Ganaxolone

Ganaxolone (3α-hydroxy-3β-methyl-5α-pregnan-20-one) (GNX) is the 3β-methylated synthetic analog of allo-pregnanolone; it belongs to a class of compounds referred to as neurosteroids. GNX is an allosteric modulator of GABA_A receptors acting through binding sites which are distinct from the benzodiazepine binding site. It has activity in a broad range of animal models of epilepsy. GNX has been shown to be well tolerated in adults and children. In early phase II studies, GNX has been shown to have activity in adult patients with partialonset seizures and epileptic children with history of infantile spasms. It is currently undergoing further development in infants with newly diagnosed infantile spasms, in women with catamenial epilepsy, and in adults with refractory partial-onset seizures.     

Clinical experience with open-label topiramate use in infants younger than 2 years of age

To assess the efficacy, safety, and tolerability of topiramate in infants younger than 24 months of age, we conducted an open-label, multicenter chart review study of infants who received topiramate. Twenty-eight patients were evaluated. All had refractory epilepsy. The mean age of seizure onset was 3.8 months (range 0-10 months). Refractory infantile spasms were the most common epilepsy syndrome. Among infants without infantile spasms, complex partial seizures were the prominent seizure type in eight, followed by simple partial seizures in six. Topiramate was prescribed as add-on therapy in 25 cases and a s monotherapy in 3 cases. Seven of the eight infantile spasms cases improved on topiramate therapy, attaining topiramate monotherapy in three infants. Half of the infants with other seizure types responded to topiramate. The average treatment duration among topiramate responders was 11 months. Topiramate was prescribed after a mean of 3.3 antiepilepsy drugs had been used in these infants. In no case was topiramate the first prescribed antiepilepsy drug. Adverse effects occurred only in five patients, leading to topiramate discontinuation in two patients. Topiramate was efficacious and well tolerated in infants younger than 24 months of age with refractory epilepsy. Prospective data are needed to corroborate this observation.     

A Pilot Study of Topiramate in the Treatment of Infantile Spasms

Summary: Purpose : West syndrome is a rare epileptic syndrome associated with infantile spasms, a specific abnormal electroencephalographic pattern (termed hypsarrhythmia). and mental retardation. Management of this disorder is difficult because current treatment regimens, including many anticonvulsants and hormones, are often ineffective. Topiramate (TPM) is a new antiepileptic drug that may be effective in pediatric epilepsies. We conducted a pilot study to test the effects of rapid TPM dosing in patients with refractory infantile spasms.
Methods: Eleven children with refractory infantile spasms were given an initial dose of 25 mg TPM per day in addition to their current therapy. Dosage was increased by 25 mg every 2–3 days until spasms were controlled, the maximal tolerated dose was reached, or the maximal dose of 24 mg/kg/day was achieved. Efficacy was primarily assessed by video EEG and secondarily by parental count of spasm frequency.
Results: Five (45%) subjects became spasm free during the study, with absence of infantile spasms and hypsarrhythmia (either classic or modified) proven by video EEG. Nine subjects, including the five spasm free, achieved a spasm reduction of 250%. Spasm frequency decreased from 25.6 f 19.3 to 6.9 r 5.9 spasmdday. Sixty-four percent of the subjects were able to achieve TPM monotherapy.
Conclusions: Results in this cohort of 11 patients with refractory disease show TPM to be a promising new agent for the treatment of infantile spasms.     

