Efficacy and safety of levetiracetam: An add-on trial in children with refractory epilepsy

Investigation of cross-reactivity between phenobarbital and levetiracetam in children with epilepsy: A prospective, observational multicenter study

Objectives

Pharmaceutical allergic reactions due to antiseizure medications (ASMs) are one of the major concerns in the management of patients. Finding an alternative ASM which does not cause allergic reactions and has acceptable effectiveness can be difficult. In this regard, the present study attempts to investigate the cross-reactivity between phenobarbital and levetiracetam in children under treatment for seizure control.

Materials & Methods

The present study is a prospective, observational independent assessor study. 30 children with epilepsy who were hypersensitive to phenobarbital therapy were studied. In order to evaluate the cross-reactivity of the drugs, levetiracetam replaced phenobarbital to control seizure. Within 6 months, any allergic reactions and seizure recurrences were evaluated in the patients.

Results

53 % of the children in this study were female. The mean age of patients was 42.4 months. In patients' follow up no cross-reactive responses were observed in any of the patients. Seizure recurrence rate was 30 % in the first six months of follow up that with increasing dosage in the second six months of follow-up, decreased to 10 %.

Conclusion

Based on the results of this study, in children with epilepsy controlled by phenobarbital if allergic reactions to phenobarbital occur, levetiracetam may be used as a suitable alternative medicine.

Efficacy of Levetiracetam in Treatment of Childhood Stuttering

Background:

Stuttering is a kind of speech disorder that affects about 1% of total population. As the origin of this disorder is not obviously diagnosed yet, various remedies have been practiced and among them different medicines have been studied, but unfortunately no significant effective drugs have been recognized yet. As stuttering imposes a great social and mental costs to the patients and their families, finding an effective medicine will help significantly. In this study we have focused on the effects of levetiracetam (LEV) treatment on children suffering from stuttering.

Methods:

In this clinical trial study, 30 children aged > 3 years (median 3.8 years) with stuttering and abnormal sleep electroencephalogram (EEG) were treated by LEV and followed-up for a minimum period of 6 weeks. The starting dose of 20 mg/kg/day was increased at an interval of 1 week by 20 mg/kg/day, if necessary, up to maximum dose of 60 mg/kg/day.

Results:

Overall LEV was effective in 70% of patients, decreasing stuttering to at least 50%. Three children (10%) became stuttering-free and only in one (3.3%) child an increase in stuttering was observed. There were statistically significant differences for efficacy in the presence of variables such as age groups, seizure, stuttering family history, and EEG data.

Conclusions:

LEV is an effective drug for treatment of childhood stuttering in those that have abnormal sleep EEG.

Safety of levetiracetam among infants younger than 12 months--Results from a European multicenter observational study

BACKGROUND

There are limited data on the use of the antiepileptic drug (AED) levetiracetam for the treatment of infants.

AIM

To prospectively evaluate the safety of levetiracetam oral solution and its impact on epilepsy severity in infants with different seizure types.

METHODS

This noninterventional post-authorization safety study included patients 1-11 months of age. Patients' treatment - levetiracetam dose, and addition, withdrawal or changes in the doses of concomitant medications and AEDs - was at the discretion of the physician. The primary variable was treatment-emergent adverse events (TEAEs).

RESULTS

Of 101 infants, 75 completed and 26 discontinued the study. Mean age was 6.0 months, 50 were male, most (80%) took 1 ≥ concomitant AED and had cryptogenic or symptomatic epilepsy that was focal (38.6%) or generalized (20.8%), particularly frontal lobe epilepsy (20.0%) or West syndrome/infantile spasms (20.0%). Among known aetiologies, congenital factors (22.8%) such as dysplastic lesions or perinatal events (17.8%) were predominant. Overall, 54.5% of patients had ≥ 1 TEAE. Five patients experienced drug-related TEAEs - convulsion, irritability, somnolence and hypotonia, all listed in the product label, with the exception of hypotonia, which was reported for one patient and resolved without any change in study medication. Seven patients discontinued due to TEAEs, mainly due to infantile spasms and respiratory disorders. At study end, 71.8% of patients showed improvement in epilepsy severity, 18.8% remained stable and 9.4% showed worsening. Levetiracetam did not appear to have a negative effect on growth parameters.

CONCLUSION

In this prospective study, which included the largest number of patients in this age range so far, levetiracetam was found to be well tolerated and efficacious for the treatment of infants with epilepsy.

Clinical features of long-term low-dose levetiracetam treatment for epilepsy

BACKGROUND

The aim of this study was to assess the rate of response to long-term low-dose levetiracetam (LEV) treatment and the clinical factors associated with response.

METHODS

The response to low-dose LEV of 43 patients with epilepsy (22 male, 21 female; age range, 5-39 years; median age, 13 years) was retrospectively assessed. Patients aged <15 years received <20 mg/kg/day LEV, whereas those aged ≥15 years received <1000 mg/day LEV. Clinical features were compared between responders to low-dose LEV, responders to the recommended dose, and non-responders.

