of a levetiracetam-naive patient, (median dose, 26.9 mg/kg; N = 15) with an unintentional exposure, developing drowsiness or ataxia was 6 times that of a patient who was not naïve to levetiracetam (median dose, 70.1 mg/kg; N = 20) (Odds ratio [OR], 6.0; 95% confidence interval [CI], 1.03-35.91).Of the 82 cases, 17 (20.7%) developed untoward clinical effects of drowsiness and/or ataxia. Eighty patients (97.6%) were treated and discharged from the emergency department, and two patients (2.4%) were admitted. The two patients admitted included a two-month old who was accidentally given a dose 10 times that of her usual dose and a 3-year old who was lethargic on arrival to the hospital after ingestion of an unknown dose. Of all patients, 66 patients (80.5%) had no effect from the drug exposure. The medical outcome was considered to be minor in 15 cases (18.3%), and moderate in 1 case (1.2%). There were no cases with major outcomes and no deaths.

CONCLUSIONS

Pediatric levetiracetam exposures were associated with few transient clinical effects. Poison Control Centers may wish to consider acuity of ingestion when developing send-in protocols.

Measurement of levetiracetam drug levels to assist with seizure control and monitoring of drug interactions with other anti-epileptic medications (AEMs)

PURPOSE

Levetiracetam (LEV) therapeutic range (20-40mg/L) and potential drug interactions were assessed in people with epilepsy (PWE).

METHOD

Fifty-two PWE had LEV and concomitant medications [carbamazepine (CBZ); valproate (VPA); lamotrigine (LTG)] blood levels measured and compared to seizure activity. Lacosamide (LCM) levels were unavailable. Adopted therapeutic ranges were: 20-40mg/L - LEV; 25-50μmol/L - total CBZ; 6-13μmol/L - free CBZ; 300-750μmol/L - total VPA; 30-75μmol/L - free VPA; and 40-60μmol/L - LTG. Seizure-freedom was assessed and patients followed for almost two years.

RESULTS

23 of 52 PWE (44%) used LEV monotherapy and 16/23 (70%) had 'therapeutic' LEV with 13/16 (81%) seizure-free. 29 of 52 (56%) used polytherapy and 16/29 (55%) had 'therapeutic' LEV with 7/16 (44%) seizure-free. 11 of 29 (38%) used CBZ: 4/11 (36%) had therapeutic mean LEV levels and 7/11 (64%) were seizure-free. Fourteen (48%) used VPA: 9/14 (64%) had therapeutic mean LEV levels and 8/14 (57%) were seizure-free. 13 of 29 (45%) used LTG: 8/13 (62%) had therapeutic mean LEV levels and 5/13 (38%) were seizure-free. LEV did not alter CBZ, but CBZ affected LEV. LEV elevated VPA free levels but not VPA total levels. Dosage/concentration was lowered with polytherapy.

CONCLUSION

LEV range (20-40mg/L) assisted epilepsy management and anti-epileptic medication interactions were suggested with polytherapy thus possibly explaining the impaired efficacy of LEV with polytherapy.

Anticonvulsant drugs and hematological disease

Many antiepileptic drugs (AEDs) are associated with hematological disorders that range from mild thrombocytopenia or neutropenia to anemia, red cell aplasia, until bone marrow failure. Fortunately, potentially fatal hematological disorders such as aplastic anemia are very rare. This review investigates hematological effects associated with classic and newer AEDs: a PubMed search indexed for MEDLINE was undertaken to identify studies in adults, children and animals using the name of all anticonvulsant drugs combined with the terms "hematological disease" and "hematological abnormalities" as key words. The most common hematological alterations occur with older AEDs than newer. Indeed, careful hematological monitoring is needed especially using carbamazepine, phenytoin and valproic acid. The pathogenetic mechanisms are still unknown: they seem to be related to an immunological mechanism, but drugs pharmacokinetics and pharmacodynamics interactions may also play an important role. Further research is needed to assess the real pathogenetic mechanism at the basis of hematological complications caused by AEDs.

Prospects of levetiracetam as a neuroprotective drug against status epilepticus, traumatic brain injury, and stroke

Levetiracetam (LEV) is an anti-epileptic drug commonly used for the treatment of partial onset and generalized seizures. In addition to its neuromodulatory and neuroinhibitory effects via its binding to the synaptic vesicle protein SV2A, multiple studies have suggested neuroprotective properties for LEV in both epileptic and non-epileptic conditions. The purpose of this review is to discuss the extent of LEV-mediated protection seen in different neurological conditions, the potential of LEV for easing epileptogenesis, and the possible mechanisms that underlie the protective properties of LEV. LEV has been found to be particularly beneficial for restraining seizures in animal models of spontaneous epilepsy, acute seizures, and status epilepticus (SE). However, its ability for easing epileptogenesis and cognitive dysfunction following SE remains controversial with some studies implying favorable outcomes and others reporting no beneficial effects. Efficacy of LEV as a neuroprotective drug against traumatic brain injury (TBI) has received much attention. While animal studies in TBI models have showed significant neuroprotection and improvements in motor and memory performance with LEV treatment, clinical studies suggest that LEV has similar efficacy as phenytoin in terms of its ability to prevent post-traumatic epilepsy. LEV treatment for TBI is also reported to have fewer adverse effects and monitoring considerations but electroencephalographic recordings suggest the presence of increased seizure tendency. Studies on stroke imply that LEV is a useful alternative to carbamazepine for preventing post-stroke seizures in terms of efficacy and safety. Thus, LEV treatment has promise for restraining SE-, TBI-, or stroke-induced chronic epilepsy. Nevertheless, additional studies are needed to ascertain the most apt dose, timing of intervention, and duration of treatment after the initial precipitating injury and the mechanisms underlying LEV-mediated beneficial effects.