Topiramate: efficacy and tolerability in children according to epilepsy syndromes

To evaluate the efficacy and tolerability of topiramate (TPM) as add-on therapy in children less than 12 years of age with refractory epilepsy, according to epilepsy syndromes, we conducted an open, prospective, pragmatic and multicenter study in France. Efficacy was assessed, especially according to epilepsy syndromes, as well as tolerability. We included 207 children (41 of whom were less than 4 years of age). TPM was effective (responders with >50% decrease in seizure frequency) in 50% of 128 patients with partial epilepsy, and in 44% of 79 patients with generalized epilepsy. In case of generalized epilepsy, responders more frequently had generalized symptomatic epilepsy, severe myoclonic epilepsy and myoclono-astatic epilepsy, whereas response rate was mild in both infantile spasms and Lennox-Gastaut syndrome (LGS). Improvement was well maintained in all patients during the treatment period (median 5.6 months). Seizure frequency/severity increased (worsening) in 13% of patients with partial epilepsy and 17% with generalized epilepsy (particularly in those with infantile spasms), and resulted in withdrawal of TPM for 8%. The most frequently reported adverse events were moderate neurobehavioral and gastrointestinal disorders. Adverse events led to withdrawal of TPM from 13.5% of patients. Children less than 4 years of age had particularly good tolerability. Results confirm that TPM is effective and well tolerated in children under 12 years of age in a broad range of epilepsy syndromes, including refractory partial epilepsy, and symptomatic and myoclonic generalized epilepsy. Use of TPM should be considered in children under 4 years of age, and slow and progressive titration is important.     

The efficacy and side effects of topiramate on refractory epilepsy in infants and young children: a multi-center clinical trial.

OBJECTIVES: This study has been conducted to assess the efficacy and safety of topiramate in refractory epilepsies in infants and young children. METHODS: A prospective clinical trial was performed in three tertiary care hospitals, on 47 children aged 6-60 months with refractory epilepsy. Topiramate was added to at least two baseline anti-epileptic drugs. The efficacy was rated according to seizure type, frequency and duration. RESULTS: Children with refractory epilepsy were classified according to their clinical, neuro-imaging, and neurophysiological profile into infantile spasms (IS) (9 cases, 19%), Lennox-Gastaut syndrome (LGS) (25 cases, 53%) and other epilepsies (13 cases, 28%). Children were also classified into cryptogenic and symptomatic epilepsy. Topiramate was introduced as add-on therapy in a daily dose of 1 mg/kg/day for 2 weeks, followed by increments of 1-3 mg/kg/day at 2-week intervals, up to a maximum of 10 mg/kg/day. After a minimum treatment period of 6 months, 28 (60%) of the children had a satisfactory response (completely seizure free, or more than a 50% seizure reduction). The remaining 19 children (40%) had an unsatisfactory response (50% or less reduction in seizure frequency, no change or increased seizure frequency). Topiramate appeared to be equally effective in infantile spasms, Lennox-Gastaut syndrome and children with other types of epilepsy, with no significant difference between those with a satisfactory and an unsatisfactory response (p=0.089). There was also no significant difference in response between patients with cryptogenic and symptomatic epilepsy (p=0.360). Mild to moderate adverse effects, mainly somnolence, anorexia and nervousness, were present in 25 (53%) of children. One of the children developed hypothyroidism. CONCLUSION: Although the long term safety and possible adverse effects of topiramate have not been fully established in infants and young children, this study has shown that it is a useful option for children with frequent seizures unresponsive to standard anti-epileptic drugs.     

Clinical evaluation of ganaxolone in pediatric and adolescent patients with refractory epilepsy

PURPOSE: A pilot study of the safety, tolerability, dose range and potential efficacy of ganaxolone for the treatment of refractory epilepsy in pediatric and adolescent subjects. METHODS: We report the results of a nonrandomized, nonblinded, open-label, dose-escalation trial of ganaxolone in pediatric subjects (5-15 years) suffering from refractory epilepsy. Subjects received an oral suspension of ganaxolone in a 1:1 complex with beta-cyclodextrin in a dose escalation (1 mg/kg, b.i.d. to 12 mg/kg t.i.d.) schedule over 16 days. This was followed by a maintenance period for 8 weeks. Subjects that showed significant response were eligible for a compassionate use extension period. RESULTS: Fifteen subjects enrolled, eight completed the trial and three continued in the open-label compassionate-use extension period. All subject exhibited refractory partial or generalized epilepsy. In an intent-to-treat analysis, four (25%) were considered substantial responders (>or=50% reduction in seizure frequency), two (13%) were considered moderate responders (between 25 and 50% reduction in seizure frequency) and the remainder were considered nonresponders (<24% reduction). Three subjects entered the extension phase, one remained essentially seizure-free for over 3.5 years of ganaxolone administration. Ganaxolone was tolerated well. A total of 17 adverse events were reported in 10 patients, all were considered mild to moderate in severity. Somnolence was the most frequently (nine) reported adverse event. CONCLUSIONS: This pilot study is consistent with other clinical studies indicating that ganaxolone has anticonvulsant activity in humans. The results of this study encourage the further study of ganaxolone as an antiepileptic therapy.     

