Levetiracetam Intravenous Infusion: A Randomized, Placebo-controlled Safety and Pharmacokinetic Study

Levetiracetam Dosing Based on Glasgow Coma Scale Scores in Pediatric Traumatic Brain Injury Patients

INTRODUCTION

 Severe traumatic brain injury (TBI) increases the risk of early posttraumatic seizures (EPTS). Guidelines suggest the use of prophylactic antiseizure agents, including levetiracetam. This study aims to evaluate the feasibility of using levetiracetam dosing based on Glasgow Comas Scale (GCS) scores with higher doses used for more severe TBI.

METHODS

 Patients 6 months to 18 years old admitted to Penn State Hershey Children's Hospital (PSHCH) with a TBI who received levetiracetam for EPTS prophylaxis with at least one documented GCS score were included. Patients were divided into two cohorts: before and after implementation of the pediatric TBI Cerner PowerPlan at PSHCH which standardized levetiracetam dosing based on GCS scores. Primary outcome was appropriate dosing of levetiracetam based on GCS. Secondary outcomes included seizure occurrence and adverse effects.

RESULTS

 Eighty-five patients were included: 42 in the pre-PowerPlan group and 43 in the post-PowerPlan group. Overall, 46 (54%) patients received the appropriate levetiracetam dose based on GCS (pre-PowerPlan, n = 19 [45%] vs. post-PowerPlan n = 27 [63%], p = 0.104). Sixty-four percent of severe TBI patients received appropriate levetiracetam dosing after implantation of the PowerPlan compared with 28% prior to the PowerPlan (p = 0.039). Three patients in each group experienced a seizure while on levetiracetam. Two patients experienced agitation and somnolence attributed to levetiracetam.

CONCLUSION

 Levetiracetam dosing based on GCS scores in pediatric TBI patients is a novel approach, and dosing accuracy may be increased with use of a PowerPlan. Additional large-scale studies are needed to evaluate efficacy and safety of this approach prior to widespread implementation.

Pharmacokinetics of Levetiracetam Seizure Prophylaxis in Severe Traumatic Brain Injury

BACKGROUND

Drug pharmacokinetics (PK) are altered in neurocritically ill patients, and optimal levetiracetam dosing for seizure prophylaxis is unknown.

OBJECTIVE

This study evaluates levetiracetam PK in critically ill patients with severe traumatic brain injury (sTBI) receiving intravenous levetiracetam 1000 mg every 8 (LEV8) to 12 (LEV12) hours for seizure prophylaxis.

METHODS

This prospective, open-label study was conducted at a level 1 trauma, academic, quaternary care center. Patients with sTBI receiving seizure prophylaxis with LEV8 or LEV12 were eligible for enrollment. Five sequential, steady-state, postdose serum levetiracetam concentrations were obtained. Non-compartmental analysis (NCA) and compartmental approaches were employed for estimating pharmacokinetic parameters and projecting steady-state trough concentrations. Pharmacokinetic parameters were compared between LEV8 and LEV12 patients. Monte Carlo simulations (MCS) were performed to determine probability of target trough attainment (PTA) of 6 to 20 mg/L. A secondary analysis evaluated PTA for weight-tiered levetiracetam dosing.

RESULTS

Ten male patients (5 LEV8; 5 LEV12) were included. The NCA-based systemic clearance and elimination half-life were 5.3 ± 1.2 L/h and 4.8 ± 0.64 hours. A one-compartment model provided a higher steady-state trough concentration for the LEV8 group compared with the LEV12 group (13.7 ± 4.3 mg/L vs 6.3 ± 1.7 mg/L; P = 0.008). Monte Carlo simulations predicted regimens of 500 mg every 6 hours, 1000 mg every 8 hours, and 2000 mg every 12 hours achieved therapeutic target attainment. Weight-tiered dosing regimens achieved therapeutic target attainment using a 75 kg breakpoint.

CONCLUSION AND RELEVANCE

Neurocritically ill patients exhibit rapid levetiracetam clearance resulting in a short elimination half-life. Findings of this study suggest regimens of levetiracetam 500 mg every 6 hours, 1000 mg every 8 hours, or 2000 mg every 12 hours may be required for optimal therapeutic target attainment. Patient weight of 75 kg may serve as a breakpoint for weight-guided dosing to optimize levetiracetam therapeutic target attainment for seizure prophylaxis.

A Simulation-Based Assessment of Levetiracetam Concentrations Following Fixed and Weight-Based Loading Doses: A Meta-Regression and Pharmacokinetic Modeling Analysis

Current recommendations for refractory status epilepticus (SE) unresponsive to benzodiazepines suggest a loading dose of levetiracetam (LEV) of 60 mg/kg to a maximum of 4500 mg. LEV therapeutic drug monitoring can help guide therapy and is garnering increasing attention. The objective of this study is to simulate the probability of target attainment (PTA) of fixed dose and weight-based loading doses of LEV with respect to established therapeutic target concentrations. Meta-regression of the current literature was performed to evaluate the relationship between intravenous LEV loading dose and seizure cessation in refractory SE patients. A previously published pharmacokinetic model was used to simulate the PTA capacity of competing single intravenous dosing schemes (fixed vs weight-based dosing) to achieve maximum (Cpeak) and 12-h (C12h) plasma concentrations that exceed 12 mg/L. The meta-regression indicated that dosage was not a statistically significant modulator of seizure control at dosages between 20 and 60 mg/kg. Stochastic simulations showed all dosing schemes achieved plasma Cpeak >12 mg/L, but C12h levels were <12 mg/L in subjects over 60 kg with a fixed dose ≤2000 mg or in subjects <60 kg with a weight-based dose <30 mg/kg. Dosages of 40 and 60 mg/kg provided ≥90% PTAs across all weights. Using a weight-based loading dose of 40 mg/kg, up to a suggested maximum of 4500 mg, improves the likelihood of achieving a sustained therapeutic drug concentration after the initial LEV dose, whereas fixed <3000 mg may not achieve the desired concentration before maintenance dosing.

Effectiveness of Levetiracetam versus phenytoin in preventing seizure in traumatic brain injury patients: A systematic review and meta-analysis

OBJECTIVE

Traumatic brain injury (TBI) and the subsequent Post-traumatic seizure (PTS) is a growing public health concern. Generally, anti-seizure drugs (ASDs) are recommended for PTS prophylaxis and treatment. This meta-analysis aimed to review the current state of knowledge and the evidence for the efficacy and safety of Levetiracetam (LEV) on the incidence of seizure in TBI patients compared to Phenytoin (PHT).

METHODS

A search was carried out based on PubMed, MEDLINE, Europe PMC database, and Cochrane Library up to November 2023. A total of 16 studies (3 randomized clinical trials, 10 retrospective cohort studies, and 3 prospective cohort studies) including 5821 TBI patients included in our meta-analysis. We included studies comparing LEV and PHT after brain injury in both adults and children. Risk of bias assessment was done for randomized controlled trials (RCTs) with a risk-of-bias tool (RoB-2) and the Newcastle-Ottawa Scale (NOS) was used to assess the quality of cohort studies. Two RCTs in our meta-analysis had a high risk of bias, therefore we applied sensitivity analysis to evaluate the robustness of our results.

RESULTS

The most commonly reported dosage for LEV was 500 mg twice daily and for PHT it was 5 mg/kg. There was no significant difference between LEV and PHT groups in reducing the early seizure incidence (OR = 0.85; 95% CI = [0.60, 1.21]; p = 0.375, fixed-effect, I2 = 21.75%). The result of sensitivity analysis for late seizure showed no significant difference between LEV and PHT in reducing the late seizure occurrence after TBI (OR = 0.87; 95% CI = [0.21, 3.67]; p = 0.853, fixed-effect, I2 = 0%). The mortality in TBI patients treated with LEV was not statistically significant compared to the PHT group (OR = 1.11; 95% CI = [0.92, 1.34], p = 0.266). The length of stay in the hospital was not significantly different between the LEV and PHT groups (MD = -1.33; 95% CI = [-4.55, 1.90]; p = 0.421). However, in comparison to PHT, LEV shortened the length of ICU stay (MD = -2.25; 95% CI = [-3.58, -0.91]; p =0.001). In terms of adverse effects, more patients in the PHT group have experienced adverse events compared to LEV but the difference was not significant (OR = 0.69; 95% CI = [0.44, 1.08]; p = 0. 11).

CONCLUSION

The results of our meta-analysis showed LEV and PHT have similar effects on the occurrence of early and late seizures in TBI patients. Therefore, none of the drugs is superior to the other in reducing PTS. However, treating TBI patients with LEV did not shorten the length of hospital stay in comparison to PHT but reduced the length of ICU stay significantly. The analysis showed that patients in the LEV experienced fewer side effects than in the PHT group, while it was not sufficiently clear whether all reported side effects were related to the drug alone or other factors. The mortality was similar between the LEV and PHT groups. Finally, we recommend more high-quality randomized controlled trials to confirm the current findings before making any recommendations in practice.

A review of the pharmacology and clinical applications of levetiracetam in dogs and cats

OBJECTIVE

To review and summarize the pharmacology of the antiepileptic drug (AED), levetiracetam (LEV), and to discuss its clinical utility in dogs and cats.

