Randomized controlled trial of zonisamide for the treatment of refractory partial-onset seizures. Dose-dependent safety and efficacy of zonisamide: a randomized, double-blind, placebo-controlled study in patients with refractory partial seizures. Zonisamide for add-on treatment of refractory partial epilepsy: a European double-blind trial. Lamotrigine extended-release as adjunctive therapy for partial seizures. Adjunctive lamotrigine for partial seizures in patients aged 1 to 24 months. Topiramate in medically intractable partial epilepsies: double-blind placebo-controlled randomized parallel group trial. Korean Topiramate Study Group. Low-dose topiramate in adults with treatment-resistant partial-onset seizures. Double-blind placebo-controlled trial of adjunctive levetiracetam in pediatric partial seizures. Zonisamide versus topiramate in migraine prophylaxis: a double-blind randomized clinical trial.
Zonisamide is a sulfonamide antiepilepsy drug with sodium and calcium channel-blocking actions. Experience in Japan and a previous European double-blind study have demonstrated its efficacy against partial-onset seizures.
                A randomized, double-blind, placebo-controlled trial enrolling 203 patients was conducted at 20 United States sites to assess zonisamide efficacy and dose response as adjunctive therapy for refractory partial-onset seizures. Zonisamide dosages were elevated by 100 mg/d each week. The study design allowed parallel comparisons with placebo for three dosages and a final crossover to 400 mg/d of zonisamide for all patients. The primary efficacy comparison was change in seizure frequency from a 4-week placebo baseline to weeks 8 through 12 on blinded therapy.
                At 400 mg/d, zonisamide reduced the median frequency of all seizures by 40.5% from baseline, compared with a 9% reduction (p = 0.0009) with placebo treatment, and produced a > or =50% seizure reduction (responder rate) in 42% of patients. A dosage of 100 mg/d produced a 20.5% reduction in median seizure frequency (p = 0.038 compared with placebo) and a dosage of 200 mg/d produced a 24.7% reduction in median seizure frequency (p = 0.004 compared with placebo). Dropouts from adverse events (10%) did not differ from placebo (8.2%, NS). The only adverse event differing significantly from placebo was weight loss, though somnolence, anorexia, and ataxia were slightly more common with zonisamide treatment. Serum zonisamide concentrations rose with increasing dose.
                Zonisamide is effective and well tolerated as an adjunctive agent for refractory partial-onset seizures. The minimal effective dosage was 100 mg/d, but 400 mg/d was the most effective dosage. To evaluate the safety and efficacy of zonisamide (ZNS) as adjunctive treatment in patients with refractory localization-related epilepsy.
                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.
                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.
                ZNS provides dose-dependent, effective, and generally well-tolerated adjunctive therapy in patients with partial seizures. The new antiepileptic drug zonisamide was evaluated in a European multicenter parallel-group double-blind trial as add-on treatment for 139 patients with refractory partial epilepsy. During treatment with zonisamide complex partial seizures decreased by 27.7% compared to placebo (P < 0.05) and the median rate dropped from 12/month to 7.1/month with no changes in the placebo group (P < 0.007). During the 12-week double-blind phase a 50% reduction of all seizures was recorded in 29.9% of the patients treated with zonisamide vs. 9.4% during placebo. Complete remission was observed during treatment with zonisamide in 6.2%. The plasma concentrations of the concomitant antiepileptic drugs did not change markedly when zonisamide was added. Adverse events, mostly fatigue, somnolence, dizziness and ataxia, occurred in 59.2% of the patients compared to 27.9% during placebo. Zonisamide was withdrawn in two patients due to adverse events. Kidney stones were not observed nor any relevant clinical chemistry or hematological changes. Zonisamide is an effective antiepileptic drug for add-on treatment of refractory partial epilepsy. To evaluate the efficacy and tolerability of once-daily adjunctive lamotrigine extended-release (XR) for partial seizures in epilepsy.
                Patients more than 12 years old diagnosed with epilepsy with partial seizures and taking one to two baseline antiepileptic drugs were randomized to adjunctive once-daily lamotrigine XR or placebo in a double-blind, parallel-group trial. The study comprised a baseline phase, a 7-week double-blind escalation phase, and a 12-week double-blind maintenance phase during which doses of study medication and concomitant antiepileptic drugs were maintained.
                Of the 243 randomized patients, 239 (118 lamotrigine XR, 121 placebo) entered the escalation phase and received study medication. Lamotrigine XR was more effective than placebo with respect to median percent reduction from baseline in weekly partial seizure frequency (primary endpoint-entire 19-week treatment phase: 46.6% vs 24.5%, p = 0.0001 [corrected] via Wilcoxon test; escalation phase: 29.8% vs 15.6%, p = 0.027; maintenance phase: 58.4% vs 26.8%, p [corrected] < 0.0001). The percentage of patients with >or=50% reduction in partial seizure frequency (44.0% vs 20.8%, p = 0.0002) [corrected] and time to >or=50% reduction in partial seizure frequency (p = 0.0001) [corrected] also favored lamotrigine XR over placebo. A similar pattern of results was observed for secondarily generalized seizures. The most common adverse events were headache (lamotrigine XR 16%, placebo 18%) [corrected] and dizziness (lamotrigine XR 19%, [corrected] placebo 5%). Differences between lamotrigine XR and placebo on health outcomes measures were not significant.