Role of intravenous levetiracetam in seizure prophylaxis of severe traumatic brain injury patients

Traumatic brain injury (TBI) can cause seizures and the development of epilepsy. The incidence of seizures varies from 21% in patients with severe brain injuries to 50% in patients with war-related penetrating TBI. In the acute and sub-acute periods following injury, seizures can lead to increased intracranial pressure and cerebral edema, further complicating TBI management. Anticonvulsants can be used for seizure prophylaxis according to the current Parameters of Practice and Guidelines in a subset of severe TBI patients, and for a limited time window. Phenytoin is the most widely prescribed anticonvulsant in these patients. Intravenous levetiracetam, made available in 2006, is now being considered as a viable option in acute care settings if phenytoin is unavailable or not feasible due to side-effects. We discuss current data regarding the role of intravenous levetiracetam in seizure prophylaxis of severe TBI patients and the need for future studies.

Review of Levetiracetam as a First Line Treatment in Status Epilepticus in the Adult Patients - What Do We Know so Far?

With the advent of new antiepileptic drugs comes the potential for significant advances in the emergent management of status epilepticus. Traditional antiepileptic drugs possess side effect profiles that may limit their clinical utility or lead to increased patient morbidity or mortality. The relatively recent development of levetiracetam shows promise for effective control of acute status epilepticus in adults, but current objective data of its use as a first-line agent for control of status is quite limited. This paper serves to examine existing literature while considering levetiracetam as a first-line therapy in status in the adult patient population. Although existing studies are narrow in their scope, the present data lay a substantial foundation for further investigation of levetiracetam as a primary therapy in acute status epilepticus.

Regulators of synaptic transmission: roles in the pathogenesis and treatment of epilepsy

Synaptic transmission is the communication between a presynaptic and a postsynaptic neuron, and the subsequent processing of the signal. These processes are complex and highly regulated, reflecting their importance in normal brain functioning and homeostasis. Sustaining synaptic transmission depends on the continuing cycle of synaptic vesicle formation, release, and endocytosis, which requires proteins such as dynamin, syndapin, synapsin, and synaptic vesicle protein 2A. Synaptic transmission is regulated by diverse mechanisms, including presynaptic modulators of synaptic vesicle formation and release, postsynaptic receptors and signaling, and modulators of neurotransmission. Neurotransmitters released presynaptically can bind to their postsynaptic receptors, the inhibitory γ-aminobutyric acid (GABA)ergic receptors or the excitatory glutamate receptors. Once released, glutamate activates a variety of postsynaptic receptors including α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA), N-methyl-D-aspartate (NMDA), kainate, and metabotropic receptors. The activation of the receptors triggers downstream signaling cascades generating a vast array of effects, which can be modulated by a numerous auxiliary regulatory subunits. Moreover, different neuropeptides such as neuropeptide Y, brain-derived neurotrophic factor (BDNF), somatostatin, ghrelin, and galanin, act as regulators of diverse synaptic functions and along with the classic neurotransmitters. Abnormalities in the regulation of synaptic transmission play a critical role in the pathogenesis of numerous brain diseases, including epilepsy. This review focuses on the different mechanisms involved in the regulation of synaptic transmission, which may play a role in the pathogenesis of epilepsy: the presynaptic modulators of synaptic vesicle formation and release, postsynaptic receptors, and modulators of neurotransmission, including the mechanism by which drugs can modulate the frequency and severity of epileptic seizures.

Levetiracetam suppresses neuronal network dysfunction and reverses synaptic and cognitive deficits in an Alzheimer's disease model

In light of the rising prevalence of Alzheimer's disease (AD), new strategies to prevent, halt, and reverse this condition are needed urgently. Perturbations of brain network activity are observed in AD patients and in conditions that increase the risk of developing AD, suggesting that aberrant network activity might contribute to AD-related cognitive decline. Human amyloid precursor protein (hAPP) transgenic mice simulate key aspects of AD, including pathologically elevated levels of amyloid-β peptides in brain, aberrant neural network activity, remodeling of hippocampal circuits, synaptic deficits, and behavioral abnormalities. Whether these alterations are linked in a causal chain remains unknown. To explore whether hAPP/amyloid-β-induced aberrant network activity contributes to synaptic and cognitive deficits, we treated hAPP mice with different antiepileptic drugs. Among the drugs tested, only levetiracetam (LEV) effectively reduced abnormal spike activity detected by electroencephalography. Chronic treatment with LEV also reversed hippocampal remodeling, behavioral abnormalities, synaptic dysfunction, and deficits in learning and memory in hAPP mice. Our findings support the hypothesis that aberrant network activity contributes causally to synaptic and cognitive deficits in hAPP mice. LEV might also help ameliorate related abnormalities in people who have or are at risk for AD.