RESULTS

Of the 43 patients who received low-dose LEV, 13 (30%) showed improvement, defined as seizure cessation or >75% seizure reduction over 6 months for patients with monthly, weekly, and daily seizures; and over 1 year for patients with yearly seizures. Efficacy was maintained for >1 year in 10 (77%) of the 13 patients. Long-term response to low-dose LEV was significantly associated with older age at onset and fewer previous treatments with ineffective anti-epileptic drugs. All patients showing long-term response to low-dose LEV developed only focal seizures.

CONCLUSIONS

Titration of LEV starting from a low dose may be effective in selected patients. Once patients respond to low-dose treatment, maintenance of the effective dosage may prolong response.

Continuation rates of levetiracetam in children from the EULEVp cohort study

BACKGROUND

Since indication extension to children data regarding the effectiveness of levetiracetam in paediatric patients remains limited.

AIMS

Investigate the real-life effectiveness of levetiracetam in paediatric patients.

METHODS

Epileptic children (<16 years) who had initiated levetiracetam between 1 October 2006 and 31 March 2007 were included and followed for 1 year by hospital or non-hospital neurologists practising in France.

RESULTS

Among the 156 identified children, 147 were analysed: 51.7% were female, and mean (SD) age was 9.2 years (4.2). Most patients had either partial symptomatic (30.6%) or partial cryptogenic (26.5%) epilepsy, 92.5% experienced seizures during the 6 months preceding levetiracetam initiation, and 19.2% were on levetiracetam alone at initiation. One-year levetiracetam continuation rate was estimated to be 72.0% (95%CI [63.8; 78.6]). Of the 104 children continuing levetiracetam treatment at end of study, 31.7% were seizure-free during the last six months of follow-up, and 23.1% on levetiracetam alone. Discontinuation of levetiracetam (n = 41) was mainly for insufficient efficacy (58.5% of those concerned).

CONCLUSIONS

In real-life clinical practice important treatment retention and non-negligible reduction of seizure frequency may be expected.

Efficacy and safety of add-on levetiracetam in refractory childhood epilepsy

PURPOSE

The purpose of the present study was to evaluate the efficacy and safety of levetiracetam (LEV) in refractory epileptic children.

METHODS

The study group included 61 outpatients (7 generalized, 48 localization-related, 3 undetermined, 3 unclassified) aged between 16 months and 18 years. LEV was given twice daily at a total dose of 10 mg/kg/day. The final mean dose was 50.7 mg/kg/day. The mean number of prior anti-epileptic drugs was 5.2. The entire treatment period was more than 6 months after LEV administration.

RESULTS

Fifteen children (24.6%) became seizure-free for 6 months after starting LEV, and 18 (29.5%) had a seizure reduction of more than 50% for the entire 6 months. The response rate was 33/61 (54.1%). Responders included 2/3 of patients (66.7%) with epilepsy with continuous spikes and waves during slow sleep and 13/19 (68.4%) with frontal lobe epilepsy. The effective dosage of LEV in the responders demonstrated a wide range (mean, 46.1 mg/kg/day; range, 19.4-59.1 mg/kg/day), and showed bimodal distribution. Adverse events occurred in only two patients who did not require LEV discontinuation.

CONCLUSION

LEV represents an important addition to the treatments available for refractory epileptic children.

Levetiracetam in children, adolescents and young adults with intractable epilepsy: efficacy, tolerability and effect on electroencephalogram--a pilot study

Levetiracetam has been authorized for use in Israel as an add-on therapy for intractable epilepsy since May 2006. The aim of the present study was to document its effectiveness for this indication in children, adolescents, and young adults. The medical files of 78 patients aged 0.5-39 years (mean, 14.2 years) treated at our center for intractable epilepsy were reviewed. All received levetiracetam as add-on therapy following a failure to respond to at least 3 anti-epileptic drugs. Fifty-two patients (67%) had partial epilepsy and the remainder had primary generalized epilepsy. The epilepsy was symptomatic in 57%, cryptogenic in 27%, and idiopathic in 15%. Average age at first seizure was 4.1 years. In 45% of patients, the number of seizures was reduced by half with levetiracetam treatment; 11.5% of the cohort achieved complete remission. There was a statistically significant correlation between clinical seizure control and improvement in the electroencephalography findings (p = 0.0012). The drug was well tolerated, with a retention rate of 69% after one year. The most common adverse effects were irritability and impulsiveness, in 26.9% of patients. Severe behavioral side effects (psychosis, confusion) were experienced by 6.4%. In conclusion, levetiracetam is an effective and tolerable add-on agent for use in most epileptic children, adolescents, and young adults who fail to respond to at least 3 antiepileptic drugs and should be the treatment of choice in this setting. Despite the relatively high rate of behavioral side effects in this study, the retention rate at one year was high.

A revisited strategy for antiepileptic drug development in children: designing an initial exploratory step

BACKGROUND

Randomized controlled trials (RCTs) in refractory paediatric epilepsy usually involve the two main types of epilepsy shared by children and adults, focal epilepsy and Lennox-Gastaut syndrome (LGS). Most other epilepsy syndromes, specifically paediatric, are excluded from drug development. In order to identify among them the candidate(s) for dedicated RCTs with a new drug, the European Medicine Agency (EMA) recently recommended proceeding in two steps: (1) an exploratory (prospective-observational) trial (POT) including a large variety of paediatric epilepsy syndromes and (2) a subsequent RCT in each of those that disclose a signal for possible efficacy.

