Levetiracetam for managing neurologic and psychiatric disorders

Semi-rational engineering of ω-transaminase for enhanced enzymatic activity to 2-ketobutyrate

Transaminases (EC 2.6.1.X, TAs) are important biocatalysts in the synthesis of chiral amines, and have significant value in the field of medicine. However, TAs suffer from low enzyme activity and poor catalytic efficiency in the synthesis of chiral amines or non-natural amino acids, which hinders their industrial applications. In this study, a novel TA derived from Paracoccus pantotrophus (ppTA) that was investigated in our previous study was employed with a semi-rational design strategy to improve its enzyme activity to 2-ketobutyrate. By using homology modeling and molecular docking, four surrounding sites in the substrate-binding S pocket were selected as potential mutational sites. Through alanine scanning and saturation mutagenesis, the optimal mutant V153A with significantly improved enzyme activity was finally obtained, which was 578 % higher than that of the wild-type ppTA (WT). Furthermore, the mutant enzyme ppTA-V153A also exhibited slightly improved temperature and pH stability compared to WT. Subsequently, the mutant was used to convert 2-ketobutyrate for the preparation of L-2-aminobutyric acid (L-ABA). The mutant can tolerate 300 mM 2-ketobutyrate with a conversion rate of 74 %, which lays a solid foundation for the preparation of chiral amines.

The relationship between psychiatric symptoms and the use of levetiracetam in people with epilepsy

Background: Mental health in people with epilepsy (PWE) is often overlooked, especially in developing countries.Purpose: Consequently, the current work had two objectives: (1) to estimate the burden of depression, anxiety, insomnia, and stress, and (2) to examine the association of these psychiatric/psychological symptoms with levetiracetam and other relevant clinical factors in a cohort of Jordanian PWE.Research Design: This is a cross-sectional study. The demographic and clinical data were recorded. Depression was measured by the Patient Health Questionnaire-9 (PHQ-9, Arabic-validated version) and anxiety by the General Anxiety Disorder-7 (GAD-7, Arabic-validated version). The insomnia severity index (ISI-A, Arabic version) was used to assess sleep quality, and the Perceived Stress Scale (PSS-A, Arabic version) was used to measure perceived stress.Study Sample: Data were analyzed from 280 patients, of which 178 (63.6%) received levetiracetam as monotherapy or as adjuvant.Results: Depression was reported in 150 (53.6%), anxiety in 110 (39.3%), insomnia in 131 (46.8%), and clinically significant stress in 211 (75.4%). At univariate analysis, levetiracetam was not associated with psychiatric symptoms. Multivariate logistic regression revealed that severe depressive symptoms were associated with family history (OR = 2.47, 95% CI = 1.42-4.33, P = .001) and seizure type (OR = 1.69, 95% CI = 1.01-2.80, P = .04), severe anxiety symptoms were associated with family history (OR = 1.90, 95% CI = 1.12-3.23, P = .01), severe insomnia was associated with seizure type (OR = 2.16, 95% CI = 1.33-3.5, P = .002) and severe stress was associated with marital status (OR = 2.37, 95% CI = 1.31-4.29, P = .004).Conclusions: The high psychological burden of PWE is a challenging issue that requires attention and prompt action to control its risk factors. Levetiracetam was not associated with psychiatric symptoms in this study.

Psychiatric adverse events in three phase III trials of eslicarbazepine acetate for focal seizures

OBJECTIVE

Eslicarbazepine acetate (ESL) is a once-daily (QD), oral anti-seizure medication for the treatment of focal (partial-onset) seizures. Here, we evaluate risk factors for the development of psychiatric treatment-emergent adverse events (TEAEs) in clinical trials of adjunctive ESL in adults with focal seizures.

METHODS

This post-hoc analysis evaluated data pooled from three Phase III, randomized, double-blind, placebo-controlled trials (BIA-2093-301, -302, -304). After an 8-week baseline period, patients were randomized equally to receive placebo, ESL 400 mg (not reported here), 800 mg, or 1200 mg QD (up to 2-week titration; 12-week maintenance; optional open-label extension [OLE]). Incidences of psychiatric TEAEs were evaluated according to three separate criteria: medical history of psychiatric disorders (yes/no); baseline use of psychotropic drugs (yes/no); Montgomery-Åsberg Depression Rating Scale (MADRS) score at baseline (0-6: normal; 7-19: mild depression; 20-34: moderate depression).

RESULTS

The analysis populations comprised 1251 patients for the controlled study period and 1137 patients for the 1-year OLE. Psychiatric TEAE incidence was similar between patients taking ESL and placebo in the controlled and OLE study periods and was not related to ESL dose. Psychiatric TEAEs generally occurred more frequently in patients with a medical history of psychiatric disorders, using psychotropic drugs, or with depressive symptoms than in those without a history, not using psychotropic drugs, or with no depressive symptoms. Depression and anxiety were the most frequently reported psychiatric TEAEs.

SIGNIFICANCE

Overall, in clinical trials of ESL in adults with focal seizures, incidences of psychiatric events were not statistically different between patients taking ESL and placebo, were not related to ESL dose, and generally occurred more frequently in patients with baseline psychiatric symptoms or a history of psychiatric disorders. Long-term exposure to ESL was not associated with a marked increase in the incidence of psychiatric TEAEs.

