Monotherapy for partial epilepsy: focus on levetiracetam

Efficacy and tolerability of levetiracetam in people with and without intellectual disabilities: A naturalistic case control study

INTRODUCTION

People with Intellectual Disabilities (PwID) are twenty times more likely than general population to have epilepsy. Guidance for prescribing antiseizure medication (ASM) to PwID is driven by trials excluding them. Levetiracetam (LEV) is a first-line ASM in the UK. Concerns exist regarding LEV's behavioural and psychological adverse effects, particularly in PwID. There is no high-quality evidence comparing effectiveness and adverse effects in PwID to those without, prescribed LEV.

METHODS

Pooled casenote data for patients prescribed LEV (2000-2020) at 18 UK NHS Trusts were analysed. Demographics, starting and maximum dose, adverse effects, dropouts and seizure frequency between ID (mild vs. moderate-profound (M/P)) and general population for a 12-month period were compared. Descriptive analysis, Mann-Whitney, Fisher's exact and logistic regression methods were employed.

RESULTS

173 PwID (mild 53 M/P 120) were compared to 200 without ID. Mean start and maximum dose were similar across all groups. PwID (Mild & M/P) were less likely to withdraw from treatment (P = 0.036). No difference was found between ID and non-ID or between ID groups (Mild vs M/P) in LEV's efficacy i.e. >50 % seizure reduction. Significant association emerged between ID severity and psychiatric adverse effects (P = 0.035). More irritability (14.2 %) and aggression (10.8 %) were reported in M/P PwID.

CONCLUSION

PwID and epilepsy have high rates of premature mortality, comorbidities, treatment resistance and polypharmacy but remain poorly researched for ASM use. This is the largest studied cohort of PwID trialled on LEV compared to general population controls. Findings support prescribing of LEV for PwID as a first-line ASM.

Real-World Evidence on Levetiracetam-Induced Hypokalemia: An Active Comparator Cohort Study

BACKGROUND

Levetiracetam is an anti-seizure medication (ASM) with an established safety profile. However, a potential safety signal of hypokalemia following levetiracetam use was published in the World Health Organization newsletter.

OBJECTIVE

To investigate the possible causal association between the use of levetiracetam and the development of hypokalemia.

METHOD

This was a new-user, active-comparator retrospective cohort study using Real-world Evidence Research Network data at the Saudi Food and Drug Authority from 2016 to 2022. Adults (≥ 18 years old) with an incident prescription for either levetiracetam or carbamazepine were followed for up to 6 months from the prescription date. Hypokalemia was ascertained by using diagnostic code (i.e., E87.6) or by serum potassium level below 3.5 mmol/L. A Cox proportional hazards model, adjusted with stabilized inverse probability of treatment weight, was fitted to compare the hazard of hypokalemia between levetiracetam and carbamazepine exposed patients.

RESULTS

A total of 8,982 patients entered the study cohort. The incidence rate of hypokalemia was 303 cases per 10,000 patient-years in the levetiracetam-exposed cohort compared to 57 cases per 10,000 patient-years among carbamazepine users. Compared to carbamazepine users, patients exposed to levetiracetam had an adjusted hazard ratio related to induced hypokalemia of 1.99 (95% confidence interval, 0.88-4.49). Results of sensitivity analyses were comparable to the main analysis.

CONCLUSION

The hazard ratio for hypokalemia with the use of levetiracetam versus carbamazepine was statistically comparable. However, the potential association between levetiracetam use and hypokalemia cannot be ruled out given the elevated hazard ratios from the main and sensitivity analyses. Further studies may provide a more precise assessment of this association.

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.

Evaluating the bioequivalence of levetiracetam brand and generic oral tablets available in the Saudi market in vivo

Background

Epilepsy is a common global neurological disorder. About 30% of epileptic patients are managed with anti-epileptic Drugs (AEDs). Since 2000, Levetiracetam (LEV) has been marketed around the world as an AED under the brand name Keppra, and recently more generics are found in the Saudi market as cheaper alternatives. The objective of this study is to evaluate the bioequivalence of LEV brand and generics available in the Saudi market in mice.

Methods

Pharmacokinetics (PK), liver function test, and behavioral studies were conducted for LEV brand and generic in different groups of Blab/c mice.

Results

PK results show a significance difference in PK parameters mostly evidenced with generic 3, then generic 2. The only significant different between Keppra and generic 1 was in T1/2. In addition, Keppra did not significantly increase liver enzymes in comparison to other generics. On the other hand, other generics showed less favorable results in increasing liver enzymes. Keppra reduced the number and intensity of epileptic attacks, had no mortality rate due to epilepsy, and was associated with less sever seizures attacks.