OBJECTIVE

Our objective was to address the three following issues that have not been addressed by the EMA: (1) to determine a minimal threshold for this signal; (2) to establish a list of epilepsies to evaluate; and (3) to estimate the number of patients to include in such POTs.

METHODS

We extensively reviewed the POTs (including various syndromes) and RCTs reported in paediatric patients with uncontrolled epilepsy using MEDLINE (from 1990 to 2011) and the Cochrane library. We determined the threshold as the lowest percentage of responders observed in a POT with a positive corresponding RCT. The syndromes that reached this threshold in a POT were those to evaluate in an RCT. The minimal number of patients to include for each syndrome for a POT with a new antiepileptic drug was estimated in order to reach at least this threshold of responders with a 95 % confidence interval.

RESULTS

We found the minimal responder threshold to be 25 %. We identified eight epilepsy types/syndromes reaching this threshold and estimated for each of them the minimal sample needed: refractory focal epilepsy (n = 40), Lennox-Gastaut syndrome (n = 32), infantile spasms (n = 50), Dravet syndrome (n = 32), childhood absence epilepsy (n = 12), other symptomatic generalized epilepsy (n = 38), epileptic encephalopathy with continuous spikes and waves during sleep (n = 7) and epilepsy with myoclonic-astatic seizures (n = 4) [the two last samples may be underestimated due to the lack of RCTs in these conditions].

CONCLUSION

Among the eight epilepsy types/syndromes that we recommend to systematically include in exploratory trials using the POT procedure, we assume that, for the minimal sample given above, a responder threshold of 25 % will provide a reliable efficacy signal, to be confirmed by a dedicated RCT. This strategy should avoid missing new therapeutic possibilities for children with epilepsy and reduce the off-label use of drugs in paediatric neurology.

Safety and efficacy of levetiracetam for the treatment of partial onset seizures in children from one month of age

Epilepsy is a common neurological disorder in the pediatric population, affecting up to one percent of children, and for which the mainstay of treatment is anticonvulsant medication. Despite the frequent use of anticonvulsant drugs, remarkably little is known about the safety and efficacy of most of these medications in the pediatric epilepsy population. Of 34 anticonvulsants currently approved for use by the US Food and Drug Administration (FDA), only 13 have been approved for use in children. Although infants and young children are disproportionately affected by epilepsy, there are currently only three anticonvulsant medications that have been specifically evaluated and approved for use in children younger than 2 years of age. In 2012, the FDA approved levetiracetam as an adjunctive treatment for partial onset seizures in infants and children from one month of age. Here we review the available data on levetiracetam in the pediatric epilepsy population. We first discuss the pharmacological profile of levetiracetam, including its mechanism of action, formulations and dosing, and pharmacokinetics in children. We then review the available efficacy, safety, and tolerability data in children from one month of age with partial onset seizures. We conclude that the current data leading to the approval of levetiracetam for use in infants and children with partial onset seizures is encouraging, although more work needs to be done before definitive conclusions can be drawn about the efficacy of levetiracetam across different pediatric age groups.

A long-term open-label extension study assessing cognition and behavior, tolerability, safety, and efficacy of adjunctive levetiracetam in children aged 4 to 16 years with partial-onset seizures

The objective of this study was to assess cognition and behavior in children (4-16 years; n = 103) with partial-onset seizures using the Leiter-R International Performance Scale and Achenbach Child Behavior Checklist. The study was a multicenter, open-label, noncomparative 48-week extension study (NCT00152516) of adjunctive levetiracetam (20-100 mg/kg/d, mean 50.2 mg/kg/d). Improvement from baseline in Leiter-R Memory Screen composite score at weeks 24 and 48 (mean [SD] change, +4.8 [12.6] and +4.5 [15.3]) was similar to changes observed with levetiracetam and placebo in a prior study. Child Behavior Checklist Syndrome scores improved from baseline at weeks 24 and 48 (total problems mean [SD] change, -9.3 [22.2] and -10.4 [23.4]). Adjunctive levetiracetam was well tolerated (most frequently reported central nervous system-related treatment-emergent adverse events: headache [24.3%], aggression [7.8%], irritability [7.8%]). Of the patients, 4.9% discontinued because of treatment-emergent adverse events. Levetiracetam provided good and sustained seizure control (median percentage reduction from baseline in partial-onset seizure frequency/wk during maintenance: 86.4%); 24.7% of patients had continuous seizure freedom from all seizure types for ≥40 weeks. In children, adjunctive levetiracetam was associated with long-term stability in cognitive functioning and improvement in emotional/behavioral functioning over time.

Pharmacokinetics of levetiracetam in neonates with seizures

The pharmacokinetics of levetiracetam were determined prospectively in 18 neonates with seizures. Neonates were found to have lower clearance, higher volume of distribution, and a longer half-life as compared with older children and adults. Mild somnolence was the only adverse effect.

Clinical experience with generic levetiracetam in people with epilepsy

PURPOSE

To describe the clinical outcomes of a compulsory switch from branded to generic levetiracetam (LEV) among people with epilepsy (PWE) in an outpatient setting.

