What is the evidence to use new intravenous AEDs in status epilepticus?

Modeling current practices in critical care comparative effectiveness research

Objective: To determine whether contemporaneous practices are adequately represented in recent critical care comparative effectiveness research studies. Design: All critical care comparative effectiveness research trials published in the New England Journal of Medicine from April 2019 to March 2020 were identified. To examine studies published in other high impact medical journals during the same period, such trials were subsequently also identified in the Journal of the American Medical Association and The Lancet. All cited sources were reviewed, and the medical literature was searched to find studies describing contemporary practices. Then, the designated control group or the comparable therapies studied were examined to determine if they represented contemporaneous critical care practices as described in the medical literature. Results: Twenty-five of 332 randomised clinical trials published in these three journals during this 1-year period described critical care comparative effectiveness research that met our inclusion criteria. Seventeen characterised current practices before enrolment (using surveys, observational studies and guidelines) and then incorporated current practices into one or more study arm. In the other eight, usual care arms appeared insufficient. Four of these trials randomly assigned patients to one of two fixed approaches at either end of a range of usually titrated care. However, due to randomisation, different subgroups within each arm received care that was inappropriate for their specific clinical conditions. In the other four of these trials, common practices influencing treatment choice were not reflected in the trial design, despite a prior effort to characterise usual care. Conclusion: One-third of critical care comparative effectiveness research trials published in widely read medical journals during a recent year did not include a designated control arm or comparable therapies representative of contemporary practices. Failure to incorporate contemporary practices into critical care comparative effectiveness trials appears to be a widespread design weakness.

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.

Efficacy, Safety, and Economics of Intravenous Levetiracetam for Status Epilepticus: A Systematic Review and Meta-Analysis

Objective

To evaluate efficacy, safety, and economics profiles of intravenous levetiracetam (LEV) for status epilepticus (SE).

Methods

We searched PubMed, Embase, the Cochrane Library, Clinicaltrials.gov, and OpenGrey.eu for eligible studies published from inception to June 12^th 2019. Meta-analyses were conducted using random-effect model to calculate odds ratio (OR) of included randomized controlled trials (RCTs) with RevMan 5.3 software.

Results

A total of 478 studies were obtained. Five systematic reviews (SRs)/meta-analyses, 9 RCTs, 1 non-randomized trial, and 27 case series/reports and 1 economic study met the inclusion criteria. Five SRs indicated no statistically significant difference in rates of seizure cessation when LEV was compared with lorazepam (LOR), phenytoin (PHT), or valproate (VPA). Pooled results of included RCTs indicated no statistically significant difference in seizure cessation when LEV was compared with LOR [OR = 1.04, 95% confidence interval (CI) 0.37 to 2.92], PHT (OR = 0.90, 95% CI 0.64 to 1.27), and VPA (OR = 1.47, 95% CI 0.81 to 2.67); and no statistically significant difference in seizure freedom within 24 h compared with LOR [OR = 1.83, 95% CI 0.57 to 5.90] and PHT (OR = 1.08, 95% CI 0.63 to 1.87). Meanwhile, LEV did not increase the risk of mortality during hospitalization compared with LOR (OR = 1.03, 95% CI 0.31 to 3.39), PHT (OR = 0.89, 95% CI 0.37 to 2.10), VPA (OR = 1.28, 95% CI 0.32 to 5.07), and placebo (plus clonazepam, OR = 0.73, 95% CI 0.16 to 3.38). LEV had lower need for artificial ventilation (OR = 0.23, 95% CI 0.06 to 0.92) and a lower risk of hypotension (OR = 0.15, 95% CI 0.03 to 0.84) compared to LOR. A trend of lower risk of hypotension and higher risk of agitation was found when LEV was compared with PHT. Case series and case report studies indicated psychiatric and behavioral adverse events of LEV. Cost-effectiveness evaluations indicated LEV as the most cost-effective non-benzodiazepines anti-epileptic drug (AED).

