Efficacy of Clobazam as Add-On Therapy in Patients with Refractory Partial Epilepsy

PURPOSE: Clobazam (CLB) has an important antiepileptic effect and is less expensive than the new antiepileptic drugs (AEDs), but still has not been considered as first-line drug in the treatment of epilepsy. We evaluated the efficacy of CLB as add-on therapy in patients with refractory partial epilepsy. METHODS: This was an open, retrospective study, conducted at the epilepsy clinic of our university hospital. All patients had chronic epilepsy and were being evaluated for epilepsy surgery. CLB was introduced as add-on therapy (starting with 10 mg/ day) in patients with previous failure of at least two AEDs. Information was obtained from clinical notes and follow-up visits. RESULTS: We evaluated 97 patients, 37 men and 60 women. Ages ranged from 15 to 70 years (mean, 35.8 years). Etiology of epilepsy was hippocampal atrophy in 67 (69%), cortical dysgenesis in nine (9.3%), and other etiologies in nine (9.3%). In 12 (12.3%) patients, the etiology of epilepsy was not identified despite clinical and neurologic investigation. Patients used CLB for a period ranging from 1 month to 7 years and 9 months (mean, 16.7 months) with doses ranging from 10 to 60 mg/day (mean, 29.7 mg/day). Seven (7.2%) patients were seizure free, 48 (49.4%) had > or =50% of improvement in seizure control, 39 (40.2%) had <50% of improvement in seizure control, and in three (3.1%), no data were available. CONCLUSIONS: We conclude that CLB may have efficacy equivalent to that of the new AEDs when used as add-on therapy in patients with refractory epilepsy. CLB should be considered an economic alternative in the treatment of patients with refractory epilepsy.     

Clobazam for Treatment of Intractable Epilepsy: A Critical Assessment

Summary: Clobazam (CLB), a 1,5-benzodiazepine, is a remarkably effective add-on drug for individual patients with refractory partial epilepsy. CLB has an excellent safety record. As with all benzodiazepines used for treating epilepsy, sedation and withdrawal effects, together with the development of tolerance, limit its usefulness. Recent efforts to prevent or reverse tolerance with intermittent administration of CLB or periodic injection of a benzodiazepine antagonist, flumazenil, are encouraging and justify further investigations.     

Stiripentol: efficacy and tolerability in children with epilepsy

PURPOSE: Stiripentol (STP) is a new antiepileptic drug (AED) that inhibits cytochrome P450, resulting in increased plasma concentrations of concomitant AEDs. The efficacy and tolerability of STP as an add-on therapy in children were assessed. METHODS: Two hundred twelve patients with refractory epilepsy, aged from 1 month to 20.5 years, received STP either in a single-blind, placebo-controlled trial (108 patients) or in a further open trial (104 other patients selected by epilepsy syndrome for possible efficacy based on the results of the previous trial). RESULTS: Among the 97 patients who could be analyzed for efficacy in the placebo-controlled study, the median seizure frequency was lower at 3 months with STP than with the placebo (p<0.0001); 49% responded to the drug, including 10% who became seizure free. Patients with partial epilepsy had the highest response rate (57%). Results were confirmed in the open study where 68% of the 91 patients receiving STP responded at 3 months. These patients were mainly those with partial epilepsy (73%) who were receiving carbamazepine (CBZ) (75%) as comedication (p<0.001). Ten of the 20 children with severe myoclonic epilepsy in infancy also responded with clobazam (CLB) as comedication. Efficacy was sustained long term in 74% of the 94 patients still receiving STP at a mean 30-month follow-up. Adverse events were reported in 48% of the 212 patients, mainly anorexia and loss of weight, but these events required STP discontinuation in only nine cases. Side effects were minimized in the open trial by optimizing the dose of comedication. CONCLUSIONS: STP seems to be a promising add-on drug, particularly when combined with CBZ in patients with partial childhood epilepsy refractory to vigabatrin (VGB) and with CLB in patients with severe myoclonic epilepsy in infancy.     