The synaptic vesicle glycoprotein 2A ligand levetiracetam inhibits presynaptic Ca2+ channels through an intracellular pathway

Levetiracetam (LEV) is a prominent antiepileptic drug that binds to neuronal synaptic vesicle glycoprotein 2A protein and has reported effects on ion channels, but with a poorly defined mechanism of action. We investigated inhibition of voltage-dependent Ca(2+) (Ca(V)) channels as a potential mechanism through which LEV exerts effects on neuronal activity. We used electrophysiological methods to investigate the effects of LEV on cholinergic synaptic transmission and Ca(V) channel activity in superior cervical ganglion neurons (SCGNs). In parallel, we investigated the effects of the inactive LEV R-enantiomer, (R)-α-ethyl-2-oxo-1-pyrrolidine acetamide (UCB L060). LEV but not UCB L060 (each at 100 μM) inhibited synaptic transmission between SCGNs in long-term culture in a time-dependent manner, significantly reducing excitatory postsynaptic potentials after a ≥30-min application. In isolated SCGNs, LEV pretreatment (≥1 h) but not short-term application (5 min) significantly inhibited whole-cell Ba(2+) current (I(Ba)) amplitude. In current-clamp recordings, LEV reduced the amplitude of the afterhyperpolarizing potential in a Ca(2+)-dependent manner but also increased the action potential latency in a Ca(2+)-independent manner, which suggests additional mechanisms associated with reduced excitability. Intracellular LEV application (4-5 min) caused rapid inhibition of I(Ba) amplitude, to an extent comparable to that seen with extracellular LEV pretreatment (≥1 h). Neither pretreatment nor intracellular application of UCB L060 produced any inhibitory effects on I(Ba) amplitude. These results identify a stereospecific intracellular pathway through which LEV inhibits presynaptic Ca(V) channels; resultant reductions in neuronal excitability are proposed to contribute to the anticonvulsant effects of LEV.

A double-blind, placebo-controlled trial assessing the efficacy of levetiracetam extended-release in very heavy drinking alcohol-dependent patients

BACKGROUND

Despite advances in the development of medications to treat alcohol dependence, few medications have been approved by the U.S. Food and Drug Administration. The use of certain anticonvulsant medications has demonstrated potential efficacy in treating alcohol dependence. Previous research suggests that the anticonvulsant levetiracetam may be beneficial in an alcohol-dependent population of very heavy drinkers.

METHODS

In this double-blind, randomized, placebo-controlled clinical trial, 130 alcohol-dependent patients who reported very heavy drinking were recruited across 5 clinical sites. Patients received either levetiracetam extended-release (XR) or placebo and a Brief Behavioral Compliance Enhancement Treatment intervention. Levetiracetam XR was titrated during the first 4 weeks to 2,000 mg/d. This target dose was maintained during weeks 5 through 14 and was tapered during weeks 15 and 16.

RESULTS

No significant differences were detected between the levetiracetam XR and placebo groups in either the primary outcomes (percent heavy drinking days and percent subjects with no heavy drinking days) or in other secondary drinking outcomes. Treatment groups did not differ on a number of nondrinking outcomes, including depression, anxiety, mood, and quality of life. The only difference observed was in alcohol-related consequences. The levetiracetam XR treatment group showed significantly fewer consequences than did the placebo group during the maintenance period (p = 0.02). Levetiracetam XR was well tolerated, with fatigue being the only significantly elevated adverse event, compared with placebo (53% vs. 24%, respectively; p = 0.001).

CONCLUSIONS

This multisite clinical trial showed no efficacy for levetiracetam XR compared with placebo in reducing alcohol consumption in heavy drinking alcohol-dependent patients.

Levetiracetam reverses synaptic deficits produced by overexpression of SV2A

Levetiracetam is an FDA-approved drug used to treat epilepsy and other disorders of the nervous system. Although it is known that levetiracetam binds the synaptic vesicle protein SV2A, how drug binding affects synaptic functioning remains unknown. Here we report that levetiracetam reverses the effects of excess SV2A in autaptic hippocampal neurons. Expression of an SV2A-EGFP fusion protein produced a ∼1.5-fold increase in synaptic levels of SV2, and resulted in reduced synaptic release probability. The overexpression phenotype parallels that seen in neurons from SV2 knockout mice, which experience severe seizures. Overexpression of SV2A also increased synaptic levels of the calcium-sensor protein synaptotagmin, an SV2-binding protein whose stability and trafficking are regulated by SV2. Treatment with levetiracetam rescued normal neurotransmission and restored normal levels of SV2 and synaptotagmin at the synapse. These results indicate that changes in SV2 expression in either direction impact neurotransmission, and suggest that levetiracetam may modulate SV2 protein interactions.