Conclusions

LEV has a similar efficacy as LOR, PHT, and VPA for SE, but a lower need for ventilator assistance and risk of hypotension, thus can be used as a second-line treatment for SE. However, more well-conducted studies to confirm the role of intravenous LEV for SE are still needed.

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

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

Status Epilepticus in Adults: A Review of Diagnosis and Treatment

Status epilepticus is a medical emergency that requires rapid diagnosis and treatment. Nonconvulsive status epilepticus is frequently underdiagnosed and therefore undertreated, which can lead to permanent neuronal damage resulting in disability or death. Despite the frequent occurrence and morbidity associated with status epilepticus, this topic has received little attention within the literature. A systematic approach to treatment should start with management of airway, breathing, and circulation, followed by administration of benzodiazepines and intravenous antiepileptic drugs, and rapid escalation of therapy to prevent morbidity and mortality. Armed with the information in this article, nurses will have a higher-level understanding of what to do when encountering a patient in status epilepticus.

Recent advances in epilepsy

This paper reviews advances in epilepsy in recent years with an emphasis on therapeutics and underlying mechanisms, including status epilepticus, drug and surgical treatments. Lessons from rarer epilepsies regarding the relationship between epilepsy type, mechanisms and choice of antiepileptic drugs (AED) are explored and data regarding AED use in pregnancy are reviewed. Concepts evolving towards a move from treating seizures to treating epilepsy are discussed, both in terms of the mechanisms of epileptogenesis, and in terms of epilepsy's broader comorbidity, especially depression.

Neurologic complications of transplantation

Major neurologic morbidity, such as seizures and encephalopathy, complicates 20-30% of organ and stem cell transplantation procedures. The majority of these disorders occur in the early posttransplant period, but recipients remain at risk for opportunistic infections and other nervous system disorders for many years. These long-term risks may be increasing as acute survival increases, and a greater number of "sicker" patients are exposed to long-term immunosuppression. Drug neurotoxicity accounts for a significant proportion of complications, with posterior reversible leukoencephalopathy syndrome, primarily associated with calcineurin inhibitors (i.e., cyclosporine and tacrolimus), being prominent as a cause of seizures and neurologic deficits. A thorough evaluation of any patient who develops neurologic symptoms after transplantation is mandatory, since reversible and treatable conditions could be found, and important prognostic information can be obtained.

The SAMUKeppra study in prehospital status epilepticus: lessons for future study

In the Lancet Neurology article "Prehospital treatment with levetiracetam plus clonazepam or placebo plus clonazepam in status epilepticus (SAMUKeppra): a randomised, double-blind, phase 3 trial" the authors conducted a prehospital, randomized controlled study to determine which treatment is more effective for status epilepticus (SE): benzodiazepine alone, or in combination with levetiracetam (LEV). Although the study had negative results, several aspects of the trial design likely masked any added effect that LEV may have had in controlling SE, including: higher doses of benzodiazepines, lower thresholds for determining cessation of SE, and a smaller sample size. Regardless, the study reaffirms the effectiveness and importance of early and adequate benzodiazepine dosing and helps guide us in designing future studies for treatment of SE.

Are Newer AEDs Better Than the Classic Ones in the Treatment of Status Epilepticus?

Several newer antiepileptic drugs have been increasingly used in patients with status epilepticus, especially levetiracetam and lacosamide, because of their intravenous availability. They may offer advantages in terms of tolerability; however, to date, no clear evidence suggests any advantage regarding efficacy after the use of newer antiepileptic drugs in this specific clinical setting. However, there has been a considerable revival of interest regarding some classic compounds, such as midazolam (MDZ), valproate (VPA), ketamine, or ketogenic diet. Awaiting comparative studies, which in part are ongoing, it seems reasonable, for the first choice, to rely on those agents that are best known and less expensive.