METHODS

We conducted a retrospective chart review of 760 unduplicated consecutive adult patients attending a tertiary care epilepsy clinic at Ben Taub General Hospital. On November 1, 2008 hospital policy required all patients receiving branded LEV to be automatically switched to generic LEV. We calculated the proportion of patients switching back to branded LEV and reasons for the switch back.

KEY FINDINGS

Of the 260 patients (34%) being prescribed LEV (generic and brand name) during the study period, 105 (42.9%) were switched back to brand name LEV by their treating physicians. Reasons for switch back included increase in seizure frequency (19.6% vs. 1.6%; p < 0.0001) and adverse effects (AEs) (3.3%). AEs included headache, fatigue, and aggression. Patient age was associated with switchback when controlling for gender, epilepsy classification, and treatment characteristics [relative risk (RR) 2.44; 95% confidence interval (CI) 2.09-2.84; p < 0.05)]. An increase in seizure frequency subsequent to generic substitution was associated with polytherapy compared to monotherapy (3.225; 1.512-6.880; p < 0.05).

SIGNIFICANCE

A significant proportion of patients in our cohort on generic LEV required switch back to the branded drug. Careful monitoring is imperative because a compulsory switch from branded to generic LEV may lead to poor clinical outcomes, with risk of AEs and increased seizure frequency.

Levetiracetam Extended Release as Adjuvant Therapy for the Control of Partial-onset Seizures

Extended release (XR) formulation of levetiracetam (LEV) is approved by the Food and Drug Administration as an add-on to other antiepileptic drugs (AEDs) for adults with partial onset seizures. This is based on class-I evidence demonstrating significant seizure reduction in once daily dosing. Keppra-XR is marketed with the brand name of Keppra XR since 2008 (UCB Pharma). Its original immediate release (IR) formulation has been in the market since 2000. LEV has a unique molecular structure which is chemically unrelated to existing AEDs. The precise mechanism of action is unknown. Animal studies showed binding to synaptic vesicle protein SV2A, thought to be involved in modulating synaptic neurotransmitter release. LEV-IR is proven effective as adjunctive therapy for partial-onset seizures, primary generalized tonic-clonic seizures and myoclonic seizures. It was shown to be equivalent to carbamazepine as first-line treatment for partial-onset seizures. The extended release formulation added advantages such as better tolerance and increased compliance.

Levetiracetam in childhood epilepsy

Levetiracetam is an antiepileptic drug that has been shown to be effective in various types of seizures, both partial and generalized. Although it is not yet well established because of the small number of studies, levetiracetam as both add-on therapy and monotherapy can be considered as an alternative to valproic acid in some pediatric patients. We have reviewed the available data on the efficacy, tolerability, and safety of levetiracetam in children with epilepsy. The efficacy of levetiracetam as an adjunctive therapy and as monotherapy for generalized and partial childhood epilepsies and for some types of specific epileptic syndromes of infancy and childhood (such as juvenile myoclonic epilepsy, benign rolandic epilepsy, and Jeavon syndrome) has been demonstrated in some studies. Moreover, levetiracetam may be a valuable option for children with refractory epilepsy. The reported tolerability of levetiracetam and its safety profile are favorable. Among the side effects reported, behavioral changes and even psychotic reactions seem to occur more frequently in younger patients (under 4 years of age). The onset of signs/symptoms usually occurs early, even during the titration phase, and, in many cases, at a low dosage (<20 mg/kg/day). These side effects were always observed to be reversible after discontinuation of levetiracetam. In conclusion, results from clinical trials to date suggest that levetiracetam has a full spectrum of efficacy as well as a favorable safety profile, and this drug can be considered a valuable option in the treatment of epilepsy in pediatric patients.

The safety and tolerability of newer antiepileptic drugs in children and adolescents

The newer antiepileptic drugs (AEDs) provide more therapeutic options and overall improved safety and tolerability for patients. To provide the best care, physicians must be familiar with the latest tolerability and safety data. This is particularly true in children, given there are relatively fewer studies examining the effects of AEDs in children compared with adults. Since we now have significant paediatric literature on each of these agents, we provide a comprehensive and current literature review of the newer AEDs, focusing on safety and tolerability data in children and adolescents. Because the safety profiles in children differ from those in adults, familiarity with this literature is important for child neurologists and other paediatric caregivers. We have organized the data by organ system for each AED for easier reference.

Efficacy and safety of levetiracetam as an add-on therapy in children aged less than 4 years with refractory epilepsy

In the past decade, most studies on levetiracetam were conducted on patients aged > or = 4 years of age. The authors sought to assess the efficacy and safety of levetiracetam as an adjunctive treatment of children <4 years of age with refractory epilepsy. The mean levetiracetam dosage used on the 24 patients in this study was 38.85 mg/kg per day, and the mean duration of treatment was 40 weeks. During the study, levetiracetam was tapered off in 2 patients due to seizure worsening and was discontinued in other 2 patients due to unacceptable adverse effects. Levetiracetam therapy was effective in 58.3% of patients, with 20.8% achieving seizure freedom. Eight patients showed no obvious response and the remaining 2 patients showed divergent responses. Although adverse effects were seen in 37.5% of patients, all adverse effects were tolerable or resolved with time or discontinuation. Therefore, the authors conclude that levetiracetam treatment is effective and safe in young children with refractory epilepsy.