The Use of Clobazam, Midazolam, and Nitrazepam in Epilepsy

Summary: The benzodiazepines clobazam (CLB), midazolam (MDL), and nitrazepam (NZP) all have proven efficacy in epilepsy management, but their differences in physical properties, pharmacokinetic characteristics, side-effect profiles, and intrinsic antiepileptic activity lead to different indications for use. CLB is a 1,5-benzodiazepine that causes less sedation than 1,4-benzodiazepines but offers improved antiepileptic action. It has been extensively studied in both open and controlled trials as antiepileptic therapy for a variety of seizure types. It is now widely used in European countries as adjunctive therapy for partial and secondarily generalized seizures. Clinical trial experience, however, indicates that more than 50% of patients develop tolerance to the antiepileptic effects of CLB. Therefore, CLB has had a relatively limited role as a routine antiepileptic drug. It has further use as an intermittent or occasional therapy, in which tolerance is of less concern. MDL is a water-soluble 1,4-benzodiazepine. It is the only drug in this class that is useful when given by i.m. injection, although MDL can also be administered rectally or by i.v. bolus or infusion. MDL has a very short elimination half-life and is used for emergency treatment of status epilepticus or acute seizures. NZP has reported efficacy in acute epilepsy, although it is not routinely used for this situation. Although there have been no controlled studies of NZP for chronic epilepsy treatment, this drug appears to be moderately effective in a wide range of seizure types. NZP is predominantly used in children with severe epilepsy intractable to conventional medications.     

Strategies to prevent overtreatment with antiepileptic drugs in patients with epilepsy

Overtreatment is defined here as an unnecessary and excessive drug load in the management of epilepsy leading to a suboptimal risk-to-benefit balance. Pharmacological overtreatment can often be prevented by deciding and counselling carefully about the need for antiepileptic drugs (AEDs) given the limitations of current AEDs. Although AEDs will reduce the incidence of seizures, they have no demonstrated ability to prevent epilepsy in patients at risk or to modify the course of epilepsy in patients following the first seizure. In addition, starting AEDs may not be necessary for control of epileptic seizures induced by precipitation or predisposing factors or for benign epilepsies with rare or mild seizures. Start monotherapy with the chosen first-line AED, initially at low doses titrating up to the low maintenance dose. Avoid drug loading (except for emergency treatment). If seizures continue, titrate to the limit of tolerability which will however, achieve additional seizure control in approximately 20% of patients. If, as in many patients, dosing to the limit of tolerability is not beneficial, the dose should be reduced. Switching to an average dose of another first line AED is another option to prevent overtreatment. Avoid drug overload during add-on therapy by slowly reducing the dose of the first drug in patients having adverse effects, ideally by an amount that the patient does not experience any further adverse effects, if possible, before adding another drug. If the patient does not benefit unequivocally from two-drug therapy within 3 months (and approximately 75% will not benefit), slowly transfer to monotherapy of the second drug and start with a newly chosen AED for add-on. To counteract the propensity to overmedication in chronic epilepsy is not easy. Great benefits, without loss of seizure control, are often gained by slowly reducing the overall drug load.     

Drug resistance in epilepsy: putative neurobiologic and clinical mechanisms

Drug-resistant epilepsy with uncontrolled severe seizures despite state-of-the-art medical treatment continues to be a major clinical problem for up to one in three patients with epilepsy. Although drug resistance may emerge or remit in the course of epilepsy or its treatment, in most patients, drug resistance seems to be continuous and to occur de novo. Unfortunately, current antiepileptic drugs (AEDs) do not seem to prevent or to reverse drug resistance in most patients, but add-on therapy with novel AEDs is able to exert a modest seizure reduction in as many as 50% of patients in short-term clinical trials, and a few become seizure free during the trial. It is not known why and how epilepsy becomes drug resistant, while other patients with seemingly identical seizure types can achieve seizure control with medication. Several putative mechanisms underlying drug resistance in epilepsy have been identified in recent years. Based on experimental and clinical studies, two major neurobiologic theories have been put forward: (a) removal of AEDs from the epileptogenic tissue through excessive expression of multidrug transporters, and (b) reduced drug-target sensitivity in epileptogenic brain tissue. On the clinical side, genetic and clinical features and structural brain lesions have been associated with drug resistance in epilepsy. In this article, we review the laboratory and clinical evidence to date supporting the drug-transport and the drug-target hypotheses and provide directions for future research, to define more clearly the role of these hypotheses in the clinical spectrum of drug-resistant epilepsy.     

Long-term follow-up of topiramate and lamotrigine: a perspective on quality of life.