Conversion to High Dose Gabapentin Monotherapy in Patients with Medically Refractory Partial Epilepsy

Summary: Purpose: To evaluate the safety and efficacy of high dose gabapentin (GBP) monotherapy (3,0004,800 mg/ day) in patients with medically refractory partial epilepsy.
Methods: GBP monotherapy at daily doses up to 4,800 mg was attempted in patients participating in the open-label phase of a double-blind, dose-controlled, GBP monotherapy trial. For those who achieved monotherapy, the types and severity of adverse events were assessed and the average seizure frequency per 28 days while maintained on the highest daily GBP dose was compared to the seizure frequency during the baseline phase of the double blind trial. Correlation analysis between GBP serum level, total daily dose, and percentage of seizure change from baseline was performed.
Results: A total of 45 patients participated in the open-label phase of the trial and 23 (51%) were converted successfully to GBP monotherapy. In those patients, the average daily gabapentin dose was 3,900 mg and the mean length of follow-up was 252 days. Compared to baseline, there was a mean reduction of 54%, 43%, and 14% for simple partial, complex partial and secondarily generalized seizures respectively, while maintained on high-dose GBP monotherapy. A significant linear correlation between daily GBP dosage (2,4004,800 mg) and resultant mean serum levels was found (r = 0.51; p < 0.01). There was no significant correlation between seizure frequency and total daily GBP dose or with serum levels. High-dose GBP monotherapy was well tolerated; only one patient exited the trial because of adverse events. The most common adverse event was tiredness/sleepiness and was not dose-related.
Conclusions: GBP monotherapy is well tolerated in daily doses of up to 4,800 mg and is effective in a subgroup of patients with medically refractory partial epilepsy.     

Topiramate for the treatment of infantile spasms

Topiramate is a new antiepileptic drug with a broad spectrum of efficacy. Reports on the use of topiramate for treatment of infantile spasms are limited. We prospectively followed 15 children with recently diagnosed infantile spasms treated with topiramate for efficacy and tolerability. Twelve patients had symptomatic infantile spasms, and two patients had cryptogenic infantile spasms. Topiramate was started at a dose of 3 mg/kg/day and titrated up to a dose of 27 mg/kg/day in 2 to 3 weeks. The primary efficacy measure was comparison of the seizure rate during the 2-week baseline with the median seizure rate during the first 2 months of treatment with topiramate. We also compared baseline electroencephalograms (EEGs) with post-treatment EEGs. The median seizure rate reduction during the first 2 months of treatment was 41% (P = .002). Three patients became spasm free (20%), five had > 50% reduction, and three had at least 25% reduction. Four patients did not respond. Three of 15 patients had clearing of hypsarrhythmia. Topiramate was generally well tolerated, with irritability being the most common side effect. Topiramate was efficacious and well tolerated; one patient discontinued the medication because of adverse effects. (J Child Neurol 2006;21:17-19).     