Conclusion

Keppra, the brand form of LEV, has better safety and efficacy profiles in mice compared to 3 generics found in the Saudi market. Therefore, we recommend evaluating the same parameters tested in this study in patients utilizing similar generics and brand to establish the existence of bioequivalence between LEV brand and generics.

Is the anticonvulsant activity of levetiracetam dose-dependent?

PURPOSE

Although levetiracetam (LEV) is globally established as a leading antiseizure medication (ASM) it is still a controversial matter whether dose increases correspond with an increased efficacy if LEV in the recommended dose range did not show satisfying efficacy. In our clinical perception we questioned the value of dose increases in such non-responders.

METHODS

In this retrospective monocenter study we analyzed the data of adult people with epilepsies (PWE) with focal-onset seizures who had been treated at the department of adults of the Kork Epilepsy Center between 2009 and 2019, who had been on a stable daily LEV dose and in whom LEV was further increased due to further seizures in spite of baseline LEV in a recommended daily dose range. For reasons of data homogeneity, we included only PWE with at least two definite seizures during the hospital stay under the baseline LEV dose who were treated and observed as in-patients after the increase of LEV for a period at least three-fold longer than the baseline interval before. Additional data acquisition comprised clinical data including adverse events, serum concentrations of LEV and other ASMs, and additional laboratory findings. The primary outcome variable was the change of seizure frequency prior to and after the increase of LEV.

RESULTS

Out of 518 PWE who had been on LEV during their hospital stay, a total of 61 PWE fulfilled the inclusion criteria. After a gradual dose increment, 91,8 % of PWE showed a reduced seizure frequency, 73,8 % had a reduction of seizures of 50 % or more, and 21,3 % were seizure-free during the observation period. A significant seizure reduction could be shown with a seizure count of 2,5/week prior to the increment and 0,7/week after dose increment (p < 0,00001). Seven PWE reported minor adverse events and ten PWE showed slight laboratory changes (within normal levels).

CONCLUSION

Contrary to our long-term clinical impression, LEV dose increments were reasonable and improved the seizure situation in PWE, usually without additional safety hazards.

Levetiracetam add-on for drug-resistant focal epilepsy

BACKGROUND

Drug resistance is common in focal epilepsy. In this update, we summarised the current evidence regarding add-on levetiracetam in treating drug-resistant focal epilepsy. The original review was published in 2001 and last updated in 2012.

OBJECTIVES

To evaluate the effectiveness of levetiracetam when used as an add-on treatment for people with drug-resistant focal epilepsy.

SEARCH METHODS

We searched the Cochrane Register of Studies (CRS Web, which includes the Cochrane Epilepsy Group Specialized Register and CENTRAL), MEDLINE Ovid, ClinicalTrials.gov, and the WHO International Clinical Trials Registry Platform (ICTRP) to November 2018. We contacted the manufacturers of levetiracetam and researchers in the field to seek any ongoing or unpublished trials.

SELECTION CRITERIA

Randomised, placebo-controlled trials of add-on levetiracetam treatment in people with drug-resistant focal epilepsy.

DATA COLLECTION AND ANALYSIS

Two review authors independently selected trials for inclusion, assessed trials for bias, extracted data, and evaluated the overall certainty of the evidence. Outcomes investigated included 50% or greater reduction in focal seizure frequency (response), treatment withdrawal, adverse effects (including a specific analysis of changes in behaviour), cognitive effects, and quality of life (QoL). Primary analysis was intention-to-treat. We performed meta-analysis for all outcomes using a Mantel-Haenszel approach and calculated risk ratios (RR), with 95% confidence intervals (CI) for all estimates apart from adverse effects (99% CIs). We assessed heterogeneity using a Chi² test and the I² statistic.

