Prospective, open-label, add-on study of lamotrigine in 56 children with intractable generalized epilepsy

Psychiatric and behavioral side effects of anti-epileptic drugs in adolescents and children with epilepsy

PURPOSE

The objective of the study was to compare the psychiatric and behavioral side effect (PBSE) profiles of both older and newer antiepileptic drugs (AEDs) in children and adolescent patients with epilepsy.

METHOD

We used logistic regression analysis to test the correlation between 83 non-AED/patient related potential predictor variables and the rate of PBSE. We then compared for each AED the rate of PBSEs and the rate of PBSEs that led to intolerability (IPBSE) while controlling for non-AED predictors of PBSEs.

RESULTS

922 patients (≤18 years old) were included in our study. PBSEs and IPBSEs occurred in 13.8% and 11.2% of patients, respectively. Overall, a history of psychiatric condition, absence seizures, intractable epilepsy, and frontal lobe epilepsy were significantly associated with increased PBSE rates. Levetiracetam (LEV) had the greatest PBSE rate (16.2%). This was significantly higher compared to other AEDs. LEV was also significantly associated with a high rate of IPBSEs (13.4%) and dose-decrease rates due to IPBSE (6.7%). Zonisamide (ZNS) was associated with significantly higher cessation rate due to IPBSE (9.1%) compared to other AEDs.

CONCLUSION

Patients with a history of psychiatric condition, absence seizures, intractable epilepsy, or frontal lobe epilepsy are more likely to develop PBSE. PBSEs appear to occur more frequently in adolescent and children patients taking LEV compared to other AEDs. LEV-attributed PBSEs are more likely to be associated with intolerability and subsequent decrease in dose. The rate of ZNS-attributed IPBSEs is more likely to be associated with complete cessation of AED.

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

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

Safety of lamotrigine in paediatrics: a systematic review

OBJECTIVES

To identify adverse drug reactions associated with lamotrigine in children and compare the safety profile with other antiepileptic drugs.

SETTING

Databases EMBASE (1974-April 2015), MEDLINE (1946-April 2015), PubMed and the Cochrane library for randomised controlled trials were searched for studies on safety of lamotrigine.

PARTICIPANTS

All studies involving paediatric patients aged ≤ 18 years who have received at least a single dose of lamotrigine with safety as an outcome measure were included.

PRIMARY AND SECONDARY OUTCOME MEASURES

The primary outcome measure was safety of lamotrigine. Drug interaction of lamotrigine was the secondary outcome.

RESULTS

A total of 78 articles involving 3783 paediatric patients were identified. There were 2222 adverse events (AEs) reported. Rash was the most commonly reported AE, occurring in 7.3% of the patients. Stevens-Johnson syndrome was rarely reported, with a risk of 0.09 per 100 patients. Discontinuation due to an adverse drug reaction (ADR) was recorded in 72 children (1.9% of all treated patients). Fifty-eight per cent of treatment discontinuation was attributed to different forms of rash and 21% due to increased seizures. Children on lamotrigine monotherapy had lower incidences of AEs. Headache (p=0.02), somnolence (<0.001), nausea (p=0.01), vomiting (p<0.001), dizziness (p<0.001) and abdominal pain (p=0.01) were significantly lower among children on monotherapy.

CONCLUSIONS

Rash was the most common ADR of lamotrigine and the most common reason for treatment discontinuation. Children receiving polytherapy have a higher risk of AEs than monotherapy users.

TRIAL REGISTRATION NUMBER

CRD42013006910.

Risk of a lamotrigine-related skin rash: current meta-analysis and postmarketing cohort analysis

PURPOSE

We systematically reviewed studies to provide current evidence on the incidence and risk of skin rash in patients with LTG therapy.

METHODS

PubMed and Scopus databases, up to 15 March 2014 were searched to identify relevant studies. Eligible studies included prospective studies, retrospective studies and postmarketing reports, which included data of skin rash in patients with LTG therapy.

