Efficacy and safety of pregabalin versus lamotrigine in patients with newly diagnosed partial seizures: a phase 3, double-blind, randomised, parallel-group trial

Presynaptic antiseizure medications - basic mechanisms and clues for their rational combinations

Among clinically highly efficient antiseizure medications (ASMs) there are modifiers of the presynaptic release machinery. Of them, levetiracetam and brivaracetam show a high affinity to the synaptic vesicle protein type 2 A (SV2A), whereas pregabalin and gabapentin are selective ligands for the α2δ1 subunits of the voltage-gated calcium channels. In this paper, we present recent progress in understanding the significance of presynaptic release machinery in the neurochemical mechanisms of epilepsy and ASMs. Furthermore, we discuss whether the knowledge of the basic mechanisms of the presynaptically acting ASMs might help establish a rational polytherapy for drug-resistant epilepsy.

Antiseizure Medications for Adults With Epilepsy: A Review

IMPORTANCE

Epilepsy affects approximately 65 million people worldwide. Persistent seizures are associated with a 20% to 40% risk of bodily injuries (eg, fractures, burns, concussions) over 12-month follow-up. The primary goal of epilepsy treatment is to eliminate seizures while minimizing adverse effects of antiseizure drugs (ASDs).

OBSERVATIONS

An epileptic seizure is defined as a sudden occurrence of transient signs and symptoms caused by abnormal and excessive or synchronous neuronal activity in the brain. Focal and generalized epilepsy are the 2 most frequent types of epilepsy; diagnosis is based on the type of seizures. There are 26 US Food and Drug Administration-approved medications for epilepsy, of which 24 have similar antiseizure efficacy for focal epilepsy and 9 have similar efficacy for generalized epilepsy. The decision to initiate an ASD should be individualized, but should be strongly considered after 2 unprovoked seizures or after 1 unprovoked seizure that occurred during sleep and/or in the presence of epileptiform activity on an electroencephalogram and/or in the presence of a structural lesion on the brain magnetic resonance imaging. The ASDs must be selected based on the seizure and epilepsy types, the epilepsy syndrome, and the adverse effects associated with the drug. For focal epilepsy, oxcarbazepine and lamotrigine are first-line therapy, while levetiracetam can be also considered if there is no history of psychiatric disorder. For generalized epilepsy, the selection of the ASD is based on the type of epilepsy syndrome and the patient's sex, age, and psychiatric history. Seizure freedom is achieved in approximately 60% to 70% of all patients. A total of 25% to 50% of patients also experience neurologic, psychiatric, cognitive, or medical disorders, such as mood, anxiety, and attention deficit disorders and migraines. For these patients, selecting an ASD should consider the presence of these disorders and concomitant use of medications to treat them. ASDs with cytochrome P450 enzyme-inducing properties (eg, carbamazepine, phenytoin) may worsen comorbid coronary and cerebrovascular disease by causing hyperlipidemia and accelerating the metabolism of concomitant drugs used for their treatment. They can also facilitate the development of osteopenia and osteoporosis.

CONCLUSIONS AND RELEVANCE

Epilepsy affects approximately 65 million people worldwide and is associated with increased rates of bodily injuries and mortality when not optimally treated. For focal and generalized epilepsy, selection of ASDs should consider the seizure and epilepsy types and epilepsy syndrome, as well as the patient's age and sex, comorbidities, and potential drug interactions.

Update on Antiseizure Medications 2022

EDITORS NOTE

The article "Update on Antiseizure Medications 2022" by Dr Abou-Khalil was first published in the February 2016 Epilepsy issue of Continuum: Lifelong Learning in Neurology as "Antiepileptic Drugs," and at the request of the Editor-in-Chief was updated by Dr Abou-Khalil for the 2019 issue and again for this issue.

Secular Trends in the Incidence, Prevalence, and Medications for Epilepsy from 2007 to 2015 in Taiwan: A Nationwide Population-Based Study

BACKGROUND

Patients with epilepsy have a higher mortality rate than the general population. Up-to-date estimates of epilepsy incidence, prevalence, and medication use are critical to assist policymaking.

METHODS

Using the National Taiwan Insurance Research Database, the standardized incidence and prevalence of epilepsy were estimated in each calendar year from 2007 to 2015. We used the incident cases of epilepsy to analyze the change in prescribing patterns from 2007 to 2015. Joinpoint regression was used to estimate secular trends.

RESULTS

From 2007 to 2015, the age- and sex-standardized incidence decreased from 0.72 (95% confidence interval [CI] 0.70-0.73) to 0.54 (95% CI 0.53-0.55) per 1,000 person-years, giving an annual percentage change (APC) of -2.73 (p < 0.05). Among patients younger than 20 years, the incidence did not change significantly. The age- and sex-standardized prevalence decreased from 6.94 (95% CI 6.90-6.98) to 6.86 (95% CI, 6.82-6.89) per 1,000 people, giving an APC of -0.31 (p < 0.05). However, the prevalence increased in the 35- to 49- and 50- to 64-year age-groups. The most common first-line anticonvulsant was phenytoin in 2007 and valproate in 2015. The use of levetiracetam, clobazam, and valproate increased during the study period, with APCs of 25.48% (95% CI 19.97-31.24), 6.41 (3.09-9.85), and 2.83 (1.51-4.16), respectively. The use of carbamazepine, phenytoin, and topiramate decreased; the APCs were -23.86% (95% CI -25.25 to -22.44), -6.61 (-8.40 to -4.79), and -4.29% (-7.87 to -0.57), respectively.

CONCLUSIONS

The overall prevalence and incidence of epilepsy decreased slightly from 2007 to 2015. The prescribed first-line anticonvulsant also changed over time.

Efficacy and tolerability of antiseizure drugs

Drug-resistant epilepsy occurs in 25-30% of patients. Furthermore, treatment with a first-generation antiseizure drug (ASD) fails in 30-40% of individuals because of their intolerable adverse effects. Over the past three decades, 20 newer- (second- and third-)generation ASDs with unique mechanisms of action and pharmacokinetic profiles have been introduced into clinical practice. This advent has expanded the therapeutic armamentarium of epilepsy and broadens the choices of ASDs to match the individual patient's characteristics. In recent years, research has been focused on defining the ASD of choice for different seizure types. In 2017, the International League Against Epilepsy published a new classification for seizure types and epilepsy syndrome. This classification has been of paramount importance to accurately classify the patient's seizure type(s) and prescribe the ASD that is appropriate. A year later, the American Academy of Neurology published a new guideline for ASD selection in adult and pediatric patients with new-onset and treatment-resistant epilepsy. The guideline primarily relied on studies that compare the first-generation and second-generation ASDs, with limited data for the efficacy of third-generation drugs. While researchers have been called for investigating those drugs in future research, epilepsy specialists may wish to share their personal experiences to support the treatment guidelines. Given the rapid advances in the development of ASDs in recent years and the continuous updates in definitions, classifications, and treatment guidelines for seizure types and epilepsy syndromes, this review aims to present a complete overview of the current state of the literature about the efficacy and tolerability of ASDs and provide guidance to clinicians about selecting appropriate ASDs for initial treatment of epilepsy according to different seizure types and epilepsy syndromes based on the current literature and recent US and UK practical guidelines.

Neuropharmacology of Antiseizure Drugs

BACKGROUND

Antiseizure drugs (ASDs) are the primary therapy for epilepsy, with more than 20 drugs introduced into clinical practice to date. These drugs are typically grouped by their mechanisms of action and therapeutic spectrum. This article aims to educate non-neurologists and medical students about the new frontiers in the pharmacology of ASDs and presents the current state of the literature on the efficacy and tolerability of these agents.

METHODS

Randomized controlled trials, observational studies, and evidence-based meta-analyses of ASD efficacy and tolerability as initial monotherapy for epileptic seizures and syndromes were identified in PubMed, EMBASE, the Cochrane Library, and Elsevier Clinical Pharmacology.

