What is the relative value of the standard anticonvulsants: Phenytoin and fosphenytoin, phenobarbital, valproate, and levetiracetam?

The Safety and Effectiveness of Intravenous Lacosamide for Refractory Status Epilepticus in the Critically Ill

BACKGROUND

Status epilepticus (SE) often does not respond to initial treatment. A second-line agent with a less established safety and efficacy profile is then required. This study examined the safety of intravenous (IV) lacosamide (LCM) in a critically ill population and obtained an estimate of effectiveness in patients with refractory SE on continuous video EEG monitoring (cEEG).

METHODS

Retrospective review of critically ill patients in SE on cEEG treated with IV LCM from June 2009 to April 2011.

RESULTS

Eighty-four patients in SE (43 F/41 M), mean age 59.6 years, were identified; and 59.5 % had nonconvulsive SE. The most common etiologies were ischemic and hemorrhagic strokes. There were no significant changes in serial blood pressure monitoring, PR prolongation, aspartate aminotransferase (AST), or creatinine pre- and post-LCM. There was a significant increase in alanine aminotransferase (ALT) from days 1-7 (p = 0.031). Fifty-one patients were LCM-naïve. In these patients, cessation of SE on cEEG after LCM occurred in 15.7, 25.5, 58.8, and 82.4 % by 4, 12, 24, and 48 h, respectively.

CONCLUSION

IV LCM appears safe short term in critically ill patients with SE. The retrospective estimate of effectiveness for LCM appears promising for management in SE. Prospective, randomized controlled studies are needed to better determine the role of LCM in treating SE.

Phenobarbital Versus Valproate for Generalized Convulsive Status Epilepticus in Adults: A Prospective Randomized Controlled Trial in China

OBJECTIVE

Although generalized convulsive status epilepticus (GCSE) is a life-threatening emergency, evidence-based data to guide initial drug treatment choices are lacking in the Chinese population. We conducted this prospective, randomized, controlled trial to evaluate the relative efficacy and safety of intravenous phenobarbital and valproate in patients with GCSE.

METHODS

After the failure of first-line diazepam treatment, Chinese adult patients with GCSE were randomized to receive either intravenous phenobarbital (standard doses, low rate) or valproate (standard). Successful treatment was considered when clinical and electroencephalographic seizure activity ceased. Adverse events following treatment, as well as the neurological outcomes at discharge and 3 months later, were also evaluated.

RESULTS

Overall, 73 cases were enrolled in the study. Intravenous phenobarbital was successful in 81.1% of patients, and intravenous valproate was successful in 44.4% of patients (p < 0.05). The relapse rate of status epilepticus within 24 h of receiving phenobarbital (6.7%) was significantly lower than that in patients receiving valproate (31.3%), and the total number of adverse events did not differ significantly between the two groups (p > 0.05). In the phenobarbital group, two patients (5.4%) required ventilation and two patients (5.4%) developed serious hypotension. The neurological outcomes of the phenobarbital group were generally better than those of the valproate group; however, no significant differences were observed between phenobarbital and valproate with respect to mortality (8.1 vs. 16.6%) at discharge, or mortality (16.2 vs. 30.5%) and post-symptomatic epilepsy (26.3 vs. 42.8%) at 3-month follow-up.

CONCLUSIONS

Intravenous phenobarbital appears to be more effective than intravenous valproate for Chinese adult patients with GCSE. The occurrence of serious respiratory depression and hypotension caused by phenobarbital was reduced by decreasing the intravenous infusion rate; however, even at a lower infusion rate than typically used in other institutions, intravenous phenobarbital resulted in more serious adverse events than intravenous valproate. The better outcomes in the phenobarbital group compared with the valproate group suggest that phenobarbital should be considered for the early successful treatment of GCSE.

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.

Treating epileptic emergencies - pharmacological advances

INTRODUCTION

Epileptic emergencies are frequently encountered and include ictal events as status epilepticus or seizure clusters, and non-ictal situations like postictal psychosis or acute drug side effects. The aim of this review was to describe recent pharmacological advances in the treatment of epileptic emergencies. Areas covered: Based on clinically relevant questions, a literature search was performed. The search showed that most pharmacological advances have been made in management of status epilepticus, where substantial literature has accumulated on several AEDs with potentially less side-effects than the traditional choices. The use of these drugs; valproate, levetiracetam, and lacosamide, was therefore made the main focus of this review. Pharmacological advances in treatment of other epileptic emergencies were scarce, and were therefore covered more briefly in the Expert Opinion section. Expert opinion: This section outlines our current practice in management of status epilepticus and seizures clusters. Our opinion is that valproate is an equal alternative as second line treatment to fosphenytoin, with levetiracetam considered a good choice in frail and elderly patients. Due to the lack of literature, lacosamide is used mainly as a 2^nd line drug after the failure of valproate, fosphenytoin and levetiracetam. Our review underlines the need for more research in management of epileptic emergencies.

