Dose-dependent safety and efficacy of zonisamide: a randomized, double-blind, placebo-controlled study in patients with refractory partial seizures

PURPOSE: To evaluate the safety and efficacy of zonisamide (ZNS) as adjunctive treatment in patients with refractory localization-related epilepsy. METHODS: This was a double-blind, placebo-controlled study of adjunctive ZNS in 351 patients with refractory partial seizures receiving a stable regimen of one to three antiepileptic drugs (AEDs). Patients were randomized to placebo or ZNS, 100 mg, 300 mg, or 500 mg/day (2:1:1:2) after a 12-week baseline. Dose titration was undertaken over a 6-week titration phase, which was followed by an 18-week fixed-dose assessment phase. Primary efficacy parameters were the differences between ZNS, 500 mg/day, and placebo in the change from baseline in frequency of complex partial (CP) seizures during the fixed-dose assessment phase and in the proportion of CP responders (> or =50% decrease from baseline in seizure frequency). Safety and tolerability also were assessed. RESULTS: Compared with placebo, the highest dose of ZNS (500 mg/day) resulted in a significantly greater decrease in CP seizure frequency from baseline (51.2% vs. 16.3%; p < 0.0001) and a significantly higher proportion of CP responders (52.3% vs. 21.3%; p < 0.001). Both ZNS, 500 mg/day, and 300 mg/day were statistically superior to placebo in reducing the frequency of "all seizures" and simple partial (SP) + CP seizures. For all seizures, a significant dose-response relation was observed (p < 0.0001).The most common adverse events were somnolence, headache, dizziness, and nausea during the titration phase and headache and pharyngitis during the fixed-dose assessment phase. CONCLUSIONS: ZNS provides dose-dependent, effective, and generally well-tolerated adjunctive therapy in patients with partial seizures.     

A double-blind, placebo-controlled study of topiramate in adult patients with refractory partial epilepsy

PURPOSE: The efficacy and safety of topiramate (TPM) as adjunctive therapy in the treatment of adult Chinese patients with refractory partial epilepsy were investigated in a randomized, double-blind, placebo-controlled study. METHODS: A total of 46 patients who had four or more complex partial seizures with or without secondary generalization within an 8-week baseline phase were enrolled. Patients were assigned randomly to receive TPM (n = 23) or placebo (n = 23). TPM or placebo was titrated to target doses of 300 mg/d for 6 weeks and maintained at stabilized levels for another 8 weeks. Concomitant antiepileptic drugs remained at constant previous levels during the trial. RESULTS: In all, 41 patients completed the trial (TPM group, n = 20; placebo group, n = 21). The proportion of patients with a > or =50% reduction from baseline in complex partial seizures was 11 of 23 (47.8%) in the TPM group and 3 of 23 (13.0%) in the placebo group (p = 0.01). In addition, patients treated with TPM had significantly better investigator (p = 0.014) and patient (p = 0.0005) global assessment scores than patients in the placebo group. Adverse events were mostly mild and transient, with no significant differences between treatment groups. Two patients with TPM therapy complained of weight loss. Routine blood cell counts and other laboratory results showed no significant changes from baseline in either treatment group. CONCLUSIONS: TPM 300 mg/d is effective and well tolerated as treatment for refractory partial epilepsy in adults.     

Losigamone add-on therapy in partial epilepsy: a placebo-controlled study

OBJECTIVES: To evaluate the efficacy and tolerability of losigamone (LSG). PATIENTS AND METHODS: Double-blind, placebo-controlled add-on study with 3x500 mg LSG/die for the treatment of chronic partial seizures in 203 patients (99 treated with LSG, 104 on placebo). RESULTS: The median percent change of seizures was 14.9% (LSG) versus 6.7% (placebo) (P=0.004). Seizure frequency was decreased by more than 50% in 22.3% (LSG) and 14.6% (placebo) of patients (P=0.13). Mean percent change of seizures was best in patients with only one additional anticonvulsant drug (LSG versus placebo, P=0.004). Adverse events (usually CNS-related side effects of mild to moderate intensity) were reported in 59.6% (LSG) and 37.5% (placebo) of patients. CONCLUSIONS: LSG proved to be an effective and well tolerated anticonvulsant drug for the treatment of chronic partial seizures.     