We conducted a prospective, long-term audit of lamotrigine and topiramate as add-on treatment for refractory epilepsy. A total of 55 patients participated in the study. Five years after starting the drug 7/20 patients remained on lamotrigine and 13/35 on topiramate. The patients still on the study drugs showed an improvement in seizure frequency, with 5/7 patients being seizure free on lamotrigine and 4/13 on topiramate. Furthermore, we assessed quality of life using the quality of life assessment schedule and found a significant improvement for the patients still on the study drugs. These data suggest that about one third of the patients on lamotrigine or topiramate as add-on therapy stay on the drug in the long term. These patients are likely to benefit with respect to objective and subjective outcome measures.     

Use of clobazam for the treatment of refractory complex partial seizures.

Clobazam (CLB) add-on therapy was attempted in 183 patients with intractable complex partial seizures in whom conventional benzodiazepines had been successfully discontinued before initiation of CLB. Although complete remission was initially achieved in 61, tolerance developed in almost half (49.2%) within the first 3 months, whereas 23 out of 31 patients (74.2%) who remained seizure free for the first 3 months continued to be so over the next 3 months. CLB add-on therapy proved to be significantly more effective when concurrent GTC occurred more often than yearly. In the current series, no frank psychotic episodes were elicited among the 61 patients who achieved complete suppression of long-standing complex partial seizures, which was in agreement with previous studies. From these results, we believe that CLB is an effective, safe, and inexpensive medication for add-on therapy in difficult to treat focal epilepsies, especially without concurrent use of conventional benzodiazepine compounds.     

Long-term efficacy and safety of piracetam in the treatment of progressive myoclonus epilepsy

BACKGROUND: Piracetam has been proven to be effective and well tolerated in the treatment of myoclonus in short-term studies. OBJECTIVE: To assess its long-term clinical efficacy, 11 patients with disabling myoclonus due to progressive myoclonus epilepsy were treated with piracetam in an open-label study. METHODS: Neurologic outcome (at the 1st, 6th, 12th, and 18th month of treatment) was assessed by an adjusted sum score of the following 3 indices: motor impairment, functional disability, and global assessment of disability due to myoclonus. Severity of other neurologic symptoms (seizure frequency and severity, dysarthria, and gait ataxia) also was assessed. Treatment with piracetam was initiated at a dose of 3.2 g/d that was gradually increased until stable benefit was noted (maximal dose in the trial was 20 g/d). Concomitant antiepileptic drugs were maintained at their previous dose. RESULTS: Statistically significant improvement in the total rating score was observed after introduction of piracetam at the 1st, 6th, and 12th month of treatment. Severity of other neurologic symptom scores did not improve significantly. Two patients reported drowsiness during the first 2 weeks of treatment. CONCLUSIONS: Piracetam given as add-on therapy seems to be an effective, sustained, and well-tolerated treatment of myoclonus. In patients with progressive myoclonus epilepsy, the efficacy of the drug increased during the first 12 months of treatment and then stabilized.     

Clobazam Has Equivalent Efficacy to Carbamazepine and Phenytoin as Monotherapy for Childhood Epilepsy

Summary: Purpose: To compare the effectiveness of mono-therapy clobazam (CLB) to carbamazepine (CBZ) and phenytoin (PHT) in children with epilepsy.
Methods: Children aged 2–16 years with newly diagnosed epilepsy or previous failure of one drug (for poor efficacy or side effects) were assigned to one of two study arms and then randomized–CLB versus CBZ or CLB versus PHT. Eligible children had partial epilepsies or only generalized tonic-clonic seizures. After a drug initiation protocol, monotherapy treatment mimicked the usual routines used by Canadian child neurologists. Blinding used a "double dummy" technique with blinded medication serum levels (6–point scale). Intention to treat analysis using survival curves assessed the primary end-point–length of retention on the initial medication during the year after randomization.
Results: Fifteen centers entered 235 patients: 159 randomized to CLB versus CBZ and 76 to CLB versus PHT. Altogether, in all study arms, 119 received CLB, 78 CBZ, and 38 PHT. Overall, 56% continued to receive the original medication for l year with no difference between CLB and standard therapy (CBZ and PHT). Seizure control was equivalent for all three medications, as were side effects. PHT and CBZ induced more biologic side effects, such as rash, while CLB induced slightly more behavioral effects. Tolerance developed in 7.5% of patients receiving CLB, 4.2% with CBZ and 6.7% with PHT.
Conclusions: CLB should be considered as "first line" monotherapy along with CBZ and PHT for all partial and selected generalized childhood epilepsies.     