                Once-daily adjunctive lamotrigine extended-release compared with placebo effectively reduced partial seizure frequency and was well tolerated in this double-blind study. Results support the clinical utility of this new once-daily formulation. This randomized, double-blind, placebo-controlled trial was conducted to assess the efficacy and tolerability of adjunctive lamotrigine for the treatment of partial seizures in infants aged 1 to 24 months.
                The study used a responder-enriched design in which all patients received adjunctive lamotrigine during an open-label phase (n = 177; maximum maintenance dose 5.1 mg/kg/day for those on non-enzyme-inducing antiepileptic drugs [AEDs] or valproate and 15.6 mg/kg/day for those on enzyme-inducing AEDs). Patients meeting response criteria were randomly assigned to double-blind treatment for up to 8 weeks with continued lamotrigine (n = 19) or to withdrawal from lamotrigine (placebo; n = 19) while background AEDs were maintained.
                The proportion of treatment failures (patients who met escape criteria or withdrew before completing the double-blind phase) was lower with lamotrigine (58%) than with placebo (84%). This finding was not significant in the primary analysis (two-sided chi(2) test [primary endpoint]). A post hoc sensitivity analysis of the primary endpoint was also performed (p = 0.045 by one-sided, mid-p corrected Fisher exact test). The median time to meet escape criteria was longer with lamotrigine (42 days) than with placebo (22 days) (p = 0.059). During the last 28 days of the open-label phase, 53% of the patients had a >or=50% reduction in frequency of partial seizures with lamotrigine. Additional reduction in partial seizure frequency was observed during the double-blind phase compared with the last 4 weeks of the open-label phase among those randomly assigned to lamotrigine (32% with a >or=25% reduction) but not those randomly assigned to placebo (5% with a >or=25% reduction). Lamotrigine was well tolerated, with an adverse event profile comparable to that observed in older pediatric patients.
                Lamotrigine was well tolerated, and the data indicate that it may be efficacious in the treatment of partial seizures in infants aged 1 to 24 months. To evaluate the efficacy and safety of topiramate (TPM) as add-on therapy in medically intractable partial epilepsies.
                We used a multicenter double-blind placebo-controlled randomized parallel-group trial consisting of 12 weeks of baseline phase, 10 weeks of titration phase, and 8 weeks of stabilization phase. The primary efficacy variable was the median seizure frequency reduction rate (MSFRR), and the other efficacy variables included responder rate, seizure-free rate, and global evaluations by the patient and the physician. The patient should have partial epilepsies refractory to the maximally tolerable doses of one to two antiepileptic drugs (AEDs) and should have two or more episodes of clinical seizures every 4 weeks during the baseline phase. The target dose of study drugs was 600 mg/day. The study drugs were started at the initial dose of 50 mg/day and gradually increased to the target dose over a 10-week period.
                A total of 177 patients was randomized into the TPM group (n = 91) and the placebo (PLC) group (n = 86). Baseline median seizure frequencies were 5.6 episodes/4 weeks in the TPM and the PLC groups. Among those who were randomized, 174 patients (TPM, 89 patients; PLC, 85 patients) were available for the efficacy measurement by intention-to-treat analysis. The MSFRR was 51.3% for TPM and 9.1% for PLC, which was highly in favor of TPM (p = 0.0001). The responder rate was 50.6% for TPM and 12.9% for PLC (p = 0.001). Seven (7.9%) of 89 patients taking TPM became seizure free compared with one (1.2%) of 85 patients taking PLC (p = 0.004). The global evaluation greatly favored TPM (p = 0.001). The incidence of adverse events (AEs) was higher in the TPM (81.3%) than in the PLC (48.9%) group, with central nervous system (CNS)-related AEs being the most frequent. Among individual AEs, anorexia (20.9%) and abdominal pain or discomfort (20.9%) were the most common AEs in the TPM group. AEs precipitated early drop-out in seven (7.6%) patients taking TPM and three (3.5%) patients taking PLC. No serious systemic AEs were observed.