Efficacy and safety of fosphenytoin for benign convulsions with mild gastroenteritis

OBJECTIVE

To clarify the efficacy and safety of fosphenytoin for seizures in children with benign convulsions and mild gastroenteritis.

METHODS

Using the mailing list of the Annual Zao Conference on Pediatric Neurology, we recruited patients who met the following criteria: (1) clinical diagnosis of benign convulsions with mild gastroenteritis and (2) treatment with intravenous fosphenytoin. Benign convulsions with mild gastroenteritis were defined as a condition of (a) seizures associated with gastroenteritis without electrolyte imbalance, hypoglycemia, or dehydration in patients (b) between 6 months and 3 years of age with (c) no preexisting neurological disorders, (d) no impaired consciousness, and (e) a body temperature less than 38.0 °C before and after the seizures. The efficacy of fosphenytoin was categorized as effective when cessation of seizures was achieved.

RESULTS

Data from 16 child patients were obtained (median age, 20 months). Seizures were completely controlled after the initial dose of fosphenytoin in 14 of 16 patients. The median loading dose of fosphenytoin was 22.5 mg/kg. In 10 patients, fosphenytoin was administered after other antiepileptic drugs such as diazepam and midazolam were used. Adverse effects of fosphenytoin, excessive sedation, or intravenous fluid incompatibility were not observed in any patients.

CONCLUSION

Fosphenytoin is effective and well tolerated among children with benign convulsions with mild gastroenteritis.

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.

Efficacy and safety of fosphenytoin for acute encephalopathy in children

PURPOSE

To evaluate the efficacy and safety of fosphenytoin (fPHT) for the treatment of seizures in children with acute encephalopathy.

METHODS

Using responses from physicians on the Annual Zao Conference on Pediatric Neurology mailing list we chose patients who met the following criteria: clinical diagnosis of acute encephalopathy and use of intravenous fPHT for the treatment of seizures. We divided the patients into two groups: acute encephalopathy with biphasic seizures and late reduced diffusion (AESD) and other encephalopathies. The efficacy of fPHT was considered effective when a cessation of seizures was achieved.

RESULTS

Data of 38 children were obtained (median age, 27 months). Eighteen children were categorized into the AESD group and 20 into the other encephalopathies group. fPHT was administered in 48 clinical events. The median loading dose of fPHT was 22.5 mg/kg and was effective in 34 of 48 (71%) events. The rate of events in which fPHT was effective did not differ according to the presence or absence of prior antiepileptic treatment, subtype of acute encephalopathy, or the type of seizures. One patient experienced apnea and oral dyskinesia as adverse effects of fPHT, whereas arrhythmia, hypotension, obvious reduction of consciousness, local irritation, phlebitis and purple grove syndrome were not observed in any patient.

CONCLUSION

fPHT is effective and well tolerated among children with acute encephalopathy.

Intravenous lacosamide or phenytoin for treatment of refractory status epilepticus

OBJECTIVES

To compare intravenous phenytoin (PHT) and intravenous lacosamide (LCM) for treatment of status epilepticus after failure of the first and second drug.

METHODS

We retrospectively identified patients from a large community hospital in northern Germany who had been diagnosed with SE between August 2008 and December 2010. Patients who had failed to respond to the first two drugs were selected for this analysis.

RESULTS

Forty-six patients (23 female, median age 68 years) were identified. LCM was used as third drug in 21 patients (median bolus 400 mg) and PHT in 15 patients (median bolus 1500 mg). Pretreatment was similar regarding substance groups (benzodiazepine as first line, levetiracetam as second line drug) and bolus doses. Status epilepticus was terminated in six patients (40%) of the PHT group and in seven patients (33%) of the LCM group. Four patients (27%) of the PHT group and no patient of the LCM group suffered from a relevant, treatment-related side effect during administration of the third drug.

CONCLUSION

Lacosamide and PHT showed similar success rates for treatment of SE when used after failure of benzodiazepines and levetiracetam. However, PHT was associated with relevant side effects that were not seen with LCM.

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.

[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.