Clinical Science

Dieter Schmidt and Wolfgang Löscher
Drug-resistant epilepsy, with uncontrolled severe seizures despite the best available drug treatment, continues to be a major clinical problem for up to one in three patients with epilepsy. Although drug resistance may emerge or disappear in the course of epilepsy or its treatment, in most patients so-called de novo drug resistance seems to exist already when treatment starts. Unfortunately, current antiepileptic drugs (AEDs) do not seem to prevent or to reverse drug resistance in most patients. However, add-on therapy with novel AEDs is able to exert a modest seizure reduction in as many as 50% of patients in short-term clinical trials, and a few percent become seizure-free during the trial. It is not known why and how epilepsy becomes drug-resistant, while other patients with seemingly identical seizure types can achieve seizure control with medication. Several possible mechanisms underlying drug resistance in epilepsy have been identified in recent years. Based on experimental and clinical studies, two major neurobiological theories have been put forward: a) removal of AEDs out of the epileptogenic tissue (where AEDs exert their effect) through excessive activity of multidrug transporters and, b) reduced efficacy through lower target sensitivity to drugs in brain tissue involved in epilepsy. On the clinical side, genetic and clinical features and structural brain lesions have been associated with drug resistance in epilepsy. In this article, we review the laboratory and clinical evidence to-date supporting the drug-transport and the drug-target hypotheses and provide directions for future research to more clearly define the role of these hypotheses in the clinical spectrum of drug-resistant epilepsy. Epilepsia 2005;46(6).

     

Tiagabine in the Management of Epilepsy

Summary: Tiagabine (TGB) is a new antiepileptic drug (AED) that uniquely reduces the uptake of the inhibitory neurotransmitter -γ-aminobutyric acid into presynaptic neuronal and glial cells. It is metabolized in the liver with an elimination half-life of approximately 7 to 9 h. Although TGB does not induce or inhibit hepatic metabolic processes, it does provide a target for other enzyme-inducing AEDs. TGB has proved effective as add-on treatment for partial seizures, with or without becoming secondarily generalized, as demonstrated in five placebo-controlled trials and six long-term open studies. Preliminary results with TGB in children with refractory epilepsy and as monotherapy are promising. Few patients withdrew from these trials because of adverse events. The most common side effects with TGB involved the central nervous system, i.e., dizziness, asthenia, somnolence, nervousness, headache, and tremor. Most adverse events occurred during dosage titration, were often transient, and were usually of mild to moderate severity. The recommended maintenance dose for TGB, when combined with enzyme-inducing drugs as add-on therapy, is 30 to 50 mg/day. Trials are under way in patients with primarily generalized seizures and in newly diagnosed epilepsy. TGB is a well-tolerated and effective novel AED that will find an enduring place in the management of epilepsy.     

托吡酯单药治疗各型癫癎的临床研究

目的观察托吡酯单药治疗成人和儿童各型癫癎的临床效果与安全性.方法用开放性试验的方法对34例癫癎患者进行了添加转单药以及首诊单药的托吡酯治疗;以加用托吡酯前3个月的月均发作频率为基准,与单用或转换单用托吡酯进入稳定期后3个月的月均发作频率进行比较,按常规计算发作减少百分比的中位值和有效率百分比.结果托吡酯无论在添加转单药还是单药的治疗上均有明显疗效,且抗谱广,可用于单纯部分性发作有或全面性发作、复杂部分性发作有或全面性发作、婴儿痉挛症,无耐药现象.14岁以上者托吡酯单药治疗的剂量明显低于添加治疗组.托吡酯的副反应以中枢神经系统最常见,但导致治疗中断的副反应尚未见到.结论托吡酯是一个广谱抗癫癎药,疗效肯定,无耐药性,无严重副反应,可用于单药治疗.     

International Experience with Tiagabine Add-On Therapy

Summary: Tiagabine (TGB) hydrochloride is a novel antiepileptic drug (AED) that is a potent and specific inhibitor of γ-aminobutyric acid (GABA) uptake into glial and neuronal elements. In accordance with medical and regulatory standards, the clinical development program for TGB as an AED has assessed the value of TGB in add-on treatment, focusing mainly on partial seizures, including secondarily generalized seizures. Five add-on, placebo-controlled trials and six non-comparative, open-label, long-term multicenter trials have been or are being conducted in Australia, Europe, and the U.S.A. The results of these trials, involving 2,261 patients, indicate that TGB has efficacy as add-on therapy in patients with epilepsy difficult to control with existing AEDs. Efficacy of TGB is also sustained with long-term treatment. A clear dose-response has been demonstrated, and the minimal effective dose level is 30 mg. TGB is also tolerated, and with long-term therapy no new or more severe types of adverse events develop. These studies have included a wide age range of patients, including adolescents and the elderly.     

