Felbamate in the Treatment of Lennox-Gastaut Syndrome: Results of a 12-Month Open-Label Study Following a Randomized Clinical Trial

Summary: Felbamate (FBM) is a new antiepileptic drug (AED) that has been evaluated in partial seizures and in the Lennox-Gastaut syndrome (LGS). When tested against placebo in an add-on, randomized, double-blind trial in 73 children with LGS, FBM significantly reduced the frequencies of astatic (atonic) seizures and generalized tonic-clonic seizures plus total seizure counts. In addition, FBM-treated subjects improved significantly on a parent-rated global evaluation and had fewer injuries. Overall, ˜50% of subjects experienced a 50% or greater reduction in total seizure frequency and a dose-response relationship was apparent. The improvement that occurred in the double-blind study has been sustained for at least 12 months in subsequent open-label follow-up studies. In the first month of FBM treatment, 62% of the subjects who had previously received placebo had a reduction in total seizure frequency of >50%. By the 12-month follow-up point, approximately half of the patients had a 50% reduction in total seizure count. Astatic seizures responded even better, with two-thirds of patients having a reduction of >50% in astatic seizure frequency after 12 months of treatment. Based on adverse experience reports thus far, FBM appears to be well tolerated. FBM is the first drug to be shown effective in the LGS in randomized controlled trials. Although few subjects with LGS became seizure free, the frequency of the most severe seizure types decreased and the patients' global functioning improved.     

The efficacy of felbamate as add-on therapy to valproic acid in the Lennox-Gastaut syndrome

We studied the efficacy of felbamate (FBM) in combination with valproic acid (VPA) in 13 patients with the Lennox-Gastaut syndrome and evaluated the contribution of each drug. Following stabilization on VPA monotherapy, FBM or placebo titration was performed for two observation periods lasting 7 weeks with a washout period between them. 6-h video-electroencephalography was recorded following each observation period. In addition to examining the effects of the drugs with parental reports and video-EEG, we compared video-EEG data with families' seizure reports. Based on parental counts for the 7-week observation periods, patients had 40% fewer drop attacks (p < 0.03, Wilcoxon rank sum test) and 60% fewer total seizures (p < 0.02) on VPA and FBM. VPA level rose by 12.7% when FBM was added (p < 0.01). When the effect of FBM was factored out, VPA had a significant effect on drop attack frequency, although not total number of seizures. FBM's therapeutic effect on drop attacks is due in part to increased VPA levels, although the combination may be synergistic for the effect on total seizure number.     

The long-term use of felbamate in children with severe refractory epilepsy.

The aim of the study was to assess the efficacy and safety of felbamate (FBM) as add-on therapy in pediatric patients with severe uncontrolled seizures during a 3-year follow-up. Thirty-six patients were enrolled between February 1994 and February 1997. Patients suffered from partial epilepsy (n=13), Lennox-Gastaut syndrome (LGS) (n=9), infantile spasms (IS) n=8 or other forms of generalized epilepsy (n=6). FBM was titrated weekly from 15 up to 45 mg/kg. By February 1995, all patients had hematological and biochemical monitoring prior to FBM therapy and every 15 days during the study. The results achieved at different treatment durations were analyzed. Overall efficacy measured as > or =50% reduction in seizure frequency varied during follow-up: 69% at 3 months, progressively decreasing to 66% at 6 months, to 47% at 1 year and 41% of the initial cohort at the end of the study. Most frequent side effects were anorexia, weight loss, urinary retention, somnolence, nervousness and insomnia. FBM controlled a broad spectrum of otherwise refractory seizures. Best results were obtained against simple partial seizures with or without secondary generalization, tonic and atonic seizures. A substantial improvement in seizure control was maintained in one-third of the patients for at least 3 years.     

Felbamate in the Treatment of Refractory Partial-Onset Seizures

Summary: Felbamate (FBM) is a new antiepileptic drug (AED) that has been tested in open and controlled studies in patients with therapy-refractory partial-onset seizures. Proof of efficacy is based on results of five controlled studies (three with polytherapy and two with monotherapy). In two of the three polytherapy studies, a classic placebo crossover design was used. The third study used a novel design evaluating the efficacy of FBM in a placebo-controlled parallel design in patients completing an evaluation for epilepsy surgery. The primary efficacy variable in this study was the number of patients who experienced a fourth seizure before the end of the study. Forty-six percent of patients randomized to FBM stopped treatment prematurely because of the occurrence of a fourth seizure compared with 88% randomized to placebo. Two studies investigating the efficacy in monotherapy were performed. Both studies used an identical trial design comparing FBM with a low dosage of valproate (VPA). The efficacy of FBM was found to be superior to the low-dosage VPA for both studies. Open long-term follow-up studies have confirmed the long-term efficacy of FBM for up to 12 months. Overall, FBM was well tolerated in both poly- and monotherapy.     