MAIN RESULTS

This update included 14 trials (2455 participants), predominantly possessing low risks of bias. Participants were adults in 12 trials (2159 participants) and children in the remaining two (296 participants). The doses of levetiracetam tested were 500 mg/day to 4000 mg/day in adults, and 60 mg/kg/day in children. Treatment ranged from 12 to 24 weeks. When individual doses were examined, levetiracetam at either 500 mg/day or 4000 mg/day did not perform better than placebo for the 50% or greater reduction in seizure frequency outcome (500 mg: RR 1.60, 95% CI 0.71 to 3.62; P = 0.26; 4000 mg: RR 1.64, 95% CI 0.59 to 4.57; P = 0.34). Levetiracetam was significantly better than placebo at all other individual doses (1000 mg to 3000 mg). RR was significantly in favour of levetiracetam compared to placebo when results were pooled across all doses (RR 2.37, 95% CI 2.02 to 2.78; 14 studies, 2455 participants; moderate-certainty evidence). Dose-response analysis demonstrated that the odds of achieving response (50% or greater reduction in seizure frequency) were increased by nearly 40% (odds ratio (OR) 1.39, 95% CI 1.23 to 1.58) for each 1000 mg increase in dose of levetiracetam. There were important levels of heterogeneity across multiple comparisons. Participants were not significantly more likely to experience treatment withdrawal with levetiracetam than with placebo (pooled RR 1.11, 95% CI 0.89 to 1.40; 13 studies, 2428 participants; high-certainty evidence). Somnolence was the most common adverse effect, affecting 13% of participants, and it was significantly associated with levetiracetam compared to placebo (pooled RR 1.62, 99% CI 1.19 to 2.20; 13 studies, 2423 participants; moderate-certainty evidence). Changes in behaviour were negligible in adults (1% affected; RR 1.79, 99% CI 0.59 to 5.41), but significant in children (23% affected; RR 1.90, 99% CI 1.16 to 3.11). Levetiracetam had a positive effect on some aspects of cognition and QoL in adults and worsened certain aspects of child behaviour.

AUTHORS' CONCLUSIONS

Overall, this review update finds that in both adults and children with drug-resistant focal epilepsy, levetiracetam added on to usual care is more effective than placebo at reducing seizure frequency, it is unlikely to be stopped by patients, and it has minimal adverse effects outside of potential worsening behaviour in children. These findings are unchanged from the previous review update in 2012. This review update contributes two key additional findings: 1. a 500 mg daily dose of levetiracetam is no more effective than placebo at reducing seizures; and 2. the odds of response (50% reduction in seizure frequency) are increased by nearly 40% for each 1000 mg increase in dose of levetiracetam. It seems reasonable to continue the use of levetiracetam in both adults and children with drug-resistant focal epilepsy.

Late drug-resistance in mild MTLE: Can it be influenced by preexisting white matter alterations?

OBJECTIVE

To identify early structural alterations preceding the development of drug-resistance in mild mesial temporal lobe epilepsy (mMTLE), a drug-responsive syndrome ideal for investigating epilepsy pathophysiology and potential prognostic markers of long-term clinical outcome, using magnetic resonance imaging (MRI) at baseline and after 12-year follow-up.

METHODS

Since 2002, a total of 55 participants with a baseline diagnosis of mMTLE underwent three-dimensional (3D) T1 1.5T MRI. Based on long-term outcome (follow-up 12 ± 3 years), we identified 39 patients with stable mMTLE (smMTLE) and 16 patients who had developed drug-resistance overtime (refractory MTLE [rMTLE]). At follow-up, 21 smMTLE and 13 rMTLE patients underwent 3T-MRI including diffusion-weighted scans. Structural images were processed using longitudinal voxel-based morphometry and standard Freesurfer analysis. Statistical analyses were carried out accounting for age, age at onset, gender, hippocampal volume, and hippocampal sclerosis (Hs).

RESULTS

Patients presented similar demographic, clinical, and Hs features. White matter volume of the arcuate fasciculi, corticospinal tracts, left retrosplenial cingulum, and left inferior longitudinal fasciculus was reduced only in rMTLE patients before the development of drug-resistance. At follow-up, rMTLE showed decreased fractional anisotropy in the corpus callosum, superior longitudinal fasciculi, and major bundles of the right hemisphere.

SIGNIFICANCE

White matter temporal and extratemporal abnormalities are preexisting in patients with mild MTLE who will develop drug-resistance, independently from the presence of Hs. Thus, these changes might be due to an inherited genetic alteration rather than a subordinate worsening after repeated seizures, multiple antiepileptic drugs, or initial precipitating factors.

Assessment of psychiatric and behavioral adverse effects of antiepileptic drugs monotherapy: Could they have a neuroendocrine correlation in persons with epilepsy?

OBJECTIVE

The study investigated overall adverse event (AE) burden and specifically psychiatric and behavioral side effects (PBAEs) in persons with epilepsy (PWE) on antiepileptic drugs (AEDs) monotherapy. It also assessed their correlation with neuroendocrine and oxidative stress biomarkers.