DATA SOURCES

Veterinary and human peer-reviewed medical literature and the authors' clinical experience.

SUMMARY

LEV is an AED with mechanisms of action distinct from those of other AEDs. In people and small animals, LEV exhibits linear kinetics, excellent oral bioavailability, and minimal drug-drug interactions. Serious side effects are rarely reported in any species. LEV use is gaining favor for treating epilepsy in small animals and may have wider clinical applications in patients with portosystemic shunts, neuroglycopenia, and traumatic brain injury. In people, LEV may improve cognitive function in patients with dementia.

CONCLUSION

LEV is a well-tolerated AED with well-documented efficacy in human patients. Although its use is becoming more common in veterinary medicine, its role as a first-line monotherapy in small animal epileptics remains to be determined. This review of the human and animal literature regarding LEV describes its role in epileptic people and animals as well as in other disease states and provides recommendations for clinical usage.

Effects of levetiracetam treatment on autonomic nervous system functions in pediatric epilepsy patients

BACKGROUND

This study investigated the effects of levetiracetam (LEV) treatment on cardiac rhythm and heart rate variability.

METHODS

The study included two groups of patients diagnosed with non-lesional epilepsy who had not yet been treated and who presented to the outpatient pediatric neurology clinic at Van Training and Research Hospital, Van, Turkey, between 2019 and 2020. The heart rate variability (HRV) of 47 patients in the first group, before and at the 3rd month of treatment, and intravenous (IV) LEV loading in 13 patients in the second group was evaluated by Holter electrocardiography (ECG).

RESULTS

It was determined that the values of triangular index, standard deviation of the RR intervals over a 24-hour period (SDNN), standard deviation of all 5-minute mean RR intervals (SDANN), mean of standard deviations of all normal RR intervals (SDNNI), the percentage of RR intervals with >50-millisecond variation (PNN50), and the square root of mean squared differences of successive RR intervals (RMSSD). HRV of 47 patients under LEV treatment significantly increased in the 3rd month of treatment compared to baseline (p < 0.05). No difference was found in HRV between the intravenous loading and the control group (p > 0.05).

CONCLUSIONS

Our study suggests that the sympathovagal balance before treatment in the patient group is in favor of the sympathetic nervous system and that the sympathovagal imbalance improves after treatment. Our results show that LEV monotherapy and loading have no negative effect on HRV and potential cardiac arrhythmia risk in children with epilepsy.

Pharmacokinetic considerations surrounding the use of levetiracetam for seizure prophylaxis in neurocritical care - an overview

INTRODUCTION

Levetiracetam (LEV) is one of the most widely used anti-seizure medications (ASMs) in clinical practice. This is due both to a different mechanism of action when compared to other ASMs and its easy handling. Indeed, because of its interesting pharmacokinetic properties, it is often used outside of the labelled indications, notably in the neurocritical setting as prophylaxis of epileptic seizures.

AREAS COVERED

A literature search was conducted and the most relevant studies on the pharmacokinetic properties of LEV were selected by two independent investigators. Current evidence on the use of ASM prophylaxis in the neurocritical setting was also reviewed, highlighting and discussing the strengths and limits of LEV as drug of choice for anti-epileptic prophylaxis in this scenario.

EXPERT OPINION

LEV has a "near-ideal" pharmacokinetic profile, which makes it an attractive drug for ASM prophylaxis in neurocritical care. However, current recommendations restrict ASMs prophylaxis to very selected circumstances and the role of LEV is marginal. Moreover, studies are generally designed to compare LEV versus phenytoin, whereas studies comparing LEV versus placebo are lacking. Further randomized trials will be needed to better elucidate LEV utility and its neuroprotective role in the neurocritical setting.

Physiologically-based pharmacokinetic modeling of oxcarbazepine and levetiracetam during adjunctive antiepileptic therapy in children and adolescents

Oxcarbazepine (OXZ) and levetiracetam (LEV) are two new generation anti‐epileptic drugs, often co‐administered in children with enzyme‐inducing antiepileptic drugs (EIAEDs). The anti‐epileptic effect of OXZ and LEV are linked to the exposure of OXZ’s active metabolite 10‐monohydroxy derivative (MHD) and (the parent) LEV, respectively. However, little is known about the confounding effect of age and EIAEDs on the pharmacokinetics (PKs) of MHD and LEV. To address this knowledge gap, physiologically‐based pharmacokinetic (PBPK) modeling was performed in the PK‐Sim software using literature data from children greater than or equal to 2 years of age. Age‐related changes in clearance (CL) of MHD and LEV were characterized, both in the presence (group 1) and absence (group 2) of concomitant EIAEDs. The drug‐drug interaction effect of EIAEDs was estimated as the difference in CL estimates between groups 1 and 2. PBPK modeling suggests that bodyweight normalized CL (ml/min/kg) is higher in younger children than their older counterparts (i.e., due to an influence of age). Concomitant EIAEDs further increase MHD’s CL to a fixed extent of 25% at any age, but EIAEDs’ effect on LEV’s CL increases with age from 20% (at 2 years) to 30% (at adolescence). Simulations with the maximum recommended doses (MRDs) revealed that children between 2 and 4 years and greater than 4 years, who are not on EIAEDs, are at risk of exceeding the reference exposure range for OXZ and LEV, respectively. This analysis demonstrates the use of PBPK modeling in understanding the confounding effect of age and comedications on PKs in children and adolescents.

The Pharmacokinetics of Levetiracetam in Critically Ill Adult Patients: An Intensive Care Unit Clinical Study

The aim of this study was to investigate levetiracetam pharmacokinetics in critically ill adult intensive care patients and to identify pathophysiological factors affecting its kinetics. Fourteen critically ill patients in an intensive care unit were enrolled in the study and received intravenous levetiracetam. Blood samples were collected at specific time points to determine the levetiracetam pharmacokinetics. Patient characteristics such as renal function, demographics, disease severity, organ dysfunction, and biochemical laboratory tests were evaluated for their influence on the kinetics of levetiracetam. Estimated glomerular filtration rate (eGFR) had a statistically significant (p = 0.001) effect on levetiracetam clearance. None of the other patient characteristics had a statistically significant effect on the pharmacokinetics. Simulations of dosing regimens revealed that even typically administered doses of levetiracetam may result in significantly increased concentrations and risk of drug toxicity in patients with impaired renal function. The Acute Physiology and Chronic Health Evaluation II (APACHE II) score differed significantly among the three groups with different epileptic activity (p = 0.034). The same groups also differed in terms of renal function (p = 0.031). Renal dysfunction should be considered when designing levetiracetam dosage. Patients with a low APACHE II score had the lowest risk of experiencing epileptic seizures.

Safety of Intravenous Push Levetiracetam Compared to Intravenous Piggyback at a Tertiary Academic Medical Center: A Retrospective Analysis

INTRODUCTION

Medication administration via intravenous push presents multiple potential advantages; however, there may be an increased risk of adverse drug reactions. In 2020, Brigham and Women's Hospital changed levetiracetam intravenous administration to intravenous push (IVP).

OBJECTIVE

The purpose of this analysis was to compare the safety profile of IVP to intravenous piggyback (IVPB) levetiracetam administration.

METHODS

This institutional review board-approved, single-center, pre-post analysis was performed between 1 November, 2019 and 30 May, 2020. The electronic health record was used to identify all administrations of intravenous levetiracetam greater than 1000 mg in patients ≥ 18 years old. The major safety outcomes included hypotension, bradycardia, drug-induced sedation, and intravenous site reactions such as phlebitis and infiltration. The major efficiency outcome was the time from pharmacy order verification to first-dose administration.

RESULTS

A total of 498 administrations in 162 patients were included in the analysis: 252 administrations in 84 patients in the IVP group and 246 administrations in 78 patients in the IVPB group. The incidence of bradycardia was 7 vs 3 (3.2% vs 1.5%, p = 0.34); hypotension 10 vs 6 (5.2% vs 3.5%, p = 0.44); sedation 21 vs 36 (19.3% vs 27.9%, p = 0.12); and peripheral IV site reactions 0 vs 1 (0% vs 0.6%, p = 0.39) in the IVP vs IVPB groups, respectively. The median time between order verification and first-dose administration was significantly reduced in the IVP vs IVPB group (23.5 vs 55 min, p < 0.001).

CONCLUSIONS

Intravenous push levetiracetam administration of doses up to 4000 mg was associated with a similar incidence of cardiovascular, sedation, and infusion site-related adverse events compared to IVPB and resulted in a significant reduction in time to first-dose administration. Intravenous push levetiracetam in doses as high as 4000 mg may be considered safe with appropriate monitoring.

Treating Status Epilepticus: Phenytoin Versus Levetiracetam

For decades, phenytoin has been the drug of choice for the treatment of epilepsy but also the second-line treatment for status epilepticus (SE). However, newer antiepileptic drugs (AEDs) have emerged as safer alternatives for the suppression of seizures. Consequently, phenytoin has recently fallen under scrutiny in the research world, prompting many studies to compare its efficacy to these other drugs, most notably levetiracetam. Levetiracetam is a second-generation AED, which is gaining wide clinical use as the second-line agent in treating SE patients. This review focuses on several clinical studies that have directly compared the effectiveness of phenytoin and levetiracetam in suppressing SE seizure activity. Additionally, this review highlights several advantages of using levetiracetam over phenytoin in this clinical context.