Felbamate: Successful Development of a New Compound for the Treatment of Epilepsy

Summary: Felbamate (FBM) is an effective and safe novel antiepileptic drug (AED) for add-on treatment in adults with refractory partial seizures as shown in three pivotal controlled trials. In addition, FBM is effective and safe in monotherapy in adults with refractory partial seizures. FBM is also effective and safe as add-on therapy for children and adults with refractory Lennox-Gastaut syndrome. The effective daily dosage is ˜30–45 mg/kg divided into three or four doses with resulting plasma concentrations of 50–80 mg/L. The safety profile of FBM is limited to mild gastrointestinal complaints, insomnia, and nonspecific CNS symptoms. Six pivotal controlled trials, with both classic and innovative design, showed that FBM is a useful AED.     

A double-blind, randomized trial of topiramate in Lennox-Gastaut syndrome. Topiramate YL Study Group.

OBJECTIVE: To evaluate the efficacy and safety of topiramate as adjunctive therapy for Lennox-Gastaut syndrome in a multicenter, double-blind, placebo-controlled trial. BACKGROUND: Conventional antiepileptic drugs are frequently ineffective against multiple-seizure types of Lennox-Gastaut syndrome. METHODS: Ninety-eight patients >1 year to <30 years of age, with slow spike-and-wave patterns on EEG, seizure types including drop attacks, and either a history of or active atypical absence seizures, were assigned to an 11-week, double-blind treatment phase with either topiramate or placebo. Topiramate was titrated to target doses of approximately 6 mg/kg/d. RESULTS: For drop attacks, the most severe seizures associated with this syndrome, the median percentage reduction from baseline in average monthly seizure rate was 14.8% for the topiramate group and -5.1% (an increase) for the placebo group (p = 0.041). Topiramate-treated patients demonstrated greater improvement in seizure severity than did placebo-treated patients based on parental global evaluations (p = 0.037). The percentage of patients with a > or = 50% reduction from baseline in major seizures (drop attacks and tonic-clonic seizures) was greater in the topiramate group (15/46 or 33%) than in the control group (4/50 or 8%; p = 0.002). The most common adverse events in both groups were CNS related; there were no discontinuations from topiramate therapy due to adverse events. CONCLUSIONS: Topiramate adjunctive therapy was effective in reducing the number of drop attacks and major motor seizures and in improving seizure severity as determined by parental global evaluation.     

Felbamate Monotherapy: Implications for Antiepileptic Drug Development

Summary: We studied the effect of felbamate (FBM) monotherapy on seizure rate in patients with partial and secondarily generalized seizures undergoing presurgical monitoring at a single site. The study design was a double-blind placebo-controlled parallel monotherapy trial. Forty patients whose seizures had not been controlled by standard antiepileptic drugs (AEDs) were randomized. Seizure type was confirmed by video-EEG monitoring. All baseline AEDs were discontinued, and patients were drug-free for 5.3 ± 2.4 days before randomization to FBM or placebo. After a 4-day titration, seizures were counted for 14 days. Patients receiving FBM had significantly lower seizure rates, whether all randomized patients, patients who survived titration, or study completers were compared. Eight of 19 placebo patients randomized to placebo, as compared with 13 of 21 receiving FBM, completed the 18-day study. Two FBM patients dropped out due to seizures, and 6 dropped out due to side effects, including anxiety, difficulty sleeping, abdominal discomfort, acute psychosis, and orobuccal dyskinesias. Ten placebo patients met the criteria for premature discontinuation owing to seizures, and 1 had an episode of panic. There was no evidence of hepatic or hematologic toxicity. FBM reduces seizure frequency in patients with localization-related epilepsy.     

A comparison of seizure outcome after callosotomy in patients with Lennox-Gastaut syndrome and a positive or negative history for West syndrome.