Levetiracetam Mechanisms of Action: From Molecules to Systems

Epilepsy is a chronic disease that affects millions of people worldwide. Antiepileptic drugs (AEDs) are used to control seizures. Even though parts of their mechanisms of action are known, there are still components that need to be studied. Therefore, the search for novel drugs, new molecular targets, and a better understanding of the mechanisms of action of existing drugs is still crucial. Levetiracetam (LEV) is an AED that has been shown to be effective in seizure control and is well-tolerable, with a novel mechanism of action through an interaction with the synaptic vesicle protein 2A (SV2A). Moreover, LEV has other molecular targets that involve calcium homeostasis, the GABAergic system, and AMPA receptors among others, that might be integrated into a single mechanism of action that could explain the antiepileptogenic, anti-inflammatory, neuroprotective, and antioxidant properties of LEV. This puts it as a possible multitarget drug with clinical applications other than for epilepsy. According to the above, the objective of this work was to carry out a comprehensive and integrative review of LEV in relation to its clinical uses, structural properties, therapeutical targets, and different molecular, genetic, and systemic action mechanisms in order to consider LEV as a candidate for drug repurposing.

Reactive metabolites of the anticonvulsant drugs and approaches to minimize the adverse drug reaction

Several generations of antiepileptic drugs (AEDs) are available in the market for the treatment of seizures, but these are amalgamated with acute to chronic side effects. The most common side effects of AEDs are dose-related, but some are idiosyncratic adverse drug reactions (ADRs) that transpire due to the formation of reactive metabolite (RM) after the bioactivation process. Because of the adverse reactions patients usually discontinue the medication in between the treatment. The AEDs such as valproic acid, lamotrigine, phenytoin etc., can be categorized under such types because they form the RM which may prevail with life-threatening adverse effects or immune-mediated reactions. Hepatotoxicity, teratogenicity, cutaneous hypersensitivity, dizziness, addiction, serum sickness reaction, renal calculi, metabolic acidosis are associated with the metabolites of drugs such as arene oxide, N-desmethyldiazepam, 2-(1-hydroxyethyl)-2-methylsuccinimide, 2-(sulphamoy1acetyl)-phenol, E-2-en-VPA and 4-en-VPA and carbamazepine-10,11-epoxide, etc. The major toxicities are associated with the moieties that are either capable of forming RM or the functional groups may itself be too reactive prior to the metabolism. These functional groups or fragment structures are typically known as structural alerts or toxicophores. Therefore, minimizing the bioactivation potential of lead structures in the early phases of drug discovery by a modification to low-risk drug molecules is a priority for the pharmaceutical companies. Additionally, excellent potency and pharmacokinetic (PK) behaviour help in ensuring that appropriate (low dose) candidate drugs progress into the development phase. The current review discusses about RMs in the anticonvulsant drugs along with their mechanism vis-a-vis research efforts that have been taken to minimize the toxic effects of AEDs therapy.

Antiepileptic Drugs-Induced Enuresis in Children: An Overview

Objective: To evaluate enuresis-induced antiepileptic drugs in children. Data Sources: A PubMed search (1917 to July 2020) was performed using the following keywords and associated medical subject headings: antiepileptic drugs, enuresis, pediatric population, drug-induced enuresis, and epilepsy. Study Selection and Data Extraction: The search was conducted to find the role of antiepileptic drugs-induced enuresis in children in studies published in English. Data Synthesis: Enuresis or bedwetting is an underreported adverse drug reaction of antiepileptic drugs. Owing to that fact, it is a condition that is outgrown with age and also could cause embarrassment. As antiepileptic drugs sometimes need to be taken for a long duration until epilepsy relapses, the occurrence of enuresis in this situation can be troublesome for both the child and the caretaker. Even though enuresis is proposed to have a significant effect on the child's psychology, it is still considered to be a condition that is outgrown with age. This article includes a review of antiepileptic drugs reported to have caused enuresis in children. Conclusions: If a child develops enuresis as an adverse drug reaction, this adds further challenges to their life. A better understanding of this potential adverse effect may help prevent unwanted stress. Though the exact mechanisms are not known, the hypothesis generated is from the occurred cases, most of which relapsed when the drug was withdrawn. Considering the gravity of epilepsy in children, more detailed studies need to be conducted on this adverse effect to ensure a safe and effective treatment in children.