Evaluation of Time to Administration, Benzodiazepine Use, and Safety of Intravenous Push Levetiracetam in a Neuro-Spine Intensive Care Unit

PURPOSE

The purpose of this study was to evaluate the time to medication administration, clinical effect, and safety of a recent Pharmacy and Therapeutics Committee-approved change in the administration of levetiracetam from intravenous piggyback (IVPB) over 15 min to undiluted intravenous push (IVP) over 2-5 min at a large academic medical center.

METHODS

The primary outcome was the time from order verification to the administration of IVP levetiracetam versus IVPB levetiracetam. The secondary outcome was any benzodiazepine administered in the time between levetiracetam order verification and administration in both groups. Adult patients admitted to the neuro-spine intensive care unit in the 6 months prior to and after the policy change, and who received at least one dose of 1000 mg or higher of IVP or IVPB levetiracetam for active seizures, were included in this retrospective, observational, institutional review board-approved study. Data were analyzed using descriptive statistics, χ², and the Mann-Whitney U-test as appropriate.

RESULTS

Of the 2055 hospital-wide levetiracetam doses ordered within the study period, 316 doses were screened for enrollment and 160 were enrolled with 60 and 100 patients assigned to the IVP and IVPB groups, respectively. There were no differences between the groups at baseline. The majority of the population was male, 57 years old, had no significant renal dysfunction (defined as a creatinine clearance of less than 60 ml/min), and had a seizure etiology of malignancy or traumatic brain injury. A significant reduction in the time to administration of levetiracetam was found with IVP compared with IVPB administration (28 vs. 80 min, p < 0.0001). A subsequent reduction in patients who received benzodiazepines in the interim of levetiracetam order verification and administration was also associated with IVP compared with IVPB (2% vs. 13%, p = 0.042). There were no differences found in the rates of adverse effects between groups.

CONCLUSIONS

Administration of levetiracetam doses up to 2000 mg via IVP is a safe method of administration that results in a reduction of time to medication administration and a reduction of benzodiazepine use.

Pharmacokinetics of levetiracetam in neurosurgical ICU patients

BACKGROUND/OBJECTIVES

The pharmacokinetics (PK) of drugs is dramatically altered in critical illness. Augmented renal clearance (ARC), a phenomenon characterized by creatinine clearance (CrCl) greater than 130 ml/min/1.73m², is commonly described in critically ill patients. Levetiracetam, an antiepileptic drug commonly prescribed for seizure prophylaxis in the neurosurgical ICU, undergoes predominant elimination via the kidneys. Hence, we hypothesize that current dosing practice of intravenous (IV) levetiracetam 500 mg twice daily is inadequate for critically ill patients due to enhanced drug elimination. The objectives of our study were to describe the population PK of levetiractam using a nonparametric approach to design an optimal dosing regimen for critically ill neurosurgical patients.

METHODS

This was a prospective, observational, population PK study. Serial blood samples were obtained from neurosurgical ICU patients who received at least one dose of IV levetiracetam. We used uHPLC to analyze these samples and Pmetrics™ software to perform PK analysis.

RESULTS

Twenty subjects were included, with a median age of 54 years and CrCl of 104 ml/min. A two-compartmental model with linear elimination adequately described the profile of levetiracetam. Mean clearance (CL) was 3.55 L/h and volume of distribution (V) was 18.8 L. No covariates were included in the final model. Monte Carlo simulations showed a low probability of target attainment (PTA, trough at steady state of ≥6 mg/L) with a standard dose of 500 mg twice daily. A dose of at least 1000 mg twice daily was required to achieve 80% PTA. Two subjects, both with subtherapeutic trough levels, developed early onset seizures.

CONCLUSION

Our study examined the population PK of levetiracetam in a critically ill neurosurgical population. We found that this population displayed higher clearance and required higher doses to achieve target levels.

Comparative Efficacy of IV Phenytoin, IV Valproate, and IV Levetiracetam in Childhood Status Epilepticus

Background and Purpose

Status epilepticus (SE) is a common pediatric neurological emergency that requires immediate and vigorous management. Currently, phenytoin is the most common agent used in the setting of SE following benzodiazepine for further seizure prevention. Other drugs recently introduced for management of SE are valproic acid and levetiracetam.

Methods

This prospective randomized study included 150 pediatric patients admitted as SE. Patients were randomized into three equal groups (50 each) to receive one of the three anticonvulsants in addition to standard treatment. Patients were monitored in hospital regarding their vitals, time to regain consciousness, and seizure recurrence.

Results

At 24 hours seizures were controlled in 44 patients (88%) in phenytoin group, 39 patients (78%) in levetiracetam (LEV) group and 46 patients (92%) in valproate (VAL) group (p=0.115). The mean time to regain consciousness in phenytoin, LEV and VAL groups was 122.3±45.4, 120.8±42.8, and 75.0±30.7 minutes (mean±standard deviation) respectively. Patients in VAL group regained consciousness earlier than both phenytoin and LEV group patients (p<0.0001). At 3 months follow-up, seven (14.28%) out of 49 patients in phenytoin group, 14 (28.57%) out of 49 in LEV group and two (4%) out of 50 patients in VAL group had a seizure recurrence (p=0.0032).

Conclusions

In our study we found that both IV LEV and IV VAL safe and efficacious. The primary outcome, seizure recurrence at 24 hours, did not show a statistically significant difference in three groups (p>0.05). Also, seizure recurrence at 1 week did not reach a statistically significant difference. However, time to regain consciousness and seizure recurrence at 3 months was significantly less in VAL group (p<0.05).

Safety and Tolerability of Rapid Administration Undiluted Levetiracetam

BACKGROUND/OBJECTIVE

Levetiracetam (LEV) is an antiepileptic drug used widely in patients with a favorable safety profile. Studies evaluating the safety and efficacy of intravenous (IV) LEV included volumes of at least 100 mL. Minimally diluted doses administered over 5-6 min were found to be both safe and effective. Given the complexities of admixing, this practice can be impractical and result in delays in antiepileptic therapy. This study aimed to retrospectively review the safety and tolerability of rapid administration of undiluted LEV doses ≤ 1000 mg.

METHODS

This was a retrospective study evaluating adverse drug reactions associated with undiluted LEV from January 1, 2018-June 1, 2018. Patients were included if they received at least one dose of undiluted LEV and were ≥ 18 years old. Safety endpoints were reviewed and collected from the time administration until hospital discharge. Endpoints included injection site pain and discomfort, injection site erythema, extravasation, IV line replacement, and any documented adverse effect leading to IV LEV discontinuation. Descriptive statistics were used to analyze the data.

RESULTS

A total of 199 patients were included in the study totaling 1626 doses of LEV. Most patients were administered LEV 1000 mg (60.8%), through a peripheral line (64.3%), and were prescribed LEV for seizure prophylaxis (58.3%). Patients received a mean of 8.1 ± 8 doses for a mean duration of therapy of 5 ± 4.5 days. About 98.5% of patients did not experience an adverse effect, whereas 1.5% of patients experienced agitation, delirium, confusion, and/or lethargy, which is well known to LEV therapy.

CONCLUSIONS

Rapid administration of undiluted LEV doses ≤ 1000 mg were well tolerated with no concentration-related side effects. Further prospective research is needed to confirm this observation as well as the safety of higher doses.

Population Pharmacokinetics of Levetiracetam in Patients with Traumatic Brain Injury and Subarachnoid Hemorrhage Exhibiting Augmented Renal Clearance

BACKGROUND AND OBJECTIVE

Patients with severe trauma exhibit augmented renal clearance, which can alter the dosing requirement of renally eliminated drugs. This study aimed to develop a population pharmacokinetic model for levetiracetam in patients with severe traumatic brain injury and aneurysmal subarachnoid hemorrhage, and use it to describe optimal dosing regimens.

METHODS

This was a prospective open-label observational study. Critically ill adult patients with severe traumatic brain injury or aneurysmal subarachnoid hemorrhage without renal dysfunction and receiving levetiracetam were eligible. Serial levetiracetam plasma concentrations were analyzed to develop a population pharmacokinetic model and perform dosing simulations.

RESULTS

A two-compartment model best described the concentration-time data from 30 patients. The mean ± standard deviation parameter estimates were bioavailability (F) of 0.8 ± 0.2, absorption rate constant of 2.4 ± 2 h^-1, clearance 2.5 ± 1.1 L/h, central volume of distribution 8.9 ± 3.0 L/h, and transfer rate constraints of 1.8 ± 1.1 h^-1 from central to peripheral compartments and 0.7 ± 0.3 h^-1 from peripheral to central compartments. For the simulated intermittent dosing regimens, on average, the median trough concentration reduced by 50% for every 40-mL/min/1.73 m² increase in urinary creatinine clearance. Simulated doses of at least 6 g/day were required for some levels of augmented renal clearance.