PURPOSE: This retrospective study was designed to clarify the role of West syndrome in post-callosotomy seizure outcome in patients with Lennox-Gastaut syndrome. METHODS: From September 1989 to May 1999, 74 patients diagnosed with Lennox-Gastaut syndrome received anterior corpus callosotomy at Taipei Veterans General Hospital, Taiwan. All patients were followed for more than 4 years after surgery. Among them, 21 (28.4%) patients had a history of West syndrome (Group A) whereas 53 (71.6%) patients did not have a history of West syndrome (Group B). Postoperative seizure outcome was compared for these two patient groups. RESULTS: A total of 16 (76.2%) patients in Group A (positive history) and 29 (54.7%) patients in group B (negative history) achieved significant improvement in seizures after surgery (e.g., seizure reduction of more than 50%). There was no statistical significance (p=0.088) in the difference in outcome between the two groups. CONCLUSIONS: A history of West syndrome does not appear to influence post-callosotomy seizure outcome in patients with Lennox-Gastaut syndrome.     

Efficacy and tolerability of adjunctive brivaracetam in adults with uncontrolled partial‐onset seizures: A phase IIb,randomized, controlled trial

Purpose: To evaluate the efficacy and tolerability of adjunctive brivaracetam (BRV), a novel high‐affinity synaptic vesicle protein 2A ligand that also displays inhibitory activity at neuronal voltage‐dependent sodium channels, in adult epilepsy patients with uncontrolled partial‐onset seizures. Methods: A phase IIb, double‐blind, randomized, placebo‐controlled, parallel‐group, dose‐ranging study (N01114; NCT00175929) was conducted in patients aged 16–65 years. To be included in the study, patients were required to have experienced four or more partial‐onset seizures during a 4‐week prospective baseline, despite treatment with 1–2 concomitant antiepileptic drugs. Patients were randomized in a ratio of 1:1:1 to receive BRV 50 mg/day (BRV50), 150 mg/day (BRV150), or placebo. A 3‐week up‐titration period was followed by a 7‐week maintenance period (total treatment period of 10 weeks). Key Findings: A total of 157 patients were randomized (intent‐to‐treat [ITT] population; BRV50 n = 53, BRV150 n = 52, placebo n = 52) and overall 148 (94.3%) completed the study. The percent reduction in baseline‐adjusted partial‐onset seizure frequency/week over placebo during the 7‐week maintenance period (primary efficacy outcome) did not reach statistical significance (14.7% for BRV50 [p = 0.093] and 13.6% for BRV150 [p = 0.124]). However, during the entire 10‐week treatment period a statistically significant difference was observed for both BRV groups (17.7% for BRV50 [p = 0.026] and 16.3% for BRV150 [p = 0.043]). The median percent reduction from baseline in partial‐onset seizure frequency/week during the maintenance period was 38.2% for BRV50 (p = 0.017) and 30.0% for BRV150 (p = 0.113) versus 18.9% in the placebo group. During the treatment period, this was 34.9% for BRV50 (p = 0.004) and 28.3% for BRV150 (p = 0.070) compared with 16.3% for placebo. Fifty percent responder rates during the maintenance period were 23.1% for placebo compared with 39.6% for BRV50 (odds ratio [OR] 2.17, p = 0.077) and 33.3% for BRV150 (OR 1.66, p = 0.261). During the treatment period, 50% responder rates were 17.3% for placebo compared with 35.8% for BRV50 (OR 2.69, p = 0.038) and 30.8% for BRV150 (OR 2.15, p = 0.114). Nine patients were free from partial‐onset seizures during the 10‐week treatment period (five patients [9.4%] in the BRV50 group and three [5.8%] in the BRV150 group compared with one patient [1.9%] in the placebo group). Treatment‐emergent adverse events (TEAEs) reported during the treatment period were mostly mild‐to‐moderate with similar incidence across treatment groups (BRV50 36/53, 67.9%; BRV150 35/52, 67.3%; placebo 37/52, 71.2%). The most frequently reported TEAEs in BRV groups were headache, fatigue, nasopharyngitis, nausea, somnolence, and dizziness, although nausea had a higher incidence in the placebo group. Significance: In this double‐blind, placebo‐controlled, phase IIb study of adjunctive BRV (50 and 150 mg/day) in adults with uncontrolled partial‐onset seizures, the primary efficacy analysis did not reach statistical significance; however, statistically significant differences compared with placebo were observed on several secondary efficacy outcomes. BRV was well tolerated.     