Pharmacokinetic Monitoring of Levetiracetam in Portuguese Refractory Epileptic Patients: Effect of Gender, Weight and Concomitant Therapy

Levetiracetam is a second-generation antiepileptic drug, widely used in the treatment of focal and generalized epilepsy due to its pharmacokinetic and safety profiles. Its pharmacokinetic monitoring is ascribed as useful to personalize its dosing regimen. The aim of the present study was to describe, for the first time, the pharmacokinetics of levetiracetam in Portuguese refractory epileptic patients. Therefore, a retrospective study was carried out on 65 Portuguese refractory epileptic patients (pharmacokinetic study: 48; validation study: 17) admitted to the Refractory Epilepsy Centre of the Centro Hospitalar e Universitário de Coimbra, Coimbra, Portugal. The pharmacokinetic parameters of levetiracetam were estimated by applying a one-compartment model with first-order absorption and elimination analysis. Male patients showed higher distribution volume (Vd/F) and oral clearance (CL/F) than female patients (median Vd/F: 52.40 L in males and 38.60 L in females, p = 0.011; median CL/F: 4.71 L/h in males and 3.91 L/h in females, p = 0.028). Higher values of Vd/F (p = 0.026) and CL/F (p = 0.003) were also found in overweight patients relative to normal weight and obese patients. Carbamazepine was the co-administered antiepileptic drug that mostly affected the pharmacokinetics of levetiracetam, increasing both Vd/F (61.30 L with carbamazepine and 39.10 L without carbamazepine, p = 0.007) and CL/F (6.71 L/h with carbamazepine and 3.91 L/h without carbamazepine, p < 0.001). The pharmacokinetics of levetiracetam was affected by gender, body mass index, and co-administration of carbamazepine. This study highlights the impact of several factors on the CL/ and Vd/F of levetiracetam when administered to refractory epileptic patients. The importance of its pharmacokinetic monitoring in clinical pharmacy stands out, thereby enabling the optimization of antiepileptic drug therapy.

NEDD: a network embedding based method for predicting drug-disease associations

BACKGROUND

Drug discovery is known for the large amount of money and time it consumes and the high risk it takes. Drug repositioning has, therefore, become a popular approach to save time and cost by finding novel indications for approved drugs. In order to distinguish these novel indications accurately in a great many of latent associations between drugs and diseases, it is necessary to exploit abundant heterogeneous information about drugs and diseases.

RESULTS

In this article, we propose a meta-path-based computational method called NEDD to predict novel associations between drugs and diseases using heterogeneous information. First, we construct a heterogeneous network as an undirected graph by integrating drug-drug similarity, disease-disease similarity, and known drug-disease associations. NEDD uses meta paths of different lengths to explicitly capture the indirect relationships, or high order proximity, within drugs and diseases, by which the low dimensional representation vectors of drugs and diseases are obtained. NEDD then uses a random forest classifier to predict novel associations between drugs and diseases.

CONCLUSIONS

The experiments on a gold standard dataset which contains 1933 validated drug-disease associations show that NEDD produces superior prediction results compared with the state-of-the-art approaches.

Integration of postmortem amygdala expression profiling, GWAS, and functional cell culture assays: neuroticism-associated synaptic vesicle glycoprotein 2A (SV2A) gene is regulated by miR-133a and miR-218

Recent genome-wide studies have begun to identify gene variants, expression profiles, and regulators associated with neuroticism, anxiety disorders, and depression. We conducted a set of experimental cell culture studies of gene regulation by micro RNAs (miRNAs), based on genome-wide transcriptome, proteome, and miRNA expression data from twenty postmortem samples of lateral amygdala from donors with known neuroticism scores. Using Ingenuity Pathway Analysis and TargetScan, we identified a list of mRNA-protein-miRNA sets whose expression patterns were consistent with miRNA-based translational repression, as a function of trait anxiety. Here, we focused on one gene from that list, which is of particular translational significance in Psychiatry: synaptic vesicle glycoprotein 2A (SV2A) is the binding site of the anticonvulsant drug levetiracetam ((S)-α-Ethyl-2-oxo-1-pyrrolidineacetamide), which has shown promise in anxiety disorder treatments. We confirmed that SV2A is associated with neuroticism or anxiety using an original GWAS of a community cohort (N = 1,706), and cross-referencing a published GWAS of multiple cohorts (Ns ranging from 340,569 to 390,278). Postmortem amygdala expression profiling implicated three putative regulatory miRNAs to target SV2A: miR-133a, miR-138, and miR-218. Moving from association to experimental causal testing in cell culture, we used a luciferase assay to demonstrate that miR-133a and miR-218, but not miR-138, significantly decreased relative luciferase activity from the SV2A dual-luciferase construct. In human neuroblastoma cells, transfection with miR-133a and miR-218 reduced both endogenous SV2A mRNA and protein levels, confirming miRNA targeting of the SV2A gene. This study illustrates the utility of combining postmortem gene expression data with GWAS to guide experimental cell culture assays examining gene regulatory mechanisms that may contribute to complex human traits. Identifying specific molecular mechanisms of gene regulation may be useful for future clinical applications in anxiety disorders or other forms of psychopathology.

Prediction Tools for Psychiatric Adverse Effects After Levetiracetam Prescription

Importance

Levetiracetam is a commonly used antiepileptic drug, yet psychiatric adverse effects are common and may lead to treatment discontinuation.

Objective

To derive prediction models to estimate the risk of psychiatric adverse effects from levetiracetam use.