CONCLUSIONS

Patients with severe traumatic brain injury and aneurysmal subarachnoid hemorrhage with augmented renal clearance are at risk of not achieving target levetiracetam plasma concentrations. We suggest dose titration guided by measured creatinine clearance, and/or, therapeutic drug monitoring if available, to minimize the risk of seizures.

Levetiracetam pharmacokinetics in critically ill patients undergoing renal replacement therapy

PURPOSE

To determine clearance of levetiracetam in patients requiring continuous renal replacement therapy (CRRT) or sustained low efficiency dialysis (SLED).

MATERIALS AND METHODS

Adult patients with acute kidney injury or end stage renal disease requiring either CRRT or SLED and levetiracetam were eligible for inclusion. Simultaneous arterial, venous, and effluent samples for analysis of levetiracetam concentrations were collected every two hours for up to 6-8 h. Levetiracetam clearance (CL) and half-life (t_1/2) were calculated for each modality.

RESULTS

Eight CRRT patients and 4 SLED patients completed the study: 67% male, mean age 50 ± 13 years, and 83% had AKI. Seven CRRT patients received continuous venovenous hemodiafiltration (CVVHDF) [median pre-replacement rate 700 mL/h (range 500-1000), post-replacement rate 500 mL/h (range 200-1000), effluent rate 2500 mL/h (range 1700-3650) and delivered CRRT dose 27 mL/kg/h (range 19-54)] and one patient received CVV hemofiltration (CVVH). The mm mean levetiracetam CL during CVVHDF was 31.2 ± 8.5 mL/min, and the and the mean t_1/2 was 10.4 ± 2.2 h. For the patient requiring CVVH, clearance and t_1/2 were 22.5 mL/min and 9.5 h, respectively. Mean levetiracetam CL during SLED performed at a blood flow rate of 250 mL/min and a dialysate flow rate of 100 mL/min was 74.0 ± 25.3 mL/min and t_1/2 was 4.8 ± 2.3 h.

CONCLUSIONS

Levetiracetam clearance was substantial with both modalities under the operating conditions reported. There is the potential for subtherapeutic concentrations with current recommended dosing strategies that account only for kidney function and not these extracorporeal routes of elimination.

Levetiracetam as an alternative to phenytoin for second-line emergency treatment of children with convulsive status epilepticus: the EcLiPSE RCT

BACKGROUND

Convulsive status epilepticus is the most common neurological emergency in children. Its management is important to avoid or minimise neurological morbidity and death. The current first-choice second-line drug is phenytoin (Epanutin, Pfizer Inc., New York, NY, USA), for which there is no robust scientific evidence.

OBJECTIVE

To determine whether phenytoin or levetiracetam (Keppra, UCB Pharma, Brussels, Belgium) is the more clinically effective intravenous second-line treatment of paediatric convulsive status epilepticus and to help better inform its management.

DESIGN

A multicentre parallel-group randomised open-label superiority trial with a nested mixed-method study to assess recruitment and research without prior consent.

SETTING

Participants were recruited from 30 paediatric emergency departments in the UK.

PARTICIPANTS

Participants aged 6 months to 17 years 11 months, who were presenting with convulsive status epilepticus and were failing to respond to first-line treatment.

INTERVENTIONS

Intravenous levetiracetam (40 mg/kg) or intravenous phenytoin (20 mg/kg).

MAIN OUTCOME MEASURES

Primary outcome - time from randomisation to cessation of all visible signs of convulsive status epilepticus. Secondary outcomes - further anticonvulsants to manage the convulsive status epilepticus after the initial agent, the need for rapid sequence induction owing to ongoing convulsive status epilepticus, admission to critical care and serious adverse reactions.

RESULTS

Between 17 July 2015 and 7 April 2018, 286 participants were randomised, treated and consented. A total of 152 participants were allocated to receive levetiracetam and 134 participants to receive phenytoin. Convulsive status epilepticus was terminated in 106 (70%) participants who were allocated to levetiracetam and 86 (64%) participants who were allocated to phenytoin. Median time from randomisation to convulsive status epilepticus cessation was 35 (interquartile range 20-not assessable) minutes in the levetiracetam group and 45 (interquartile range 24-not assessable) minutes in the phenytoin group (hazard ratio 1.20, 95% confidence interval 0.91 to 1.60; p = 0.2). Results were robust to prespecified sensitivity analyses, including time from treatment commencement to convulsive status epilepticus termination and competing risks. One phenytoin-treated participant experienced serious adverse reactions.

LIMITATIONS

First, this was an open-label trial. A blinded design was considered too complex, in part because of the markedly different infusion rates of the two drugs. Second, there was subjectivity in the assessment of 'cessation of all signs of continuous, rhythmic clonic activity' as the primary outcome, rather than fixed time points to assess convulsive status epilepticus termination. However, site training included simulated demonstration of seizure cessation. Third, the time point of randomisation resulted in convulsive status epilepticus termination prior to administration of trial treatment in some cases. This affected both treatment arms equally and had been prespecified at the design stage. Last, safety measures were a secondary outcome, but the trial was not powered to demonstrate difference in serious adverse reactions between treatment groups.

CONCLUSIONS

Levetiracetam was not statistically superior to phenytoin in convulsive status epilepticus termination rate, time taken to terminate convulsive status epilepticus or frequency of serious adverse reactions. The results suggest that it may be an alternative to phenytoin in the second-line management of paediatric convulsive status epilepticus. Simple trial design, bespoke site training and effective leadership were found to facilitate practitioner commitment to the trial and its success. We provide a framework to optimise recruitment discussions in paediatric emergency medicine trials.

FUTURE WORK

Future work should include a meta-analysis of published studies and the possible sequential use of levetiracetam and phenytoin or sodium valproate in the second-line treatment of paediatric convulsive status epilepticus.

TRIAL REGISTRATION

Current Controlled Trials ISRCTN22567894 and European Clinical Trials Database EudraCT number 2014-002188-13.

FUNDING

This project was funded by the National Institute for Health Research (NIHR) Health Technology Assessment programme and will be published in full in Health Technology Assessment; Vol. 24, No. 58. See the NIHR Journals Library website for further project information.

Efficacy and safety profile of intravenous levetiracetam versus phenytoin in convulsive status epilepticus and acute repetitive seizures in children

PURPOSE

Although phenytoin is one of the most commonly used antiepileptic drugs (AEDs), it has potential serious side effects and drug interactions. Levetiracetam is a relatively newer AED with favorable pharmacokinetics and could be an effective and safer option for the treatment of convulsive status epilepticus (CSE). We aimed to compare the efficacy and safety profile of intravenous levetiracetam and phenytoin as second-line treatment agents in children with CSE and acute repetitive seizures (ARS).

METHOD

Two hundred seventy-seven patients aged between 1 month and 18 years who received intravenous levetiracetam or phenytoin as a second-line AED with the diagnosis of CSE or ARS were retrospectively evaluated. Drug efficacy was defined as control of seizures without the need for any additional medication after completion of the infusion and no recurrence in the following 12 h. The primary outcome was drug efficacy. The secondary outcomes included application of an additional second-line AED, induction of anesthesia, and admission to the intensive care unit (ICU), and drug-related adverse reactions.

RESULTS

No differences were found between the two treatment groups with regard to patient characteristics and seizure type. The efficacy of levetiracetam was higher than that of phenytoin (77.6% vs 57.7%, P = 0.011) in children with CSE. There was no significant difference between the efficacy rates of levetiracetam and phenytoin for ARS (55.8% vs 58.8%, P = 0.791). Overall, drug efficacy was 70.9% for levetiracetam and 58.1% for phenytoin (P = 0.048). For CSE, the need for additional second-line treatment, anesthesia induction, and ICU admission was higher in the phenytoin group (P = 0.001, P = 0.038, P = 0.02, respectively). Drug-related adverse reactions were more frequent in the phenytoin group than the levetiracetam group (23.3% vs 1.4%; P < 0.001). The most common adverse reaction in the phenytoin group was hypotension. Phenytoin-related anaphylaxis was detected in one patient. No serious adverse effects related to levetiracetam were observed.

CONCLUSIONS

Intravenous levetiracetam seems as effective as intravenous phenytoin in emergency treatment of children with ARS and more effective for CSE in stopping the seizure with less risk of recurrence. Levetiracetam has fewer cardiovascular side effects and has a safer profile than phenytoin. Intravenous levetiracetam is a favorable option as a first second-line AED for pediatric seizures.

Albumin nanoparticles coated with polysorbate 80 for the targeted delivery of antiepileptic drug levetiracetam into the brain

The aim of the study was to target levetiracetam (LEV) into the brain by albumin nanoparticles. The levetiracetam-loaded albumin nanoparticles (LEV-NPs) were formulated by desolvation. The particle size of LEV-NPs was 153.7 ± 44.8 nm and the zeta potential was - 10.8 mV. The in vitro LEV release, in pH 6.8 phosphate buffer, was determined by dialysis and showed a biphasic pattern of drug release and ranged in between 40.42 ± 2.6% w/w and 63.61 ± 2.12% w/w. The biodistribution study was conducted on male Wistar rats. The LEV was given as i.v. injection in tail vein, and the formulations were the free drug, LEV-NPs, and levetiracetam-loaded albumin nanoparticles further coated with 1% polysorbate 80 (LEV-NPs-PS 80). A significant increase in LEV concentration was achieved in the brain for LEV-NPs-PS 80 when compared with LEV free drug. The LEV concentration achieved in the brain after administering free drug and LEV-NPs-PS 80 was 5.28 ± 1.79 and 18.54 ± 2.38 μg/gm respectively. The LEV-NPs-PS 80 enhanced LEV concentration in the brain by 3.51-fold when compared with the free drug. Graphical abstract.