Felbamate in the Treatment of Partial-Onset Seizures

Summary: Felbamate (FBM, Felbatol/Taloxa) has been the object of several trials that are innovative and unique. First, FBM is the first antiepileptic drug (AED) to have been submitted to a controlled efficacy study in patients with the Len-nox-Gastaut syndrome (LGS) before being submitted for regulatory approval. Second, FBM was tested in patients discontinued from other AEDs for presurgical monitoring. Third, FBM was the first experimental AED to have been tested in controlled monotherapy trials. Overall, these studies succeeded in demonstrating that FBM is relatively safe and effective against both partial-onset seizures and the generalized seizures occurring in the LGS. The results of some of these studies could not always be expressed by using the more familiar concept of percent seizure reduction because, for ethical reasons, the efficacy variable had to be defined in terms of time to the n^lh seizure or in terms of escape criteria. This may make it more difficult to evaluate just how effective FBM is in comparison with other AEDs. Another reason why the efficacy of FBM cannot yet be fully assessed is that in all the studies the FBM dosage was limited to a maximum of 3,600 mg/day or 45 mg/kg/day. At this dosage, FBM produced no toxicity in the majority of patients, and its full therapeutic effect may have to be re-evaluated in the future at higher dosages.     

The Efficacy of Lamotrigine in Children and Adolescents with Refractory Generalized Epilepsy: A Randomized, Double-Blind, Crossover Study

Summary: Purpose: We report a double-blind, placebo-controlled crossover study of lamotrigine (LTG) as add-on treatment in therapy-resistant, generalized epilepsy in children and adolescents (n = 30).
Methods: Twenty patients had Lennox-Gastaut syndrome. Each patient acted as his or her own control. LTG and placebo were randomly added to existing antiepileptic medication (AEDs). The LTG dosage was individualized in an open phase preceding the placebo/treatment phase. Patients who responded to LTG in the open phase went on to the double-blind phase. "Responders" were defined as patients with a >50% seizure reduction or less severe seizures or both, or improved behavior or improved motor skills or both. "Nonresponders" were defined as children who showed no positive effects of LTG with plasma levels of 10 μg/ml or children who had adverse events during the open phase.
Results: There was a clear statistically significant reduction of seizure frequency in LTG compared with placebo treatment. None of the children studied showed abnormal biochemical or hematologic findings, or changes in plasma levels of concomitantly administered AEDs.
Conclusions: LTG is a well-tolerated and effective treatment in children with intractable generalized epilepsies, including those with Lennox-Gastaut syndrome. The study design allowed a double-blind placebo-controlled assessment of LTG although the participating children used 19 different AED combinations at entry.     

拉莫三嗪治疗Lennox-Gastaut综合征的临床观察

应用拉莫三嗪添加、开放性自身对照法观察Lennox-Gastaut综合征患者8例,观察时间为3～31个月。结果:应用LTG后,2例患者(25%)癫痫发作停止,4例患者(50%)癫痫发作减少大于75%,总有效率75%。LTG对Lennox-Gastaut综合征的各型癫痫发作均有较好效果,脑电图有改善的倾向。部分患者应用LTG治疗后生活质量有一定的改善。副作用少。治疗前后各项实验室检查未见有临床意义的异常改变。     

Felbamate: A Clinical Trial for Complex Partial Seizures

We performed a randomized, double-blind, three-period cross-over study of felbamate (FBM, 2-phenyl-1,3-propanediol dicarbamate: Carter-Wallace 554) in patients with complex partial seizures. Patients continued carbamazepine (CBZ) throughout the study and were observed in the hospital for the entire trial period. The entry criteria required at least six seizures in a 3-week baseline period (and no more than 1 week with a single seizure) with CBZ alone. Thirty subjects were randomized. Two left the study after randomization, 1 owing to seizure exacerbation, and 1 owing to hyponatremia, which may have been related to CBZ therapy. The daily dosage of 50 mg/kg (maximum 3,000 mg) FBM per day was well tolerated by all 28 patients who completed the study. Only mild adverse experience were observed during the trial. FBM reduced CBZ level (p less than 0.0001; 95% confidence interval -28%, -20%). There was no significant difference in seizure frequency between placebo and FBM periods (one-sided p = 0.172), but when a correction was made for the lower CBZ level noted during FBM periods, the data suggested a strong antiseizure effect of FBM.     