METHODS

This cross-sectional observational study was conducted at a tertiary care hospital between 2016 and 2018. Persons with epilepsy above 18 years on monotherapy of levetiracetam (LEV) and conventional AEDs {carbamazepine (CBZ), phenytoin (PHT), or valproate (VPA)} for at least 6 months were enrolled. Validated questionnaires, 'Mini-International Neuropsychiatric Interview (MINI 7.02)', 'Depression, Anxiety, and Stress Scale 21 (DASS-21)', 'Buss-Perry Aggression Questionnaire (BPAQ)', 'patient-weighted Quality of life Index in Epilepsy (QOLIE-10)', 'Pittsburgh Sleep Quality Index (PSQI)', and 'Liverpool Adverse Events Profile (LAEP)' were used to assess the PBAEs, quality of life, sleep quality, and AE profile. A subgroup of PWE recruited consecutively were considered for estimation of the following neuroendocrine biomarker levels: brain-derived neurotrophic factor (BDNF), homovanillic acid (HVA), 5-hydroxyindoleacetic acid (5-HIAA), and total antioxidant capacity (TAC) which were then correlated with scores of above questionnaires.

RESULTS

After screening 220 PWE, 163 PWE (58 on LEV and 105 on conventional AEDs) with a mean age of 29 ± 10 years were enrolled. Mini-International Neuropsychiatric Interview revealed that LEV group had higher association with PBAEs and lower quality of sleep compared to conventional AEDs (p = 0.032 and 0.046, respectively). Other scales did not show significant difference between LEV and conventional AEDs. In the subset of PWE (n = 74, 36 on LEV and 38 on conventional AEDs), LEV group had more association with the PBAEs (p = 0.010), higher physical aggression and anger components of BPAQ (p = 0.03 and 0.02, respectively), and more AE (p = 0.049) than conventional AED group. However, there was no significant difference in neuroendocrine biomarker levels.

CONCLUSION

Levetiracetam had a higher association with PBAEs and more AE when compared to conventional AEDs. There was no differential correlation of AEDs with the following neuroendocrine markers: BDNF, HVA, 5-HIAA, and TAC. These facts necessitate exploration of other mechanisms for LEV-induced PBAEs.

A randomized, double-blind, double-dummy, multicenter trial comparing the efficacy and safety of extended- and immediate-release levetiracetam in people with partial epilepsy

PURPOSE

The aim of this trial was to compare the efficacy and safety of two formulations of levetiracetam in people with partial epilepsy over a 12-week treatment period.

METHODS

We performed a randomized, paralleled, and multicenter trial that consisted of a 4-week single-blind placebo run-in, followed by a 12-week double-blind, double-dummy treatment phase to compare the efficacy and safety of levetiracetam extended-release (LEV-ER) and immediate-release (LEV-IR) tablets as an adjunctive treatment in adult patients with uncontrolled epilepsy.

RESULTS

The median partial-onset seizure (POS) frequency per week (min-max) was 0.3 (0.0, 17.4; 95% confidence interval [95% CI] 1.3, 4.8) in the LEV-ER group and 0.3 (0.0, 31.4; 95% CI - 0.1, 4.3) in the LEV-IR group. No serious adverse events occurred during the trial period. Both groups had the same responder rate (58.6%), while a higher rate of seizure freedom over the treatment period was noted in the LEV-ER group compared with the LEV-IR group (27.6% vs. 13.8%, respectively). The European Quality of Life-5 Dimensions scores significantly increased in the LEV-ER-treated group, in contrast to the scores in the LEV-IR group, which decreased (7.2 vs. - 1.5, p = 0.03).

CONCLUSION

These results suggest that LEV-ER is equivalent to LEV-IR in reducing the frequency of POS and has a similar tolerability as LEV-IR as an add-on therapy. In addition, LEV-ER treatment improved the health-related quality of life of people with uncontrolled partial epilepsy.

Fetal safety of levetiracetam use during pregnancy

The aim of this study is to evaluate the effect of levetiracetam treatment during pregnancy on fetus.. The pregnant women with epilepsy (PWWE) who were exposed to levetiracetam treatment during pregnancy in the form of monotherapy or polytherapy were retrospectively evaluated. They were compared with the PWWE who did not use the antiepileptic drug (AED) during pregnancy. A total of 102 pregnancies were examined. While 35 patients never used AED during pregnancy, 30 patients received only levetiracetam therapy, and 37 patients received levetiracetam with at least one combined AED. While no major congenital malformation (MCM) was determined in the group of patients who never used AED and who received levetiracetam monotherapy, 2 MCMs were determined in the group receiving multiple AED therapy with levetiracetam. This study showed that the use of levetiracetam as monotherapy during pregnancy was at the same risk level as the group who never used AED and that the risk increased when it was used as a part of polytherapy. In conclusion, these findings support the current understanding that LEV may be a feasible option for PWWE.