Levetiracetam in the treatment of neonatal seizures: a pilot study

PURPOSE

At present, neonatal seizures are usually treated with Phenobarbital (PB) despite the limited efficacy and the potential risk this treatment holds for the developing brain. We report here a prospective pilot feasibility study on the use of Levetiracetam as monotherapy in the treatment of neonatal seizures.

METHODS

Six newborns (body weight>2000 g, gestational age>30 weeks) presenting with neonatal seizures were enrolled. Patients whose seizures were caused by electrolyte disturbances or hypoglycemia, or whose seizures did respond to pyridoxine were excluded. Patients previously treated with other antiepileptic drugs (AEDs), with the exception of single PB doses before and during titration, were excluded. LEV was administered orally, increasing the dose by 10mg/(kg day) over 3 days. Endpoint was the need of any additional AEDs (or PB) after day 3, or 3 months of LEV treatment. A decision regarding further treatment was made on an individual basis and follow-up was documented up to 8 months of age.

RESULTS

No severe adverse effects were observed. Mild sedation was reported in one infant. All six patients treated with oral LEV became seizure free within 6 days. Five patients remained seizure free after 3 months with ongoing LEV monotherapy. One infant developed pharmacoresistant epilepsy. Seizures relapsed later in the clinical course of two more patients, one of whom was no longer under LEV therapy.

DISCUSSION

Results from our small patient group indicate that LEV may be an alternative therapeutic option in neonatal seizures.

Efficacy and safety of adjunctive levetiracetam therapy in pediatric intractable epilepsy

To investigate the efficacy and safety of levetiracetam adjunctive therapy in childhood intractable epilepsy, data were reviewed for 130 children who had >or=4 seizures per month, whose seizures were intractable to an initial >or=2 antiepileptic drugs, and who could be monitored for at least 6 months after levetiracetam add-on. Reduction in seizure frequency and related variables were investigated. Sixty-two of the 130 patients (48%) showed a seizure reduction of >or=50%, and 28 patients (22%) became seizure-free. A reduction in seizures by >or=50% was observed in 33/64 in children with partial seizures (52%) and in 29/66 children with generalized seizures (44%). Efficacy did not differ significantly among seizure types. Overall efficacy was unaffected by abnormalities evident from magnetic resonance imaging, by mental retardation, or by maintenance dose of levetiracetam. The mean maintenance dose of levetiracetam was 47.0mg/kg per day (S.D. = +/- 29.7), and mean follow-up duration was 13.4 months (S.D. =+/- 8.7). No demographic features differed significantly between patients with seizure freedom and without seizure remission. Levetiracetam was discontinued in 24 children at last visit (retention rate, 82%). The most common complaint was irritability (5%), and none of the adverse events were life threatening. In conclusion, levetiracetam adjunctive therapy is effective and safe for childhood intractable epilepsy.

Levetiracetam as add-on therapy in different subgroups of "benign" idiopathic focal epilepsies in childhood

Several recent studies have shown that levetiracetam (LEV) can be beneficial in the treatment of children with typical rolandic epilepsy (RE). Reports about the effectiveness of LEV in the treatment of children with the less benign variants in the spectrum of "benign" idiopathic focal epilepsies are still rare. Little is known about the effect of LEV on interictal epileptiform discharges in these syndromes. We report on LEV therapy in 32 children (mean age: 10.6 years, range: 4-14) with RE or variants like atypical benign idiopathic partial epilepsy of childhood (ABIPEC), Landau-Kleffner syndrome (LKS), and continuous spikes and waves during sleep (CSWS) and in children with benign idiopathic focal epileptiform discharges of childhood (BIFEDC). Cognitive and behavioral problems, not seizures, may be related to the pathological EEG. Patients with a reduction in seizure frequency >50% and/or reduction in BIFEDC >90% 3 months after having started LEV therapy were defined as responders. The average dose of LEV was 39 mg/kg body wt per day; LEV was given in monotherapy to 31.3% of the patients. Overall, 20 of 32 patients (62.5%) did benefit: 12 of 24 patients had a >50% reduction in seizure frequency; 2 of 24 patients (8.3%) were completely seizure free; 18 of 32 patients (56.3%) had a >90% reduction in BIFEDC (including CSWS); 6 of 32 (18.8%) had an EEG completely free of epileptiform discharges; and 17 of 32 (53.1%) showed improvement in cognition and/or language functions and/or behavior. Surprisingly, LEV tended to be more helpful in atypical rolandic epilepsies and other variants.

Levetiracetam in children with refractory epilepsy: lack of correlation between plasma concentration and efficacy

PURPOSE

The goals of this study are to evaluate the efficacy and tolerability of levetiracetam (LEV) as add-on therapy in children with refractory epilepsies and to determine the value of LEV blood level monitoring in this population.

METHODS

Sixty-nine children (39 males and 30 females) treated with LEV between 2006 and 2007 were selected. Their medical files were reviewed for LEV efficacy and tolerability. In a subgroup of children currently taking LEV, plasma concentrations were determined by high performance liquid chromatography by ultraviolet detection (HPLC-UV) method and correlated with the given dose per kilo as well as clinical response.