Efficacy and tolerability of the new antiepileptic drugs: comparison of two recent guidelines

BACKGROUND: Until the early 1990s six major compounds (carbamazepine, ethosuximide, phenobarbital, phenytoin, primidone, and valproic acid) were available for the treatment of epilepsy. However, these drugs have pharmacokinetic limitations, teratogenic potential, and a negative effect on cognitive functions that impairs the quality of patients' lives and limits the use of these drugs in some patients. In addition, 20-30% of patients are refractory to these drugs. RECENT DEVELOPMENTS: The development of ten new antiepileptic drugs (vigabatrin, felbamate, gabapentin, lamotrigine, topiramate, tiagabine, oxcarbazepine, levetiracetam, zonisamide, and pregabalin) has expanded treatment options. The newer drugs may be better tolerated, have fewer drug interactions, and seem to affect cognitive functions to a lesser extent than old drugs. Guidelines on the use of new antiepileptic drugs have been developed in the USA and in the UK. Both guidelines offer a clear picture of the efficacy, safety, and tolerability of the new antiepileptic drugs and agree on their use as add-on treatment in patients who do not respond to conventional drugs. The guidelines differ in the type and strength of recommendations. Whereas the US guidelines recommend treatment in newly diagnosed epilepsy with a standard drug or a new drug depending on the individual patient's characteristics, the UK guidelines recommend that a new antiepileptic drug should be considered only if there is no benefit from an old antiepileptic drug, an old drug is contraindicated, there is a previous negative experience with the same drug, or the patient is a woman of childbearing potential. WHERE NEXT: The limited amount of information on the new antiepileptic drugs may explain the discrepancies among the two guidelines and between these and other recommendations. Comparative, pragmatic, long-term and open trials should be done to show long-term efficacy and comparative features of the new antiepileptic drugs, and to better assess the effect on quality-of-life, cost-effectiveness, tolerability, and teratogenic potential. In addition, the conflicts should be resolved between the needs of the regulatory bodies and those of the treating physicians. Finally, there is a need for trial designs to be standardised.     

Evaluation of acceptance and commitment therapy for drug refractory epilepsy: a randomized controlled trial in South Africa--a pilot study

PURPOSE: Psychological interventions in the treatment of epilepsy have been developed and evaluated for many years but the amount of research has hardly made an impact on how epilepsy is treated. The purpose of this study was to develop and evaluate a psychological treatment program consisting of acceptance and commitment therapy (ACT) together with some behavioral seizure control technology shown to be successful in earlier research. METHODS: The method consisted of a randomized controlled trial group design with repeated measures (n=27). All participants had an EEG verified epilepsy diagnosis with drug refractory seizures. Participants were randomized into one of two conditions, ACT or supportive therapy (ST). Therapeutic effects were measured by examining changes in quality of life (SWLS and WHOQOL) and seizure index (frequency x duration). Both treatment conditions consisted of only nine hours of professional therapy distributed in two individual and two group sessions during a four-week period. RESULTS: The results showed significant effects over all of the dependent variables for the ACT group as compared to the ST group at six- and twelve-month follow-ups. CONCLUSIONS: The results from this study suggest that a short-term psychotherapy program combined with anticonvulsant drugs may help to prevent the long-term disability that occurs from drug refractory seizures.     

Monotherapy trials: prerequisite data.

Is it possible for an antiepileptic drug (AED) to be effective as add-on therapy in refractory epilepsy but ineffective as monotherapy for the same seizure type(s)? If the answer is 'no', why not award a new AED a monotherapy licence once it has been shown to be effective as adjunctive treatment in placebo controlled, dose-ranging studies in patients with difficult-to-control epilepsy? The recent comparative study between carbamazepine and remacemide, however, suggests that subtle pharmacokinetic/pharmacodynamic interactions between established and new AEDs can indicate efficacy in add-on studies that does not necessarily transfer to monotherapy. There is some evidence that an AED whose primary mechanism of action does not involve blockade of voltage-dependent sodium channels may do less well than carbamazepine in terms of efficacy end-points in a double-blind, head-to-head comparison. These observations lead to the conclusion that monotherapy trials are, indeed, required. They should be undertaken after proof of efficacy has been obtained using a single short presurgical AED withdrawal study backed up by a substantive dose-ranging phase III efficacy trial. There is no reason to recommend earlier assessment since the clinical need for new AEDs is in refractory epilepsy. The subsequent monotherapy trial programme should contain elements utilising comparative and withdrawal designs. Sponsors should be able to seek a licence for their drug either as a first choice treatment in newly diagnosed epilepsy or as substitution monotherapy once treatment with at least one other AED has failed.     