RESULTS

The choice of ASD varies primarily according to the seizure type. Practical guidelines for ASD selection in patients with new-onset and drug-resistant epilepsy were recently published. The guidelines have shown that the newer-generation drugs, which have unique mechanistic and pharmacokinetic properties, are better tolerated but have similar efficacy compared with the older drugs. Several ASDs are effective as first-line monotherapy in focal seizures, including lamotrigine, carbamazepine, phenytoin, levetiracetam, and zonisamide. Valproate remains the first-line drug for many patients with generalized and unclassified epilepsies. However, valproate should be avoided, if possible, in women of childbearing potential because of teratogenicity. Toxicity profile precludes several drugs from use as first-line treatment, for example, vigabatrin, felbamate, and rufinamide.

CONCLUSIONS

Antiseizure drugs have different pharmacologic profiles that should be considered when selecting and prescribing these agents for epilepsy. These include pharmacokinetic properties, propensity for drug-drug interactions, and adverse effects.

Study protocol for a phase II randomised, double-blind, placebo-controlled trial of perampanel as an antiepileptogenic treatment following acute stroke

INTRODUCTION

Stroke is a common cause of epilepsy that may be mediated via glutamate dysregulation. There is currently no evidence to support the use of antiseizure medications as primary prevention against poststroke epilepsy. Perampanel has a unique antiglutamatergic mechanism of action and may have antiepileptogenic properties. This study aims to evaluate the efficacy and safety of perampanel as an antiepileptogenic treatment in patients at high risk of poststroke epilepsy.

METHODS AND ANALYSIS

Up to 328 patients with cortical ischaemic stroke or lobar haemorrhage will be enrolled, and receive their first treatment within 7 days of stroke onset. Patients will be randomised (1:1) to receive perampanel (titrated to 6 mg daily over 4 weeks) or matching placebo, stratified by stroke subtype (ischaemic or haemorrhagic). Treatment will be continued for 12 weeks after titration. 7T MRI will be performed at baseline for quantification of cerebral glutamate by magnetic resonance spectroscopy and glutamate chemical exchange saturation transfer imaging. Blood will be collected for measurement of plasma glutamate levels. Participants will be followed up for 52 weeks after randomisation.The primary study outcome will be the proportion of participants in each group free of late (more than 7 days after stroke onset) poststroke seizures by the end of the 12-month study period, analysed by Fisher's exact test. Secondary outcomes will include time to first seizure, time to treatment withdrawal and 3-month modified Rankin Scale score. Quality of life, cognitive function, mood and adverse events will be assessed by standardised questionnaires. Exploratory outcomes will include correlation between cerebral and plasma glutamate concentration and stroke and seizure outcomes.

ETHICS AND DISSEMINATION

This study was approved by the Alfred Health Human Research Ethics Committee (HREC No 44366, Reference 287/18).

TRIAL REGISTRATION NUMBER

ACTRN12618001984280; Pre-results.

Seizure outcome after epilepsy surgery for patients with normal MRI: A Single center experience

OBJECTIVE

To analyze the surgical outcome in non-lesional intractable focal epilepsies in our center and to find possible predictors for better outcome.

METHODS

This is a retrospective study for 40 adult patients with intractable focal epilepsy following at KFSHRC-Riyadh, who underwent presurgical evaluation followed by resective surgery and continued follow up for a minimum of 2 years. The surgery outcome was evaluated based on the type of surgical procedure and histopathology results.

RESULTS

Out of all 40 patients studied, seizure freedom was achieved in 19 (47.5 %) and 17 (42.5 %) patients at the first and second year respectively in all non-lesional cases. Seizure freedom in non-lesional temporal lobe surgery was achieved in 10 (45 %) of patients at 2 years, 5 (38 %) in non-lesional frontal lobe patients at 2 years and 8 (44 %), 7 (38 %) for all extratemporal at 1 and 2 years respectively. Good prognosis was seen in patients with localized positron emission tomography (PET), had no aura and had a clear ictal onset either on scalp electroencephalogram (EEG) or subdural invasive electroencephalogram.

SIGNIFICANCE

The best surgical outcome is achievable in patients with non-lesional focal epilepsy. This study highlights the prognostic value of the PET scan and ictal scalp/subdural invasive EEG.

[Pharmacoeconomic aspects of monotherapy of focal epilepsy]

AIM

To perform a clinical/economic comparison of monotherapy with antiepileptic drugs (AED) in patients with newly diagnosed focal epilepsy (FE) based on the results of previous studies.

MATERIAL AND METHODS

The most common AEDs (carbamazepine (CBZ), oxcarbazepine (OXZ), lamotrigine (LTG), lacosamide (LCM)) were compared in patients, aged 16 years and over, with illness duration of five years.

RESULTS AND CONCLUSION

CBZ, OXZ and LCM can be used as monotherapy in patients with newly diagnosed FE. Monotherapy with LCM is associated with lowest costs for stopping focal seizures and the highest percentage of seizure-free patients. CBZ remains the most economical AED: the cost-effectiveness is minimal compared to all other AEDs used in the study. However, monotherapy with LCM is advisable if it is necessary to minimize side-effects in patients with newly diagnosed FE.

Position paper of a German interdisciplinary round table on future designs of trials on adjunctive treatment with antiseizure drugs

PURPOSE

Current trials on adjunctive treatment with antiseizure drugs often do not reveal results which are relevant for clinical practice.

METHOD

Therefore, an interdisciplinary group of German experts discussed a new framework for future antiseizure drug (ASD) trials in adults. This group included members of the executive board of the German Society of Epileptology, of the German institutes for health technology assessment (HTA), of patient organizations and of drug manufacturers. Agreement was reached by consensus decision making after intensive discussion of the findings of a narrative review of the current literature.

RESULTS

The group jointly recommends that ASD trials in adults should be based on and include relevant patient groups, e.g. elderly patients and patients with relevant co-morbidities, should adopt a study duration of at least 12 months, should avoid placebo arms, should include active comparators of clinical relevance, may be designed as open label trials with blinded outcome measurements, should focus on patient relevant outcomes that reflect the impact of benefits and harms of treatments on daily living, such as seizure freedom and seizure severity as well as retention rate, functional outcomes and quality of life as compound measures, and should avoid arbitrary and non-sensitive primary endpoints such as dichotomized changes in seizure frequency.

CONCLUSIONS

This paper focused on improved head-to-head trials on adjunctive treatment with antiseizure drugs. The group welcomes any further work and discussion to enhance future studies which can be applied to the entire spectrum of potentially meaningful study populations and outcomes.

Pharmacodynamic interactions of antiepileptic drugs: From bench to clinical practice

BACKGROUND

Approximately 50% of patients do not achieve seizure control with antiepileptic drug (AED) monotherapy, and polytherapy, with more than one AED, is often required. To date, no evidence-based criteria on how to combine AEDs exist.

OBJECTIVE

This narrative review aimed to provide critical findings of the available literature about the role of pharmacodynamic AEDs' interactions in patients whose epilepsies were treated with polytherapy.

METHODS

Electronic databases, Medical Literature Analysis and Retrieval System Online (MEDLINE) and Excerpta Medica dataBASE (EMBASE), were systematically searched to identify relevant studies on pharmacodynamic AEDs' interactions in patients with epilepsy.

RESULTS AND CONCLUSION

Most data on AED combinations are coming from animal models and preclinical studies. Combining AEDs with different mechanisms of actions seems to have greater effectiveness and lower risk of adverse event development. Conversely, the combination of AEDs may cause pharmacodynamic synergistic effects that may result in not only increased efficacy but also more adverse effects. Despite some AED associations that have been proven to be effective in specific epilepsy/seizure type (e.g., phenobarbital+/phenytoin for tonic seizures and ethosiximide + valproate for absences; lamotrigine + valproate for various epilepsy/seizure types), no clear and definitive evidence exists about AED combinations in humans. Examples of pharmacodynamic interactions that possibly explain the synergistic effects on efficacy or adverse effects include the combination between vigabatrin or pregabalin and sodium channel blockers (supra-additive antiseizure effect) and lacosamide combined with other sodium channel blockers (infra-additive antiseizure effect and neurotoxicity synergistic). The pharmacodynamic lamotrigine-valproate interaction is also supported by synergistic adverse events. Therefore, well-designed double-blind prospective studies recruiting a sufficient number of patients possibly with a crossover design and carefully ascertain the role of pharmacokinetic interactions and variations of AEDs' levels in the blood are needed.