Variation within voltage-gated calcium channel genes and antipsychotic treatment response in a South African first episode schizophrenia cohort

Voltage-gated calcium channels have been implicated in schizophrenia aetiology; however, little is known about their involvement in antipsychotic treatment response. This study investigated variants within the calcium channel subunit genes for association with antipsychotic treatment response in a first episode schizophrenia cohort. Twelve regulatory variants within seven genes were shown to be significantly associated with treatment outcome. Most notably, the CACNA1B rs2229949 CC genotype was associated with improved negative symptomology, where the C allele was predicted to abolish a miRNA-binding site (has-mir-5002-3p), suggesting a possible mechanism of action through which this variant may have an effect. These results implicate the calcium channel subunits in antipsychotic treatment response and suggest that increased activation of these channels may be explored to enhance or predict antipsychotic treatment outcome.

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.

Newer antiepileptic drugs compared to levetiracetam as adjunctive treatments for uncontrolled focal epilepsy: An indirect comparison

PURPOSE

Newer antiepileptic drugs (AEDs), such as Eslicarbazepine (ESL), Lacosamide (LAC), Perampanel (PER) and Brivaracetam (BRV), have been marketed as adjunctive treatments for partial-onset seizures. Our aim was to compare the efficacy and tolerability of newer AEDs with Levetiracetam (LEV), when used as add-on treatments for uncontrolled focal epilepsy.

METHOD

We conducted an online database search on PubMed, Embase, Cochrane Online Library and Clinicaltrials.gov for all available randomized controlled trials (RCTs) investigating the therapeutic effects of newer AEDs or LEV vs placebo. Indirect comparisons for clinical efficacy and tolerability at different doses between the newer AEDs and LEV were then performed using Indirect Treatment Comparison (ITC) software.

RESULTS

Twenty-four RCTs with a total of 8540 patients were included. Compared to LEV, ESL, LAC and BRV did not showed significant difference in efficacy at all dose level. PER showed lower 50% response rates and seizure-free rates at the highest effective recommended dosages. Treatment-emergent adverse events (TEAEs) and withdrawal rates due to adverse events (AEs) of LAC and PER were higher than LEV at the highest effective recommended dosages, and overall AE rates from ESL were higher than LEV.

CONCLUSIONS

Indirect comparisons suggested that ESL, LAC and BRV were not inferior to LEV in efficacy. ESL, LAC and PER may have a possible worse tolerability profile compared to LEV at high dose. But BRV may exhibit a similar tolerability to LEV. Newer AEDs cannot exceed the LEV on efficacy and tolerability.

A Study of Fasoracetam's Solid State Forms: A Potential Anti-Alzheimer Pharmaceutical

Different solid state forms of the research chemical fasoracetam, which counters the effects of Alzheimer's disease, have been subjected to a thermal and structural analysis. Single crystals were obtained from solution evaporation and from the melt. Single-crystal X-ray analyses of the crystals show the existence of 2 hydrated and 1 non-hydrated crystalline form of fasoracetam. Under ambient conditions, the hydrate form I is found to be the most stable form, showing a melting point of 57C. This low melting point, combined with possible water losses could cause problems when formulating the hydrated form and impact the storage conditions of the compound.

Brivaracetam: review of its pharmacology and potential use as adjunctive therapy in patients with partial onset seizures

Brivaracetam (BRV), a high-affinity synaptic vesicle protein 2A ligand, reported to be 10–30-fold more potent than levetiracetam (LEV), is highly effective in a wide range of experimental models of focal and generalized seizures. BRV and LEV similarly bind to synaptic vesicle protein 2A, while differentiating for other pharmacological effects; in fact, BRV does not inhibit high voltage Ca²⁺ channels and AMPA receptors as LEV. Furthermore, BRV apparently exhibits inhibitory activity on neuronal voltage-gated sodium channels playing a role as a partial antagonist. BRV is currently waiting for approval both in the United States and the European Union as adjunctive therapy for patients with partial seizures. In patients with photosensitive epilepsy, BRV showed a dose-dependent effect in suppressing or attenuating the photoparoxysmal response. In well-controlled trials conducted to date, adjunctive BRV demonstrated efficacy and good tolerability in patients with focal epilepsy. BRV has a linear pharmacokinetic profile. BRV is extensively metabolized and excreted by urine (only 8%–11% unchanged). The metabolites of BRV are inactive, and hydrolysis of the acetamide group is the mainly involved metabolic pathway; hepatic impairment probably requires dose adjustment. BRV does not seem to influence other antiepileptic drug plasma levels. Six clinical trials have so far been completed indicating that BRV is effective in controlling seizures when used at doses between 50 and 200 mg/d. The drug is generally well-tolerated with only mild-to-moderate side effects; this is confirmed by the low discontinuation rate observed in these clinical studies. The most common side effects are related to central nervous system and include fatigue, dizziness, and somnolence; these apparently disappear during treatment. In this review, we analyzed BRV, focusing on the current evidences from experimental animal models to clinical studies with particular interest on potential use in clinical practice. Finally, pharmacological properties of BRV are summarized with a description of its pharmacokinetics, safety, and potential/known drug–drug interactions.