Outcome of short-term antiepileptic treatment in patients with solitary cerebral cysticercus granuloma

OBJECTIVES: The duration of antiepileptic drug (AED) therapy in cases of solitary cerebral cysticercus granuloma (SCCG) presents a major dilemma and the efficacy of short-term (6 months) vs long-term (2 years) AED therapy has been studied. MATERIALS AND METHODS: Prospective randomized study of short-term vs long-term AED treatment with SCCG has been undertaken. A total of 206 subjects with new onset seizures with SCCG were randomized into two groups: group A (98 patients) were treated for 6 months and group B (108 patients) were treated for 2 years with AED therapy. The patients were evaluated periodically during and at least 18 months after the tapering of drugs. RESULTS: Partial seizures with or without secondary generalization has been found to be the commonest manifestation occurring in 80.6% of patients with SCCG. In group A 66.3% and in group B 57.4% patients showed complete resolution of computerized tomographic lesion and rest had punctated residual calcification. Statistically, no significant difference in the recurrence of seizures was found in two groups with disappearance of lesion but the difference between calcified residua and complete resolution subset was significant. In patients having residual calcification, 42.2% in group A and 21.7% in group B had recurrence of seizures and the difference was statistically significant (Z = 1.97, P < 0.05). CONCLUSIONS: The study revealed that SCCG with epilepsy is a benign self-limiting disease. A longer duration of therapy is not warranted in patients having total resolution of lesion. Calcified lesion was found to be the most common cause of recurrence of seizures. Higher recurrence rate was observed in short-term therapy in patients having calcified lesions and may require long-term AED treatment.     

Long-term treatment with vigabatrin - 10 years of clinical experience.

This report describes the long-term follow-up of 56 patients with refractory partial epilepsy who, within 3 months of vigabatrin add-on therapy (3 g/day), showed a reduction in monthly seizure frequency of more than 50%. The short-term (6 months) and long-term (5 years) effects of vigabatrin on seizure frequency in this patient cohort have been published separately. The reduction in seizure frequency appeared to be long-lasting in the patients followed-up (n = 36) and, importantly, a significant number of the patients (n = 7) became seizure-free, especially during long-term treatment. Thus, the efficacy of vigabatrin appears to be progressive, at least in patients who show an early response to treatment. These results are consistent with experimental findings that suggest that vigabatrin may have anti-epileptogenic and neuroprotective effects.     

The use of lamotrigine, vigabatrin and gabapentin as add-on therapy in intractable epilepsy of childhood.

PURPOSE: Lamotrigine (LTG), vigabatrin (VGB) and gabapentin (GBP) are three anti-epileptic drugs (AEDs) used in the treatment of children with epilepsy for which long-term retention rates are not currently well known. This study examines the efficacy, long-term survival and adverse event profile of these three agents used as add-on therapy in children with refractory epilepsy over a 10-year period. METHODS: Three separate audits were conducted between February 1996 and September 2000. All children studied had epilepsy refractory to other AEDs. Efficacy was confirmed if a patient became seizure free or achieved >50% reduction in seizure frequency for 6 months or more after starting therapy. Adverse events and patient survival for each drug were recorded at the end of the study period. RESULTS: Between September 1990 and February 1996, 132 children received LTG, 80 VGB and 39 GBP. At the 10-year follow-up audit, 33% of the children on LTG had a sustained beneficial effect on their seizure frequency in contrast to 19% for VGB and 15% for GBP. No significant difference in efficacy was found in children with partial seizures. Children with epileptic encephalopathy (EE) including myoclonic-astatic epilepsy and Lennox-Gastaut Syndrome (LGS) achieved a more favorable response to LTG. The main reasons for drug withdrawal were lack of efficacy for VGB, apparent worsening of seizures for GBP and the development of a rash for LTG. CONCLUSIONS: Lamotrigine is a useful add-on therapy in treating children with epilepsy. It has a low adverse event profile and a sustained beneficial effect in children with intractable epilepsy.