Changes in Real-world Practice Patterns of Antiepileptic Drugs for Status Epilepticus: A Nationwide Observational Study in Japan

Intravenous (i.v.) phenytoin/fosphenytoin is recommended as the second-line therapy of antiepileptic drugs in patients with status epilepticus (SE). i.v. Levetiracetam is regarded as an effective and safe equivalent with i.v. phenytoin/fosphenytoin. However, i.v. levetiracetam is not covered by public health insurance for SE in most countries. For this study, we performed the real-world practice pattern survey of antiepileptic drugs for status epilepticus using the nationwide inpatient database. We used the Japanese Diagnosis Procedure Combination inpatient database in Japan and identified all cases of emergency admission attributable to status epilepticus from March 2011 through March 2018. We described the patient characteristics and practice pattern of antiepileptic drugs. The analysis conducted for this study examined 31,472 cases. As the second-line therapy, the use of i.v. levetiracetam increased rapidly from 2016; 35% of cases received i.v. levetiracetam in 2017. By contrast, the use of i.v. phenytoin/fosphenytoin decreased from 2016. In-hospital mortality decreased year-by-year. No year-by-year change was observed for deaths within 24 h, length of hospital stay, drug-induced hepatitis, or drug-induced eruption. Although the use of levetiracetam for treatment of SE is not compensated by public health insurance in Japan, i.v. levetiracetam use is increasing dramatically as the second-line SE therapy. We propose that health insurance coverage be extended to include i.v. levetiracetam treatment for SE.

Rapidity of CNS Effect on Photoparoxysmal Response for Brivaracetam vs. Levetiracetam: A Randomized, Double-blind, Crossover Trial in Photosensitive Epilepsy Patients

INTRODUCTION

Both levetiracetam (LEV) and brivaracetam (BRV) eliminate the electroencephalogram photoparoxysmal response (PPR) in the human phase IIa photosensitivity model of epilepsy. The physiochemical properties of BRV differ from those of LEV, having higher potency and lipophilicity plus 10- to 15-fold greater affinity for synaptic vesicle glycoprotein 2A.

OBJECTIVE

We compared the rapidity of the effects of both drugs in the central nervous system (CNS) of patients with photosensitive epilepsy using time to PPR elimination post-intravenous infusion as a pharmacodynamic endpoint.

METHODS

Using a randomized, double-blind, two-period, balanced, crossover design, we tested patients with photosensitive epilepsy with equipotent milligram doses of intravenous LEV 1500 mg versus BRV 100 mg post-15-min intravenous infusion (part 1) and post-5-min intravenous infusion (part 2, same doses). Eight patients per part were deemed sufficient with 80% power to determine a 70% reduction for intravenous BRV:LEV intrapatient time ratio to PPR elimination, with a 0.05 two-sided significance level. Plasma antiseizure medicine concentrations were measured using liquid chromatography/mass spectrometry.

RESULTS

Nine patients [six women; mean age 27.8 years (range 18-42)] completed the study; seven of these participated in both parts 1 and 2. In 31 of 32 instances, patients experienced PPR elimination. In mixed-effects model time analysis, BRV eliminated PPRs more quickly than did LEV (median 2 vs. 7.5 min, respectively). However, no statistically significant difference in BRV:LEV time ratio to PPR elimination was observed for two of our multiple primary outcomes: for the 15-min infusion alone (p = 0.22) or the 5-min infusion alone (p = 0.11). However, BRV was faster when we excluded an outlier patient in part 1 (p = 0.0016). For our remaining primary outcome, parts 1 and 2 data combined, the median intrapatient BRV:LEV time ratio was 0.39 [95% confidence interval (CI) 0.16-0.91], i.e., PPR elimination was 61% faster with BRV, p = 0.039. PPR was completely eliminated in ≤ 2 min in 11 patients with BRV and in four patients with LEV. No period or carryover effects were seen. No serious or severe adverse effects occurred. At PPR elimination (n = 16), median plasma [BRV] was 250 ng/mL (range 30-4100) and median plasma [LEV] was 28.35 μg/mL (range 1-86.7).

CONCLUSION

Outcome studies directly comparing LEV and BRV are needed to define the clinical utility of the response with BRV, which was several minutes faster than that with LEV.

CLINICAL TRIALS

ClinTrials.gov Identifier = NCT03580707; registered 07-09-18.

Seizure Prophylaxis in Traumatic Brain Injury: A Comparative Study of Levetiracetam and Phenytoin Cerebrospinal Fluid Levels in Trauma Patients with Signs of Increased Intracranial Pressure Requiring Ventriculostomy

Background

One of the most common life-threatening injuries to trauma patients arriving in the emergency department (ED) is traumatic brain injury (TBI). Traditionally, intravenous medications have been given as seizure prophylaxis in patients demonstrating signs of increased intracranial pressure (ICP), as post-traumatic seizures in trauma patients are associated with higher morbidity and mortality. Medications traditionally given for this indication such as phenytoin have been established to reach therapeutic levels in the cerebrospinal fluid (CSF) quickly and are effective in preventing post-traumatic seizures but often have a large side-effect profile. A newer medication that is being used for seizure prophylaxis in patients with epilepsy is levetiracetam. Levetiracetam typically has a better side effect profile, but it has not been demonstrated that the drug reaches therapeutic levels in the CSF as quickly as phenytoin. Studies have shown levetiracetam and phenytoin to be equivocal in the prevention of post-TBI seizure prophylaxis.

Methods

This was a prospective, randomized, case-control study at a Level II trauma center of adult patients (age >/= 18 years) who suffered severe TBI (sTBI) requiring the placement of an external ventricular drain (EVD) from May 2017 to June 2018. Twelve patients were randomly placed into one of two groups for the administration of antiepileptic medication (either levetiracetam or phenytoin), allowing for the subsequent serial collection of CSF for the analysis of therapeutic levels of antiepileptic medications. Levetiracetam or phenytoin was administered at standardized fixed doses per our neurosurgical center standard protocol. CSF was collected before either drug was administered, 60 minutes after completion of administration and 360 minutes after completion of drug administration. Data analysis was performed to compare the time frame for which therapeutic levels of the medications were achieved in the CSF. The published steady-state and therapeutic CSF level of levetiracetam is 32 mcg/ml and phenytoin is 2 mcg/ml.

Results

A trend was observed in which the closer the fixed dosage approximated the weight-based dosing of phenytoin, the more their CSF phenytoin level increased (and approximated the therapeutic range) with an associated R-squared value of 0.6274. This trend was not found in patients receiving levetiracetam.

Conclusions

Levetiracetam does not reach levels needed for seizure prophylaxis in human CSF when loaded at standard dosing regimens in the acute setting. Phenytoin does reach levels needed for seizure prophylaxis in human CSF with standardized regimen dosing when dosages approximate weight-based dosing. If needed, in the acute setting phenytoin should have additional doses given prior to six hours after the loading dose to achieve therapeutic CSF levels. 

Phenytoin versus levetiracetam as prophylaxis for postcraniotomy seizure in patients with no history of seizures: systematic review and meta-analysis

OBJECTIVEDe novo seizure following craniotomy (DSC) for nontraumatic pathology may adversely affect medical and neurological outcomes in patients with no history of seizures who have undergone craniotomies. Antiepileptic drugs (AEDs) are commonly used prophylactically in patients undergoing craniotomy; however, evidence supporting this practice is limited and mixed. The authors aimed to collate the available evidence on the efficacy and tolerability of levetiracetam monotherapy and compare it with that of the classic AED, phenytoin, for DSC.METHODSPubMed, Embase, Web of Science, and the Cochrane Library were searched for studies that compared levetiracetam with phenytoin for DSC prevention. Inclusion criteria were adult patients with no history of epilepsy who underwent craniotomy with prophylactic usage of phenytoin, a comparator group with levetiracetam treatment as the main treatment difference between the two groups, and availability of data on the numbers of patients and seizures for each group. Patients with brain injury and previous seizure history were excluded. DSC occurrence and adverse drug reaction (ADR) were evaluated. Seizure occurrence was calculated using the Peto odds ratio (POR), which is the relative effect estimation method of choice for binary data with rare events.RESULTSData from 7 studies involving 803 patients were included. The DSC occurrence rate was 1.26% (4/318) in the levetiracetam cohort and 6.60% (32/485) in the phenytoin cohort. Meta-analysis showed that levetiracetam is significantly superior to phenytoin for DSC prevention (POR 0.233, 95% confidence interval [CI] 0.117-0.462, p < 0.001). Subgroup analysis demonstrated that levetiracetam is superior to phenytoin for DSC due to all brain diseases (POR 0.129, 95% CI 0.039-0.423, p = 0.001) and tumor (POR 0.282, 95% CI 0.117-0.678, p = 0.005). ADRs in the levetiracetam group were cognitive disturbance, thrombophlebitis, irritability, lethargy, tiredness, and asthenia, whereas rash, anaphylaxis, arrhythmia, and hyponatremia were more common in the phenytoin group. The overall occurrence of ADR in the phenytoin (34/466) and levetiracetam (26/432) groups (p = 0.44) demonstrated no statistically significant difference in ADR occurrence. However, the discontinuation rate of AEDs due to ADR was 53/297 in the phenytoin group and 6/196 in the levetiracetam group (POR 0.266, 95% CI 0.137-0.518, p < 0.001).CONCLUSIONSLevetiracetam is superior to phenytoin for DSC prevention for nontraumatic pathology and has fewer serious ADRs that lead to discontinuation. Further high-quality studies that compare levetiracetam with placebo are necessary to provide evidence for establishing AED guidelines.