RESULTS

Fifty-one patients (74%) had a more than 50% reduction in seizure frequency with 16 patients (23%) becoming seizure free on LEV. Eighteen (26%) patients had a less than 50% reduction in seizure frequency. Adverse events due to LEV ranged from mild to moderate in only 18 patients (26%). The most frequently observed were drowsiness, behavioral difficulties, increase in seizure frequency and headaches. The majority (60.5%) of the responders received doses between 10 and 50mg/kg/day and had a plasma concentration (PC) between 5 and 40microg/ml. However, we found no clear correlation between PC and efficacy.

CONCLUSION

Levetiracetam given twice a day in children with refractory epilepsy reduces seizure frequency in all types of epilepsy. In children, LEV is a broad spectrum anticonvulsant with a favourable safety profile.

Levetiracetam as add-on therapy for idiopathic generalized epilepsy syndromes with onset during adolescence: analysis of two randomized, double-blind, placebo-controlled studies

PURPOSE

To assess the efficacy and tolerability of adjunctive levetiracetam in idiopathic generalized epilepsy (IGE) syndromes with onset during adolescence: juvenile absence epilepsy (JAE), juvenile myoclonic epilepsy (JME), and generalized tonic-clonic seizures on awakening (GTCSA).

METHODS

Supplementary analysis of two double-blind, placebo-controlled trials. Patients received levetiracetam (target dose: adults 3000 mg/day; children 60 mg/kg/day; n=15 JAE, 78 JME, and 22 GTCSA) or placebo (n=12 JAE, 89 JME, and 27 GTCSA) for 16-24 weeks (including 4-week uptitration) in addition to 1-2 antiepileptic drugs.

RESULTS

Responder rates (> or =50%) were significantly higher for levetiracetam versus placebo for JAE (53.3% vs. 25.0%; p=0.004), JME (61.0% vs. 24.7%; p<0.001), and GTCSA (61.9% vs. 29.6%; p=0.024). Seizure freedom rates were significantly higher for levetiracetam versus placebo for JME (20.8% vs. 3.4%; p=0.002); differences between treatment groups for JAE (33.3% vs. 8.3%; p=0.15) and GTCSA (23.8% vs. 11.1%; p=0.45) appeared to be clinically relevant, but did not reach statistical significance. The most frequent adverse events on levetiracetam were headache (levetiracetam 16.8% and placebo 14.8%) and somnolence (levetiracetam 9.7% and placebo 3.9%).

CONCLUSIONS

Adjunctive levetiracetam was well tolerated and provided effective seizure control over 16-24 weeks in patients with insufficiently controlled IGE syndromes with onset during adolescence (JAE, JME, and GTCSA), supporting levetiracetam's broad spectrum of efficacy.

Adjunctive levetiracetam in infants and young children with refractory partial-onset seizures

PURPOSE

To evaluate the efficacy and tolerability of adjunctive levetiracetam in very young children (aged 1 month to <4 years) with partial-onset seizures inadequately controlled with one or two antiepileptic drugs.

METHODS

This multicenter, double-blind, randomized, placebo-controlled study consisted of a 48-h inpatient baseline video-EEG (electroencephalography) and a 5-day inpatient treatment period (1-day up-titration; 48-h evaluation video-EEG in the last 2 days). Children who experienced at least two partial-onset seizures during the 48-h baseline video-EEG were randomized to either levetiracetam [40 mg/kg/day (age 1 to <6 months); 50 mg/kg/day (age >or=6 months to <4 years] or placebo.

RESULTS

Of 175 patients screened, 116 patients were randomized [60 levetiracetam; 56 placebo; intent-to-treat (ITT) population], and 111 completed the study. The responder rate in average daily partial-onset seizures frequency (48-h video-EEG monitoring; primary efficacy variable) was 43.1% for levetiracetam [modified ITT (mITT) = 58] versus 19.6% for placebo (mITT = 51; p=0.013), with odds ratio for response 3.11 [95% confidence interval (CI), 1.22-8.26]. The median percent reduction from baseline in average daily partial-onset seizure frequency was 43.6% for levetiracetam and 7.1% for placebo with a median difference between treatment groups of 39.2% (95% CI, 17.5-62.2; p < 0.001). In general, levetiracetam was well tolerated. Treatment-emergent adverse events were reported by 55.0% levetiracetam- and 44.6% placebo-treated patients (ITT population). The most frequently reported adverse events were somnolence (13.3% levetiracetam, 1.8% placebo) and irritability (11.7% levetiracetam, 0% placebo).

DISCUSSION

Adjunctive levetiracetam is an efficacious and well-tolerated treatment for partial-onset seizures in infants and young children.

Review of levetiracetam, with a focus on the extended release formulation, as adjuvant therapy in controlling partial-onset seizures

Levetiracetam is a second-generation antiepileptic drug (AED) with a unique chemical structure and mechanism of action. The extended release formulation of levetiracetam (Keppra XR(); UCB Pharma) was recently approved by the Food and Drug Administration for adjunctive therapy in the treatment of partial-onset seizures in patients 16 years of age and older with epilepsy. This approval is based on a double-blind, randomized, placebo-controlled, multicenter, multinational trial. Levetiracetam XR allows for once-daily dosing, which may increase compliance and, given the relatively constant plasma concentrations, may minimize concentration-related adverse effects. Levetiracetam's mode of action is not fully elucidated, but it has been found to target high-voltage, N-type calcium channels as well as the synaptic vesicle protein 2A (SV2A). Levetiracetam has nearly ideal pharmacokinetics. It is rapidly and almost completely absorbed after oral ingestion, is <10% protein-bound, demonstrates linear kinetics, is minimally metabolized through a pathway independent of the cytochrome P450 system, has no significant drug-drug interactions, and has a wide therapeutic index. The most common reported adverse events with levetiracetam XR were somnolence, irritability, dizziness, nausea, influenza, and nasopharyngitis. Levetiracetam XR provides an efficacious and well-tolerated treatment option for adjunctive therapy in the treatment of partial-onset seizures.