Design, Setting, and Participants

Retrospective open cohort study. All patients meeting the case definition for epilepsy after the Acceptable Mortality Reporting date in The Health Improvement Network (THIN) database based in the United Kingdom (inclusive January 1, 2000, to May 31, 2012) who received a first-ever prescription for levetiracetam were included. Of 11 194 182 patients registered in THIN, this study identified 7400 presumed incident cases (66.1 cases per 100 000 persons) over a maximum of 12 years' follow-up. The index date was when patients received their first prescription code for levetiracetam, and follow-up lasted 2 years or until an event, loss to follow-up, or censoring. The analyses were performed on April 22, 2018.

Exposure

A presumed first-ever prescription for levetiracetam.

Main Outcomes and Measures

The outcome of interest was a Read code for any psychiatric sign, symptom, or disorder as reached through consensus by 2 authors. This study used regression techniques to derive 2 prediction models, one for the overall population and one for those without a history of a psychiatric sign, symptom, or disorder during the study period.

Results

Among 1173 patients with epilepsy receiving levetiracetam, the overall median age was 39 (interquartile range, 25-56) years, and 590 (50.3%) were female. A total of 14.1% (165 of 1173) experienced a psychiatric symptom or disorder within 2 years of index prescription. The odds of reporting a psychiatric symptom were significantly elevated for women (odds ratio [OR], 1.41; 95% CI, 0.99-2.01; P = .05) and those with a preexposure history of higher social deprivation (OR, 1.15; 95% CI, 1.01-1.31; P = .03), depression (OR, 2.20; 95% CI, 1.49-3.24; P < .001), anxiety (OR, 1.74; 95% CI, 1.11-2.72; P = .02), or recreational drug use (OR, 2.02; 95% CI, 1.20-3.37; P = .008). The model performed well after stratified k = 5-fold cross-validation (area under the curve [AUC], 0.68; 95% CI, 0.58-0.79). There was a gradient in risk, with probabilities increasing from 8% for 0 risk factors to 11% to 17% for 1, 17% to 31% for 2, 30% to 42% for 3, and 49% when all risk factors were present. For those free of a preexposure psychiatric code, a second model performed comparably well after k = 5-fold cross-validation (AUC, 0.72; 95% CI, 0.54-0.90). Specificity was maximized using threshold cutoffs of 0.10 (full model) and 0.14 (second model); a score below these thresholds indicates safety of prescription.

Conclusions and Relevance

This study derived 2 simple models that predict the risk of a psychiatric adverse effect from levetiracetam. These algorithms can be used to guide prescription in clinical practice.

Y-Site Compatibility of Intravenous Levetiracetam With Commonly Used Critical Care Medications

Purpose: Levetiracetam is an antiepileptic medication commonly used in critical care areas for seizure treatment or prophylaxis. Compatibility data of levetiracetam with other critical care medications are limited, which can make administration challenging. This study aims to assess the physical Y-site compatibility of intravenous levetiracetam with some other commonly used critical care medications. Methods: Y-site administration was simulated by independently mixing levetiracetam with each of 11 selected medications in a 4-dram, colorless, screw-cap, glass vial, at a 1:1 ratio. Clinically used concentrations of each medication were compounded in 0.9% sodium chloride following United States Pharmacopeia chapter 797 standards. Physical compatibility was observed and assessed at 0, 15, and 30 minutes after mixing. Medication mixtures were considered physically incompatible if there was visual evidence of color change, gas evolution, haze, or particulate formation, pH change >10%, or if they had an absorbance value >0.010 A. Results: No evidence of physical incompatibility was observed during simulated Y-site testing with cisatracurium 1 mg/mL, dexmedetomidine 4 µg/mL, fosphenytoin 15 mg PE/mL, norepinephrine 16 mg/mL, norepinephrine 32 mg/mL, norepinephrine 64 mg/mL, piperacillin-tazobactam 33.75 mg/mL, propofol 10 mg/mL, vancomycin 5 mg/mL, or vasopressin 1 unit/mL when tested in 0.9% sodium chloride. Levetiracetam was incompatible with piperacillin-tazobactam 45 mg/mL. Conclusion: Levetiracetam 5 mg/mL in 0.9% sodium chloride was found to be physically compatible for 30 minutes with 10 of the 11 medications tested during simulated Y-site administration.

Levetiracetam Protects Against Cognitive Impairment of Subthreshold Convulsant Discharge Model Rats by Activating Protein Kinase C (PKC)-Growth-Associated Protein 43 (GAP-43)-Calmodulin-Dependent Protein Kinase (CaMK) Signal Transduction Pathway

Background

Subclinical epileptiform discharges (SEDs) are defined as epileptiform electroencephalographic (EEG) discharges without clinical signs of seizure in patients. The subthreshold convulsant discharge (SCD) is a frequently used model for SEDs. This study aimed to investigate the effect of levetiracetam (LEV), an anti-convulsant drug, on cognitive impairment of SCD model rats and to assess the associated mechanisms.

Material/Methods

A SCD rat model was established. Rats were divided into an SCD group, an SCD+ sodium valproate (VPA) group, and an SCD+ levetiracetam (LEV) group. The Morris water maze was used to evaluate the capacity of positioning navigation and space exploration. The field excitatory post-synaptic potentials (fEPSPs) were evaluated using a bipolar stimulation electrode. NCAM, GAP43, PS95, and CaMK II levels were detected using Western blot and RT-PCR, respectively. PKC activity was examined by a non-radioactive method.