Anaesthesia and epilepsy

Epilepsy is the most common serious neurological disorder, with a prevalence of 0.5-1% of the population. While the traditional antiepileptic drugs (AEDs) still play a significant role in treatment of seizures, there has been an influx of newer agents over the last 20 yr, which are now in common usage. Anaesthetists are frequently faced with patients with epilepsy undergoing emergency or elective surgery and patients suffering seizures and status epilepticus in the intensive care unit (ICU). This review examines perioperative epilepsy management, the mode of action of AEDs and their interaction with anaesthetic agents, potential adverse effects of anaesthetic agents, and the acute management of seizures and refractory status epilepticus on the ICU. Relevant literature was identified by a Pubmed search of epilepsy and status epilepticus in conjunction with individual anaesthetic agents.

The teratogenic potencies of valproic acid derivatives and their effects on biological end-points are related to changes in histone deacetylase and Erk1/2 activities

Valproic acid (VPA) is a known teratogen. In the present study, the effects of VPA and seven VPA derivatives with different teratogenic potencies (isobutyl-, 5-methyl-, ethyl-, propyl-, butyl-, pentyl- and hexyl-4-yn-VPA) were investigated in L929 cells in vitro. Evaluated end-points included changes in cell proliferation, growth, cell cycle distribution, morphology, speed, glycogen synthase kinase-3β (GSK-3β) and Erk1/2 phosphorylation, and histone H3 acetylation. Changes in proliferation, growth, speed, Erk1/2 and GSK-3β-Tyr216 phosphorylation, and H3 acetylation were significantly associated with the teratogenic potencies of the VPA derivatives. However, in contrast to changes in Erk1/2 phosphorylation and H3 acetylation, significant changes in GSK-3β phosphorylation could only be obtained in response to prolonged incubation at high drug concentration. There was an association between changes in H3 acetylation and GSK-3β-Tyr216 phosphorylation, whereas none of these end-points were associated with changes in Erk1/2 phosphorylation. These results suggest that the teratogenic potencies of VPA and VPA derivatives are related to effects on both Erk1/2 and histone deacetylase activities, whereas changes in GSK-3β activity are possibly a secondary effect.

Second-line status epilepticus treatment: comparison of phenytoin, valproate, and levetiracetam

PURPOSE

Phenytoin (PHT), valproic acid (VPA), or levetiracetam (LEV) are commonly used as second-line treatment of status epilepticus (SE), but comparative studies are not available.

METHODS

Among 279 adult SE episodes identified prospectively in our tertiary care hospital over 4 years, we retrospectively identified 187 episodes in which PHT, VPA, or LEV were given after benzodiazepines. Patients with postanoxic SE were not included. Demographics, clinical SE features, failure of second-line treatment to control SE, new handicap, and mortality at hospital discharge were assessed. Uni- and multivariable statistical analyses were applied to compare the three agents.

KEY FINDINGS

Each compound was used in about one third of SE episodes. VPA failed to control SE in 25.4%, PHT in 41.4%, and LEV in 48.3% of episodes in which these were prescribed. A deadly etiology was more frequent in the VPA group, whereas SE episodes tended to be more severe in the PHT group. After adjustment for these known SE outcome predictors, LEV failed more often than VPA [odds ratio (OR) 2.69; 95% confidence interval (CI) 1.19-6.08]; 16.8% (95% CI: 6.0-31.4%) of second-line treatment failures could be attributed to LEV. PHT was not statistically different from the other two compounds. Second-line treatment did not seem to influence new handicap and mortality, whereas etiology and the SE Severity Score (STESS) were robust independent predictors.

SIGNIFICANCE

Even without significant differences on outcome at discharge, LEV seems less efficient than VPA to control SE after benzodiazepines. A prospective comparative trial is needed to address this potentially concerning finding.

Medical management of refractory status epilepticus

This review discusses the medical management of pediatric refractory status epilepticus, defined here as persistent seizures of any type after the administration of 2 appropriate anticonvulsants. The use of both nonanesthetic and anesthetic anticonvulsants is discussed along with the relative strengths and weaknesses of each agent. Appropriate treatment goals and the use of electroencephalographic monitoring are described as are reasonable treatment algorithms. Finally, ethical considerations are briefly discussed in the context of available outcome data.

Status epilepticus treatment and outcome in children: what might the future hold?

Status epilepticus is a life-threatening emergency that requires urgent treatment. Over the past decade, numerous advances have been made in the management of status epilepticus. Clinical studies have now established the benefit of early, aggressive treatment of status epilepticus with benzodiazepines in both prehospital and hospital settings. Neuroscientific advances are revealing mechanisms of status epilepticus that could translate into targets for treating acute status epilepticus and even reducing epileptogenesis. This article discusses future trends in the diagnosis, neurobiology, and treatment of status epilepticus.