RESULTS

Forty-one articles met the entry criteria. A total of 4447 patients with LTG therapy from 26 prospective studies, 2977 patients from 8 retrospective studies, and 26,126 patients from 5/7 postmarketing reports were included. The overall incidence of skin rash with LTG therapy was 9.98% (444/4447) from prospective studies, 7.19% (214/2977) from retrospective studies, and 2.09% (547/26,126) from postmarketing reports. A meta-analysis of the risk of skin rash in 21 prospective studies, did not show a significant difference between patients with LTG and other drugs, including placebo, other ADEs or lithium (OR 0.99-2.41). In 6 respective studies, there was a significantly higher OR in patients with LTG compared with those with non-aromatic AEDs. However, there was no significant difference in rash risk between patients with LTG and aromatic AEDs.

CONCLUSIONS

Our study showed that LTG significantly increased the risk of developing a skin rash compared to non-aromatic AEDs. Our results support the need for large prospective population-based studies and clinical trials to determine whether LTG increases the risk of developing a skin rash than compared to other drugs.

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.

Clobazam as an adjunctive therapy in treating seizures associated with Lennox-Gastaut syndrome

Lennox-Gastaut syndrome (LGS) is a devastating childhood epilepsy syndrome characterized by the occurrence of multiple types of seizures and cognitive decline. Most children suffer from frequent seizures that are refractory to current medical management. Recent clinical trials have suggested that addition of clobazam may improve the clinical outcome for some LGS patients. Although clobazam has been available for over five decades, it has only recently been approved by the US Food and Drug Administration for this indication. As a 1,5-benzodiazepine, clobazam is structurally related to the widely used 1,4-benzodiazepines, which include diazepam. Clobazam has been shown to modulate GABAergic neurotransmission by positive allosteric modulation of GABA(A) receptors, and to increase expression of transporters for both GABA and glutamate. The active metabolite n-desmethylclobazam (norclobazam) also modulates GABA(A) receptors, and the relative importance of these two compounds in the clinical effectiveness of clobazam remains an open question. Clinical trials involving clobazam as an addon therapy in a variety of pediatric epilepsy populations have found a significant improvement in seizure control. In patients with LGS, clobazam may have greatest efficacy for drop seizures. Longstanding clinical experience suggests that clobazam is a safe and well tolerated antiepileptic drug with infrequent and mild adverse effects. These results suggest that adjunctive treatment with clobazam may be a reasonable option for LGS patients, particularly those who are treatment-resistant.

Medical management of Lennox-Gastaut syndrome

Lennox-Gastaut syndrome occurs in 3% of children with epilepsy and is characterized by multiple seizure types, slow spike-and-wave discharges and a poor prognosis for seizure control and cognitive development. Although randomized controlled trials of adjunctive felbamate, lamotrigine, topiramate and rufinamide have demonstrated a > or =50% reduction in seizure frequency, very few children achieve complete seizure control and a Cochrane review of the treatment of Lennox-Gastaut syndrome concluded that the optimum treatment was uncertain and that no drug has been shown to be highly efficacious. Valproate, lamotrigine and topiramate were considered recently by expert panels in the US and Europe to be the first-line drugs. The ketogenic diet may be more effective than antiepileptic drugs and should be considered early in treatment. An improvement in the management of Lennox-Gastaut syndrome requires a better understanding of the pathophysiology of this disorder and the development of animal models in which to test new compounds.

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.

Treatment of Lennox-Gastaut Syndrome (LGS)

Lennox-Gastaut Syndrome (LGS) is a severe form of epilepsy that usually starts in early to mid childhood and is characterized by multiple seizure types, abnormal electroencephalogram with slow spike-and-wave discharges and cognitive problems. Numerous approaches are currently used to treat LGS, including use of conventional antiepileptic drugs (most commonly sodium valproate, lamotrigine and topiramate), other drug interventions (corticosteroids and intravenous immunoglobulin) and nonpharmacologic treatments (ketogenic diet, corpus callosotomy and vagus nerve stimulation). Rufinamide is the most recent antiepileptic drug to have shown efficacy in the treatment of LGS. Despite the variety of therapeutic options, there have been only five double-blind, placebo-controlled clinical trials of antiepileptic drugs in LGS and none of these were head-to-head comparison trials. The evidence supporting the use of available treatments for LGS is, therefore, not robust. Here, we review the evidence supporting the use of specific therapies in LGS and provide recommendations on how to set appropriate treatment goals, select treatments and minimize polypharmacy. A suggested treatment algorithm is presented and discussed. Sodium valproate is recommended for first-line therapy; if seizures persist, alternative interventions should be trialed on an individually tailored basis.