Update on Antiepileptic Drugs 2019

PURPOSE OF REVIEW

This article is an update from the article on antiepileptic drug (AED) therapy published in the last Continuum issue on epilepsy and is intended to cover the vast majority of agents currently available to the neurologist in the management of patients with epilepsy. Treatment of epilepsy starts with AED monotherapy. Knowledge of the spectrum of efficacy, clinical pharmacology, and modes of use for individual AEDs is essential for optimal treatment for epilepsy. This article addresses AEDs individually, focusing on key pharmacokinetic characteristics, indications, and modes of use.

RECENT FINDINGS

Since the previous version of this article was published, three new AEDs, brivaracetam, cannabidiol, and stiripentol, have been approved by the US Food and Drug Administration (FDA), and ezogabine was removed from the market because of decreased use as a result of bluish skin pigmentation and concern over potential retinal toxicity.Older AEDs are effective but have tolerability and pharmacokinetic disadvantages. Several newer AEDs have undergone comparative trials demonstrating efficacy equal to and tolerability at least equal to or better than older AEDs as first-line therapy. The list includes lamotrigine, oxcarbazepine, levetiracetam, topiramate, zonisamide, and lacosamide. Pregabalin was found to be less effective than lamotrigine. Lacosamide, pregabalin, and eslicarbazepine have undergone successful trials of conversion to monotherapy. Other newer AEDs with a variety of mechanisms of action are suitable for adjunctive therapy. Most recently, the FDA adopted a policy that a drug's efficacy as adjunctive therapy in adults can be extrapolated to efficacy in monotherapy. In addition, efficacy in adults can be extrapolated for efficacy in children 4 years of age and older. Both extrapolations require data demonstrating that an AED has equivalent pharmacokinetics between its original approved use and its extrapolated use. In addition, the safety of the drug in pediatric patients has to be demonstrated in clinical studies that can be open label. Rational AED combinations should avoid AEDs with unfavorable pharmacokinetic interactions or pharmacodynamic interactions related to mechanism of action.

SUMMARY

Knowledge of AED pharmacokinetics, efficacy, and tolerability profiles facilitates the choice of appropriate AED therapy for patients with epilepsy.

Immediate and controlled-release pregabalin for the treatment of epilepsy

Introduction: Epilepsy is a common neurological disease requiring complex therapies, which are unable to achieve seizure control in 30% of patients. Poor adherence has been recognized as a possible determinant of drug-resistance. Prolonged-release formulations of antiepileptic drugs might help increase adherence and minimize side effects.Areas covered: Pregabalin (PGB) has peculiar pharmacodynamics and almost ideal pharmacokinetics, except for a short half-life and therefore requiring multiple daily dosing. PGB immediate-release (IR) is effective in focal-onset epilepsy (FOE), neuropathic pain, generalized anxiety disorder, and fibromyalgia, despite some tolerability issues, especially at higher doses. The controlled-release formulation (CR) shares PGB IR advantages and requires slight dose adjustments to guarantee bioavailability. In 2014, PGB CR (165 and 330 mg/day) failed to prove superior to placebo in a randomized placebo-controlled trial on 323 subjects with drug-resistant FOE, although it was just as tolerable. Therefore, PGB CR is not currently licensed for epilepsy.Expert opinion: Considering the disappointing results of the only controlled trial, PGB CR is unlikely to become an established epilepsy treatment anytime soon. Nevertheless, given its peculiar properties and potential advantages, PGB (in either formulation) should be further evaluated in specific populations of patients, especially fragile subjects with several comorbidities and complex polytherapies.

Clinical opinion: Earlier employment of polytherapy in sequential pharmacotherapy of epilepsy

Modern pharmacotherapy for epilepsy consists of orderly, sequential drug trials, in which antiepileptic drugs (AEDs) are chosen under the concept of individual patient-oriented (or - tailored) pharmacotherapy. Although monotherapy has been established as the preferred mode of AEDs therapy in both newly diagnosed and drug resistant epilepsies, there are still lack of evidence to favor either monotherapy or polytherapy in epilepsy, which has generated continuing controversies on the preferred mode of pharmacotherapy. However, each mode of pharmacotherapy may have both advantages and disadvantages, which are different and variable related to individual case scenario. We conducted a brief comparative overview between monotherapy and polytherapy to provide clues for earlier employment of polytherapy in each steps of sequential drug trials. Previous claims about the advantages of monotherapy over polytherapy are not supported but gradually losing its ground by the introduction of a large number of drugs carrying pharmacological advantages for combination therapy. Current evidence stresses the importance of combining drugs having synergistic interactions for better outcome of polytherapy, which has not been considered in previous clinical investigations comparing monotherapy and polytherapy. It is likely that a significant improvement in the outcome of current AEDs therapy is feasible by earlier employment of polytherapy as well as identification of combination drug regimens carrying synergistic interactions. At present, lamotrigine(LTG) and valproate(VPA) combination regimen is the only well documented synergistic regimen, but there are a long-list of candidate regimens requiring future trials in appropriate designs.

Antiepileptic monotherapy in newly diagnosed focal epilepsy. A network meta-analysis

Second and third generation AEDs have been directly compared to controlled-release carbamazepine (CBZ-CR) as initial monotherapy for new-onset focal epilepsy. Conversely, no head-to-head trials have been performed. The aim of this study was to estimate the comparative efficacy and tolerability of the antiepileptic monotherapies in adults with newly diagnosed focal epilepsy through a network meta-analysis (NMA). Randomized, double-blinded, parallel group, monotherapy studies comparing any AED to CBZ-CR in adults with newly diagnosed untreated epilepsy with focal-onset seizures was identified. The outcome measures were the seizure freedom for 6 and 12 months, the occurrence of treatment-emergent adverse events (TEAEs), and the treatment withdrawal due to TEAEs. Mixed treatment comparisons were conducted by a Bayesian NMA using the Markov chain Monte Carlo methods. Effect sizes were calculated as odds ratios (ORs) with 95% credible intervals (CrIs). Four trials were included involving 2856 participants, 1445 for CBZ-CR and 1411 for the comparative AEDs. Monotherapy AEDs compared to CBR-CR were levetiracetam (LEV), zonisamide (ZNS), lacosamide (LCM), and eslicarbazepine acetate (ESL). There were no statistical differences in the 6- and 12-month seizure freedom and TEAEs occurrence between LEV, ZNS, LCM, ESL, and CBZ-CR In the analysis of drug withdrawal due to TEAEs, LCM treatment was associated with a significantly lower discontinuation rate than CBZ-CR (OR 0.659, 95% CrI 0.428-0.950). LEV, ZNS, LCM, and ESL are effective initial monotherapy treatments in adult patients with newly diagnosed focal epilepsy and represent suitable alternatives to CBZ-CR.

Comparative effectiveness of add-on therapy with newer-generation antiepileptic drugs in Bulgarian patients with refractory epilepsy

OBJECTIVES

The objective of this study is to perform an open, prospective study on various aspects of comparative effectiveness of newer-generation antiepileptic drugs as add-on therapy in Bulgarian patients with drug-resistant epilepsy.

METHODS

The study was performed with the participation of 1259 patients with epilepsy who attended the Clinic of Neurology at the University Hospital in Plovdiv, Bulgaria for regular visits and completed diaries about seizure frequency, severity, and adverse events.