Efficacy and safety of levetiracetam 1000-3000 mg/day in patients with refractory partial-onset seizures: a multicenter, open-label single-arm study

PURPOSE: To evaluate the efficacy and tolerability of levetiracetam as add-on therapy in patients with refractory partial-onset seizures in a protocol designed to reflect clinical practice. METHODS: All patients in this open-label, single-arm study entered an 8-week baseline period followed by a 4-week titration period and a 12-week maintenance period. Patients initially received levetiracetam 1000 mg/day (administered bid) and could increase to 2000 mg/day after 2 weeks, and to 3000 mg/day after another 2 weeks, to obtain adequate seizure control. During the 12-week maintenance period, the dose of levetiracetam could not be increased but could be decreased once if tolerability warranted. Seizure count and adverse events were recorded by patients in a diary. Quality of life and global evaluation of disease evolution were also evaluated. RESULTS: Ninety-nine patients were enrolled and 91 completed the study. A steady dose was maintained over the last 8 weeks of treatment or longer in 84 patients, with 89.3% of these patients receiving 3000 mg/day, 9.5% receiving 2000 mg/day, and 1.2% receiving 1000 mg/day. A 35.9% median percent reduction from baseline in weekly frequency of partial-onset seizures was observed over the entire treatment period. The median partial-onset seizure count decreased from 2.3 per week during the baseline period to 1.3 per week over the treatment period. A total of 42.4% of patients were responders (> or = 50% reduction from baseline in weekly seizure frequency) over the treatment period; two patients were seizure-free from the first day of treatment throughout the treatment period. The most frequent drug-related adverse events were fatigue (27.3% of patients), somnolence (11.1%), headache (8.1%), and dizziness (8.1%). CONCLUSION: Levetiracetam as add-on therapy at doses up to 3000 mg/day effectively reduced the frequency of partial-onset seizures in patients with refractory epilepsy and was well-tolerated in this study, bridging conditions of placebo-controlled clinical trials and clinical practice.     

Rufinamide as an adjuvant treatment in children with Lennox-Gastaut syndrome

PurposeTo evaluate the efficacy of rufinamide as an add-on treatment in children and adolescents with Lennox-Gastaut syndrome (LGS).MethodsThe study was an open-label, observational clinical trial of rufinamide as an add-on treatment in intractable LGS patients. This intent-to-treat trial included 4 weeks of scheduled titrated doses and a 12-week maintenance phase with a target dose of 20–40 mg/kg rufinamide, adjusted according to its effectiveness and tolerability after a baseline period of 4 weeks. The primary outcome was measured by the seizure-reduction rate according to individual seizure type over the 12-week maintenance period.ResultsOne hundred and twenty-eight patients with LGS who were determined to be unresponsive to one or more antiepileptic drugs or dietary therapy were enrolled. Of the 128 patients enrolled, 112 (87.5%) completed the study. After add-on rufinamide treatment, 46 patients (35.9%) achieved a more than 50% reduction in seizure frequency and 10 (7.8%) patients became seizure-free. When we identified those who responded with an at least 50% reduction in seizure frequency, 39.4% of the responders reported reductions in convulsive seizures, 36.4% in drop attacks, 33.3% in myoclonic seizures, and 20.0% in epileptic spasms. Overall, 32.8% of patients reported adverse effects, which were mostly mild and transient in nature. The most common adverse effects were fatigue (15 patients, 11.7%) and poor appetite (9 patients, 7.0%). Twenty-one (16.4%) patients experienced an increased seizure frequency.ConclusionsRufinamide appears to be a safe and effective adjuvant treatment for many cases of intractable LGS.     

Vigabatrin as Initial Therapy for Infantile Spasms: A European Retrospective Survey

Purpose: The efficacy and tolerability of vigabatrin (VGB) as an add-on therapy in the treatment of infantile spasm (IS) prompted physicians to explore its use as the first drug in this seizure type. Methods: Our retrospective study included 250 infants diagnosed with IS; the data obtained were subjected to peer-group review. Of this infant population, 192 infants were considered to have classic IS and had received VGB as their first treatment for the spasms. There was a slight preponderance of boys (57%) in this population. Mean age of IS onset was 5.8 months; 60% had typical hypsarrhythmia. Results: Initial suppression of spasms was obtained in 68% of infants with a median time to response of 4 days at an average VGB dose of 99 mg/kg/day. The best response was seen in those infants with tuberous sclerosis (96% response) and in those younger than 3 months at onset of spasms (90% response). Of these infants, 43 (22%) of 192 subsequently had other types of seizures, and a recurrence of infantile spasms occurred in 28 (21%) of 131 responders. At the end of this study, 96 of 192 infants who could be evaluated were seizure free with VGB monotherapy. Treatment appeared to be well tolerated, with only 33 (13%) infants with adverse events, of which the most common were somnolence (15 patients) and hyper-kinesia (eight patients). In only two cases did adverse events require VGB withdrawal. Conclusion: This study supports the opinion that VGB may be considered an initial treatment for IS regardless of cause.     