Nitrazepam for the treatment of Lennox-Gastaut syndrome

Lennox-Gastaut syndrome is a severe childhood epileptic syndrome with encephalopathy and multiple seizure types, which are often intractable to treatment. Most of these children will ultimately become mentally retarded and dependent on others for their daily care. Antiepileptic drugs are the mainstay of treatment, however, no particular drug is entirely effective. Apart from the use of antiepileptic drugs, nonpharmacologic treatments are also considered (i.e., callosotomy, ketogenic diet, and vagus nerve stimulation), which have proven to be partially effective. We prospectively studied 14 children (11 months-8 years of age) with medication-resistant Lennox-Gastaut syndrome, being treated with nitrazepam (open-label compassionate protocol). We compared the 1-month baseline seizure frequency with the median seizure rate reduction during the first 12 months of treatment with nitrazepam. The median seizure rate reduction during the first 12 months of treatment with nitrazepam was 41% (P = 0.001), with more than 50% seizure reduction in 60% of patients. Two patients became seizure free, five patients demonstrated at least 50% reduction in seizure rates, six patients had at least 25% seizure rate reduction, and one patient did not respond. No patient had any serious adverse effects. Side effects included sedation in six children (40%) and drooling in nine patients (60%).     

Efficacy and safety of dexmethylphenidate extended-release capsules in children with attention-deficit/hyperactivity disorder

OBJECTIVE: The efficacy and safety of dexmethylphenidate extended release (d-MPH-ER) was compared to placebo in pediatric patients with attention-deficit/hyperactivity disorder (ADHD). METHOD: This multicenter, randomized, double-blind, placebo-controlled, parallel-group, two-phase study included 97 patients (ages 6-17 years) with DSM-IV-defined ADHD. The study was carried out between 2001 and 2003. After a 2-week evaluation phase, patients were randomized to d-MPH-ER or placebo for 7 weeks. Flexible d-MPH-ER dosing (30 mg/day) was permitted for 5 weeks, then patients remained on their optimal dose during the last 2 study weeks. The primary efficacy measure was change from baseline to final rating in Conners ADHD/DSM-IV Scale-Teacher version (CADS-T) total subscale score. Secondary efficacy variables included changes from baseline to final visit in CADS-T Inattentive and Hyperactive-Impulsive subscale scores, CADS-P DSM-IV total subscale score and Inattentive and Hyperactive-Impulsive subscale scores, Clinical Global Impressions-Improvement (CGI-I) and CGI-Severity (CGI-S) scale scores, and Child Health Questionnaire Parent Form 50 scores. RESULTS: d-MPH-ER improved CADS-T total scores significantly compared with placebo (p <.001), and 67.3% of d-MPH-ER patients were rated much improved or very much improved on CGI-I at final visit versus 13.3% of placebo patients (p <.001). More patients taking d-MPH-ER (49.1%) than placebo (25.5%) spontaneously reported adverse events suspected as drug related. CONCLUSIONS: Once-daily d-MPH-ER was more effective than placebo in the treatment of ADHD in children and adolescents.     

Role of rufinamide in the management of Lennox-Gastaut syndrome (childhood epileptic encephalopathy)

Rufinamide, a triazole derivative that is structurally distinct from currently marketed antiepileptic drugs (AEDs), is in development for the adjunctive treatment of Lennox-Gastaut syndrome (LGS) in children and adults. Rufinamide is well absorbed after oral administration, demonstrates low protein binding, and is metabolized by enzymatic hydrolysis without involvement of cytochrome P450 enzymes, conferring a low drug interaction potential. In a randomized, double-blind trial involving 138 adult and pediatric patients with LGS, compared with placebo, rufinamide 45 mg/kg/day resulted in significantly superior reductions in drop attacks (median change −42.5% vs +1.4% with placebo) and total seizures (−32.1% vs −11.7% with placebo), accompanied by significantly higher responder rates. These results are comparable with findings reported for other AEDs in randomized, controlled clinical trials in patients with LGS. Rufinamide produced statistically significant seizure reduction which was maintained during long-term therapy and accompanied by good tolerability. The most frequently reported adverse events from a pooled safety database evaluating short- and long-term therapy were headache (22.9% and 29.5%), dizziness (15.5% and 22.5%) and fatigue (13.6% and 17.7%). Rufinamide therefore presents a favorable efficacy and tolerability profile and is a promising candidate for the adjunctive therapy of LGS.     