Exploring the interaction of SV2A with racetams using homology modelling, molecular dynamics and site-directed mutagenesis

The putative Major Facilitator Superfamily (MFS) transporter, SV2A, is the target for levetiracetam (LEV), which is a successful anti-epileptic drug. Furthermore, SV2A knock out mice display a severe seizure phenotype and die after a few weeks. Despite this, the mode of action of LEV is not known at the molecular level. It would be extremely desirable to understand this more fully in order to aid the design of improved anti-epileptic compounds. Since there is no structure for SV2A, homology modelling can provide insight into the ligand-binding site. However, it is not a trivial process to build such models, since SV2A has low sequence identity to those MFS transporters whose structures are known. A further level of complexity is added by the fact that it is not known which conformational state of the receptor LEV binds to, as multiple conformational states have been inferred by tomography and ligand binding assays or indeed, if binding is exclusive to a single state. Here, we explore models of both the inward and outward facing conformational states of SV2A (according to the alternating access mechanism for MFS transporters). We use a sequence conservation analysis to help guide the homology modelling process and generate the models, which we assess further with Molecular Dynamics (MD). By comparing the MD results in conjunction with docking and simulation of a LEV-analogue used in radioligand binding assays, we were able to suggest further residues that line the binding pocket. These were confirmed experimentally. In particular, mutation of D670 leads to a complete loss of binding. The results shed light on the way LEV analogues may interact with SV2A and may help with the on-going design of improved anti-epileptic compounds.

The fetal safety of Levetiracetam: a systematic review

OBJECTIVE

To systematically review the available published evidence on the fetal safety of Levetiracetam with focus on birth defects.

RESULTS

Eight studies met the inclusion criteria; five pregnancy registries and one population based cohort study. A total of 27 major congenital malformations were reported among 1213 Levetiracetam monotherapy - exposed pregnant women, yielding an overall major malformation rate of 2.2% (27/1213) [95% confidence interval of 1.53-3.22]. In contrast, Levetiracetam polytherapy was associated with significantly higher malformation rate of 6.3% (34/541) [95% CI of 4.53-8.65] (P<0.001). Additionally 2 studies investigating child neurodevelopment in Levetiracetam - exposed children revealed that the measured achievements were well above those children exposed to valproic acid, and similar to unexposed controls.

CONCLUSIONS

The current evidence suggests that the overall risk of major malformation after first trimester exposure to Levetiracetam is within the population baseline risk of 1-3%, with no apparent adverse effects on long term child development.

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.

Insights from zebrafish and mouse models on the activity and safety of ar-turmerone as a potential drug candidate for the treatment of epilepsy

In a previous study, we uncovered the anticonvulsant properties of turmeric oil and its sesquiterpenoids (ar-turmerone, α-, β-turmerone and α-atlantone) in both zebrafish and mouse models of chemically-induced seizures using pentylenetetrazole (PTZ). In this follow-up study, we aimed at evaluating the anticonvulsant activity of ar-turmerone further. A more in-depth anticonvulsant evaluation of ar-turmerone was therefore carried out in the i.v. PTZ and 6-Hz mouse models. The potential toxic effects of ar-turmerone were evaluated using the beam walking test to assess mouse motor function and balance. In addition, determination of the concentration-time profile of ar-turmerone was carried out for a more extended evaluation of its bioavailability in the mouse brain. Ar-turmerone displayed anticonvulsant properties in both acute seizure models in mice and modulated the expression patterns of two seizure-related genes (c-fos and brain-derived neurotrophic factor [bdnf]) in zebrafish. Importantly, no effects on motor function and balance were observed in mice after treatment with ar-turmerone even after administering a dose 500-fold higher than the effective dose in the 6-Hz model. In addition, quantification of its concentration in mouse brains revealed rapid absorption after i.p. administration, capacity to cross the BBB and long-term brain residence. Hence, our results provide additional information on the anticonvulsant properties of ar-turmerone and support further evaluation towards elucidating its mechanism of action, bioavailability, toxicity and potential clinical application.