Clinical Efficacy and Safety of Injectable Levetiracetam Versus Phenytoin as Second-Line Therapy in the Management of Generalized Convulsive Status Epilepticus in Children: An Open-Label Randomized Controlled Trial

Background and Purpose

There is sparsity of quality evidence for the use of drugs after first-line benzodiazepines in convulsive status epilepticus in children. The aim of the study was to compare the clinical efficacy and safety of intravenous levetiracetam versus intravenous phenytoin as second-line drugs in the management of generalized convulsive status epilepticus in children.

Methods

This open-label randomized controlled trial was conducted in the Emergency Department of The Children's Hospital and The Institute of Child Health, Multan, Pakistan over a period of 4 years and 6 months from January 2014 to June 2018. This study included 600 children with generalized convulsive status epilepticus: 300 in the 40 mg/kg levetiracetam group, and 300 in the 20 mg/kg phenytoin group. Cessation of a clinical seizure (seizure cessation rate) within 30 minutes after the end of drug administration was the primary outcome in this study, and the presence or absence of adverse effects was noted as the secondary outcome. Data were analyzed using SPSS (version 20.0).

Results

The children in the levetiracetam and phenytoin were aged 3.5±0.2 and 3.4±0.2 years (mean±SD), respectively, their seizure durations before the start of treatment were 25.1±0.6 and 23.8±0.4 minutes, and their treatment efficacies were 278/300 (92.7%) and 259/300 (83.3%). Levetiracetam was significantly more effective than phenytoin (p=0.012), with no significant difference in safety. Adverse events were observed in eight children in the phenytoin group.

Conclusions

Levetiracetam is significantly more effective than phenytoin for the treatment of convulsive status epilepticus in children who have failed to respond to benzodiazepines.

Pharmacology of new and developing intravenous therapies for the management of seizures and epilepsy

INTRODUCTION

Antiepileptic drugs (AEDs) are administered orally for chronic use. Parenteral formulations might be necessary when the oral route is not feasible (e.g. an impairment of consciousness, trauma, dysphagia, gastrointestinal illness) or for treatment of seizure emergencies. At present, few intravenous (IV) formulations are available on the market.

AREAS COVERED

The purpose of this review is to summarize the pharmacological characteristics and clinical applications of IV medications that have been recently introduced to the armamentarium of epilepsy therapy or are currently being developed. Apart from AEDs, other compounds belonging to different pharmacological classes (e.g. diuretics, anesthetics), which have shown potential effectiveness in seizure control, are taken into consideration, and the pathophysiological premises supporting their use for epilepsy treatment are illustrated. The authors give particular focus to immunomodulatory and immunosuppressive agents, which have become the therapeutic cornerstones for immune-mediated epilepsies, despite regulatory obstacles.

EXPERT OPINION

In several circumstances, especially in the case of seizure-related emergencies, clinical practice seems not match literature-based evidence, and several IV AEDs are still used off-label. Strong evidence derived from randomized clinical trials (RCTs) is needed to support the effectiveness and tolerability of any therapeutic approach, however common and "accepted' it may be, in order to guarantee patient safety and well-being.

Pharmacokinetic and Pharmacodynamic Evaluation of Intravenous Levetiracetam in Children With Epilepsy

This study aimed to evaluate the safety and tolerability of intravenous (IV) levetiracetam (LEV) as a monotherapy in children aged 1 month-16 years and to explore the pharmacokinetics (PK) of IV LEV and the time to seizure after IV then oral administration of LEV in pediatric children with epilepsy. Children diagnosed with acute unprovoked seizures requiring in-hospital IV LEV administration were included. After administration, the clinical seizure outcomes, side effects, and the Korean-Child Behavior Checklist were monitored and the PK and repeated time to seizure were analyzed via modeling using NONMEM software. Overall, 37 children with epilepsy were enrolled and underwent a PK analysis (median age, 4.6 years; median weight, 18.0 kg). Nine children (24.3%) had seizure recurrence during the follow-up period (median, 3.8 months) and 5 children (13.5%) experienced LEV-associated adverse events such as irritability (n = 2; 5.4%) and somnolence (n = 3; 8.1%). The plasma LEV concentrations after IV LEV were best described by a one-compartment linear PK model. Only body weight was associated with both the clearance and volume of distribution of LEV. The Weibull distribution model described the time to seizure recurrence well; no statistically significant predictor for the time to seizure was identified. Therefore, IV LEV was a well-tolerated and effective alternative in children with acute unprovoked seizures, and models for the PK and time to repeated seizure recurrence after LEV were successfully developed. In particular, the current use of a weight-based IV LEV dosing regimen in pediatric children is practical.

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.

A serious adverse event secondary to rapid intravenous levetiracetam injection in a dog

OBJECTIVE

To describe a serious adverse event as a result of rapid intravenous injection of undiluted levetiracetam in a dog.

CASE SUMMARY

An 8-year-old female spayed Chihuahua was evaluated for cluster seizures and tachypnea. The patient was administered an intravenous dose of undiluted levetiracetam (60 mg/kg) and immediately developed tachycardia, hyperglycemia, hypotension, and a dull mentation. The patient's blood pressure and mentation did not respond to intravenous fluid boluses but improved immediately after administration of epinephrine intravenously. The patient subsequently developed respiratory failure necessitating mechanical ventilation, prior to cardiac arrest. Necropsy examination noted a pulmonary inflammatory cell infiltrate, pulmonary edema, and interstitial pneumonia.

NEW OR UNIQUE INFORMATION PROVIDED

This report documents a serious adverse event associated with intravenous levetiracetam administration to a dog.

A meta-analysis of randomized controlled trials on levetiracetam in the treatment of pediatric patients with epilepsy

OBJECTIVE

To evaluate clinical efficacy, safety, and tolerability of levetiracetam as mono- or adjunctive therapy in the treatment of children and adolescents with epilepsy.

MATERIALS AND METHODS

We performed a meta-analysis of randomized controlled trials published from January 2007 to December 2016 in the databases Web of Science, Medline, Embase, Cochrane Library, and PubMed, Bing, Baidu, Google Scholar, Chinese National Knowledge Infrastructure (CNKI), and Wanfang Data. All of the studies eligible were compared for the efficacy, safety, and tolerability of levetiracetam with other antiepileptic drugs (AEDs) in epilepsy.

RESULTS

Thirteen randomized controlled trials on a total of 1,013 patients met the inclusion criteria in present study. Compared with other AEDs (oxcarbazepine, valproate, sulthiame, carbamazepine, and placebo), we found that levetiracetam had a comparable seizure-free rate (RR 1.16, 95% CI 1.03-1.31; P=0.30). Regarding seizure-frequency reduction ≥50% from baseline, levetiracetam also seemed equivalent to other AEDs (RR 1.08, 95% CI 1.01-1.16; P=0.35). In spite of patients treated with levetiracetam having a lower incidence of side effects compared with patients treated with other AEDs (RR 0.90, 95% CI 0.77-1.06), the difference between them was minute and not statistically significant (P=0.22).

CONCLUSION

Based on this meta-analysis, it seemed that levetiracetam had comparable effects concerning efficacy, tolerability, and adverse events. Nevertheless, 13 studies were insufficient to draw a conclusion that levetiracetam is effective as mono- and adjunctive therapy for all types of epilepsy syndromes and seizures. Larger-sample and more well-designed trials are needed to justify the widespread use of levetiracetam in the treatment of children and adolescents.

A Systematic Appraisal of Neurosurgical Seizure Prophylaxis: Guidance for Critical Care Management

Clinical decisions are often made in the presence of some uncertainty. Health care should be based on a combination of scientific evidence, clinical experience, economics, patient value judgments, and preferences. Seizures are not uncommon following brain injury, surgical trauma, hemorrhage, altered brain metabolism, hypoxia, or ischemic events. The impact of seizures in the immediate aftermath of injury may be a prolonged intensive care stay or compounding of the primary injury. The aim of brain injury management is to limit the consequences of the secondary damage. The original intention of seizure prophylaxis was to limit the incidence of early-onset seizures. However, clinical trials have been equivocal on this point, and there is concern about the adverse effects of antiepileptic drug therapy. This review of the literature raises concerns regarding the arbitrary division of seizures into early onset (7 d) and late onset (8 d and beyond). In many cases it would appear that seizures present within 24 hours of the injury or after 7 days, which would be outside of the scope of current seizure prophylaxis guidance. There also does not appear to be a pathophysiological reason to divide brain injury-related seizures into these timeframes. Therefore, a solution to the conundrum is to reevaluate current practice. Prophylaxis could be offered to those receiving intensive care for the primary brain injury, where the impact of seizure would be detrimental to the management of the brain injury, or other clinical judgments where prophylaxis is prudent. Neurosurgical seizure management can then focus attention on which agent has the best adverse effect profile and the duration of therapy. The evidence seems to support levetiracetam as the most appropriate agent. Although previous reviews have identified an increase cost associated with the use of levetiracetam, current cost comparisons with phenytoin demonstrate a marginal price differential. The aim of this review is to assimilate the applicable literature regarding seizure prophylaxis. The final guidance is a forum upon which further clinical research could evaluate a new seizure prophylaxis paradigm.