RESULTS

Oxcarbazepine was used in 82 patients, topiramate in 120 patients, lamotrigine in 73 patients, levetiracetam in 135 patients, pregabalin in 47 patients, tiagabine in 43 patients, gabapentin in 18 patients, lacosamide in 12 patients, and retigabine in 6 patients. During the first 24 months of study, improvement of seizure severity and frequency was most frequent in patients on treatment with pregabalin and levetiracetam and rarest in those on treatment with oxcarbazepine. The retention rate of patients on pregabalin and tiagabine was significantly lower compared to the retention rate of patients on most of the other antiepileptic drugs. The frequency of adverse events was higher in patients on treatment with tiagabine and pregabalin.

CONCLUSION

Despite some similar characteristics of newer-generation antiepileptic drugs' effectiveness, levetiracetam stands out with better dynamic improvement of seizure severity and frequency and satisfactory tolerability; typical for pregabalin is a very good dynamic improvement of seizure severity and frequency mainly in patients with focal seizures, but a lower tolerability, and the main advantage of oxcarbazepine is a good tolerability, efficacy, however, is less satisfactory.

From clinical trials of antiepileptic drugs to treatment

Rational prescribing should be based on the assessment of high-quality evidence about the benefits and risks of available treatment options. Because clinical trials, particularly randomized controlled trials (RCTs), provide the best source of evidence, their design and results need to be carefully scrutinized. The majority of RCTs of antiepileptic drugs (AEDs) have been designed to address regulatory requirements, and generally they involve restrictive eligibility criteria, rigid dosing schemes, short duration of follow-up, and comparison with placebo rather than standard treatments. Although these studies have high internal validity, they are conducted in a setting that is distant from routine clinical practice and therefore their usefulness in guiding treatment decisions is limited. Information more directly applicable to clinical practice can be derived from a relatively small number of comparative effectiveness monotherapy RCTs, although the design of some of these studies was probably biased in favor of the sponsor's product. Alarmingly, there is a paucity of well-designed trials in epilepsy syndromes other than focal epilepsies, and no RCTs at all in most of the less common epileptic syndromes of infancy and childhood. In the light of these shortcomings, there is scope for re-assessing regulatory requirements to facilitate generation of data more directly applicable to the routine clinical setting. Likewise, research-funding organizations should be sensitized about the lack of adequate evidence to guide therapeutic practice in epilepsy, and the need to promote high-quality comparative effectiveness trials. Future prospective pragmatic trials may benefit from the increasingly widespread availability of electronic health records.

Practice guideline update summary: Efficacy and tolerability of the new antiepileptic drugs I: Treatment of new-onset epilepsy: Report of the American Epilepsy Society and the Guideline Development, Dissemination, and Implementation Subcommittee of the American Academy of Neurology

Objective: To update the 2004 American Academy of Neurology (AAN) guideline for treating new-onset focal or generalized epilepsy (GE) with second- and third-generation antiepileptic drugs (AEDs). Methods: The 2004 AAN criteria was used to systematically review literature (January 2003 to November 2015), classify pertinent studies according to the therapeutic rating scheme, and link recommendations to evidence strength. Results: Several second-generation AEDs are effective for new-onset focal epilepsy. Data are lacking on efficacy in new-onset generalized tonic-clonic seizures, juvenile myoclonic epilepsy, or juvenile absence epilepsy, and on efficacy of third-generation AEDs in new-onset epilepsy. Recommendations: Lamotrigine (LTG) should (Level B) and levetiracetam (LEV) and zonisamide (ZNS) may (Level C) be considered in decreasing seizure frequency in adults with new-onset focal epilepsy. LTG should (Level B) and gabapentin (GBP) may (Level C) be considered in decreasing seizure frequency in patients ≥60 years with new-onset focal epilepsy. Unless there are compelling adverse-effect-related concerns, ethosuximide (ETS) or valproic acid (VPA) should be considered before LTG to decrease seizure frequency in treating absence seizures in childhood absence epilepsy (Level B). No high-quality studies suggest clobazam, eslicarbazepine, ezogabine, felbamate, GBP, lacosamide, LEV, LTG, oxcarbazepine, perampanel, pregabalin, rufinamide, tiagabine, topiramate, vigabatrin, or ZNS is effective in treating new-onset epilepsy because no high-quality studies exist in adults of various ages. A recent FDA strategy allows extrapolation of efficacy across populations; therefore, for focal epilepsy, eslicarbazepine and lacosamide (oral only for pediatric use) as add-on or monotherapy in persons ≥4 years old and perampanel as monotherapy received FDA approval.

Practice guideline update summary: Efficacy and tolerability of the new antiepileptic drugs I: Treatment of new-onset epilepsy

Objective

To update the 2004 American Academy of Neurology (AAN) guideline for treating new-onset focal or generalized epilepsy with second- and third-generation antiepileptic drugs (AEDs).

Methods

The 2004 AAN criteria were used to systematically review literature (January 2003–November 2015), classify pertinent studies according to the therapeutic rating scheme, and link recommendations to evidence strength.

Results

Several second-generation AEDs are effective for new-onset focal epilepsy. Data are lacking on efficacy in new-onset generalized tonic-clonic seizures, juvenile myoclonic epilepsy, or juvenile absence epilepsy, and on efficacy of third-generation AEDs in new-onset epilepsy.

Recommendations

Lamotrigine (LTG) should (Level B) and levetiracetam (LEV) and zonisamide (ZNS) may (Level C) be considered in decreasing seizure frequency in adults with new-onset focal epilepsy. LTG should (Level B) and gabapentin (GBP) may (Level C) be considered in decreasing seizure frequency in patients ≥60 years of age with new-onset focal epilepsy. Unless there are compelling adverse effect–related concerns, ethosuximide or valproic acid should be considered before LTG to decrease seizure frequency in treating absence seizures in childhood absence epilepsy (level B). No high-quality studies suggest clobazam, eslicarbazepine, ezogabine, felbamate, GBP, lacosamide, LEV, LTG, oxcarbazepine, perampanel, pregabalin, rufinamide, tiagabine, topiramate, vigabatrin, or ZNS is effective in treating new-onset epilepsy because no high-quality studies exist in adults of various ages. A recent Food and Drug Administration (FDA) strategy allows extrapolation of efficacy across populations; therefore, for focal epilepsy, eslicarbazepine and lacosamide (oral only for pediatric use) as add-on or monotherapy in persons ≥4 years old and perampanel as monotherapy received FDA approval.

KBG syndrome involving a single-nucleotide duplication in ANKRD11

KBG syndrome is a rare autosomal dominant genetic condition characterized by neurological involvement and distinct facial, hand, and skeletal features. More than 70 cases have been reported; however, it is likely that KBG syndrome is underdiagnosed because of lack of comprehensive characterization of the heterogeneous phenotypic features. We describe the clinical manifestations in a male currently 13 years of age, who exhibited symptoms including epilepsy, severe developmental delay, distinct facial features, and hand anomalies, without a positive genetic diagnosis. Subsequent exome sequencing identified a novel de novo heterozygous single base pair duplication (c.6015dupA) in ANKRD11, which was validated by Sanger sequencing. This single-nucleotide duplication is predicted to lead to a premature stop codon and loss of function in ANKRD11, thereby implicating it as contributing to the proband's symptoms and yielding a molecular diagnosis of KBG syndrome. Before molecular diagnosis, this syndrome was not recognized in the proband, as several key features of the disorder were mild and were not recognized by clinicians, further supporting the concept of variable expressivity in many disorders. Although a diagnosis of cerebral folate deficiency has also been given, its significance for the proband's condition remains uncertain.