Pharmacodynamic potentiation of antiepileptic drugs' effects by some HMG-CoA reductase inhibitors against audiogenic seizures in DBA/2 mice

It is known that the 3-hydroxy-3-methylglutaryl coenzyme A (HMG-CoA) reductase inhibitors (statins) are effective in both the primary and the secondary prevention of ischemic heart disease. Increasing evidence indicates that statins have protective effects in several neurological diseases including stroke, cerebral ischemia, Parkinson disease, multiple sclerosis, traumatic brain injury and epilepsy. The aim of the present research was to evaluate the effects of some HMG-CoA reductase inhibitors (i.e. lovastatin, simvastatin, atorvastatin, fluvastatin and pravastatin) commonly used for the treatment of hypercholesterolemia in the DBA/2 mice, an animal model of generalized tonic-clonic seizures. Furthermore, the co-administration of these compounds with some antiepileptic drugs (AEDs; i.e. carbamazepine, diazepam, felbamate, gabapentin, lamotrigine, levetiracetam, oxcarbazepine, phenobarbital, phenytoin, topiramate and valproate) was studied in order to identify possible positive pharmacological interactions. Simvastatin only was active against both the tonic and clonic phase of audiogenic seizures, whereas the other statins tested were only partially effective against the tonic phase with the following order of potency: lovastatin>fluvastatin>atorvastatin; pravastatin was completely ineffective up to the dose of 150mg/kg. The co-administration of ineffective doses of all statins with AEDs generally increased the potency of the latter reducing their ED50 values. In particular, simvastatin was the most active in potentiating the activity of AEDs and the combinations of statins with carbamazepine, diazepam, felbamate, lamotrigine, topiramate and valproate were the most favorable, whereas, the co-administrations with the other AEDs studied was in most cases neutral. The increase in potency was generally associated with an enhancement of motor impairment (TD50); however, the therapeutic index (TD50/ED50) of combined treatment of AEDs with statins was predominantly more favorable than control. Statins administration did not significantly affect the total plasma but, in some cases, it increased the free plasma levels and the brain concentrations of some of the AEDs studied (i.e. carbamazepine, diazepam, phenytoin and valproate); however, these alterations where not statistically significant. Therefore, with the exception of the latter compounds, we might exclude pharmacokinetic interactions and conclude that for the most of AEDs, potentiation was of pharmacodynamic nature. In conclusion, simvastatin, fluvastatin, lovastatin and atorvastatin showed an additive anticonvulsant effect when co-administered with some AEDs, most notably carbamazepine, diazepam, felbamate, lamotrigine, topiramate and valproate, implicating a possible therapeutic relevance of such drug combinations. The present results suggest that statins, besides the beneficial cardiovascular effects, might be able to affect brain areas, which might participate in the regulation of seizure susceptibility.

Polypharmacy and the role of physical medicine and rehabilitation

Polypharmacy and inappropriate prescribing practices lead to higher rates of mortality and morbidity, particularly in vulnerable populations, such as the elderly and those with complex medical conditions. Physical medicine and physiatrists face particular challenges given the array of symptoms treated across a spectrum of conditions. This clinical review focuses on polypharmacy and the associated issue of potentially inappropriate prescribing. The article begins with a review of polypharmacy along with relevant aspects of pharmacokinetics and pharmacodynamics in the elderly. The adverse effects and potential hazards of selected medications commonly initiated and managed by rehabilitation specialists are then discussed with specific attention to pain medications, neurostimulants, antipsychotics, antidepressants, antispasmodics, sleep medications, and antiepileptics. Of particular concern is the notion that an adverse effect of one medication can mimic an indication for another and lead to a prescribing cascade and further adverse medication events. Appropriate prescribing practices mandate an accurate, current medication list, yet errors and inaccuracies often plague such lists. The evidence to support explicit (medications to avoid) and implicit (how to evaluate) criteria is presented along with the role of physicians and patients in prescribing medications. A brief discussion of "medication debridement" or de-prescribing strategies follows. In the last section, we draw on the essence of physiatry as a team-based endeavor to discuss the potential benefits of collaboration. In working to optimize medication prescribing, efforts should be made to collaborate not only with pharmacists and other medical specialties but with members of inpatient rehabilitation teams as well.

Effect of levetiracetam monotherapy on background EEG activity and cognition in drug-naïve epilepsy patients

OBJECTIVE

To investigate the cognitive effect of levetiracetam (LEV) monotherapy with quantitative electroencephalogram (EEG) analysis and neuropsychological (NP) tests.

METHODS

Twenty-two drug-naïve epilepsy patients were enrolled. EEG recordings were performed before and after LEV therapy. Relative power of discrete frequency bands was computed, as well as alpha peak frequency (APF) at occipital electrodes. Eighteen patients performed a battery of NP tests twice across LEV treatment.