A multicentre randomised controlled trial of levetiracetam versus phenytoin for convulsive status epilepticus in children (protocol): Convulsive Status Epilepticus Paediatric Trial (ConSEPT) - a PREDICT study

Background

Convulsive status epilepticus (CSE) is the most common life-threatening childhood neurological emergency. Despite this, there is a lack of high quality evidence supporting medication use after first line benzodiazepines, with current treatment protocols based solely on non-experimental evidence and expert opinion. The current standard of care, phenytoin, is only 60% effective, and associated with considerable adverse effects. A newer anti-convulsant, levetiracetam, can be given faster, is potentially more efficacious, with a more tolerable side effect profile. The primary aim of the study presented in this protocol is to determine whether intravenous (IV) levetiracetam or IV phenytoin is the better second line treatment for the emergency management of CSE in children.

Methods/Design

200 children aged between 3 months and 16 years presenting to 13 emergency departments in Australia and New Zealand with CSE, that has failed to stop with first line benzodiazepines, will be enrolled into this multicentre open randomised controlled trial. Participants will be randomised to 40 mg/kg IV levetiracetam infusion over 5 min or 20 mg/kg IV phenytoin infusion over 20 min. The primary outcome for the study is clinical cessation of seizure activity five minutes following the completion of the infusion of the study medication. Blinded confirmation of the primary outcome will occur with the primary outcome assessment being video recorded and assessed by a primary outcome assessment team blinded to treatment allocation. Secondary outcomes include: Clinical cessation of seizure activity at two hours; Time to clinical seizure cessation; Need for rapid sequence induction; Intensive care unit (ICU) admission; Serious adverse events; Length of Hospital/ICU stay; Health care costs; Seizure status/death at one-month post discharge.

Discussion

This paper presents the background, rationale, and design for a randomised controlled trial comparing levetiracetam to phenytoin in children presenting with CSE in whom benzodiazepines have failed. This study will provide the first high quality evidence for management of paediatric CSE post first-line benzodiazepines.

Trial registration

Prospectively registered with the Australian and New Zealand Clinical Trial Registry (ANZCTR): ACTRN12615000129583 (11/2/2015). UTN U1111–1144-5272. ConSEPT protocol version 4 (12/12/2014).

Emergency treatment with levetiracetam or phenytoin in status epilepticus in children-the EcLiPSE study: study protocol for a randomised controlled trial

Background

Convulsive status epilepticus (CSE) is the most common life-threatening neurological emergency in childhood. These children are also at risk of significant morbidity, with acute and chronic impact on the family and the health and social care systems. The current recommended first-choice, second-line treatment in children aged 6 months and above is intravenous phenytoin (fosphenytoin in the USA), although there is a lack of evidence for its use and it is associated with significant side effects. Emerging evidence suggests that intravenous levetiracetam may be effective as a second-line agent for CSE, and fewer adverse effects have been described. This trial therefore aims to determine whether intravenous phenytoin or levetiracetam is more effective, and safer, in treating childhood CSE.

Methods/design

This is a phase IV, multi-centre, parallel group, randomised controlled, open-label trial. Following treatment for CSE with first-line treatment, children with ongoing seizures are randomised to receive either phenytoin (20 mg/kg, maximum 2 g) or levetiracetam (40 mg/kg, maximum 2.5 g) intravenously. The primary outcome measure is the cessation of all visible signs of CSE as determined by the treating clinician. Secondary outcome measures include the need for further anti-seizure medications or rapid sequence induction for ongoing CSE, admission to critical care areas, and serious adverse reactions. Patients are recruited without prior consent, with deferred consent sought at an appropriate time for the family. The primary analysis will be by intention-to-treat. The primary outcome is a time to event outcome and a sample size of 140 participants in each group will have 80% power to detect an increase in CSE cessation rates from 60% to 75%. Our total sample size of 308 randomised and treated participants will allow for 10% loss to follow-up.

Discussion

This clinical trial will determine whether phenytoin or levetiracetam is more effective as an intravenous second-line agent for CSE, and provide evidence for management recommendations. In addition, this trial will also provide data on which of these therapies is safer in this setting.

Trial registration

ISRCTN identifier, ISRCTN22567894. Registered on 27 August 2015

EudraCT identifier, 2014-002188-13. Registered on 21 May 2014

NIHR HTA Grant: 12/127/134

Electronic supplementary material

The online version of this article (doi:10.1186/s13063-017-2010-8) contains supplementary material, which is available to authorized users.

Disposition of levetiracetam in healthy adult horses

Nine horses received 20 mg/kg of intravenous (LEV_IV ); 30 mg/kg of intragastric, crushed immediate release (LEV_CIR ); and 30 mg/kg of intragastric, crushed extended release (LEV_CER ) levetiracetam, in a three-way randomized crossover design. Crushed tablets were dissolved in water and administered by nasogastric tube. Serum samples were collected over 48 hr, and levetiracetam concentrations were determined by immunoassay. Mean ± SD peak concentrations for LEV_CIR and LEV_CER were 50.72 ± 10.60 and 53.58 ± 15.94 μg/ml, respectively. The y-intercept for IV administration was 64.54 ± 24.99 μg/ml. The terminal half-life was 6.38 ± 1.97, 7.07 ± 1.93 and 6.22 ± 1.35 hr for LEV_CIR , LEV_CER, and LEV_IV , respectively. Volume of distribution at steady-state was 630 ± 73.4 ml/kg. Total body clearance after IV administration was 74.40 ± 19.20 ml kg^-1  hr^-1 . Bioavailability was 96 ± 10, and 98 ± 13% for LEV_CIR and LEV_CER , respectively. A single dose of Levetiracetam (LEV) was well tolerated. Based on this study, a recommended dosing regimen of intravenous or oral LEV of 32 mg/kg every 12 hr is likely to achieve and maintain plasma concentrations within the therapeutic range suggested for humans, with optimal kinetics throughout the dosing interval in healthy adult horses. Repeated dosing and pharmacodynamic studies are warranted.

Levetiracetam Pharmacokinetics in a Patient with Intracranial Hemorrhage Undergoing Continuous Veno-Venous Hemofiltration

Patient: Male, 78

Final Diagnosis: Right thalamic intraparenchymal hemorrhage with intraventricular extension

Symptoms: Altered mental status • left sided weakness

Medication: Levetiracetam

Clinical Procedure: Continuous renal replacement therapy

Specialty: Critical Care Medicine

Antiepileptic Drugs Impair Shortening of Isolated Cardiomyocytes

Background

Most antiepileptic drugs (AEDs) inhibit seizure generation by acting on voltage-dependent ion channels. Voltage-dependent sodium and calcium channels are commonly expressed in brain and heart, suggesting that AEDs may have considerable cardiodepressive effects, thereby facilitating sudden cardiac death as a potential cause of sudden unexpected death in epilepsy. Here, we investigated the effects of carbamazepine (CBZ), lamotrigine (LTG), and levetiracetam (LEV) alone and in combination on the shortening properties of isolated ventricular cardiomyocytes of wild-type mice.

Methods

Properties of murine cardiomyocytes were determined by recording the sarcomere shortening with a video imaging system before, during, and after administration of AEDs in different concentrations and combinations. We assessed (i) the number of successful shortenings during continuous electrical stimulation (electromechanical coupling) and (ii) the shortening amplitude as well as other shortening-related properties upon repetitive electrical stimulation at 4 Hz. Data are given as mean ± SEM.

Results

At 100 μM, CBZ (10 cells), LTG (11 cells), and LEV (11 cells) alone had no effect on the electromechanical coupling but reversibly reduced shortening amplitudes by 15 ± 4, 24 ± 3, and 11 ± 3%, respectively. Increasing the LTG concentration to 250 (21 cells) and 500 μM (4 cells) reversibly inhibited the electromechanical coupling in 62 and 100% of the experiments. Importantly, simultaneous application of CBZ, LTG, and LEV at 100 μM also impaired the electromechanical coupling in 8 of 19 cardiomyocytes (42%) and reduced the shortening amplitude by 21 ± 4%.

Conclusion

Our data show that AEDs reversibly impair cardiac excitation and contraction. Importantly, the blocking effect on electromechanical coupling appears to be additive when different AEDs are simultaneously applied. The translational value of these experimental findings into clinical practice is limited. Our results, however, suggest that rationale AED therapy may be important with respect to cardiac side effects and potential facilitation of serious cardiac dysfunction especially when AEDs are used in combination or at very high doses.