Results

LEV shortens the latency of platform seeking in SCD rats in positioning navigation. fEPSP slopes were significantly lower in the SCD group, and LEV treatment significantly enhanced the fEPSP slopes compared to the SCD group (P<0.05). The NCAM and GAP-43 levels were increased and PSD-95 levels were increased in SCD rats (P<0.05), which were improved by LEV treatment. The PKC activity and CaMK II levels were decreased in SCD rats and LEV treatment significantly enhanced PKC activity and increased CaMK II levels.

Conclusions

Cognitive impairment in of SCD model rats may be caused by decreased PKC activity, low expression of CaMK II, and inhibition of LTP formation. LEV can improve cognitive function by activating the PKC-GAP-43-CaMK signal transduction pathway.

Synaptic vesicle protein 2A as a potential biomarker in synaptopathies

Measuring synaptic density in vivo using positron emission tomography (PET) imaging-based biomarkers targeting the synaptic vesicle protein 2A (SV2A) has received much attention recently due to its potential research and clinical applications in synaptopathies, including neurodegenerative and psychiatric diseases. Fluid-based biomarkers in proteinopathies have previously been suggested to provide information on pathology and disease status that is complementary to PET-based measures, and the same can be hypothesized with respect to SV2A. This review provides an overview of the current state of SV2A PET imaging as a biomarker of synaptic density, the potential role of fluid-based biomarkers for SV2A, and related future perspectives.

Conformational Preference and Spectroscopical Characteristics of the Active Pharmaceutical Ingredient Levetiracetam

The analysis of the possible conformers and the conformational change between solid and liquid states of a particular drug molecule are mandatory not only for describing reliably its spectroscopical properties but also for understanding the interaction with the receptor and its mechanism of action. Therefore, here we investigated the free-energy conformational landscape of levetiracetam (LEV) in gas phase as well as in water and ethanol, aiming to describe the 3-dimensional structure and energetic stability of its conformers. Twenty-two unique conformers were identified, and their energetic stability was determined at density functional theory B3LYP/6-31+G(2d,2p) level of theory. The 6 most stable monomers in water, within a relative free-energy window of 0.71 kcal mol^-1 and clearly separated in energy from the remaining subset of 16 conformers, as well as the 3 most stable dimers were then used to compute the Boltzmann populations-averaged UV-Vis and NMR spectra of LEV. The conformational landscape in solution is distinctly different from that corresponding to gas phase, particularly due to the relative orientations of the butanamide group. Aiming to clarify the stability of the possible dimers of LEV, we also investigated computationally the structure of a set of 11 nonhydrated and hydrated homochiral hydrogen-bonded LEV dimers.

Identification and management of tardive dyskinesia: A case series and literature review

Tardive dyskinesia (TD) is a serious, disabling and potentially permanent, neurological hyperkinetic movement disorder that occurs after months or years of taking dopamine receptor-blocking agents. The pathophysiology of TD is complex, multifactorial and still not fully understood. Although there is no identified effective and standard treatment for TD, several agents have been tried for the management of this motor disturbance. The aim of this case series is to review the literature in regard to the identification, diagnosis and the treatment of TD with anticholinergics, anticholinergic medication withdrawal, cholinergic agents, botulinum toxin intramuscular injections, tetrabenazine, levetiracetam, propranolol and zolpidem, and to describe one case of TD that responded favorably to clonazepam and two cases of TD that responded favorably to Ginkgo biloba.

Novel Levetiracetam Derivatives That Are Effective against the Alzheimer-like Phenotype in Mice: Synthesis, in Vitro, ex Vivo, and in Vivo Efficacy Studies

We have synthesized a series of heptamethylene-linked levetiracetam-huprine and levetiracetam-(6-chloro)tacrine hybrids to hit amyloid, tau, and cholinergic pathologies as well as β-amyloid (Aβ)-induced epileptiform activity, some of the mechanisms that eventually lead to cognitive deficits in Alzheimer's disease patients. These hybrids are potent inhibitors of human acetylcholinesterase and butyrylcholinesterase in vitro and moderately potent Aβ42 and tau antiaggregating agents in a simple E. coli model of amyloid aggregation. Ex vivo determination of the brain acetylcholinesterase inhibitory activity of these compounds after intraperitoneal injection to C57BL6J mice has demonstrated their ability to enter the brain. The levetiracetam-huprine hybrid 10 significantly reduced the incidence of epileptic seizures, cortical amyloid burden, and neuroinflammation in APP/PS1 mice after a 4-week treatment with a 5 mg/kg dose. Moreover, the hybrid 10 rescued transgenic mice from cognitive deficits, thereby emerging as an interesting disease-modifying anti-Alzheimer drug candidate.

Retracted Article: Multiwalled carbon nanotube wrapped nanoflake graphene composites for sensitive biosensing of leviteracetum

Current research work presents the detection of leviteracetum by using nanoflakes of graphene (GNF) and multiwalled carbon nanotube (MWCNT) decorated on fluorine-doped tin oxide (FTO) glass as sensing platform.