Use of a new antiepileptic drug or an old one as first drug for treatment of absence epilepsy

Treatment of absence epilepsy requires understanding the efficacy and side effects of several drugs, one of which first became available more than 50 years ago. Methods for drug development and procedures for evaluating their safety and efficacy over that time have changed dramatically. Observational studies of the efficacy of ethosuximide, a drug developed in the 1950s, reported complete seizure control in 40-60% of patients. Valproic acid, a drug with a broad spectrum of effect, showed robust efficacy as well for control of absence seizures. Because side effects limit use in some patients, newer drugs were evaluated in patients with absence seizures. Of drugs becoming available in the last 15 years, lamotrigine has some effect in absence seizures. Although older and newer drugs presently are used without the rigorous underpinnings of the highest quality of evidence, our analysis found that ethosuximide, valproate, and lamotrigine are effective in the treatment of absence seizures, with ethosuximide quite possibly being the first drug of choice.

Treatment of Lennox-Gastaut syndrome: overview and recent findings

Lennox-Gastaut syndrome (LGS) is a rare, age-related syndrome, characterized by multiple seizure types, a specific electro-encephalographic pattern, and mental regression. However, published data on the etiology, evolution, and therapeutic approach of LGS are contradictory, partly because the precise definition of LGS used in the literature varies. In the most recent classification, LGS belongs to the epileptic encephalopathies and is highly refractory to all antiepileptic drugs. Numerous treatments, medical and non-medical, have been proposed and results mostly from open studies or case series have been published. Sometimes, patients with LGS are included in a more global group of patients with refractory epilepsy. Only 6 randomized double-blind controlled trials of medical treatments, which included patients with LGS, have been published. Overall, treatment is rarely effective and the final prognosis remains poor in spite of new therapeutic strategies. Co-morbidities need specific treatment. This paper summarizes the definition, diagnosis and therapeutic approach to LGS, including not only recognized antiepileptic drugs, but also "off label" medications, immune therapy, diet, surgery and some perspectives for the future.

Long-term tolerability and efficacy of lamotrigine in infants 1 to 24 months old

This open-label study was designed to evaluate the long-term tolerability and efficacy of lamotrigine in 1- to 24-month-old infants with partial seizures. The study enrolled both lamotrigine-naïve patients and patients who had been previously exposed to lamotrigine in a randomized, double-blind, placebo-controlled study. Patients (n = 204) received lamotrigine according to a dosing schedule that depended on prior experience with lamotrigine and concurrent antiepileptic drug therapy for up to 48 weeks or their second birthday, whichever occurred last. Total duration of lamotrigine exposure (which included exposure during the placebo-controlled study in lamotrigine-experienced patients) was >/=24 weeks in 92% of patients, >/=48 weeks in 70% of patients, and >/=72 weeks in 20% of patients. A total of 20 (10%) patients (8 lamotrigine-naïve patients and 12 lamotrigine-experienced patients) transitioned to lamotrigine monotherapy. The most common adverse events were pyrexia (45% of patients), upper-respiratory tract infection (28%), and ear infection (22%). The only adverse event considered reasonably attributable to study medication in >2% of patients was irritability (n = 10; 5% of patients). No cases of serious rash were reported. The median percent reduction from baseline in partial seizure frequency in the sample as a whole was 74%. Seizure frequency was reduced by >/=50% from pre-lamotrigine baseline in 62% of patients in the sample as a whole, 60% of the lamotrigine-naïve subgroup, and 63% of the lamotrigine-experienced subgroup. In the sample as a whole, 13% of patients were seizure free during the Treatment Phase. Investigators considered clinical status at the last clinic visit to be improved (mildly, moderately, or markedly) relative to prelamotrigine clinical status in 76% of patients (150/197) and to be unchanged in 19% (37/197). In this study-the first large prospective investigation of the long-term tolerability and efficacy of an antiepileptic drug in a patient population 2 years and younger-lamotrigine administered for up to approximately 72 weeks was well tolerated and associated with good seizure control.