Prehospital treatment with levetiracetam plus clonazepam or placebo plus clonazepam in status epilepticus (SAMUKeppra): a randomised, double-blind, phase 3 trial

BACKGROUND

Generalised convulsive status epilepticus (GCSE) should be treated quickly. Benzodiazepines are the only drug treatment available so far that is effective before admission to hospital. We assessed whether addition of the antiepileptic drug levetiracetam to the benzodiazepine clonazepam would improve prehospital treatment of GCSE.

METHODS

We did a prehospital, randomised, double-blind, phase 3, placebo-controlled, superiority trial to determine the efficacy of adding intravenous levetiracetam (2.5 g) to clonazepam (1 mg) in treatment of GCSE in 13 emergency medical service centres and 26 hospital departments in France. Randomisation was done at the Paris Descartes Clinical Research Unit with a list of random numbers generated by computer. Adults with convulsions lasting longer than 5 min were randomly assigned (1:1) by prehospital physicians to receive levetiracetam or placebo in combination with clonazepam. All physicians and paramedics were masked to group assignments. If the status epilepticus lasted beyond 5 min after drug injection, a second dose of 1 mg clonazepam was given. The primary outcome was cessation of convulsions within 15 min of drug injection. We analysed the modified intention-to-treat population that had received at least one injection of clonazepam and levetiracetam or placebo, excluding patients without valid consent and those randomised more than once. The trial is registered at EudraCT, number 2007-005782-35.

FINDINGS

Between July 20, 2009, and Dec 15, 2012, 107 patients were randomly assigned to receive placebo and 96 were assigned to receive levetiracetam. The trial was discontinued on Dec 15, 2012 when interim analysis showed no evidence of a treatment difference, and 68 patients in each group were included in the modified intention-to-treat analysis. Convulsions stopped at 15 min of drug injection in 57 of 68 patients (84%) receiving clonazepam and placebo and in 50 of 68 patients (74%) receiving clonazepam and levetiracetam (percentage difference -10.3%, 95% CI -24.0 to 3.4). Three deaths, 19 of 47 (40 %) serious adverse events, and 90 of 197 (46%) non-serious events were reported in the levetiracetam group, and four deaths, 28 of 47 (60%) serious events, and 107 of 197 (54%) non-serious events were reported in the placebo group.

INTERPRETATION

The addition of levetiracetam to clonazepam treatment presented no advantage over clonazepam treatment alone in the control of GCSE before admission to hospital. Future prehospital trials could assess the efficacy of clonazepam alone as a first-line treatment in status epilepticus and the efficacy of a second injection of clonazepam with another antiepileptic drug as second-line treatment.

FUNDING

UCB Pharma.

Pharmacotherapy for Status Epilepticus

Status epilepticus (SE) represents the most severe form of epilepsy. It is one of the most common neurologic emergencies, with an incidence of up to 61 per 100,000 per year and an estimated mortality of 20 %. Clinically, tonic-clonic convulsive SE is divided into four subsequent stages: early, established, refractory, and super-refractory. Pharmacotherapy of status epilepticus, especially of its later stages, represents an "evidence-free zone," due to a lack of high-quality, controlled trials to inform clinical decisions. This comprehensive narrative review focuses on the pharmacotherapy of SE, presented according to the four-staged approach outlined above, and providing pharmacological properties and efficacy/safety data for each antiepileptic drug according to the strength of scientific evidence from the available literature. Data sources included MEDLINE and back-tracking of references in pertinent studies. Intravenous lorazepam or intramuscular midazolam effectively control early SE in approximately 63-73 % of patients. Despite a suboptimal safety profile, intravenous phenytoin or phenobarbital are widely used treatments for established SE; alternatives include valproate, levetiracetam, and lacosamide. Anesthetics are widely used in refractory and super-refractory SE, despite the current lack of trials in this field. Data on alternative treatments in the later stages are limited. Valproate and levetiracetam represent safe and effective alternatives to phenobarbital and phenytoin for treatment of established SE persisting despite first-line treatment with benzodiazepines. To date there are no class I data to support recommendations for most antiepileptic drugs for established, refractory, and super-refractory SE. Limiting the methodologic heterogeneity across studies is required and high-class randomized, controlled trials to inform clinicians about the best treatment in established and refractory status are needed.