Levetiracetam in refractory pediatric epilepsy

Levetiracetam, one of the newer-generation antiepilepsy drugs, is not currently approved for use in children. Given its favorable efficacy, pharmacokinetic, and, particularly, safety profile in adults, we felt that it may be a useful antiepilepsy drug for children with refractory epilepsy. We treated 39 patients (mean age 8.6 years) with open-label levetiracetam for up to 9 months. Seizure frequency, drug dosages, adverse events, and neurologic examinations were documented at baseline and routine follow-up visits. Levetiracetam, as add-on therapy, was effective in reducing seizure frequency in a variety of seizure types but was most effective for partial-onset seizures. Fourteen patients were discontinued for lack of efficacy or adverse events. Ten patients reported improvements in cognition or behavior. Levetiracetam was generally effective and well tolerated in this open-label study. Its apparent positive effects on cognition in some patients are encouraging. Large, well-controlled studies are needed to fully define levetiracetam's potential in children with refractory epilepsy.     

Long-term safety and efficacy of gabapentin (neurontin) as add-on therapy in patients with refractory partial seizures

In an international, multicenter, open-label study, the long-term efficacy and safety of gabapentin (GBP, Neurontin) as add-on therapy were investigated in 203 patients with partial seizures refractory to standard antiepileptic drugs (AEDs). All patients enrolled in this study had experienced improved seizure control with GBP in one of four previous, short-term studies. Patients received mean GBP dosages of 1,283 to 2,220 mg/day for periods of ⩽1,894 days (mean, 385 days). For purposes of efficacy analyses, data were divided into 12-week treatment periods. During long-term treatment, the efficacy of GBP was shown to be maintained by several primary efficacy measures. In all of the 12-week treatment periods, the percentage of change in seizure frequency from baseline was equal to or less than −24%, responder rate was >35%, and response ratio ranged between −0.2 and −0.338. Results for secondary efficacy measures also indicated that efficacy was maintained. The favorable safety profile of GBP also was maintained during long-term treatment. Our results suggest that GBP is an effective, safe, and well-tolerated add-on treatment for long-term use in patients with partial seizures refractory to standard AEDs.     

The SKATE study: an open-label community-based study of levetiracetam as add-on therapy for adults with uncontrolled partial epilepsy

The Safety of Keppra as Adjunctive Therapy in Epilepsy (SKATE) study aimed to evaluate the safety and efficacy of levetiracetam (Keppra, LEV) as add-on therapy for refractory partial seizures in clinical practice. This Phase IV, 16-week, open-label study recruited patients > or =16-year old with treatment-resistant partial seizures. LEV (1000 mg/day) was added to a stable concomitant antiepileptic drug regimen. LEV dosage was adjusted based on seizure control and tolerability to a maximum of 3000 mg/day. 1541 patients (intent-to-treat population) were recruited including 1346 (87.3%) who completed the study and 77.0% who declared further continuing on LEV after the trial. Overall, 50.5% of patients reported at least one adverse event that was considered related to LEV treatment. The most frequently reported drug-related adverse events were mild-to-moderate somnolence, fatigue, dizziness and headache. Serious adverse events considered related to LEV occurred in 1.0% of patients. 7.5% of patients reported adverse events as the most important reason for study drug discontinuation. The median reduction from baseline in the frequency of all seizures was 50.2%; 15.8% of patients were seizure free; 50.1% had seizure frequency reduction of > or =50%. At the end of the study, 60.4% of patients were considered by the investigator to show marked or moderate improvement. There was a significant improvement in health-related quality of life as assessed with the QOLIE-10-P (total score increasing from 55.6 to 61.6; p<0.001). This community-based study suggests that LEV is well tolerated and effective as add-on therapy for refractory partial seizures in adults. These data provide supportive evidence for the safety and efficacy of LEV demonstrated in the pivotal Phase III placebo-controlled studies.     