Efficacy and safety of eslicarbazepine acetate as adjunctive treatment in adults with refractory partial-onset seizures: A randomized, double-blind, placebo-controlled, parallel-group phase III study

Purpose: To study the efficacy and safety of eslicarbazepine acetate (ESL) as adjunctive therapy for refractory partial seizures in adults with ≥4 partial‐onset seizures (simple or complex, with or without secondary generalization) per 4 weeks despite treatment with 1–2 antiepileptic drugs (AEDs). Methods: This multicenter, parallel‐group study had an 8‐week, single‐blind, placebo baseline phase, after which patients were randomized to placebo (n = 102) or once‐daily ESL 400 mg (n = 100), 800 mg (n = 98), or 1,200 mg (n = 102) in the double‐blind treatment phase. ESL starting dose was 400 mg; thereafter, ESL was titrated at weekly 400‐mg steps to the full maintenance dose (12 weeks). Results: Seizure frequency adjusted per 4 weeks over the maintenance period (primary endpoint) was significantly lower than placebo in the ESL 1,200‐mg (p = 0.0003) and 800‐mg (p = 0.0028) groups [analysis of covariance (ANCOVA) of log‐transformed seizure frequency]. Responder rate was 20% (placebo), 23% (400 mg), 34% (800 mg), and 43% (1,200 mg). Median relative reduction in seizure frequency was 16% (placebo), 26% (400 mg), 36% (800 mg), and 45% (1,200 mg). The most frequent concomitant AEDs were carbamazepine (56–62% of patients), lamotrigine (25–27%), and valproic acid (22–28%). Similar efficacy results were obtained in patients administered ESL with or without carbamazepine as concomitant AED. Discontinuation rates caused by adverse events (AEs) were 3.9% (placebo), 4% (400 mg), 8.2% (800 mg), and 19.6% (1,200 mg). AEs in >10% of any group were dizziness, headache, and diplopia. Most AEs were mild or moderate. Discussion: ESL, 800 and 1,200 mg once‐daily, was well tolerated and more effective than placebo in patients who were refractory to treatment with one or two concomitant AEDs.     

Febrile seizures in patients with complex partial seizures

Febrile seizures occurred in 14 of 155 (9%) out-patients with complex partial seizures. Twelve patients had prolonged or recurrent febrile seizures, convulsive status epilepticus or a transient postictal neurological deficit. Febrile seizures were associated with perinatal abnormalities, an earlier onset of epilepsy and with a poor seizure control. Recurrent febrile seizures or those with complicating features are associated with an unfavourable therapeutic outcome in adult patients with complex partial seizures.     

Gabapentin in refractory partial epilepsy — a trial in India

Gabapentin (GBP) has been shown to be effective an add-on drug for the treatment of refractory partial epilepsy. We undertook an open clinical trial to test its efficacy for the first time in India. Twenty-six patients with refractory partial seizures (> 4 per month) were given GBP in a titrated dose and the seizure frequency was noted for 3 months. The mean reduction in seizures was significant: 15.87 (SD = 4.5) vs 5.80 (SD = 10.25). The mean percentage change (PCH) from the baseline was - 36. Twenty-one of 26 (80%) patients had a reduction in the number of seizures, and 13/26 (50%) were identified as responders (> 50% reduction in seizures). The responders were significantly younger than the nonresponders. Adverse events were mild and noted in 46% patients. Although the trial has its limitations, this is probably the first trial of GBP in a developing country.     

Controlled trial of lamotrigine (Lamictal®) for treatment-resistant partial seizures

The antiepileptic effect of lamotrigine (Lamictal®) was assessed in a double-blind, placebo-controlled, crossover trial in 56 adult patients with refractory partial seizures. Lamotrigine or placebo was added to the patients' existing antiepileptic drugs (AEDs). The dose of lamotrigine varied from 75 to 400 mg daily. Thirty-eight patients completed the trial and 7 withdrew because of adverse experiences. There was a statistically significant reduction in seizure counts on lamotrigine compared with placebo for total seizures (30.3% reduction, 95% CI 8.4%, 47.0%), complex partial seizures (29.2.% reduction, 95% CI 3.8%, 47.9%) and secondary generalised seizures (37.9%, CI 18.9%, 52.4%). The analysis of total seizure days showed a similar significant reduction during lamotrigine treatment for the same seizure categories. There was no statistically significant difference in reporting of adverse events between lamotrigine and placebo except for dizziness which was reported more frequently on lamotrigine than on placebo. There were no differences in abnormal haematological or biochemical findings between lamotrigine and placebo, and lamotrigine had no effect on plasma concentrations of concomitant AEDs.     