Efficacy and Tolerability of Antiepileptic Drugs in Patients with Focal Epilepsy: Systematic Review and Network Meta-analyses

Several newer antiepileptic drugs (AEDs) have been introduced into clinical practice, offering choices for individualizing the treatment of epilepsy since AEDs have different efficacy and tolerability profiles. In particular, questions exist regarding which AEDs are the best options for the monotherapy of focal epilepsy. Is carbamazepine (CBZ), which is considered the standard treatment for focal epilepsy, still the best option for monotherapy of focal epilepsy, despite the emergence of new AEDs? In this systematic review, we compared the relative tolerability of all available AEDs for monotherapy of all types of epilepsy as well as their efficacy in the monotherapy of focal epilepsy. In addition, we compared CBZ with other AEDs for the monotherapy of focal epilepsy. We performed a search of the MEDLINE/PubMed, Scopus, Web of Science, and Cochrane Central Register of Controlled Trials (CENTRAL) databases for randomized controlled clinical trials. To compare the relative efficacy and tolerability of the AEDs, we performed network meta-analyses using a Bayesian random-effects model. Sensitivity analyses were conducted to determine the robustness of the results. A total of 65 studies were included in this review, composing 16,025 patients. Clobazam, levetiracetam, lamotrigine, oxcarbazepine, sulthiame, topiramate, and valproate had the best efficacy profiles and demonstrated no evidence of superiority or inferiority compared with CBZ. However, CBZ showed the greatest risk of patient discontinuation due to intolerable adverse reactions, whereas lamotrigine had the best safety profile and an 81% probability of being the best for the tolerability outcome of patient withdrawals from the study due to intolerable adverse reactions, followed by sulthiame (60%) and clobazam (51%). The newer AEDs-levetiracetam, lamotrigine, oxcarbazepine, sulthiame, and topiramate-should be considered for monotherapy of focal epilepsy because they were demonstrated to be as effective as the older ones (CBZ, clobazam, and valproate) for the treatment of focal epilepsy and were more tolerable. Lamotrigine was the AED with the best tolerability profile, suggesting that it may be the best option for the treatment of focal epilepsy in children and adults.

Empirical estimation of under-reporting in the U.S. Food and Drug Administration Adverse Event Reporting System (FAERS)

BACKGROUND

To examine how closely reporting rates in the FDA Adverse Event Reporting System (FAERS) reflect expected rates of known adverse drug events (ADEs).

METHODS

We selected three groups of drugs to reflect hypothesized variation in sensitivity to reporting, including statins, biologics, and narrow therapeutics index drugs (NTI). The numbers of ADEs in FAERS were divided by utilization estimates from ambulatory health care data (NAMCS/NHAMCS) to calculate a reported proportion. One sample z-test for proportions compared the proportion of ADEs reported to an expected ADE proportion derived from drug labels, reference databases, and peer-reviewed papers.

RESULTS

The majority of drug-ADE pairs showed significant under-reporting. For example, roughly 0.01% to 44% of statin events were reported (z-test p < 0.0001). Biological (0.002% to >100%) and NTI (20% to >100%) drugs had relatively higher reporting rates. Roughly 20% to 33% of the minimum number of expected serious events were reported with biologics and NTI drugs.

CONCLUSIONS

This study supports previous evidence of under-reporting of ADEs in spontaneous reporting data. But, under-reporting varies considerably by the type of drug and the type of ADEs, and this variability in under-reporting should be considered when interpreting safety signals.

Efficacy, safety, and tolerability of lacosamide monotherapy versus controlled-release carbamazepine in patients with newly diagnosed epilepsy: a phase 3, randomised, double-blind, non-inferiority trial

BACKGROUND

Further options for monotherapy are needed to treat newly diagnosed epilepsy in adults. We assessed the efficacy, safety, and tolerability of lacosamide as a first-line monotherapy option for these patients.

METHODS

In this phase 3, randomised, double-blind, non-inferiority trial, patients from 185 epilepsy or general neurology centres in Europe, North America, and the Asia Pacific region, aged 16 years or older and with newly diagnosed epilepsy were randomly assigned in a 1:1 ratio, via a computer-generated code, to receive lacosamide monotherapy or controlled-release carbamazepine (carbamazepine-CR) twice daily. Patients, investigators, and trial personnel were masked to treatment allocation. From starting doses of 100 mg/day lacosamide or 200 mg/day carbamazepine-CR, uptitration to the first target level of 200 mg/day and 400 mg/day, respectively, took place over 2 weeks. After a 1-week stabilisation period, patients entered a 6-month assessment period. If a seizure occurred, the dose was titrated to the next target level (400 or 600 mg/day for lacosamide and 800 or 1200 mg/day for carbamazepine-CR) over 2 weeks with a 1-week stabilisation period, and the 6-month assessment period began again. Patients who completed 6 months of treatment and remained seizure-free entered a 6-month maintenance period on the same dose. The primary efficacy outcome was the proportion of patients remaining free from seizures for 6 consecutive months after stabilisation at the last assessed dose. The predefined non-inferiority criteria were -12% absolute and -20% relative difference between treatment groups. This trial is registered with ClinicalTrials.gov, number NCT01243177.

FINDINGS

The trial was done between April 27, 2011, and Aug 7, 2015. 888 patients were randomly assigned treatment. 444 patients taking lacosamide and 442 taking carbamazepine-CR were included in the full analysis set (took at least one dose of study treatment), and 408 and 397, respectively, were included in the per-protocol set. In the full analysis set, 327 (74%) patients in the lacosamide group and 308 (70%) in the carbamazepine-CR group completed 6 months of treatment without seizures. The proportion of patients in the full analysis set predicted by the Kaplan-Meier method to be seizure-free at 6 months was 90% taking lacosamide and 91% taking carbamazepine-CR (absolute treatment-difference: -1·3%, 95% CI -5·5 to 2·8 relative treatment difference: -6·0%). Kaplan-Meier estimates results were similar in the per-protocol set (92% and 93%; -1·3%, -5·3 to 2·7; -5·7%). Treatment-emergent adverse events were reported in 328 (74%) patients receiving lacosamide and 332 (75%) receiving carbamazepine-CR. 32 (7%) patients taking lacosamide and 43 (10%) taking carbamazepine-CR had serious treatment-emergent adverse events, and 47 (11%) and 69 (16%), respectively, had treatment-emergent adverse events that led to withdrawal.

INTERPRETATION

Treatment with lacosamide met the predefined non-inferiority criteria when compared with carbamazepine-CR. Therefore, it might be useful as first-line monotherapy for adults with newly diagnosed epilepsy.

FUNDING

UCB Pharma.

Not all that glitters is gold: A guide to the critical interpretation of drug trials in epilepsy

Clinical trials represent the best source of evidence on which to base treatment decisions. For such evidence to be utilized meaningfully, however, it is essential that results are interpreted correctly. This requires a good understanding of strengths and weaknesses of the adopted design, the clinical relevance of the outcome measures, and the many factors that could affect such outcomes. As a general rule, uncontrolled studies tend to provide misleading evidence as a result of the impact of confounders such as regression to the mean, patient‐related bias, and observer bias. On the other hand, although randomized controlled trials (RCTs) are qualitatively superior, aspects of their execution may still decrease their validity. Bias and decreased validity in RCTs may occur by chance alone (for example, treatment groups may not necessarily be balanced for important variables despite randomization) or because of specific features of the trial design. In the case of industry‐driven studies, bias often influences the outcome in favor of the sponsor's product. Factors that need to be carefully scrutinized include (1) the purpose for which the trial is conducted; (2) potential bias due to unblinding or lack of blinding; (3) the appropriateness of the control group; (4) the power of the study in detecting clinically relevant differences; (5) the extent to which eligibility criteria could affect outcomes and be representative of routine clinical practice; (6) whether the treatments being compared are used optimally in terms of dosing, duration of treatment, and other variables; (7) the appropriateness of the statistical comparisons; (8) the clinical relevance of the outcome measures and whether all key outcome information is reported (for example, responder rates in completers); and (9) potential bias in the way results are presented and discussed. This article discusses each of these aspects and illustrates the discussion with examples taken from published antiepileptic drug trials.

Cross-sectional study of Pfizer-sponsored clinical trials: assessment of time to publication and publication history

OBJECTIVE

To estimate the proportion of Pfizer-sponsored clinical trials that completed in 2010 and are published as manuscripts in the peer-reviewed literature, and to assess the manuscript development history.

DESIGN

Retrospective, cross-sectional analysis.