Prevention of status epilepticus-induced brain edema and neuronal cell loss by repeated treatment with high-dose levetiracetam

The management of status epilepticus (SE) is important to prevent mortality and the development of post-SE symptomatic epilepsy. Acquired epilepsy after an initial brain insult by SE can be experimentally reproduced in the murine model of SE induced by pilocarpine. In the present study, we evaluated the possibility of treatment with a high-dose of levetiracetam in this model. Repeated treatment with high-dose levetiracetam after termination of SE by diazepam significantly prevented the incidence of spontaneous recurrent seizures and mortality for at least 28 days. To determine the brain alterations after SE, magnetic resonance imaging was performed. Both T2-weighted imaging and diffusion-weighted imaging showed changes in the limbic regions. These changes in the limbic regions demonstrated the development of cytotoxic edema three hours after SE, followed by the development of vasogenic edema two days after SE. In the pilocarpine-SE model, the incidence of spontaneous recurrent seizures after SE was strongly associated with neuronal damage within a few hours to days after SE by the development of vasogenic edema via the breakdown of the blood-brain barrier in the limbic regions. High-dose levetiracetam significantly suppressed the parameters in the limbic areas. These data indicate that repeated treatment with high-dose levetiracetam for at least two days after SE termination by diazepam is important for controlling the neuronal damage by preventing brain edema. Therefore, these findings suggest that early treatment with high-dose levetiracetam after SE termination by diazepam may protect against adverse sequelae via the inhibition of neurotoxicity induced by brain edema events.

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.

Status epilepticus: an update

Status epilepticus (SE) still results in significant mortality and morbidity. Whereas mortality depends mainly on the age of the patient as well as the cause, morbidity is often due to the myriad of complications that occur during prolonged admission to an intensive care environment. Although SE is a clinical diagnosis in most cases (convulsant), its treatment requires support by continuous electroencephalographic recording to ensure cessation of potential nonconvulsive elements of SE. Treatment has recently changed to incorporate four stages and must be initiated at the earliest possible time.

Efficacy and safety of intravenous valproate for status epilepticus: a systematic review

INTRODUCTION

The effectiveness of valproate (VPA) in the treatment of focal and generalized epilepsies is well established. The drug has a wide spectrum of action, good tolerability, and has been available as an injectable formulation since 1993. Despite the lack of class A evidence, it has been used extensively in various forms of status epilepticus (SE).

AIM

Our aim was to present a systematic review of data from randomized and non-randomized controlled trials to evaluate the efficacy and safety of intravenous VPA for the treatment of SE.

METHODS

Data sources included MEDLINE, back tracing of references in pertinent studies, and contact with the manufacturer of VPA (Sanofi-Aventis).

RESULTS

Overall, the search strategy yielded 433 results (425 MEDLINE, seven congress abstracts, one unpublished study); after excluding duplicate publications and case reports, 30 studies were identified (the earliest was published in 1993, the most recent in 2012); ten were controlled (six randomized controlled trials, four non-randomized controlled studies), and 20 uncontrolled trials (eight prospective observational studies, 12 retrospective case series). The cumulative literature describes the experiences of 860 patients with various forms of SE treated with intravenous VPA. The overall response rate to abrogate SE was 70.9% (601/848; 95% confidence interval [CI] 67.8-73.9). Response rates to intravenous VPA were better in children than in adults and did not differ between the SE types. The most commonly reported effective doses were between 15 and 45 mg/kg in bolus (6 mg/kg/min) followed by 1-3 mg/kg/h infusion. Safety studies of intravenous VPA administration in patients with SE showed a low incidence of adverse events overall (<10%), mainly dizziness, thrombocytopenia, and mild hypotension, which was independent of infusion rates. Of note, good cardiovascular and respiratory tolerability was observed in these studies, even at high doses and fast infusion rates (up to 30 mg/kg at 10 mg/kg/min), despite multiple morbidities or other antiepileptic drugs. The most serious concern relates to the possibility of acute encephalopathy, sometimes related to hepatic abnormalities or hyperammonemia.