Randomized, Double-Blind, Placebo-Controlled, Clinical Trial of D-α-Tocopherol (Vitamin E) as Add-on Therapy in Uncontrolled Epilepsy

Summary: In a double-blind, cross-over trial, vitamin E, and placebo were compared as add-on therapy in 43 patients with uncontrolled epilepsy. The study consisted of a 3-month baseline period followed by two treatment phases of vitamin E or placebo with cross-over to the second phase after 3 months. No significant side effects were noted during the study. Mean seizure frequency in the baseline period was 15.9 ± 10.5 as compared with 11.8 ± 10.9 during the placebo phase and 13.7 ± 11.1 during the vitamin E phase. No significant change in seizure frequency was observed with vitamin E as compared with placebo (p > 0.1). Similar observation was noted in subgroups with generalized seizures (n = 25), partial with secondarily generalized seizures (n = 11), or complex partial seizures (CPS) (n = 7). This study did not corroborate the earlier claims of therapeutic efficacy of vitamin E as add-on therapy in refractory epilepsy in adults.     

Use of the modified Atkins diet in infantile spasms refractory to first-line treatment

This prospective, open label, uncontrolled study was performed to evaluate the efficacy and tolerability of the modified Atkins diet in children with refractory infantile spasms. Fifteen consecutive children aged six months to three years having daily infantile spasms in clusters with electroencephalographic evidence of hypsarrhythmia despite treatment with hormonal treatment (oral corticosteroids/adrenocorticotrophic hormone) and/or vigabatrin, and at least one additional anti-epileptic drug were enrolled. Children with known or suspected inborn errors of metabolism or systemic illnesses were excluded. Carbohydrate intake was restricted to ten grams/day. Among these 12 boys and three girls (median age-24 months), 13 had symptomatic etiology. After three months of diet, six children were spasm free. The time to spasm freedom after diet initiation ranged from two days to two months. The most frequent adverse effect observed was constipation. The modified Atkins diet was found to be effective and well tolerated in children with refractory infantile spasms (ClinicalTrials.gov identifier: NCT01006811).     

Randomised, placebo-controlled study of vigabatrin as first-line treatment of infantile spasms

PURPOSE: Vigabatrin (VGB) has been shown to be an effective drug in the treatment of infantile spasms (West syndrome) in predominantly retrospective and open but also in prospective studies. This prospective, randomised, and placebo-controlled trial of VGB in infantile spasms was considered to be justified and feasible to confirm or refute these previous findings. METHODS: Forty children with newly diagnosed infantile spasms received either VGB or placebo for 5 days in a double blind, placebo-controlled, parallel-group study, after which all the infants continuing in the study were treated openly with VGB for a minimum of 24 weeks. RESULTS: Compared with baseline, at the end of the double-blind phase, the patients treated with VGB had a 78% (95% confidence interval, 55-89%) reduction in spasms compared with 26% (-56-65%) in the group treated with placebo (p = 0.020). Seven VGB-treated patients and two placebo-treated patients were spasm free on the final day of the double-blind period (p = 0.063). At the end of the study, 15 children (38% of the original 40 patients or 42% of the 36 patients who entered the open phase) were spasm free with VGB monotherapy. No patient withdrew from the study because of an adverse event. CONCLUSIONS: This unique randomized, placebo-controlled study is the first to demonstrate the efficacy of a specific drug in the treatment of West syndrome and supports the results of previously published open and prospective trials. It further confirms that VGB could be considered as the drug of first choice in treating infantile spasms.     