The Seizuring Cat

Practical relevance Although seizures occur less commonly in cats compared with dogs, they are one of the most common forms of neurological disease in the feline patient. Cats may experience both focal (partial) and generalized seizures and causes are divided into primary disorders, in which there is no underlying cause (ie, idiopathic epilepsy), and secondary disorders. Cats with secondary seizure disorders have either an underlying structural lesion or metabolic disease.

Patient group Seizures affect cats of all ages. Cats with idiopathic epilepsy tend to be younger (approximately 3.5 years) than cats with secondary seizure disorders (approximately 8 years).

Audience This review of feline seizures is directed at all veterinarians who treat cats, both in an emergency setting as well as in general practice.

Clinical challenges Refractory seizures are often a diagnostic and therapeutic challenge. A systematic approach to the seizuring cat is described, easing the task of diagnosing the cause of the seizures. In addition, novel antiepileptics are discussed, which can be used as add-on drugs in challenging feline seizure cases.

Evidence base Compared with the canine counterpart, the literature regarding treatment of feline seizures is less established. Recent clinical trials and studies are focusing on new treatment options for feline seizures. Specifically, these studies, some of which are ongoing, have led to the use of levetiracetam, zonisamide and pregabalin as add-on antiepileptics in cases that are refractory to phenobarbital.

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.

The safety and efficacy of levetiracetam versus phenytoin for seizure prophylaxis after traumatic brain injury: A systematic review and meta-analysis

BACKGROUND

The standard for early traumatic brain injury (TBI) seizure prophylaxis is phenytoin (PHT). Levetiracetam (LEV) has been proposed as an alternative to PHT. The aim of this study was to evaluate the safety and efficacy of LEV on TBI seizure when compared with PHT.

METHODS

A search was carried out based on the databases from Pubmed, Embase and the Cochrane database up to May 2015. The relative risk (RR) and the relevant 95% confidence intervals (CI) were determined.

RESULTS

Eight observational studies and one randomized controlled trial involving 2035 cases were included. The results indicated that no significant differences in terms of overall seizure (RR = 0.90; 95% CI = 0.51-1.53; p = 0.68), early seizure (RR = 1.06; 95% CI = 0.37-3.07; p = 0.92) and late seizure (RR = 1.10; 95% CI = 0.43-2.79; p = 0.85) occurrence. However, LEV was associated with a lower adverse drug reaction rate (RR = 0.43; 95% CI = 0.23-0.81; p = 0.01). Moreover, there were no significant differences in terms of mortality, length of ICU or hospital stay between groups.

CONCLUSIONS

The meta-analysis suggests that LEV appears to have a similar efficacy to PHT on TBI. A better safety profile of LEV is supported by this analysis.

Intravenous levetiracetam in critically ill children

Background:

To report the effectiveness and safety of intravenous (IV) levetiracetam (LEV) in the treatment of critically ill children with acute repetitive seizures and status epilepticus (SE) in a children's hospital.

Materials and Methods:

We retrospectively analyzed data from children treated with IV LEV.

Results:

The mean age of the 108 children was 69.39 ± 46.14 months (1-192 months). There were 58 (53.1%) males and 50 (46.8%) females. LEV load dose was 28.33 ± 4.60 mg/kg/dose (10-40 mg/kg). Out of these 108 patients, LEV terminated seizures in 79 (73.1%). No serious adverse effects were observed but agitation and aggression were developed in two patients, and mild erythematous rash and urticaria developed in one patient.

Conclusion:

Antiepileptic treatment of critically ill children with IV LEV seems to be effective and safe. Further study is needed to elucidate the role of IV LEV in critically ill children.

Intravenous levetiracetam versus phenobarbital in children with status epilepticus or acute repetitive seizures

Purpose

This study compared the efficacy and tolerability of intravenous (i.v.) phenobarbital (PHB) and i.v. levetiracetam (LEV) in children with status epilepticus (SE) or acute repetitive seizure (ARS).

Methods

The medical records of children (age range, 1 month to 15 years) treated with i.v. PHB or LEV for SE or ARS at our single tertiary center were retrospectively reviewed. Seizure termination was defined as seizure cessation within 30 minutes of infusion completion and no recurrence within 24 hours. Information on the demographic variables, electroencephalography and magnetic resonance imaging findings, previous antiepileptic medications, and adverse events after drug infusion was obtained.

Results

The records of 88 patients with SE or ARS (median age, 18 months; 50 treated with PHB and 38 with LEV) were reviewed. The median initial dose of i.v. PHB was 20 mg/kg (range, 10–20 mg/kg) and that of i.v. LEV was 30 mg/kg (range, 20–30 mg/kg). Seizure termination occurred in 57.9% of patients treated with i.v. LEV (22 of 38) and 74.0% treated with i.v. PHB (37 of 50) (P=0.111). The factor associated with seizure termination was the type of event (SE vs. ARS) in each group. Adverse effects were reported in 13.2% of patients treated with i.v. LEV (5 of 38; n=4, aggressive behavior and n=1, vomiting), and 28.0% of patients treated with i.v. PHB (14 of 50).

Conclusion

Intravenous LEV was efficacious and safe in children with ARS or SE. Further evaluation is needed to determine the most effective and best-tolerated loading dose of i.v. LEV.

Intravenous and Intramuscular Formulations of Antiseizure Drugs in the Treatment of Epilepsy

Intravenous and intramuscular antiseizure drugs (ASDs) are essential in the treatment of clinical seizure emergencies as well as in replacement therapy when oral administration is not possible. The parenteral formulations provide rapid delivery and complete (intravenous) or nearly complete (intramuscular) bioavailability. Controlled administration of the ASD is feasible with intravenous but not intramuscular formulations. This article reviews the literature and discusses the chemistry, pharmacology, pharmacokinetics, and clinical use of currently available intravenous and intramuscular ASD formulations as well as the development of new formulations and agents. Intravenous or intramuscular formulations of lorazepam, diazepam, midazolam, and clonazepam are typically used as the initial treatment agents in seizure emergencies. Recent studies also support the use of intramuscular midazolam as easier than the intravenous delivery of lorazepam in the pre-hospital setting. However, benzodiazepines may be associated with hypotension and respiratory depression. Although loading with intravenous phenytoin was an early approach to treatment, it is associated with cardiac arrhythmias, hypotension, and tissue injury at the injection site. This has made it less favored than fosphenytoin, a water-soluble, phosphorylated phenytoin molecule. Other drugs being used for acute seizure emergencies are intravenous formulations of valproic acid, levetiracetam, and lacosamide. However, the comparative effectiveness of these for status epilepticus (SE) has not been evaluated adequately. Consequently, guidelines for the medical management of SE continue to recommend lorazepam followed by fosphenytoin, or phenytoin if fosphenytoin is not available. Intravenous solutions for carbamazepine, lamotrigine, and topiramate have been developed but remain investigational. The current ASDs were not developed for use in emergency situations, but were adapted from ASDs approved for chronic oral use. New approaches for bringing drugs from experimental models to treatment of human SE are needed.

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.

Intramuscular and rectal therapies of acute seizures

The intramuscular (IM) and rectal routes are alternative routes of delivery for antiepileptic drugs (AEDs) when the intravenous route is not practical or possible. For treatment of acute seizures, the AED used should have a short time to maximum concentration (Tmax). Some AEDs have preparations that may be given intramuscularly. These include the benzodiazepines (diazepam, lorazepam, and midazolam) and others (fosphenytoin, levetiracetam). Although phenytoin and valproate have parenteral preparations, these should not be given intramuscularly. A recent study of prehospital treatment of status epilepticus evaluated a midazolam (MDZ) autoinjector delivering IM drug compared to IV lorazepam (LZP). Seizures were absent on arrival to the emergency department in 73.4% of the IM MDZ compared to a 63.4% response in LZP-treated subjects (p < 0.001 for superiority). Almost all AEDs have been evaluated for rectal administration as solutions, gels, and suppositories. In a placebo-controlled study, diazepam (DZP) was administered at home by caregivers in doses that ranged from 0.2 to 0.5 mg/kg. Diazepam was superior to placebo in reduced seizure frequency in children (p < 0.001) and in adults (p = 0.02) and time to recurrent seizures after an initial treatment (p < 0.001). Thus, at this time, only MZD given intramuscularly and DZP given rectally appear to have the properties required for rapid enough absorption to be useful when intravenous routes are not possible. Some drugs cannot be administered rectally owing to factors such as poor absorption or poor solubility in aqueous solutions. The relative rectal bioavailability of gabapentin, oxcarbazepine, and phenytoin is so low that the current formulations are not considered to be suitable for administration by this route. When administered as a solution, diazepam is rapidly absorbed rectally, reaching the Tmax within 5-20 min in children. By contrast, rectal administration of lorazepam is relatively slow, with a Tmax of 1-2h. The dependence of gabapentin on an active transport system, and the much-reduced surface area of the rectum compared with the small intestine, may be responsible for its lack of absorption from the rectum. This article is part of a Special Issue entitled "Status Epilepticus".