CONCLUSIONS

The published experience is consistent with VPA being a safe and effective therapeutic option for patients with established SE who have previously failed conventional first-line treatment with benzodiazepines, but high-quality randomized controlled trials are needed to inform clinicians on its comparative effectiveness in SE.

Pediatric seizures

Seizures are a commonly encountered condition within the emergency department and, because of this, can engender complacency on the part of the physicians and staff. Unfortunately, there is significant associated morbidity and mortality with seizures, and they should never be regarded as routine. This point is particularly important with respect to seizures in pediatric patients. The aim of this review is to provide a current view of the various issues that make pediatric seizures unique and to help elucidate emergent evaluation and management strategies.

Seizures and the neurosurgical intensive care unit

The cause of seizures in the neurosurgical intensive care unit (NICU) can be categorized as emanating from either a primary brain pathology or from physiologic derangements of critical care illness. Patients are typically treated with parenteral antiepileptic drugs. For early onset ICU seizures that are easily controlled, data support limited treatment. Late seizures have a more ominous risk for subsequent epilepsy and should be treated for extended periods of time or indefinitely. This review ends by examining the treatment algorithms for simple seizures and status epilepticus and the role newer antiepileptic use can play in the NICU.

Causes of status epilepticus

Status epilepticus (SE) is the most extreme form of epilepsy. It describes a prolonged seizure that may occur in patients with previous epilepsy or in acute disorders of the central nervous system. It is one of the most common neurologic emergencies, with an incidence of up to 41 per 100,000 per year and an estimated mortality is 20%. The three major determinants of prognosis are the duration of SE, patient age, and the underlying cause. Common and easily recognized causes of SE include cerebrovascular disorders, brain trauma, infections, and low antiepileptic drug levels in patients with epilepsy. Less common causes present a clinical and diagnostic challenge, but are major determinants of prognosis. Among them, inflammatory causes and inborn errors of metabolism have gained wide interest; recent insights into these causes have contributed to a better understanding of the pathophysiology of SE and its appropriate treatment. This review focuses on the different etiologies of SE and emphasizes the importance of prompt recognition and treatment of the underlying causes.

Levetiracetam add-on for drug-resistant focal epilepsy: an updated Cochrane Review

BACKGROUND

Epilepsy is an important neurological condition and drug resistance in epilepsy is particularly common in individuals with focal seizures. In this review, we summarise the current evidence regarding a new antiepileptic drug, levetiracetam, when used as add-on treatment for controlling drug-resistant focal epilepsy. This is an update to a Cochrane Review that was originally published in 2001.

OBJECTIVES

To evaluate the effectiveness of levetiracetam, added on to usual care, in treating drug-resistant focal 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 Issue 7, 2012), and MEDLINE (1946 to August week 1, 2012). We also 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 quality of evidence. Outcomes investigated included 50% or greater reduction in focal seizure frequency (response); less than 50% reduction in focal seizure frequency (non-response); treatment withdrawal; adverse effects (including a specific analysis of changes in behaviour); cognitive effects and quality of life (QoL). Risk ratios (RR) with 95% confidence intervals (CIs) were used as measures of effect (99% CIs for adverse effects). Primary analyses were Intention-to-Treat (ITT). Dose response and inter-trial heterogeneity were evaluated in regression models.