Radiosynthesis of (11)C-Levetiracetam: A Potential Marker for PET Imaging of SV2A Expression

The multistep preparation of (11)C-levetiracetam ((11)C-LEV) was carried out by a one-pot radiosynthesis with 8.3 ± 1.6% (n = 8) radiochemical yield in 50 ± 5.0 min. Briefly, the propionaldehyde was converted to propan-1-imine in situ as labeling precursor by incubation with ammonia. Without further separation, the imine was reacted with (11)C-HCN to form (11)C-aminonitrile. This crude was then reacted with 4-chlorobutyryl chloride and followed by hydrolysis to yield (11)C-LEV after purification by chiral high-performance liquid chromatography (HPLC). Both the radiochemical and enantiomeric purities of (11)C-LEV were >98%.

Mechanisms of levetiracetam in the control of status epilepticus and epilepsy

Status epilepticus (SE) is a major clinical emergency that is associated with high mortality and morbidity. SE causes significant neuronal injury and survivors are at a greater risk of developing acquired epilepsy and other neurological morbidities, including depression and cognitive deficits. Benzodiazepines and some anticonvulsant agents are drugs of choice for initial SE management. Despite their effectiveness, over 40% of SE cases are refractory to the initial treatment with two or more medications. Thus, there is an unmet need of developing newer anti-SE drugs. Levetiracetam (LEV) is a widely prescribed anti-epileptic drug that has been reported to be used in SE cases, especially in benzodiazepine-resistant SE or where phenytoin cannot be used due to allergic side-effects. Levetiracetam’s non-classical anti-epileptic mechanisms of action, favorable pharmacokinetic profile, general lack of central depressant effects, and lower incidence of drug interactions contribute to its use in SE management. This review will focus on LEV’s unique mechanism of action that makes it a viable candidate for SE treatment.

Molecular structure, normal coordinate analysis, harmonic vibrational frequencies, NBO, HOMO-LUMO analysis and detonation properties of (S)-2-(2-oxopyrrolidin-1-yl) butanamide by density functional methods

Density functional theory (DFT) computations have become an efficient tool in the prediction of molecular structure, harmonic force fields, vibrational wave numbers as well as the IR and Raman intensities of pharmaceutically important molecule. In this work, we report harmonic vibrational frequencies, molecular structure, NBO and HOMO, LUMO analysis and detonation properties of (S)-2-(2-oxopyrrolidin-1-yl) butanamide. The solid phase FT-IR and FT-Raman spectra of (S)-2-(2-oxopyrrolidin-1-yl) butanamide were recorded in the region 4000-450 cm(-1) and 4000-50 cm(-1) respectively. Harmonic frequencies of this compound were determined and analyzed by DFT utilizing 6-31G(d,p), 6-31+G(d,p) basis sets. The assignments of the vibrational spectra have been carried out with the help of Normal Coordinate Analysis (NCA) following the Scaled Quantum Mechanical Force Field Methodology (SQMFF). The calculated infrared and Raman spectra of the title compounds were also stimulated utilizing the scaled force fields and the computed dipole derivatives for IR intensities and polarizability derivatives for Raman intensities. The change in electron density (ED) in the σ(*) and π(*) antibonding orbital's and stabilization energies E(2) have been calculated by Natural Bond Orbital (NBO) analysis to give clear evidence of stabilization originating in the hyperconjugation of hydrogen-bonded interaction. Heat of formation (HOF) and calculated density were estimated to evaluate detonation properties using Kamlet-Jacobs equations. The linear polarizability (α) and the first order hyperpolarizability (β) values of the investigated molecule have been computed using DFT calculations. The calculated HOMO and LUMO energies show that charge transfer occurs within the molecule. The observed and calculated wave numbers are found to be in good agreement. On the basis of vibrational analyses, the thermodynamic properties of title compound at different temperatures have been calculated.

Apparent dose-dependent levetiracetam-induced de novo major depression with suicidal behavior

Levetiracetam (LEV) is a novel antiepileptic drug (AED) approved for the adjunctive treatment of generalized and partial seizures. LEV has no clinically significant drug interactions and has limited adverse effects. The psychiatric adverse effects of LEV include de novo psychosis, affective disorder, and aggression. LEV-induced suicidal behavior has been reported infrequently with a past history of affective disorders. The authors report an apparent dose/concentration-dependent LEV-induced de novo major depression with near fatal suicide attempt in a patient without prior history of affective disorder. Psychiatric evaluation with emphasis on historic/current affective disorders, impulsive-aggressive behaviors, and assessment of risk factors for suicidal behaviors is indicated in treating patients with epilepsy with LEV. Clinicians should consider therapeutic drug monitoring to optimize therapeutic LEV treatment.

An observational trial to investigate the efficacy and tolerability of levetiracetam in trigeminal neuralgia

OBJECTIVE

To explore the efficacy and tolerability of levetiracetam in medical treatment of trigeminal neuralgia.

BACKGROUND

Antiepileptic drugs (AEDs) are considered as first-line treatment for trigeminal neuralgia, although their use is often limited due to incomplete efficacy and tolerability. Newer AEDs with improved safety profile may be useful in this disorder.