Use of second-generation antiepileptic drugs in the pediatric population

Epilepsy is common in the pediatric population. Nine second-generation antiepileptic drugs have been approved in the US for use in epilepsy over the past 15 years: felbamate, gabapentin, lamotrigine, topiramate, tiagabine, levetiracetam, oxcarbazepine, zonisamide, and pregabalin. Their use in pediatric patients is fairly widespread, despite most of these agents not having US FDA indications for use. Felbamate and gabapentin were the first two second-generation antiepileptic drugs to be approved in the US. Felbamate use has been limited because of the occurrence of hepatotoxicity and aplastic anemia. Although gabapentin is a fairly well tolerated antiepileptic drug, its use has also been limited as a result of inconsistent efficacy and concern about seizure exacerbation. Lamotrigine and topiramate are broad-spectrum antiepileptic drugs with efficacy in a wide variety of seizure types. Both agents have some tolerability concerns: rash with lamotrigine and neuropsychiatric events with topiramate. There are very little data on tiagabine use in children, but this agent appears to be effective and to have a good tolerability profile. Levetiracetam is a second-generation antiepileptic agent that is available intravenously. Considering its good efficacy, fast onset of action, and low incidence of serious adverse effects, its use in the acute setting could potentially increase. Oxcarbazepine and zonisamide have been relatively well studied in pediatric seizure patients, including use as monotherapy. Both agents have demonstrated good efficacy and tolerability for patients as young as 1 month old. Vigabatrin and rufinamide are currently not available in the US, but have been shown to have some success in other countries. Pregabalin is the newest antiepileptic agent, but lacks pediatric data currently.

Add-on levetiracetam in children and adolescents with refractory epilepsy: results of an open-label multi-centre study

PURPOSE

To study the efficacy and tolerability of add-on levetiracetam in children and adolescents with refractory epilepsy.

METHODS

In this prospective multi-centre, open-label, add-on study, 33 children aged 4-16 years (median 8.5 years) with epilepsy refractory to at least two antiepileptic drugs were treated with levetiracetam in addition to their present treatment regimen with a follow-up of 26 weeks. The starting dose of 10 mg/kg/day was increased with 2-week steps of 10 mg/kg/day, if necessary, up to a maximum dose of 60 mg/kg/day.

RESULTS

Retention rate was 69.7% after 26 weeks on a median levetiracetam dosage of 22 mg/kg/day. Four children dropped-out because levetiracetam was ineffective, four because seizure frequency increased and/or seizures became more severe, and two because they developed aggressive behaviour. Compared to their baseline seizure frequency, 13 children (39.4%) had a >50% seizure reduction 12 weeks after initiation of levetiracetam, and 17 children (51.5%) at 26 weeks. At 26 weeks, nine children (27.3%) had been seizure-free for at least the last 4 weeks, terminal remission ranged from 0 to 187 days (mean 46 days). Levetiracetam was effective in both partial and primary generalized seizures, but had most effect in partial seizures. Most reported side effects were hyperactivity (48.5%), somnolence (36.4%), irritability (33.3%) and aggressive behaviour (27.3%). Severity of most side effects was mild. Five children had a serious adverse event, which all concerned hospital admissions that were not related to levetiracetam use.

CONCLUSION

Levetiracetam proved to be an effective and well-tolerated add-on treatment in this group of children with refractory epilepsy.

Levetiracetam or oxcarbazepine as monotherapy in newly diagnosed benign epilepsy of childhood with centrotemporal spikes (BECTS): an open-label, parallel group trial

To evaluate the efficacy and tolerability of levetiracetam or oxcarbazepine as monotherapy in children with newly diagnosed benign epilepsy with centrotemporal spikes (BECTS). Twenty-one children (11 males, 10 females), aged between 5 and 13 years (mean 10.5 years), and 18 (10 M, 8 F), aged between 3.3 and 14 years (mean 8.4 years), were randomised to receive monotherapy with levetiracetam or oxcarbazepine, respectively. LEV was titrated up to 20-30 mg/kg/once or twice a day, and OXC up to 20-35 mg/kg once or twice a day. Thirty-nine consecutive children (21 males, 18 females), aged between 3.3 and 14 years (mean 10.7 years), were recruited into the study. Twenty-one were randomised on LEV (11 male, 10 female; mean age 10.5 years), and 18 on OXC (10 male, 8 female; mean age 8.4 years). After a mean follow-up period of 18.5 months (range 12-24 months), 19 out of 21 patients (90.5%) on levetiracetam, and 13 out of 18 (72,22%) on oxcarbazepine did not have further seizures. Mean serum level of LEV was 4.1 microg/ml (range 1.3-9.0), and of OXC was 15.2 microg/ml (range 4.2-27.5). Adverse side effects on LEV were reported in 3 children (14.3%), represented by mild and transient decreased appetite (2) and cephalalgia (1). They were reported on OXC in 2/18 (11.1%), including headache (1), and sedation (1). These preliminary data from an open, parallel group study suggest that levetiracetam and oxcarbazepine may be potentially effective and well tolerated drugs for children with BECTS who require treatment.