A randomized, double-blind, placebo-controlled, parallel-group study of rufinamide as adjunctive therapy for refractory partial-onset seizures

Purpose: Efficacy and safety of adjunctive rufinamide (3,200 mg/day) was assessed in adolescents and adults with inadequately controlled partial‐onset seizures receiving maintenance therapy with up to three antiepileptic drugs (AEDs). Methods: This randomized, double‐blind, placebo‐controlled, parallel‐group, multicenter study comprised a 56‐day baseline phase (BP), 12‐day titration phase, and 84‐day maintenance phase (MP). The primary efficacy variable was percentage change in total partial seizure frequency per 28 days (MP vs. BP). Secondary efficacy outcome measures included ≥50% responder rate and reduction in mean total partial seizure frequency during the MP. Safety and tolerability evaluation included adverse events (AEs), physical and neurologic examinations, and laboratory values. Pharmacokinetic and pharmacodynamic assessments were conducted. Results: Three hundred fifty‐seven patients were randomized: 176 to rufinamide and 181 to placebo. Patients had a median of 13.3 seizures per 28 days during BP; 86% were receiving ≥2 AEDs. For the intent‐to‐treat population, the median percentage reduction in total partial seizure frequency per 28 days was 23.25 for rufinamide versus 9.80 for placebo (p = 0.007). Rufinamide‐treated patients were more than twice as likely to have had a ≥50% reduction in partial seizure frequency (32.5% vs. 14.3%; p < 0.001) and had a greater reduction in median total partial seizure rate per 28 days during the MP (13.2 vs. 5.2; p < 0.001). Treatment‐emergent AEs occurring at ≥5% higher incidence in the rufinamide group compared with placebo were dizziness, fatigue, nausea, somnolence, and diplopia. Conclusions: Adjunctive treatment with rufinamide reduced total partial seizures in refractory patients. AEs reported were consistent with the known tolerability profile of rufinamide.     

Double-blind placebo-controlled evaluation of flunarizine as adjunct therapy in epilepsy with complex partial seizures

Flunarizine was compared to placebo in a double-blind cross-over trial of 2 16-week treatment periods separated by a 4-week wash-out period. The patients had epilepsy with complex partial seizures with or without secondary generalised seizures. Twenty-nine patients entered the trial, but 7 dropped out. Of the 22 patients completing the trial, 13 were women; the median was 39 years (range 15-58) and the median duration of epilepsy 23 years (range 4-55). There was no statistically significant difference between flunarizine 15 mg daily and placebo as adjunct therapy in total seizure frequency, neuropsychological tests, and patient's preferences. No interactions with concomitant antiepileptic drugs and no laboratory abnormalities were registered.     

Chronic epilepsy with complex partial seizures is not always medically intractable--a long-term observational study

OBJECTIVE: To study the prognosis of patients with complex partial seizures (CPS) with or without simple partial (SPS) and secondarily generalized tonic-clonic seizures (GTCS) and to analyze the factors related to the degree of medical responsiveness. MATERIAL AND METHODS: A total of 266 adult patients with CPS were included in a hospital based observational survey with a follow-up of 2 to 25 years. Clinical characteristics, seizure frequency, electroencephalography (EEG), cerebral computed tomography (CCT) and magnetic resonance imaging (MRI) findings were analyzed. Patients were categorized according to their degree of medical responsiveness into one of three groups: seizure free, improved control (>50% seizure reduction) and poor control. RESULTS: Mean age at follow-up was 44.7 years (SD 14.7, range 19-93). Mean age at seizure onset was 18.1 years (SD 14.7, median 15, range 1-79). Complete seizure control was achieved in 40%, improved seizure control in 36% and poor seizure control in 24%. Patients entered remission after a mean period of 15.7 years (SD 12.6, median 13, range 1-54) of active epilepsy. A third of all seizure-free patients were still in remission 6.1 years (SD 5.3, median 3.5, range 1-18) after discontinuation of antiepileptic drugs (AED). Patients with poor seizure control had a significantly younger age at onset (P<0.01), a higher initial seizure frequency (more than 3 per month) (P<0.01), abnormal neurological examination (P<0.01), and were more often mentally handicapped (P<0.01). Multiple logistic regression analysis revealed a high initial seizure frequency, mental handicap and an abnormal neurological examination as independent risk factors for poor seizure control. A positive family history, a history of febrile convulsions and/or psychosis, an abnormal EEG or MRI was not predictive of poor outcome. CONCLUSIONS: Not all patients with CPS were medically intractable. Seizure remission can be achieved after a long time of active epilepsy. Poor seizure control was associated with a high initial seizure frequency, mental handicap and abnormal neurological examination.     