Effects of antiepileptic medications on psychiatric and behavioral comorbidities in children and adolescents with epilepsy

The three goals of this article are (1) to delineate the limitations in determining the actual incidence of antiepileptic drug (AED) psychiatric and behavioral side effects; (2) to summarize existing data on the direct effects of AEDs on psychiatric and behavioral comorbidities and examine the relationship between these direct effects and specific AED mechanisms of action; and (3) to recognize the indirect effects of AEDs on psychiatric and behavioral medications that can result in aggravation of these comorbidities through drug-drug interactions. All of these data are then combined and formatted into a practical algorithm useful in many clinical situations.

Behavioral and psychiatric adverse events associated with antiepileptic drugs commonly used in pediatric patients

Multiple factors-including the efficacy of the antiepileptic drug for the particular seizure type, availability of pediatrics-friendly formulations, the ease of dosing and titration, and tolerability issues, such as possible drug interactions and adverse events-affect the selection of the best antiepileptic drug for a child with epilepsy. Behavioral problems are common in children with epilepsy and can be aggravated or initiated by antiepileptic drug therapy. The types and frequencies of antiepileptic drug-associated behavioral events can influence a clinician's drug selection, drug management, and counseling of parents. Unfortunately, appreciating differences among antiepileptic drugs in behavioral adverse event profiles is problematic because, among other reasons, methodologies for reporting, collecting, and analyzing adverse events are not uniform across trials, and there is marked heterogeneity in study design among trials. This review summarizes incidence rates for behavioral and psychiatric adverse events taken from studies of children with epilepsy. These rates are reported for the 10 most commonly prescribed antiepileptic drugs (valproic acid, carbamazepine, phenobarbital, lamotrigine, phenytoin, levetiracetam, oxcarbazepine, topiramate, zonisamide, and gabapentin), grouped according to their predominant mechanism of action. Despite the numerous methodologic inconsistencies, some similarities in adverse event profiles among antiepileptic drugs that share mechanisms of action are apparent. Moreover, the overwhelming body of data on the behavioral effects of phenobarbital should convince clinicians that, whenever possible, it should not be used as the initial-or even the second-monotherapy in children with epilepsy.

Lamotrigine as adjunctive therapy in patients with refractory epilepsy and mental retardation

This study evaluated the effects of lamotrigine as adjunctive therapy for refractory epilepsy in patients with mental retardation. Patients with epilepsy and mental retardation having uncontrolled seizures despite treatment with other antiepileptic drugs were eligible (n=67). The open-label study comprised a Baseline Phase, an Escalation Phase during which lamotrigine was titrated to a target dose, an 8-week Maintenance Phase during which doses of lamotrigine and concomitant antiepileptic drugs were maintained, and a 12-week Optimization Phase during which doses of lamotrigine and other antiepileptic drugs could be adjusted. Almost half (44%) of patients experienced a 50% reduction in seizure frequency during the Maintenance Phase after addition of lamotrigine; 15% of patients became seizure-free. A similar pattern of results was reported for the Optimization Phase. Investigator-rated clinical status was improved relative to baseline in 66 and 74% of patients at the end of the Maintenance and Optimization Phases, respectively. Most patients experienced improvements in seizure frequency, duration, and intensity during the Maintenance Phase (62 to 72%) and the Optimization Phase (65 to 74%). Many patients were rated as having improved social functioning during the Maintenance Phase (42%) and the Optimization Phase (46%). The Aberrant Behavior Checklist score for lethargy and the mean Habilitative Improvement Scale score were improved at the ends of the Maintenance and Optimization Phases relative to baseline (P< or =0.04). One limitation of this study is its open-label design, which limits the ability definitively to attribute the clinical improvements to lamotrigine. Adjunctive lamotrigine in patients with refractory epilepsy and mental retardation appears to decrease seizure frequency and improve behavior while permitting a reduction in dose of concomitant antiepileptic drugs.