SETTING

Clinical trials registered in ClinicalTrials.gov that completed in 2010 for approved, Pfizer prescription products in patients or vaccines in healthy participants.

MAIN OUTCOME MEASURES

The proportion of studies for which the primary outcome(s) was published and the median time from study completion to publication. The manuscript development history included the number of times a manuscript was submitted before it was accepted for publication.

RESULTS

Among registered clinical trials for which Pfizer was the sponsor that completed in 2010, 76 met all inclusion criteria. The primary outcome(s) for 65 (85%) studies was published in 71 manuscripts; the median time to publication was 31 months (range 3-63 months). Of the remaining 11 studies, 2 had been submitted to at least one journal, 2 had not yet been submitted and 7 had no plans to publish because the study had terminated early due to recruitment challenges. Manuscripts accepted at the first choice journal were published at median time of 28 months (range 8-63, n=31), those accepted at second choice journal were published at 32 months (3-45, n=19), and for those accepted at third choice journal, it was 40 months (range 24-53, n=13).

CONCLUSIONS

The publication rate and median time to publication from study completion for Pfizer-sponsored studies were comparable to those previously reported for combined analyses of industry and non-industry sectors. Opportunities exist for sponsors, authors and journals to explore ideas that would facilitate more timely publication for clinical trial results. However, to be effective, such changes may need to revisit the entire publication process.

Specific adverse effects of antiepileptic drugs--A true-to-life monotherapy study

BACKGROUND

In patients taking antiepileptic drugs (AEDs) for epilepsy, adverse effects (AEs) often lead to unfavorable quality of life, impaired adherence, and, eventually, discontinuation of pharmacological treatment. In a true-to-life sample of subjects from our academic epilepsy outpatient clinic, we aimed to identify predictors for overall high AE burden and for specific AEs focusing on patients on monotherapy.

METHODS

All patients ≥16years of age with epilepsy for ≥12months were routinely asked to complete the Liverpool Adverse Event Profile (LAEP) just before their appointment. Demographic, epilepsy, and treatment variables were derived from our comprehensive outpatient database.

RESULTS

Out of 841 patients, 438 (61% female, mean age: 44.7±17.1years) on monotherapy were included in this study. Levetiracetam (n=151), lamotrigine (n=167), valproic acid (n=73), or controlled-release carbamazepine (n=47) were the most commonly used antiepileptic drugs (AEDs). Independent predictors for general high AE burden (LAEP score≥45) were duration of epilepsy, lack of 12-month seizure freedom, and partial epilepsy, but none of the four individual AEDs. The most frequent LAEP-defined specific AEs were sleepiness, difficulty concentrating, tiredness, and memory problems. The three most frequent independent predictors for each of the 19 AEs were lack of 12-month seizure freedom (13/19 AEs), individual AED (7/19 AEs), and partial epilepsy (6/19 AEs). Levetiracetam was independently associated with anger/aggression, nervousness/agitation, upset stomach, depression, and sleep disturbance; lamotrigine with nervousness/agitation, upset stomach, and difficulty concentrating; and valproic acid with upset stomach and shaky hands.

CONCLUSION

Individual AEDs independently predicted some specific AEs, but not overall high AE burden. Our findings may help to characterize patients with epilepsy who are at high risk for specific AEs. Dose reduction or change to another AED may reduce LAEP score and potential nonadherence.

Long-term Effectiveness of Antiepileptic Drug Monotherapy in Partial Epileptic Patients: A 7-year Study in an Epilepsy Center in China

BACKGROUND

It is important to choose an appropriate antiepileptic drug (AED) to manage partial epilepsy. Traditional AEDs, such as carbamazepine (CBZ) and valproate (VPA), have been proven to have good therapeutic effects. However, in recent years, a variety of new AEDs have increasingly been used as first-line treatments for partial epilepsy. As the studies regarding the effectiveness of new drugs and comparisons between new AEDs and traditional AEDs are few, it is determined that these are areas in need of further research. Accordingly, this study investigated the long-term effectiveness of six AEDs used as monotherapy in patients with partial epilepsy.

METHODS

This is a retrospective, long-term observational study. Patients with partial epilepsy who received monotherapy with one of six AEDs, namely, CBZ, VPA, topiramate (TPM), oxcarbazepine (OXC), lamotrigine (LTG), or levetiracetam (LEV), were identified and followed up from May 2007 to October 2014, and time to first seizure after treatment, 12-month remission rate, retention rate, reasons for treatment discontinuation, and adverse effects were evaluated.

RESULTS

A total of 789 patients were enrolled. The median time of follow-up was 56.95 months. CBZ exhibited the best time to first seizure, with a median time to first seizure of 36.06 months (95% confidential interval: 30.64-44.07). CBZ exhibited the highest 12-month remission rate (85.55%), which was significantly higher than those of TPM (69.38%, P = 0.006), LTG (70.79%, P = 0.001), LEV (72.54%, P = 0.005), and VPA (73.33%, P = 0.002). CBZ, OXC, and LEV had the best retention rate, followed by LTG, TPM, and VPA. Overall, adverse effects occurred in 45.87% of patients, and the most common adverse effects were memory problems (8.09%), rashes (7.76%), abnormal hepatic function (6.24%), and drowsiness (6.24%).

CONCLUSION

This study demonstrated that CBZ, OXC, and LEV are relatively effective in managing focal epilepsy as measured by time to first seizure, 12-month remission rate, and retention rate.

Efficacy and safety of conversion to monotherapy with eslicarbazepine acetate in adults with uncontrolled partial-onset seizures: a historical-control phase III study

Background

Eslicarbazepine acetate (ESL, Aptiom®) is a once-daily (QD) anticonvulsant, approved as adjunctive treatment of partial-onset seizures (POS). It is extensively converted after oral administration to eslicarbazepine, and is believed to exert its effect through inhibition of voltage-gated sodium channels. The possible role of ESL as monotherapy to treat POS has not yet been established.

Methods

This study was an 18-week, multicenter, randomized double-blind trial of gradual conversion to ESL monotherapy in adults with POS not well controlled by 1–2 antiepileptic drugs (AEDs), using historical data as the control. The study comprised an 8-week baseline period, a 2-week titration period, a 6-week AED conversion period, a 10-week monotherapy period, and either a 1-week taper period or optional entry to an open-label extension study. The primary endpoint compared the Kaplan–Meier (KM)-estimated 112-day exit rate with a threshold value calculated from the historical controls.

Results

There were 172 randomized patients; 154 (90%) entered the AED conversion period and 121 (70%) completed the study. The KM-estimated exit rates [confidence interval (CI)] were 15.6% [8.1–28.7%] for ESL 1200 mg, and 12.8% [7.5–21.5%] for ESL 1600 mg. The upper limits of the 95% CI KM-estimates were below the pre-specified threshold for historical control of 65.3%, indicating that ESL was efficacious in reducing seizure-related exits, compared with historical control. During the 18-week double-blind treatment period, median reductions in standardized seizure frequency occurred with ESL 1200 mg (36.1%) and ESL 1600 mg (47.5%). The responder rates (a 50% or greater reduction in seizure frequency from baseline) during the 18-week double-blind period and the monotherapy period, respectively, were 35.2% and 38.9% for ESL 1200 mg, and 46.0% and 46.0% for ESL 1600 mg. The overall adverse event profile was consistent with the known safety profile of ESL.

Conclusions

These findings indicate that ESL monotherapy (1200 and 1600 mg QD) was efficacious and well tolerated in this study.

Trial registration

NCT01091662; EudraCT No. 2010-018684-42.

Electronic supplementary material

The online version of this article (doi:10.1186/s12883-015-0305-5) contains supplementary material, which is available to authorized users.