METHODS

Patients suffering from trigeminal neuralgia (either primary or secondary) refractory to previous treatments were recruited to be treated with levetiracetam (3-4 g/day) for 16 weeks as add-on therapy, after a 2-week baseline period. Rescue medication was allowed in both the baseline and treatment phases. The primary efficacy measure was the number of attacks per day. The patients' efficacy evaluation, the patients' global evaluation for both safety and efficacy, changes in the Hamilton Depression Scale, the Hamilton Anxiety Scale, and the Quality of Life Measure Short Form-36 were secondary parameters.

RESULTS

Twenty-three patients were included in the analysis. After treatment and compared to the baseline phase, the number of daily attacks decreased by 62.4%. All secondary parameters changed significantly with the exception of the Quality of Life Measure Short Form-36 score. Seven patients withdrew from the study. Five patients (21.7%) reported side effects and 2 withdrew.

CONCLUSIONS

Levetiracetam may be effective and safe in trigeminal neuralgia treatment. Confirmation in a randomized controlled study is needed.

Emerging treatment strategies in Tourette syndrome: what's in the pipeline?

Tourette syndrome (TS) is a neurodevelopmental disorder characterized by multiple motor/phonic tics and a wide spectrum of behavioral problems (e.g., complex tic-like symptoms, attention deficit hyperactivity disorder, and obsessive-compulsive disorder). TS can be a challenging condition even for the specialists, because of the complexity of the clinical picture and the potential adverse effects of the most commonly prescribed medications. Expert opinions and consensus guidelines on the assessment and treatment of tic disorders have recently been published in Europe and Canada. All pharmacological treatment options are mere symptomatic treatments that alleviate, but do not cure, the tics. We still lack evidence of their effects on the natural long-term course and on the prognosis of TS and how these treatments may influence the natural course of brain development. The most commonly prescribed drugs are dopamine antagonists, such as typical (e.g., haloperidol, pimozide) and atypical neuroleptics (e.g., risperidone, aripiprazole), and α-2-adrenoreceptor agonists (e.g., clonidine). However, several studies have investigated the efficacy and tolerability of alternative pharmacological agents that may be efficacious, including the newest atypical antipsychotic agents (e.g., paliperidone, sertindole), tetrabenazine, drugs that modulate acetylcholine (e.g., nicotine) and GABA (e.g., baclofen, levetiracetam), tetrahydrocannabinol, botulinum toxin injections, anticonvulsant drugs (e.g., topiramate, carbamazepine), naloxone, lithium, norepinephrine, steroid 5α reductase, and other neuroactive agents (buspirone, metoclopramide, phytostigmine, and spiradoline mesylate). As regards nonpharmacological interventions, some of the more recent treatments that have been studied include electroconvulsive therapy and repetitive transcranial magnetic stimulation. This review focuses primarily on the efficacy and safety of these emerging treatment strategies in TS.

The anticonvulsant levetiracetam potentiates alcohol consumption in non-treatment seeking alcohol abusers

BACKGROUND

Levetiracetam (Keppra) is a commonly prescribed anticonvulsant that has been shown to attenuate alcohol consumption in an open-label study of treatment-seeking, alcohol-dependent subjects.

METHODS

Here we performed a 42-day placebo-controlled, double-blind, randomized crossover trial to evaluate the effects of levetiracetam on moderate to heavy drinkers receiving either a low (500-1000 g/d) or a moderate (1000-2000 g/d) dose. Electronic diaries were used to monitor daily ethanol intake.

RESULTS

Across the entire group, there was no effect of levetiracetam on drinking irrespective of dose, treatment order, family history, ethnicity, sex, or adverse effects. However, a median split of the data based on the number of drinks consumed while taking placebo revealed that levetiracetam significantly increased drinking in the lower drinking subjects (n = 23, P = 0.05, t = 2.07) while having no effect on drinking in the higher half (n = 23, P = 0.75, t = 0.32). Preliminary stratification based on common polymorphisms associated with alcoholism and impulsivity indicated that subjects with alcoholism-associated alleles may drink even more while taking levetiracetam.

CONCLUSIONS

Our data suggest that levetiracetam is not an appropriate treatment for non-treatment seeking alcohol abusers and can, in fact, increase their consumption of alcohol.

Treatment with levetiracetam in a patient with pervasive developmental disorders, severe intellectual disability, self-injurious behavior, and seizures: a case report

Pervasive developmental disorder is characterized by various symptoms that often include self-injurious behavior (SIB). Episodes of SIB occur in the context of high emotional arousal, anger, or fear and may be related to epilepsy. We report the case of a 20-year-old man with pervasive developmental disorder presenting with SIB non-responsive to antipsychotic medication. Positron emission tomography showed a right temporoparietal hypometabolic focal lesion suggestive of an epileptic focus. Two weeks after initiation of levetiracetam (Keppra®), SIB disappeared, without recurrence 24 months later. Levetiracetam (Keppra®) may be beneficial for such patients.

