Objective: To assess the evidence demonstrating efficacy, tolerability, and safety of seven new antiepileptic drugs (AEDs) (gabapentin, lamotrigine, topiramate, tiagabine, oxcarbazepine, levetiracetam, and zonisamide—reviewed in the order in which these agents received approval by the US Food and Drug Administration) in the treatment of children and adults with newly diagnosed partial and generalized epilepsies. Methods: A 23-member committee, including general neurologists, pediatric neurologists, epileptologists, and doctors in pharmacy, evaluated the available evidence based on a structured literature review including MEDLINE, Current Contents, and Cochrane library for relevant articles from 1987 until September 2002, with selected manual searches up until 2003. Results: There is evidence either from comparative or dose-controlled trials that gabapentin, lamotrigine, topiramate, and oxcarbazepine have efficacy as monotherapy in newly diagnosed adolescents and adults with either partial or mixed seizure disorders. There is also evidence that lamotrigine is effective for newly diagnosed absence seizures in children. Evidence for effectiveness of the new AEDs in newly diagnosed patients with other generalized epilepsy syndromes is lacking. Conclusions: The results of this evidence-based assessment provide guidelines for the prescription of AEDs for patients with newly diagnosed epilepsy and identify those seizure types and syndromes where more evidence is necessary.

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Efficacy and tolerability of the new antiepileptic drugs I: treatment of new onset epilepsy: report of the Therapeutics and Technology Assessment Subcommittee and Quality Standards Subcommittee of the American Academy of Neurology and the American Epilepsy Society.

We developed an instrument to measure health-related quality of life (HRQOL) in epilepsy. A 99-item inventory was constructed from the RAND 36-Item Health Survey (generic core), with 9 additional generic items, 48 epilepsy-targeted items, and 6 other items concerning attitudes toward epilepsy and self-esteem. We administered the 99-item inventory to 304 adults with epilepsy at 25 epilepsy centers. Patients and patient-designated proxies completed the inventory and were retested 1-91 days later. A multitrait scaling analysis of these data led to retention of 86 items distributed in 17 multiitem scales (Cronbach's alpha ranged from 0.78 to 0.92). Factor analysis of the 17 multiitem scales yielded four underlying dimensions of health: an epilepsy-targeted dimension, a cognitive factor, mental health, and physical health. Construct validity was supported by significant patient-proxy correlations for all scales and correlations between neuropsychologic tests and self-reported emotional and cognitive function (all p values < 0.05). There were significant negative correlations between the four factor scores derived from the HRQOL scales and neurotoxicity, systemic toxicity, and health care utilization (except for the correlation between mental health factor and health care utilization; all p values < 0.05). Patients who were seizure-free in the preceding year reported better HRQOL for the overall score, three of the four factor scores, and 8 of the 17 scale scores than did patients with a high frequency of seizures. Relative validity analysis showed that the epilepsy-targeted factor and three of its four component scales were more sensitive to categorization of patients by severity of seizure frequency and type than scales tapping physical health, mental health, or cognitive function. These cross-sectional data support the reliability and validity of this measure of HRQOL in epilepsy. The addition of an epilepsy-targeted supplement to the generic core improved the sensitivity to severity of epilepsy. The 86 items included in the field testing were supplemented by three additional items to form the Quality of Life in Epilepsy (QOLIE-89) inventory.

Development of the Quality of Life in Epilepsy Inventory

Comparative responsiveness of generic and specific quality-of-life instruments.

Glutamate, GABA and epilepsy

Neuropsychological effects of epilepsy and antiepileptic drugs

The need for new antiepileptic drugs (AEDs) and more sensitive methods of assessing their efficacy is well recognized. This study was designed to evaluate the efficacy and safety of lamotrigine (LTG), a potential new AED and to develop and test new outcome measures. A health-related quality of life (HRQL) model was developed which contains previously validated measures of anxiety, depression, happiness, overall mood, self-esteem, and mastery and a specifically designed seizure severity scale with patient- and caregiver-based components. This HRQL model was used in a randomized, placebo-controlled, double-blind, cross-over study of LTG in 81 patients with refractory partial seizures. Seizure frequency was the primary measure and seizure severity and the HRQL were secondary measures of efficacy. The reduction in seizure frequency with LTG, relative to placebo, was 29.7% [95% confidence interval (CI) 17.8%, 39.9%] for total seizure count, 33.4% (95% CI 14.8%, 47.9%) for complex partial seizures (CPS) and 20.3% (95% CI 0.3%, 36.2%) for secondarily generalized tonic-clonic seizures (GTCS). However, although 41 patients elected to continue with LTG, only 11 experienced at least 50% reduction in total seizures, indicating that other factors influenced their decision. The score with LTG, relative to placebo, was significantly lower for the ictal (p = 0.017) and caregivers (p = 0.035) subscales of the seizure severity scale and significantly higher for happiness (p = 0.003) and mastery (p = 0.003). Simple correlation and multiple-regression analyses indicate that the effects on seizure frequency, seizure severity, and psychological variables appear to be independent of each other. This study indicates that LTG is effective in reducing seizure frequency and has additional favorable effects on seizure severity, mood, and perceived internal control. Some of the scales used indicate the potential of secondary measures of efficacy to enhance the sensitivity of trials of new AEDs.

Outcomes of add-on treatment with lamotrigine in partial epilepsy.

The results of a multicentre, randomised, double-blind, placebo controlled, crossover trial of lamotrigine as add-on therapy in patients with partial seizures poorly controlled by established antiepileptic drugs (AEDs) are presented. The study consisted of two 12 week treatment periods each followed by a four week washout period. During the lamotrigine treatment phase, patients received 150 mg or 300 mg daily dose depending on their concomitant AEDs to achieve concentrations in the range 1-3 mg/L. Forty one patients were entered at four centres and all patients entered completed the study. There was a highly significant (p < 0.001) decrease in total seizure counts on lamotrigine compared with placebo. Overall, 22% of patients experienced at least a 50% reduction in the total numbers of all seizures types on lamotrigine, compared with none on placebo. When the total numbers of partial seizures (simple and complex partial) were analysed there was also a significant (p < 0.05) reduction in seizure counts on lamotrigine compared with placebo. When total numbers of secondarily generalised seizures were compared the trend for a reduction in this seizure type did not achieve significance (0.05 < p < 0.1). Concomitant AED plasma concentrations were virtually unchanged. It is concluded that lamotrigine is an effective AED in the treatment of therapy-resistant partial seizures.

https://jnnp.bmj.com/content/jnnp/56/5/448.full.pdf

G. Davies

Papers

Outcomes of add-on treatment with lamotrigine in partial epilepsy.

Double-blind, placebo controlled, crossover study of lamotrigine in treatment resistant partial seizures.

Normal extracellular calcium levels block kindled seizures