Drug therapy in Lennox-Gastaut syndrome

Like West's syndrome, Lennox-Gastaut syndrome resists most of the standard anticonvulsants. Dr. Farrell discusses the first- and second-line drugs which may be used--plus the ketogenic diet.

Newer antiepileptic drugs: advantages and disadvantages

The choice of an antiepileptic drug depends firstly on its efficacy in specific seizure types and epilepsies. However, it is imperative to consider whether possible adverse events will outweigh any benefits. The advantages and disadvantages of vigabatrin, lamotrigine, gabapentin, topiramate, tiagabine and felbamate are considered in some detail, and oxcarbazepine, stiripentol, remacemide, zonisamide and levetiracetam more briefly. Vigabatrin is effective for partial seizures and infantile spasms, but visual field defects are limiting its use. Lamotrigine has a wide spectrum, needs to be prescribed with care. Gabapentin is unlikely to cause adverse effects, but has relatively poor efficacy. Topiramate is widely effective, but can be poorly tolerated. Tiagabine is relatively untried in childhood epilepsies. The use of felbamate is restricted to severe refractory epilepsies. Stiripentol can be effective in severe myoclonic epilepsy in infancy. Zonisamide has a special place in the progressive myoclonus epilepsies. Levetiracetam, remacemide and oxcarbazepine have been used mainly for partial seizures: further studies of their roles in other circumstances are required.

Lamotrigine therapy of epilepsy in tuberous sclerosis

PURPOSE

Lamotrigine (LTG), a newer antiepileptic drug (AED), has activity against both partial-onset and generalized seizures. Its reported benefits for behavior, and its effectiveness in Lennox-Gastaut syndrome and other forms of refractory epilepsy, make it a logical choice for treatment of epilepsy in tuberous sclerosis complex (TSC). We present our experience with LTG therapy of epilepsy in 57 patients with TSC.

METHODS

Patients fulfilled the diagnostic criteria for clinically definite TSC. LTG was initiated and increased until improvement in seizure frequency was noted, intolerable side effects occurred, or maximal doses were reached. Seizure frequency and behavioral changes were recorded during LTG therapy and compared with those prior to the introduction of LTG.

RESULTS

Twenty-four (42%) were seizure free, and 21 (37%) had a >50% reduction in seizure frequency. Eighteen (32%) had subjectively improved behavior and/or alertness with daily activities. Thirty-eight (67%) had no change in this regard, whereas one (2%) became worse. Responders were more likely to not have a history of infantile spasms, and to have experienced only partial seizures (p < 0.05). Otherwise no phenotypic correlations with response were apparent.

CONCLUSIONS

Among patients with TSC and epilepsy, LTG was effective and well tolerated, including as initial monotherapy. Improved alertness and behavior were apparent in many patients. The incidence of side effects is similar to that reported for other pediatric populations with symptomatic partial epilepsy. The usefulness of LTG in TSC may relate to an underlying defect of glutamatergic neurotransmission in partial epilepsy.

Treatment of epilepsy in the multiply handicapped

The medical management of epilepsy in the multi-handicapped patient requires careful evaluation, classification, and pharmacologic treatment. It is estimated that 20-40% of patients with mental retardation and cerebral palsy have epilepsy. This review reports the clinical trial data and personal experience related to the use of newer AEDs in the chronic management of epilepsy syndromes in children and adults, as well as information available on the treatment of seizures in individuals with mental retardation and associated handicaps. Furthermore, clusters of seizures, prolonged seizures and status epilepticus are more commonly seen in the multiply handicapped and mentally retarded population and require special attention. The new antiepileptic drugs felbamate, gabapentin, lamotrigine, levetiracetam, oxcarbazepine, tiagabine, topiramate, vigabatrin and zonisamide show specific advantage in some multiply handicapped patients, be it for seizure control or medication tolerance. Furthermore, new modalities of treatment for prolonged seizures allow better efficacy both outside of hospital and within hospital facilities. The treatment of epilepsy in multi-handicapped and retarded adults and children has significantly advanced in the past few years, and much of this improvement can be attributed to improved knowledge and monitoring of new antiepileptic drugs. Conventional anticonvulsants remain first line therapy for most clinicians, but newer AEDs must broaden the therapeutic option and do allow improved therapy for some multiply handicapped patients.