Felbamate monotherapy: controlled trial in patients with partial onset seizures.

Felbamate (FBM) monotherapy was evaluated in 44 patients with uncontrolled partial onset seizures in a unique, single-center, randomized, double-blind, parallel-group trial. During the 56-day baseline period, patients were required to have at least 8 seizures and to be receiving only one standard antiepileptic drug (AED) at a therapeutic level; a second AED was allowed if at a subtherapeutic level. Patients were randomized to valproate (VPA), 15 mg/kg, or to FBM, 3,600 mg/day. In the treatment phase, previous AEDs were discontinued by study day 28 (by one-third decrements on study days 1, 14, and 28). Study end points were completion of 112 study days or the fulfilling of escape criteria. Criteria for escape relative to baseline were: two-fold increase in monthly seizure frequency, two-fold increase in highest 2-day seizure frequency, single generalized tonic-clonic seizure (GTC) if none occurred during baseline, or significant prolongation of GTCs. The predetermined primary efficacy variable was the number of patients escaping in each treatment group. Nineteen patients on VPA and 3 on FBM met escape criteria (p less than 0.001, chi-square test). When overall seizure frequency among study completers was compared with baseline, the FBM group had a 50 to 65% reduction in seizure frequency. FBM adverse experiences were all mild or moderate in severity, and the incidence of adverse experiences was lower in monotherapy. FBM monotherapy was effective in the treatment of partial onset seizures with or without generalization and demonstrated a favorable safety profile.     

Evaluation of refractory epilepsy treated with vagus nerve stimulation for up to 5 years

We assessed the long-term efficacy of vagus nerve stimulation (VNS) in 64 refractory epilepsy patients. After implantation, intermittent stimulation was delivered and seizure frequency and severity were counted. Average treatment time was 20 months. Nineteen of 47 patients with partial seizures, five of nine patients with idiopathic generalized seizures, and five of eight patients with Lennox-Gastaut syndrome had >50% seizure reduction. Side effects were mild. VNS is a safe and effective treatment for refractory epilepsy.     

Lacosamide in refractory mixed pediatric epilepsy: a prospective add-on study

Lacosamide is a new antiepileptic drug that is currently approved by the US Food and Drug Administration (FDA) for adults 17 years or older for partial-onset seizures. The authors reviewed 21 pediatric patients (<17 years) with various seizure types who were started on oral lacosamide as part of a prospective add-on study as adjunctive therapy for refractory epilepsy. Five patients were excluded due to less than 3 months of meaningful follow-up. Maintenance dosages used ranged from 2.4 to 19.4 mg/kg/d. Eight of 16 (50%) patients had greater than 50% reduction in seizure frequency with adjunctive lacosamide therapy. Eight (50%) patients had generalized epilepsy including 4 with Lennox-Gastaut syndrome. Lacosamide was effective therapy for most seizure types but was particularly effective for partial-onset seizures. Lacosamide was effective in treating 5 of 8 (62.5%) localization-related epilepsies but only 2 of 8 (25%) generalized epilepsies, both Lennox-Gastaut syndrome patients with greater than 90% seizure reduction. None of these very refractory patients remained seizure free.     

Levetiracetam for partial seizures: results of a double-blind, randomized clinical trial

OBJECTIVE: To evaluate the efficacy and safety of 500 mg bid and 1500 mg bid levetiracetam as adjunctive therapy for refractory partial seizures in a double-blind, randomized, placebo-controlled, parallel-group, multicenter trial. METHODS: The authors studied patients with uncontrolled partial seizures (minimum 12 per 12 weeks), regardless of whether they became secondarily generalized, for 38 weeks. A 12-week baseline was followed by random assignment to adjunctive therapy with placebo (n = 95), levetiracetam 1000 mg/day (n = 98), or levetiracetam 3000 mg/day (n = 101). Upward titration over 4 weeks was followed by 14 weeks of fixed dose treatment, and concluded with an 8-week medication withdrawal period or entering a follow-up study. RESULTS: Of 294 patients randomized, 268 completed the study. Partial seizure frequency during the entire evaluation period (primary efficacy variable) was lower with levetiracetam compared to placebo (p /=10%), mostly mild to moderate in severity, with incidences higher than placebo were asthenia, dizziness, flu syndrome, headache, infection, rhinitis, and somnolence. CONCLUSION: Adjunctive therapy with levetiracetam was effective and well tolerated in controlling partial seizures.