MAIN RESULTS

Eleven trials (1861 participants) were included. They predominantly possessed low risks of bias. Participants were adults in nine trials (1565 participants) and children in the remaining two trials (296 participants). The dose of levetiracetam tested was 1000 to 4000 mg/day in adults, and 60 mg/kg/day in children. Treatment ranged from 12 to 24 weeks. For the 50% or greater reduction in focal seizure frequency outcome, the RR was significantly in favour of levetiracetam at all doses. The naive estimates, ignoring dose, showed children (52% responded) as better responders than adults (39% responded) on levetiracetam. 25% of children and 16% of adults responded to placebo. The Number Needed to Treat for an additional beneficial outcome for children and adults was four (95% CI three to seven) and five (95% CI four to six), respectively. The significant levels of statistical heterogeneity between trials on adults precluded valid provision of an overall RR (ignoring dose). Results for the two trials that tested levetiracetam 2000 mg on adults were sufficiently similar to be combined to give an RR for 50% or greater reduction in focal seizure frequency of 4.91 (95% CI 2.75 to 8.77), with an RR of 0.68 (95% CI 0.60 to 0.77) for non-response. At this dose, 37% and 8% of adults were responders in the levetiracetam and placebo groups, respectively. Regression analysis demonstrated that much of the heterogeneity between adult trials was likely to be explained by different doses of levetiracetam tested and different years of trial publication. There was no evidence of statistical heterogeneity between trials on children. For these trials, the RR for 50% or greater reduction in focal seizure frequency was 1.91 (95% CI 1.38 to 2.63), with an RR of 0.68 (95% CI 0.56 to 0.81) for non-response. 27% of children responded. Participants were not significantly more likely to have levetiracetam withdrawn (RR 0.98; 95% CI 0.73 to 1.32 and RR 0.80; 95% CI 0.43 to 1.46 for adults and children, respectively). For adults, somnolence (RR 1.51; 99% CI 1.06 to 2.17) and infection (RR 1.76; 99% CI 1.03 to 3.02) were significantly associated with levetiracetam. Accidental injury was significantly associated with placebo (RR 0.60; 99% CI 0.39 to 0.92). No individual adverse effect was significantly associated with levetiracetam in children. 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). Cognitive effect and QoL outcomes suggested that levetiracetam had a positive effect on cognition and some aspects of QoL in adults. In children, levetiracetam did not appear to alter cognitive function but there was evidence of worsening in certain aspects of child behaviour. The overall quality of evidence used was high.

AUTHORS' CONCLUSIONS

This update adds seven more trials to the original review, which contained four trials. At every dose analysed, levetiracetam significantly reduced focal seizure frequency relative to placebo. This indicates that levetiracetam can significantly reduce focal seizure frequency when it is used as an add-on treatment for both adults and children with drug-resistant focal epilepsy. As there was evidence of significant levels of statistical heterogeneity within this positive effect it is difficult to be precise about the relative magnitude of the effect. At a dose of 2000 mg, levetiracetam may be expected to be 3.9 times more effective than placebo; with 30% of adults being responders at this dose. At a dose of 60 mg/kg/day, levetiracetam may be expected to be 0.9 times more effective than placebo; with 25% of children being responders at this dose. When dose was ignored, children were better responders than adults by around 4% to 13%. The results grossly suggest that one child or adult may respond to levetiracetam for every four or five children or adults, respectively, that have received levetiracetam rather than placebo. The drug seems to be well tolerated in both adults and children although non-specific changes in behaviour may be experienced in as high as 20% of children. This aspect of the adverse-effect profile of levetiracetam was analysed crudely and requires further investigation and validation. It seems reasonable to continue the use of levetiracetam in both adults and children with drug-resistant focal epilepsy. The results cannot be used to confirm longer-term or monotherapy effects of levetiracetam or its effects on generalised seizures. The conclusions are largely unchanged from those in the original review. The most significant contribution of this update is the addition of paediatric data into the analysis.