Epilepsy: new advances

Epilepsy affects 65 million people worldwide and entails a major burden in seizure-related disability, mortality, comorbidities, stigma, and costs. In the past decade, important advances have been made in the understanding of the pathophysiological mechanisms of the disease and factors affecting its prognosis. These advances have translated into new conceptual and operational definitions of epilepsy in addition to revised criteria and terminology for its diagnosis and classification. Although the number of available antiepileptic drugs has increased substantially during the past 20 years, about a third of patients remain resistant to medical treatment. Despite improved effectiveness of surgical procedures, with more than half of operated patients achieving long-term freedom from seizures, epilepsy surgery is still done in a small subset of drug-resistant patients. The lives of most people with epilepsy continue to be adversely affected by gaps in knowledge, diagnosis, treatment, advocacy, education, legislation, and research. Concerted actions to address these challenges are urgently needed.

Factors predicting adverse events associated with pregabalin administered for neuropathic pain relief

BACKGROUND

Pregabalin administration is occasionally abandoned due to adverse events such as somnolence, dizziness, unsteadiness, weight gain and edema. However, the exact causes of these differences in adverse events associated with pregabalin have not been elucidated.

OBJECTIVE

To identify factors predicting adverse events associated with pregabalin administered for neuropathic pain.

METHODS

The present study was a retrospective analysis involving 208&nbsp;patients with neuropathic pain who had been treated with pregabalin in the pain clinic at the authors' hospital between July 2010 and September 2011. Variables were extracted from the clinical records for regression analysis of factors related to the occurrence of adverse events associated with pregabalin administration. Multivariate logistic regression analysis was used to examine the relationship between various predictive factors and the adverse events.

RESULTS

Predictive factors were: duration of therapy (OR 1.684&nbsp;[95%&nbsp;CI 1.179 to 2.406]; P=0.0042) for somnolence; nonsteroidal anti-inflammatory drugs (OR 0.132 [95% CI 0.030 to 0.578]; P=0.0072), age (OR 3.137 [95% CI 1.220 to 8.066]; P=0.0177) and maintenance dose (OR 0.437 [95% CI 0.217 to 0.880]; P=0.0205) for unsteadiness; serum creatinine (OR 6.439&nbsp;[95% CI 1.541 to 26.902]; P=0.0107) for body weight gain; and neurotropin (OR 8.538 [95% CI 1.159 to 62.901]; P=0.0353) and serum creatinine (OR 6.912 [95% CI 1.118 to 42.726]; P=0.0375) for edema.

CONCLUSIONS

The results of the present study indicate that care is warranted regarding long durations of therapy for somnolence, advanced age rather than dose-dependent adverse events for unsteadiness, elevated serum creatinine level for weight gain, and elevated serum creatinine level and combination use of neurotropin for edema. The safety of the combined use of pregabalin and nonsteroidal anti-inflammatory drugs were also suggested.

Pharmacotherapy of focal epilepsy

INTRODUCTION

Epilepsy is the most common neurological condition worldwide with significant psychosocial and physical morbidity. Its management requires expertise and good pharmacological knowledge of the available options.

AREAS COVERED

This review covers the management of focal epilepsy addressing the common questions arising through the patients' journey, including timing of starting initial treatment, monotherapy options, add-on treatment for refractory cases and withdrawal of medication during remission.

EXPERT OPINION

Initiating anti-epileptic drug (AED) treatment requires assessment of patient preferences and of evidence of benefit and harm. Evidence of benefit will come primarily from randomised controlled trials, although in epilepsy, most trials are undertaken to inform regulatory decision and have important limitations for informing clinical decisions. Evidence about harm may come not only from randomised trials but also from other sources. Most patients will start treatment following a second focal seizure. Carbamazepine and lamotrigine are good initial monotherapy options. Newer AEDs have proof of efficacy as monotherapy but evidence is insufficient to recommend them as first-line treatments. For refractory cases, there are an increasing number of AEDs available, but evidence of efficacy is primarily from placebo-controlled trials, and there is no robust evidence to inform a choice among treatments.

Pregabalin monotherapy in patients with partial-onset seizures: a historical-controlled trial

OBJECTIVE

To assess pregabalin monotherapy for partial-onset seizures using a historical-controlled conversion-to-monotherapy design.

METHODS

Adults with inadequately controlled partial-onset seizures while receiving 1 or 2 antiepileptic drugs during an 8-week prospective baseline were randomized to double-blind monotherapy with pregabalin 600 or 150 mg/d (4:1) for 20 weeks (8-week conversion and 12-week monotherapy period). The primary endpoint was the seizure-related exit rate for pregabalin 600 mg/d, based on discontinuations due to predefined criteria. Efficacy was declared if the upper limit of the 95% confidence interval for the exit rate was below a historical-control threshold of 74%, with stepwise evaluation using a threshold of 68%.

RESULTS

The trial was stopped early for positive efficacy after an interim analysis in 125 patients. The full study population included 161 patients, with 148 evaluable for efficacy. The mean time since epilepsy diagnosis was 14 years. Overall, 54.3% (600 mg/d) and 46.9% (150 mg/d) of patients completed 20 weeks of double-blind treatment. Seizure-related exit rate in the 600 mg/d group (27.5%; 95% confidence interval, 17.8%-37.2%) was significantly below the 74% and 68% thresholds (p < 0.001 for both). Eight patients on 600 mg/d and 2 on 150 mg/d were seizure-free throughout pregabalin monotherapy. Pregabalin's overall safety profile was consistent with prior trials.

CONCLUSIONS

Pregabalin monotherapy was safe and efficacious for patients with inadequately controlled partial-onset seizures.

CLASSIFICATION OF EVIDENCE

This study provides Class III evidence that patients with inadequately controlled partial-onset seizures switched to pregabalin monotherapy have fewer seizure-related exit events compared with historical controls switched to pseudo-placebo monotherapy.

Update on once-daily zonisamide monotherapy in partial seizures

Zonisamide is an antiepileptic drug that is structurally different from other antiepileptic agents. Its long half-life, once-daily dosing, lack of induction of hepatic enzymes, and broad spectrum of action makes it a suitable candidate for monotherapy. It has been approved as monotherapy for partial onset epilepsy in Japan and South Korea for more than a decade, and was recently approved as monotherapy in Europe. In the USA, it is only approved by the US Food and Drug Administration for adjunctive treatment of partial onset epilepsy. In this paper, we briefly review the literature on zonisamide monotherapy in partial onset epilepsy with regard to its efficacy, safety, tolerability, and long-term side effects, including a recent noninferiority trial in comparison with extended-release carbamazepine. While European regulatory agencies use noninferiority trials for approval of monotherapy, such a trial design does not meet the current regulatory requirements for approval as monotherapy in the USA.

A review on antiepileptic drugs-dependent fatigue: pathophysiological mechanisms and incidence

Fatigue represents a common side effect of several drugs, however, the underlying mechanisms have not been well identified. A depression of the central nervous system (CNS) and/or changes in peripheral processes have been associated with the development of fatigue. Antiepileptic drugs (AEDs), generally decreasing CNS excitability, are used in the treatment of seizures as well as other neurological and psychiatric diseases. Fatigue is certainly a common AEDs' side effect, although a high degree of variability exists depending on both patients' characteristics and the drug used. Here, we delineate the pathophysiological central and peripheral mechanisms by which AEDs may cause fatigue also reviewing the available clinical data in order to assess a possible AEDs rank and highlight each AEDs related risk. It appears that drugs acting on the GABAergic system have the highest incidence (with tiagabine exception) of fatigue followed by Gabapentin and Levetiracetam whereas drugs mainly inhibiting sodium channels (Carbamazepine, Eslicarbazepine, Lamotrigine, Phenytoin and Valproate) have the lowest. However, the dose used, AEDs related side effects and patients' characteristics might influence the degree of fatigue observed.

Antiepileptic drug treatment: new drugs and new strategies

PURPOSE OF REVIEW

Selection of the ideal antiepileptic drug (AED) for an individual patient can be a daunting process. Choice of treatment should be based on several factors, including but not limited to epilepsy classification, AED mechanism of action, AED side-effect profile, and drug interactions. Special consideration must be given to populations such as women, older adults, patients with other medical comorbidities, and patients who are newly diagnosed.