Simultaneous quantification of levetiracetam and gabapentin in plasma by ultra-pressure liquid chromatography coupled with tandem mass spectrometry detection

INTRODUCTION

Gabapentin (Neurontin) and levetiracetam (Keppra) are anticonvulsants with novel structures and suggested therapeutic ranges of 2-10 mg/L and 6-20 mg/L, respectively. Gabapentin is also used extensively to manage neuropathic pain, and for this indication, wherein higher doses are prescribed, plasma concentrations of 15-30 mg/L are typical.

OBJECTIVE

Here, we describe a simple rapid assay to support therapeutic drug monitoring of gabapentin and levetiracetam in plasma by ultra-pressure liquid chromatography couples to tandem mass spectrometry (UPLC-MS/MS) detection.

METHODS

After the addition of internal standard and protein precipitation of patient plasma with methanol:acetonitrile in a 50:50 ratio, 1 μL of supernatant sample is injected onto an Acquity UPLC HSS T3, 1.8 μm, 2.1 × 50 mm (Waters) column. Elution occurs using a linear gradient of acetonitrile and water, each having 0.1% formic acid added. The column is eluted into a Waters Acquity UPLC TQD, operating in a positive mode to detect gabapentin at transition 172.18 > 154.11, levetiracetam at 171.11 > 126, and internal standard (3-amino-2-naphthoic acid) at 188.06 > 170. Secondary transitions for each analyte are also monitored for gabapentin at 172.18 > 137.06, levetiracetam at 171.11 > 154, and internal standard at 188.06 > 115. Runtime is 1.5 minutes per injection with baseline resolved chromatographic separation.

RESULTS

The analytical measurement ranges were 1-150 mg/L for gabapentin and for levetiracetam. Intra-assay imprecision by the coefficient of variance (CV) was less than 8% and interassay CV was less than 5% for both analytes, at 4 different concentrations. Results obtained from patient samples were compared with results generated by established high-performance liquid chromatography-UV methods with the following regression statistics: y = 1.12x - 0.77, r = 0.996, Sy, x = 0.89, and n = 29 for gabapentin and y = 0.991x + 0.70, r = 0.997, Sy, x = 2.24, and n = 30 for levetiracetam. No analytical interferences were identified.

CONCLUSION

: In summary, a simple reliable UPLC-MS/MS method was developed and validated for routine clinical monitoring of gabapentin and levetiracetam.

Levetiracetam as an alternative therapy for Tourette syndrome

Tourette syndrome is a common childhood-onset neuropsychiatric disorder characterized by chronic tics and frequent comorbid conditions such as attention deficit disorder. Most currently used tic-suppressing drugs are frequently associated with serious adverse events. Thus, alternative therapeutic agents with more favorable side-effect profiles are being evaluated. New hypotheses and recent studies involving GABAergic system in the pathophysiology of Tourette syndrome suppose a reason for the evaluation of GABAergic drugs. Levetiracetam is a drug with an atypical GABAergic mechanism of action that might be expected to improve tics. Although trials performed to evaluate the efficacy of levetiracetam in the treatment of Tourette syndrome have provided conflicting results, it may be useful in some patients. The established safe profile of levetiracetam makes this drug an alternative for treatment if intolerance to currently used drugs appears, but additional evaluation with larger and longer duration controlled studies are necessary to assess the real efficacy in patients with Tourette syndrome.

Transitional polytherapy: tricks of the trade for monotherapy to monotherapy AED conversions

The goal of epilepsy therapy is to help patients achieve seizure freedom without adverse effects. While monotherapy is preferable in epilepsy treatment, many patients fail a first drug due to lack of efficacy or failure to tolerate an initial medication, necessitating an alteration in therapy. Sudden changes between monotherapies are rarely feasible and sometimes deleterious given potential hazards of acute seizure exacerbation or intolerable adverse effects. The preferred method for converting between monotherapies is transitional polytherapy, a process involving initiation of a new antiepileptic drug (AED) and adjusting it toward a target dose while maintaining or reducing the dose of the baseline medication. A fixed-dose titration strategy of maintaining the baseline drug dose while titrating the new medication is preferable when breakthrough seizures are occurring and no adverse effects are present. However, a flexible titration strategy involving reduction of the baseline drug dose to ensure adequate tolerability of the new adjunctive medication is preferred when patients are already experiencing adverse effects. This article reviews pharmacokinetic considerations pertinent for ensuring successful transitional polytherapy with the standard and newer antiepileptic drugs. Practical consensus recommendations "from an expect panel (SPECTRA, Study by a Panel of Experts Considerations for Therapy Replacement and Antiepileptics) for a successful monotherapy" AED conversions are then summarized. Transitional polytherapy is most successful when clinicians appropriately manage the titration strategy and consider pharmacokinetic factors germane to the baseline and new adjunctive medication.

Recent Publications on Medications and Pharmacy

Hospital Pharmacy presents this feature to keep pharmacists abreast of new publications in the medical/pharmacy literature. Articles of interest regarding a broad scope of topics are abstracted monthly. Suggestions or comments may be addressed to Jacyntha Sterling, Drug Information Specialist at Saint Francis Hospital, 6161 S Yale Ave, Tulsa, OK 74136 or e-mail: jasterling@saintfrancis.com .