[Status epilepticus]

Status epilepticus (SE) is a medical emergency. For diagnostic purposes EEG is mandatory when motor phenomena are absent or when a single seizure evolves into SE with impaired consciousness. The EEG may show focal or generalized status patterns, which must be distinguished from encephalopathies. Initially benzodiazepines are recommended; lorazepam is the drug of choice. When the SE persists, phenytoin, valproate, levetiracetam, lacosamide, and phenobarbital are administered. The choice depends on the underlying comorbidities. In this phase, only phenytoin is licensed. A generalized tonic-clonic status which is refractory is then treated with anesthetics including midazolam, disoprivan, or thiopental. The goal is to achieve burst suppression in the EEG and coadministration of antiepileptic drugs.

Levetiracetam add-on for drug-resistant localization related (partial) epilepsy

BACKGROUND

The majority of patients with epilepsy have a good prognosis and their seizures are well controlled by a single antiepileptic drug. However, up to 30% develop refractory seizures, particularly those with partial seizures. In this review, we summarise the current evidence regarding a new antiepileptic drug, levetiracetam, when used as an add-on treatment for drug-resistant localization related (partial) epilepsy.

OBJECTIVES

To evaluate the effects of levetiracetam on seizures, side effects, quality of life and cognition, when used as an add-on treatment for patients with a drug-resistant localization related (partial) epilepsy.

SEARCH STRATEGY

We searched the Cochrane Epilepsy Group trials register, the Cochrane Controlled Trials Register (Cochrane Library Issue 2, 2000). In addition, we contacted UCB SA (makers of levetiracetam) and experts in the field to seek any ongoing studies or unpublished studies.

SELECTION CRITERIA

Randomized placebo controlled add-on trials of levetiracetam in patients with a drug-resistant localization related (partial) epilepsy.

DATA COLLECTION AND ANALYSIS

Two reviewers independently selected trials for inclusion and extracted relevant data. The following outcomes were assessed: (a) 50% or greater reduction in total seizure frequency; (b) treatment withdrawal (any reason); (c) side effects; (d) cognitive effects; (e) quality of life. Primary analyses were intention to treat. Sensitivity best and worst case analyses were also undertaken. Summary odds ratios (ORs) were estimated for each outcome. Dose response was evaluated in regression models.

MAIN RESULTS

Four trials (1023 patients) were included. All four trials had data for treatment withdrawal and side effect outcomes. Three trials (904 patients) had data for 50% or greater reduction in seizure frequency. Three trials (595 patients) had data for quality of life and cognitive outcomes. The overall Odds Ratio (OR) (95% Confidence Interval (CI)) for 50% or greater reduction in total seizure frequency outcome was 3.81 (2.78,5.22). Dose regression analysis shows clear evidence that levetiracetam reduces seizure frequency with an increase in efficacy with increasing dose of levetiracetam. Approximately 15% of patients taking 1000 mg and 20-30% of patients taking 3000 mg levetiracetam per day have a 50% or greater reduction in seizure frequency. Patients were not significantly more likely to have levetiracetam withdrawn, OR (95% CI) 1.25 (0.87,1.80). The following side effects were significantly associated with levetiracetam: dizziness 2.36 (1.21, 4.61) and infection 1.82 (1.05, 3.14) whereas accidental injury was significantly associated with placebo 0.55 (0.32, 0.93). Quality of life and cognitive effect outcomes suggest that levetiracetam has a positive effect on cognition and some aspects of quality of life.

REVIEWER'S CONCLUSIONS

Levetiracetam reduces seizure frequency when used as an add-on treatment for patients with a drug-resistant localization related (partial) epilepsy, and seems well tolerated. Minimum effective and maximum tolerated doses have not been identified. The trials reviewed were of 16-24 weeks duration and results cannot be used to confirm longer term effects. Our results cannot be extrapolated to monotherapy or to patients with other seizure types or epilepsy syndromes. Great care should also be taken with any attempt to apply these results to children.