Pregabalin for the management of partial epilepsy

Pregabalin is one of the latest antiepileptic drugs introduced for the treatment of partial epilepsy. Its efficacy and safety as adjunctive therapy in refractory partial epilepsy have been established in four double-blind placebo-controlled trials (n = 1396) and 4 long-term open-label studies (n = 1480). In 3 fixed-dose trials, the proportion of patients with a ≥50% reduction in seizure frequency across the effective dose-range (150–600 mg/day) ranged between 14% and 51%, with a clear dose-response relationship. Suppression of seizure activity could be demonstrated as early as day 2. The most frequently reported CNS-related adverse events included dizziness, somnolence, ataxia and fatigue, were usually mild or moderate, and tended to be dose related. In long-term studies, weight gain was reported as an adverse event by 24% of patients. When pregabalin dose was individualized to according to response within the 150 to 600 mg/day dose range, tolerability was considerably improved compared with use of a high-dose, fixed-dose regimen (600 mg/day) without titration. In long-term studies up to 4 years, no evidence of loss efficacy was identified. During the last year on pregabalin, 3.7% of patients were seizure-free. Pregabalin appears to be a useful addition to the therapeutic armamentariun for the management of refractory partial epilepsy.     

Effect of topiramate, in combination with lidocaine, and phenobarbital, in acute encephalitis with refractory repetitive partial seizures

Objective: Acute encephalitis with refractory repetitive partial seizure (AERRPS) is a peculiar type of post-encephalitic/encephalopathic epilepsy. Here we report an analysis of AERRPS in a series of children and propose an effective treatment option for seizure control in these children. Methods: We retrospectively reviewed cases of AERRPS treated in a pediatric intensive care unit, between February 2002 and June 2006. Clinical characteristics were systemically assessed. Burst suppression coma was induced by high-dose suppressive therapy; 24-h electroencephalogram (EEG) monitoring was performed on each patient. The goal of treatment was to achieve complete clinical seizure control or burst-suppression pattern on EEG, aiming for an interburst interval of >5 s. Brain imaging was done for each patient. Results: There were nine patients (seven boys), aged 5–15 years. Clinical symptoms included fever (100%), upper respiratory symptoms (66.7%) and altered consciousness (66.7%). All patients received multiple high-dose suppressive drugs and were intubated with/without inotropic agents. Seizures in three patients were stopped after high-dose lidocaine infusion (6–8 mg/kg/h) in the acute stage and three patients were stopped after high dose phenobarbital (serum level 60–80 ug/mL) combined with high-dose oral topiramate (15–20 mg/kg/day). Follow-up for this study was 16–61 months. Two subjects died while seven developed epilepsy and/or neurologic deficits; none returned to baseline. All survivors were discharged and continued multiple antiepileptic medications. Conclusions: Our data indicates that children with AERRPS have high mortality and morbidity rates. High-dose topiramate combined with high-dose lidocaine infusion or high-dose phenobarbital in the acute stage might be an effective treatment option for children with AERRPS.     

Pregabalin add-on treatment: a randomized, double-blind, placebo-controlled, dose-response study in adults with partial seizures

Summary: Purpose: To evaluate pregabalin (PGB), 150 mg/day, and PGB, 600 mg/day, as an add‐on treatment for patients with refractory partial seizures concurrently treated with one to three anticonvulsants (AEDs). Methods: An international (13 countries), multicenter (45 centers), 12‐week, double‐blind, randomized study in which patients with partial seizures received placebo (n = 96); PGB, 150 mg/day (n = 99); or PGB, 600 mg/day (n = 92); given 3 times a day (t.i.d.). The primary efficacy criterion was reduction in seizure frequency during treatment as compared with baseline, as measured by RRatio, the symmetrical percentage change in seizure rates determined from daily seizure diaries. The RRatio between the 8‐week baseline (pretreatment phase) and the 12‐week treatment period were compared between each of the PGB groups and the placebo group by using an analysis of variance analysis of the intent‐to‐treat population. Results: PGB, 150 mg/day and 600 mg/day, were both significantly more effective than placebo in reducing the RRatio [–11.5 (p = 0.0007) and –31.4 (p ≤ 0.0001), respectively, vs. 0.9]. These RRatio values correspond to seizure‐frequency reductions from baseline of –1.8, 20.6, and 47.8% for placebo, 150 mg/day, and 600 mg/day, respectively. PGB efficacy was significantly dose related (p ≤ 0.0001). Secondary efficacy variables corroborated the findings of the primary analysis. Significantly more patients were responders (≥50% reduction in seizure frequency) in the PGB, 600 mg/day (43.5%), group than in the placebo group (6.2%) (p ≤ 0.001). PGB was well tolerated. Dose‐related, treatment‐emergent adverse events (≥10%), mostly mild or moderate in intensity, were somnolence, dizziness, ataxia, diplopia, and weight gain. The withdrawal rate due to adverse events was 10% of patients at 150 mg/day and 18.5% of patients at 600 mg/day, compared with 6.2% of patients receiving placebo. Conclusions: PGB, 150 mg/day and 600 mg/day, is highly effective and well‐tolerated add‐on therapy in patients with partial seizures.