Registry initiated to characterize vision loss associated with vigabatrin therapy

The vigabatrin patient registry was implemented in August 2009 in conjunction with Food and Drug Administration approval of vigabatrin. All US vigabatrin-treated patients must enroll in the registry. Data on prescriber specialty/location, patient demographics, and clinical characteristics are collected. Benefit-risk assessments are required early in the course of therapy. Vision assessments are required at baseline (≤ 4 weeks after therapy initiation), every 3 months during therapy, and 3 to 6 months after discontinuation. As of February 1, 2011, 2473 patients (1500 with infantile spasms, 846 with refractory complex partial seizures, 120 with other diagnoses) had enrolled; 30.4% were previously exposed to vigabatrin. Kaplan-Meier analysis of time in registry indicated that 83 and 97% of all enrolled patients with refractory complex partial seizures and infantile spasms remained beyond 3 and 1 month, respectively. The ongoing registry will provide visual status and other information on vigabatrin-treated patients for both the infantile spasm and refractory complex partial seizure indications.     

Long-term safety and efficacy of zonisamide in patients with refractory partial-onset epilepsy

Objectives –  To investigate whether zonisamide remains effective and well tolerated in the treatment of refractory partial epilepsy during long-term treatment and with flexible dosing in clinical practice.
Materials and methods –  Patients with refractory partial epilepsy who completed a fixed-dose, randomized, double-blind clinical trial were recruited in an open-label extension study with adjustment of zonisamide and other antiepileptic drug dosage according to the treating physician's usual clinical practice.
Results –  An intention-to-treat analysis of 317 patients showed that zonisamide was well tolerated with a predictable safety profile. Patient retention rates at 1, 2 and 3 years were 65.3%, 44.5% and 28.8%, respectively. Zonisamide treatment was associated with a maintained reduction in seizure frequency, with some patients achieving prolonged periods of seizure freedom.
Conclusions –  Flexible dosing with zonisamide demonstrated a good safety profile and sustained efficacy in the long-term adjunctive treatment of refractory partial epilepsy.     

Efficacy and tolerability of levetiracetam 3000 mg/d in patients with refractory partial seizures: a multicenter, double-blind, responder-selected study evaluating monotherapy. European Levetiracetam Study Group

PURPOSE: To evaluate the efficacy and tolerability of levetiracetam (LEV) monotherapy in selected patients with refractory partial seizures. METHODS: In this multicenter, double-blind, placebo-controlled, parallel-group, responder-selected study, patients were randomized (2:1 ratio) to receive oral LEV 1500 mg twice daily or placebo during a 12-week add-on phase. Treatment responders (patients with a reduction in partial seizure frequency of 50% or more compared with baseline) entered a monotherapy phase that included a maximum 12-week down-titration period and 12 weeks of monotherapy at 1500 mg twice daily. In both phases, responder rate, seizure frequency, and adverse events were analyzed. RESULTS: A total of 286 patients (placebo, n = 105; LEV, n = 181) entered the add-on phase, and 86 patients (placebo, n = 17; LEV, n = 69) were eligible for the monotherapy phase. Thirty-six of 181 patients (19.9%) who received LEV completed the entire study compared with only 10 of 105 patients (9.5%) in the placebo group (p = 0.029). The odds of completing the study on LEV were 2.36 times (95% confidence interval, 1.08, 5.57) higher than on placebo. The responder rate during the add-on phase was significantly higher in the LEV group compared with the placebo group (42.1% vs. 16.7%, respectively; p < 0.001). In the LEV monotherapy group, the median percent reduction in partial seizure frequency compared with baseline was 73.8% (p = 0.037), with a responder rate of 59.2%. Nine patients (18.4%) remained seizure-free on LEV monotherapy. CONCLUSIONS: Conversion to LEV monotherapy (1500 mg twice daily) is effective and well tolerated in patients with refractory partial seizures who responded to 3000 mg/d LEV as add-on therapy.