                TPM was highly effective and safe as add-on therapy in medically intractable partial epilepsies. Slower titration of TPM might be responsible for the lesser drop-out rate than previous trials, but the incidence of AEs was still high. The AE profile of TPM in Koreans was different from that in whites. Based on dose predictions from animal and human volunteer studies, most patients enrolled in initial randomized controlled trials of topiramate as adjunctive therapy in adults with partial-onset seizures were randomized to >or= 600 mg/day topiramate. Subsequent experience suggests that dosage needs were overestimated. This double-blind, placebo-controlled study evaluated 200 mg/day topiramate in adults with treatment-resistant partial-onset seizures receiving a concurrent enzyme-inducing antiepileptic agent (carbamazepine).
                After a 4-week baseline, 263 adults receiving carbamazepine who had at least three partial-onset seizures during the baseline period were randomized to placebo or one of two topiramate 200 mg/day treatment arms: topiramate escalated weekly 25 mg/day(8-week escalation) or 50 mg/day(4-week escalation). Therapy was then maintained for the remainder of the 12-week double-blind study.
                Median percent reduction in seizure frequency from baseline to study end was 44% with topiramate and 20% with placebo (P <or= 0.001). A significant therapeutic effect was present at 2 weeks with a dose of 100 mg/day. The most common adverse events (>or=10% incidence in topiramate-treated patients) were somnolence, fatigue, paresthesia, nervousness and anorexia; 8% of topiramate-treated patients and 2% of placebo-treated patients discontinued because of adverse events. As a result of the low incidence of adverse events, differences between titration rates in terms of tolerability were not detected.
                Topiramate 200 mg/day is an appropriate target dose as adjunctive therapy in adults with treatment-resistant partial-onset seizures, even when receiving an enzyme-inducing agent; 100 mg/day also appears to be effective. A significant therapeutic effect may be seen in the second week of treatment with a dose of 100 mg/day. To evaluate the efficacy and tolerability of levetiracetam (LEV) as adjunctive therapy in children (4 to 16 years) with treatment-resistant partial-onset seizures.
                This multicenter, randomized, placebo-controlled trial consisted of an 8-week baseline period followed by a 14-week double-blind treatment period. During the treatment period, patients received either placebo or LEV add-on therapy and were up-titrated to a target dose of 60 mg/kg/day.
                One hundred ninety-eight patients (intent-to-treat population) provided evaluable data. The reduction in partial-onset seizure frequency per week for LEV adjunctive therapy over placebo adjunctive therapy was significant (26.8%; p = 0.0002; 95% CI 14.0% to 37.6%). A 50% or greater reduction of partial seizure frequency per week was attained in 44.6% of the LEV group (45/101 patients), compared with 19.6% (19/97 patients) receiving placebo (p = 0.0002). Seven (6.9%) LEV-treated patients were seizure-free during the entire double-blind treatment period, compared with one (1.0%) placebo-treated patient. One or more adverse events were reported by 88.1% of LEV-treated patients and 91.8% of placebo patients. The most common treatment-emergent adverse events were somnolence, accidental injury, vomiting, anorexia, hostility, nervousness, rhinitis, cough, and pharyngitis. A similar number of patients in each group required a dose reduction or withdrew from the study as a result of an adverse event.
                Levetiracetam adjunctive therapy administered at 60 mg/kg/day is efficacious and well tolerated in children with treatment-resistant partial seizures. Topiramate is an antiepileptic drug that has been approved for migraine prophylaxis. Despite appropriate efficacy for migraine prophylaxis, some patients cannot tolerate its adverse effects. The aim of this study was to compare the efficacy of zonisamide, another antiepileptic drug, with topiramate in decreasing the frequency and severity of migraine attacks to determine whether it could be used as an alternative for noncompliant patients to topiramate.
                Eighty patients, recruited from referred migraineurs to our neurology clinic, who met the diagnosis and inclusion criteria were allocated randomly to group A (50-mg/d zonisamide, gradually titrated up to 200 mg/d) and group B (25-mg/d topiramate, gradually titrated up to 100 mg/d). Each patient was followed for 12 weeks and was assessed at entrance, in the fourth week and twelfth week for frequency of attacks, headache severity, need for acute medication, migraine disability assessment score, and adverse effects. A P < 0.05 was considered as the level of significant difference in all tests.
                Both drugs caused a significant decrease in frequency, severity, need for acute medication in migraine attacks, and migraine disability assessment score (P < 0.05). Except headache severity that was reduced significantly better by zonisamide (P < 0.008), there were no significant difference between the 2 groups in other items. Except for 2 cases of intolerable paresthesia, both drugs were tolerated well during the study.
                Our results indicated that zonisamide is as effective as topiramate in migraine prophylaxis and can be considered as an alternative treatment when topiramate is not tolerated well.
Zonisamide has efficacy as an add-on treatment in people with drug-resistant partial epilepsy. Minimum effective and maximum tolerated doses cannot be identified. The trials reviewed were of 12 week duration and results cannot be used to confirm longer periods of effectiveness in seizure control. The results cannot be extrapolated to monotherapy or to people with other seizure types or epilepsy syndromes.