Efficacy and safety of levetiracetam in infants and young children with refractory epilepsy

The aim of this multicentric, retrospective, and uncontrolled study was to evaluate the efficacy and safety of levetiracetam (LEV) in 81 children younger than 4 years with refractory epilepsy. At an average follow-up period of 9 months, LEV administration was found to be effective in 30% of patients (responders showing more than a 50% decrease in seizure frequency) of whom 10 (12%) became seizure free. This efficacy was observed for focal (46%) as well as for generalized seizures (42%). In addition, in a group of 48 patients, we compared the initial efficacy (evaluated at an average of 3 months of follow-up) and the retention at a mean of 12 months of LEV, with regard to loss of efficacy (defined as the return to the baseline seizure frequency). Twenty-two patients (46%) were initial responders. After a minimum of 12 months of follow-up, 9 of 48 patients (19%) maintained the improvement, 4 (8%) of whom remained seizure free. A loss of efficacy was observed in 13 of the initial responders (59%). Maintained LEV efficacy was noted in patients with focal epilepsy and West syndrome. LEV was well tolerated. Adverse events were seen in 18 (34%) patients. The main side effects were drowsiness and nervousness. Adverse events were either tolerable or resolved in time with dosage reduction or discontinuation of the drug. We conclude that LEV is safe and effective for a wide range of epileptic seizures and epilepsy syndromes and, therefore, represents a valid therapeutic option in infants and young children affected by epilepsy.

The efficacy and tolerability of levetiracetam in pharmacoresistant epileptic dogs

Twenty-two dogs with idiopathic epilepsy which were pharmacoresistant to phenobarbitone and bromide were treated with levetiracetam as an add-on medication. Records of eight dogs were used retrospectively to determine a safe, efficient levetiracetam dosage. Fourteen dogs were entered into a prospective, open label, non-comparative study. After 2 months of levetiracetam oral treatment (10 mg/kg TID), 8/14 dogs responded significantly to the treatment and seizure frequency was reduced by 50%. In dogs that remained refractory, the dosage was increased to 20 mg/kg TID for 2 months. One further dog responded to levetiracetam treatment. Levetiracetam responders had a significant decrease in seizure frequency of 77% (7.9+/-5.2 to 1.8+/-1.7 seizures/month) and a decrease in seizure days per month of 68% (3.8+/-1.7 to 1.2+/-1.1 seizure days/month). However, 6/9 responders experienced an increase in seizure frequency and seizure days after 4-8 months continuing with the levetiracetam treatment at the last effective dosage. Levetiracetam was well tolerated by all dogs and sedation was the only side-effect reported in just one of the 14 dogs.

Levetiracetam monotherapy for children and adolescents with benign rolandic seizures

To assess the efficacy, tolerability and safety of Levetiracetam (LEV) therapy, we identified 21 (15 male; 6 female) patients with a history of benign epilepsy with centrotemporal spikes (BECTS), with and without secondarily generalization in children and adolescents aged between 5.0 and 12.1 years. LEV was administered as a first drug (number of patients=9) or converted after previous treatment with other AEDs (number of patients=12). The patients were subdivided into two groups: "newly diagnosed" patients and "converted" patients. Patients were followed up for 12 months and all patients were able to continue on LEV treatment. At the end of follow-up (12 months), all patients were seizure free or showed a reduction of seizures >50%. LEV dosage ranged from 1000 to 2500mg/daily. Overall, 100% of patients completed the 12 months study, without any important side effect. Somnolence and irritability occurred in two (9.5%) patients. Our results support findings that LEV monotherapy is effective and well tolerated in children with BECTS. Prospective, large, long-term double-blind studies are needed to confirm these findings.

Levetiracetam for the treatment of neonatal seizures

Seizures are a common occurrence in the neonatal intensive care unit, especially among low-birth-weight infants. The efficacy and safety of standard anticonvulsants have not been evaluated extensively in the neonate. In addition, there is concern for the adverse effects of phenobarbital on long-term development. Levetiracetam has been a commonly prescribed oral anticonvulsant for the use of adjunctive therapy for partial seizures in adults with favorable tolerability, and it has been recently approved for children older than age 4 years. There are no published studies regarding the safety and efficacy of this medication in the infant population. This report describes the initiation of levetiracetam in 3 infants, aged 2 days to 3 months, for refractory seizures or intolerance to other anticonvulsants. Each patient was without seizure on levetiracetam monotherapy, and there were no adverse effects.

Anticonvulsant Therapy in Dogs and Cats

This article reviews anticonvulsant therapies in current use for dogs and cats and briefly describes new modes of anticonvulsant therapy that are being investigated or pending publication. Most of the information contained within the article is based on published information. Some of the information, however, is based on the author's clinical experience and is identified as such.