Add-on lamotrigine treatment in children and young adults with severe partial epilepsy: an open, prospective, long-term study

We evaluated the efficacy and safety of lamotrigine in 41 children and young adults (age range, 3-25 years; mean, 12 years) with drug-resistant, partial epilepsies, based on a prospective, add-on study. Patients had severe symptomatic/cryptogenic partial epilepsies (mean seizure frequency = 3.6/day), resistant to one to four major antiepileptic drugs. Mean seizure frequency significantly decreased (P < .001) throughout the period of treatment. A good response (>50% seizure reduction) was observed in 15 patients of whom 6 were seizure-free (follow-up: 12-48 months). Higher responder rate was found among cryptogenic epilepsies and epilepsies symptomatic of cerebral malformation, whereas patients with posthypoxic-ischemic perinatal damage were poor responders. Lamotrigine discontinuation was mainly due to lack of efficacy (46% of patients), whereas only 2 patients developed a transient skin rash and did not drop out. Lamotrigine represents a valuable treatment for severe partial epilepsies of childhood that have proved resistant to previous antiepileptic drugs.

[Lamotrigine therapy in children. Retrospective study of 32 children]

BACKGROUND

Lamotrigine is one of the new anti-epileptic drugs, which is a phenyltriazine derivative. It is considered to act via an inhibitory effect on voltage-sensitive sodium channels and to have no GABAergic action.

PATIENTS AND METHOD

We studied its efficiency in 32 children with refractory epilepsy after a treatment of at least one year with other anti-epileptic drugs. We then compared our results with other publications.

RESULTS

Good efficiency (at least 50% reduction of crises) has been demonstrated for lamotrigine in children with generalized epilepsy (62.5% good results), particularly with absence epilepsy and Lennox-Gastaut syndrome. Results are encouraging for our few patients with epilepsy with continuous spike waves during slow-wave sleep. On the other hand, more precise indications are needed in partial epilepsy.

CONCLUSION

Seizure control was generally maintained during one year of lamotrigine treatment. Association to sodium valproate is relevant for most of the authors. Adverse effects are uncommon, and we did not observe any skin rash. Lastly, improvement of behaviour and cognitive functions represents another important benefit of lamotrigine.

Managing pediatric epilepsy syndromes with new antiepileptic drugs

The management of epilepsy in the pediatric patient requires careful evaluation, classification, and pharmacologic treatment. Despite best efforts on the part of clinicians, approximately 25% of children remain refractory to appropriate medical therapies. The development of an improved classification system and the emergence of several new antiepileptic drugs have enabled some progress in this area, specifically in children with disorders such as Lennox-Gastaut syndrome and infantile spasms, which are notoriously difficult to control. However, limited data are available that define the optimal use of new antiepileptic agents in pediatric patients. To most effectively treat children with epilepsy syndromes, further research must be completed to validate the positive effects described in case reports, open-label clinical trials, and early controlled clinical trials.

Efficacy of lamotrigine and vigabatrin in drug-resistant epilepsies of childhood

It was the purpose of this study to compare the efficacy and side effects of lamotrigine (LTG) and vigabatrin (VGB) as add-on therapy in epilepsies of childhood resistant to conventional drugs. Retrospective analysis of the medical charts and electroencephalograms of 134 children (LTG 57, VGB 77) was performed considering the various epileptic seizures and syndromes. In general, LTG and VGB had similar efficacy, with 30-40 % of patients demonstrating significant improvement. Few differences according to seizure type and epileptic syndrome were observed. Primary generalized tonic-clonic seizures more frequently improved and less frequently worsened with LTG than with VGB. In tonic seizures the treatment results were significantly more favorable with VGB. Only insignificantly better results occurred with LTG in the generalized group and with VGB in the localization-related group. VGB was significantly more effective in symptomatic than in idiopathic and cryptogenic syndromes. The frequency of adverse reactions with both drugs was close to 60%. However, treatment had to be discontinued because of severe rashes in only a few patients taking LTG or because of behavior disturbances in patients taking VGB.