RESULTS

LEV therapy decreased the power of delta (1-3 Hz, p<0.01) and theta (3-7 Hz, p<0.05) bands and increased that of alpha-2 (10-13 Hz, p<0.05) and beta-2 (19-24 Hz, p<0.05) bands. Region-specific spectral change was observed: delta power change was significant in fronto-polar region, theta in anterior region, alpha-2 in broad region, and beta-2 in left fronto-central region. APF change was not significant. Improvement in diverse NP tests requiring attention, working memory, language and executive function was observed. Change in theta, alpha-2, and beta-2 power was correlated with improvement in several NP tests.

CONCLUSIONS

Our data suggest LEV is associated with acceleration of background EEG frequencies and improved cognitive function. Change in frequency band power could predict improvement in several cognitive domains across LEV therapy.

SIGNIFICANCE

Combined study of quantitative EEG analysis and NP tests can be useful in identifying cognitive effect of antiepileptic drugs.

Restless Leg Syndrome in ADHD children: levetiracetam as a reasonable therapeutic option

The comorbidity of Attention Deficit Hyperactivity Disorder (ADHD) with sleep disorders has been extensively studied. In particular, Restless Legs Syndrome (RLS) appears to be consistently more frequent in children with ADHD. Several papers also draw attention to the frequent occurrence of epileptic seizures and EEG abnormalities in ADHD children. We performed a preliminary open label study to evaluate the efficacy of Levetiracetam (LEV) to ameliorate the sleep pattern and reduce RLS symptoms in children with a complex comorbidity between Attention Deficit Hyperactivity Disorder (ADHD), RLS and focal interictal epileptic discharges (IEDs) on EEG. We recruited seven children (all males, aged between 5 and 12years) who fulfilled the following criteria: ADHD diagnosis combined subtype; presence of idiopathic RLS; and presence of focal IEDs on EEG. All children were given LEV at a starting dose of approximately 10-20mg/kg/day followed by 10mg/kg/day incrementing at 1-week intervals up to 50-60mg/kg/day given in two separate doses. At a 3 and 6month follow-up, all children showed significant improvement (p<0.05) in global International RLS Rating Scale (IRLS-RS). Parents' reports revealed improved sleep quality with fewer awakenings and restorative sleep in their children. LEV was well tolerated and no major side effects were reported. With an accessory report we observed the reduction of epileptiform EEG activity during sleep. In most patients (6 on 7) the discharges completely disappeared; in the last patient epileptiform EEG activity was significantly reduced. These children may represent a subgroup of ADHD patients in which the hyperactivity and attention difficulties might be aggravated by sleep disturbances and by IEDs. LEV could represent a therapeutic option for these comorbid conditions.

Evidence-based pharmacotherapy for pediatric obsessive-compulsive disorder and chronic tic disorders

In recent years, much progress has been made in pharmacotherapy for pediatric obsessive-compulsive disorder (OCD) and chronic tic disorders (CTDs). What were previously considered relatively intractable conditions now have an array of efficacious medicinal (and psychosocial) interventions available at clinicians’ disposal, including selective serotonin reuptake inhibitors, atypical antipsychotics, and alpha-2 agonists. The purpose of this review is to discuss the evidence base for pharmacotherapy with pediatric OCD and CTDs with regard to efficacy, tolerability, and safety, and to put this evidence in the context of clinical management in integrated behavioral healthcare. While there is no single panacea for these disorders, there are a variety of medications that provide considerable relief for children with these disabling conditions.

Comparison of the antiepileptogenic effects of an early long-term treatment with ethosuximide or levetiracetam in a genetic animal model of absence epilepsy

PURPOSE

Epilepsy is a heterogeneous syndrome characterized by recurrent, spontaneous seizures; continuous medication is, therefore, necessary, even after the seizures have long been suppressed with antiepileptic drug (AED) treatments. The most disturbing issue is the inability of AEDs to provide a persistent cure, because these compounds generally suppress the occurrence of epileptic seizures without necessarily having antiepileptogenic properties. The aim of our experiments was to determine, in the WAG/Rij model of absence epilepsy, if early long-term treatment with some established antiabsence drugs might prevent the development of seizures, and whether such an effect could be sustained.

METHODS

WAG/Rij rats were treated for ∼3.5 months (starting at 1.5 months of age, before seizure onset) with either ethosuximide (ETH; drug of choice for absence epilepsy) or levetiracetam (LEV; a broad-spectrum AED with antiabsence and antiepileptogenic properties).

RESULTS

We have demonstrated that both drugs are able to reduce the development of absence seizures, exhibiting antiepileptogenic effects in this specific animal model.

DISCUSSION

These findings suggest that absence epilepsy in this strain of rats very likely follows an epileptogenic process during life and that early therapeutic intervention is possible, thereby opening a new area of research for absence epilepsy and AED treatment strategies.