RECENT FINDINGS

Head-to-head trials between AEDs in newly diagnosed patients rarely demonstrate that one AED is more or less effective. The second-generation drugs, lamotrigine, topiramate, oxcarbazepine, zonisamide, and levetiracetam, have undergone head-to-head trials confirming similar efficacy and equal or better tolerability than standard drugs in focal epilepsy.

SUMMARY

A thoughtful approach to the AED selection process must factor in data from clinical AED trials as well as a variety of patient characteristics and confounding factors. When neurologists apply an individualized approach to AED drug selection for their patients, they can find an effective and well-tolerated drug for most patients.

Profile of once-daily zonisamide as monotherapy for treatment of partial seizures in adults

Epilepsy is one of the most common neurologic disorders, affecting about 50 million people around the world. It is recognized that around 50% of patients with newly diagnosed epilepsy become seizure-free with the first drug treatment, so the choice of first antiepileptic drug is crucial. This paper provides a comprehensive overview of zonisamide as monotherapy for partial seizures, with special attention to the possibility of a once-daily regimen. The available data suggest that zonisamide is an effective and well tolerated option as monotherapy. Once-daily dosing is indicated, considering the long plasma half-life and linear pharmacokinetics of the drug. Zonisamide 300 mg was shown to be noninferior to carbamazepine 600 mg in terms of efficacy and safety, but even lower doses may be effective. Finally, the broad spectrum of efficacy in different seizure types, the low drug interaction potential, and the possibility of weight loss make zonisamide a preferred option in many epilepsy practices. Further data on monotherapy, especially in special populations, such as women of childbearing potential, are needed.

Updated ILAE evidence review of antiepileptic drug efficacy and effectiveness as initial monotherapy for epileptic seizures and syndromes

The purpose of this report was to update the 2006 International League Against Epilepsy (ILAE) report and identify the level of evidence for long-term efficacy or effectiveness for antiepileptic drugs (AEDs) as initial monotherapy for patients with newly diagnosed or untreated epilepsy. All applicable articles from July 2005 until March 2012 were identified, evaluated, and combined with the previous analysis (Glauser et al., 2006) to provide a comprehensive update. The prior analysis methodology was utilized with three modifications: (1) the detectable noninferiority boundary approach was dropped and both failed superiority studies and prespecified noninferiority studies were analyzed using a noninferiority approach, (2) the definition of an adequate comparator was clarified and now includes an absolute minimum point estimate for efficacy/effectiveness, and (3) the relationship table between clinical trial ratings, level of evidence, and conclusions no longer includes a recommendation column to reinforce that this review of efficacy/evidence for specific seizure types does not imply treatment recommendations. This evidence review contains one clarification: The commission has determined that class I superiority studies can be designed to detect up to a 20% absolute (rather than relative) difference in the point estimate of efficacy/effectiveness between study treatment and comparator using an intent-to-treat analysis. Since July, 2005, three class I randomized controlled trials (RCT) and 11 class III RCTs have been published. The combined analysis (1940-2012) now includes a total of 64 RCTs (7 with class I evidence, 2 with class II evidence) and 11 meta-analyses. New efficacy/effectiveness findings include the following: levetiracetam and zonisamide have level A evidence in adults with partial onset seizures and both ethosuximide and valproic acid have level A evidence in children with childhood absence epilepsy. There are no major changes in the level of evidence for any other subgroup. Levetiracetam and zonisamide join carbamazepine and phenytoin with level A efficacy/effectiveness evidence as initial monotherapy for adults with partial onset seizures. Although ethosuximide and valproic acid now have level A efficacy/effectiveness evidence as initial monotherapy for children with absence seizures, there continues to be an alarming lack of well designed, properly conducted epilepsy RCTs for patients with generalized seizures/epilepsies and in children in general. These findings reinforce the need for multicenter, multinational efforts to design, conduct, and analyze future clinically relevant adequately designed RCTs. When selecting a patient's AED, all relevant variables and not just efficacy and effectiveness should be considered.

Pregabalin monotherapy for epilepsy

BACKGROUND

Many people with epilepsy suffer from poorly controlled seizures, despite current antiepileptic treatments. Due to high rates of treatment resistance, there is interest in new pharmacological treatment options such as pregabalin. However, it remains unclear whether existing evidence of pregabalin is rigorous enough to support its monotherapy.

OBJECTIVES

To determine the efficacy and tolerability of pregabalin in people with epilepsy.

SEARCH METHODS

We searched the Cochrane Epilepsy Group's Specialized Register (August 2012), the Cochrane Central Register of Controlled Trials (CENTRAL) (The Cochrane Library 2012, Issue 7 ), MEDLINE (1946 to August week 1, 2012), EMBASE (1974 to August 2012) and the Chinese Biomedical Literature Database (CBM) (1978 to August 2012). No language restrictions were imposed.

SELECTION CRITERIA

Randomised controlled trials (RCTs) comparing pregabalin with placebo or another antiepileptic drug monotherapy for epilepsy.

DATA COLLECTION AND ANALYSIS

Two review authors (QZ and LY) independently extracted trial data and assessed trial quality. We assessed the following outcomes: (1) time to withdrawal after randomisation; (2) time to achieve six-, 12- or 24-month remission; (3) the proportion of participants who remained seizure-free for six or more continuous months; (4) time to first seizure after randomisation; (5) validated quality of life measures; (6) health economic outcomes; (7) adverse effects. We expressed time-to-event outcomes as hazard ratios (HRs) with 95% confidence interval (CI), where an HR > 1 indicates an event is more likely to occur earlier on pregabalin than the comparator.

MAIN RESULTS

Two short-term studies involving 753 participants met the inclusion criteria. Only one study investigated the effects of pregabalin compared with lamotrigine in patients with newly diagnosed partial seizures, and the other study investigated the effects of pregabalin compared with gabapentin in hospitalised patients with refractory partial epilepsy. There were no studies on generalised-onset tonic-clonic seizures (with or without other generalised seizure types).We found that pregabalin was inferior in comparison to lamotrigine when measuring time to withdrawal due to inadequate seizure control after dose stabilisation from randomisation: hazard ratio (HR) 4.52; 95% confidence interval (CI) 1.93 to 10.60; time to achieve six-month remission after dose stabilisation from randomisation: HR 0.56; 95% CI 0.41 to 0.76; the proportion of participants who remained seizure-free for six or more continuous months: RR 0.76, 95% CI 0.67 to 0.87 (Europe: 0.83, 95% CI 0.69 to 0.99; Asia: RR 0.70, 95% CI 0.57 to 0.86; the Americas: RR 0.62, 95% CI 0.33 to 1.19); and time to first seizure after dose stabilisation from randomisation: HR 1.74; 95% CI 1.26 to 2.39. There was no significant difference in safety-related outcomes between pregabalin and lamotrigine, but more participants in the pregabalin group developed somnolence, weight increase and convulsion. Pregabalin was better than gabapentin when measuring time to withdrawal due to all reasons after randomisation: HR 0.25; 95% CI 0.11 to 0.57; and time to withdrawal due to inadequate seizure control after randomisation: HR 0.41; 95% CI 0.18 to 0.92. No significant difference was found in safety-related outcomes between pregabalin and gabapentin. But we found some limitations in the study design which may have had an influence on the results.

AUTHORS' CONCLUSIONS

Pregabalin seems to have similar tolerability but inferior efficacy in comparison to lamotrigine for newly diagnosed partial seizures. However, considering the limitations in the study design (such as the short-term follow-up and the low initial target dose selection), the results should be interpreted with caution. The available data were too limited to draw any conclusions between pregabalin and gabapentin. The result indicated that the treatment effects were influenced by the study regions. The clinical disadvantage of pregabalin was more prominent in Asia when compared with lamotrigine. We should determine whether pregabalin has ethnic differences in the treatment of epilepsy in the future. This review does not inform any treatment policy for patients with generalized onset tonic-clonic seizures. Further long-term trials are needed to investigate the genuine effectiveness of pregabalin as monotherapy.