SUMMARYPurpose: Brivaracetam (BRV) is a novel high-affinity synaptic vesicle protein 2A ligand in clinical development for the treatment of epilepsy. This phase III study (N01252; NCT00490035) evaluated the efficacy and safety/tolerability of BRV (20, 50, and 100 mg/day) compared with placebo (PBO) in patients aged 16-70 years with uncontrolled focal seizures with/without secondary generalization, despite treatment with one to two concomitant antiepileptic drugs at a stable and optimal dosage. Methods: This was a double-blind, randomized, placebo-controlled trial conducted across Europe and India. Eligible patients had two or more focal seizures/month for 3 months prior to screening and eight or more focal seizures during the 8-week prospective baseline. Concomitant use of levetiracetam was limited to 20% of randomized patients. Patients were randomized (1:1:1:1) to BRV 20, 50, 100 mg/day or PBO with no up-titration for 12 weeks, followed by down-titration or entry into a long-term follow-up study. The primary efficacy end point was percent reduction over PBO in baseline-adjusted focal seizure frequency/week over the 12-week treatment period. Comparison of BRV with PBO was sequential to control for multiplicity (50, 100, 20 mg/day), and thus required BRV to demonstrate superiority over PBO at 50 mg/ day to meet the primary efficacy end point. Secondary efficacy variables were median percent reduction from baseline in focal seizure frequency/week, ≥50% responder rate, and seizure freedom (all seizure types). Safety assessments included treatment-emergent adverse events (TEAEs). Key Findings: Of 399 randomized patients, 398 were included in the intent-to-treat (ITT) and safety populations. Overall, 367 (92.2%) of 398 patients completed the study (BRV: 93.9%, 88.9%, and 94.0% for 20, 50, and 100 mg/day, respectively; PBO: 92.0%) and 345 (86.7%) of 398 patients continued into long-term follow-up studies (BRV: 87.9%, 82.8%, and 88.0% for 20, 50, and 100 mg/day, respectively; PBO: 88.0%). The study did not meet its primary efficacy end point based on the predefined sequential testing strategy. Indeed, percent reduction over PBO in baseline-adjusted focal seizure frequency/week (primary efficacy analysis) was 6.8% (p = 0.239), 6.5% (p = 0.261), and 11.7% (p = 0.037) for BRV 20, 50, and 100 mg/day, respectively. Median percent reduction from baseline in focal seizure frequency/week was 30.0% (p = 0.019), 26.8% (p = 0.092), and 32.5% (p = 0.004) for BRV 20, 50, and 100 mg/day, respectively, compared with 17.0% for PBO. Responder rates (≥50%) were 27.3% (p = 0.339), 27.3% (p = 0.372), and 36.0% (p = 0.023) for BRV 20, 50, and 100 mg/day, respectively, compared with 20.0% for PBO. Complete seizure freedom was reported by 2/99, 0/99, and 4/100 patients on BRV 20, 50, and 100 mg/day, respectively, compared with 0/100 on PBO. The incidence of TEAEs was higher for BRV 20 (56/99, 56.6%), 50 (62/99, 62.6%), and 100 mg/day (63/100, 63.0%) than PBO (53/100, 53.0%); most TEAEs were mild or moderate in severity. The most frequently ...

Gamma-aminobutyric acid (GABA), one of the main inhibitory neurotransmitters in the brain, interacts with three types of receptors for GABA--GABA(A), GABA(B) and GABA(C). GABA(A) receptors, associated with binding sites for benzodiazepines and barbiturates in the form of a receptor complex, control opening of the chloride channel. When GABA binds to the receptor complex, the channel is opened and chloride anions enter the neuron, which is finally hyperpolarized. GABA(B) receptors are metabotropic, linked to a cascade of second messengers whilst the physiological meaning of ionotropic GABA(C) receptors, mainly located in the retina, is generally unknown. Novel antiepileptic drugs acting selectively through the GABA-ergic system are tiagabine and vigabatrin. The former inhibits neuronal and glial uptake of GABA whilst the latter increases the synaptic concentration of GABA by inhibition of GABA-aminotransferase. Gabapentin, designed as a precursor of GABA easily entering the brain, was shown to increase brain synaptic GABA. This antiepileptic drug also decreases influx of calcium ions into neurons via a specific subunit of voltage-dependent calcium channels. Conventional antiepileptics generally inhibit sodium currents (carbamazepine, phenobarbital, phenytoin, valproate) or enhance GABA-ergic inhibition (benzodiazepines, phenobarbital, valproate). Ethosuximide, mainly controlling absences, reduces calcium currents via T-type calcium channels. Novel antiepileptic drugs, mainly associated with an inhibition of voltage-dependent sodium channels are lamotrigine and oxcarbazepine. Since glutamate-mediated excitation is involved in the generation of seizure activity, some antiepileptics are targeting glutamatergic receptors--for instance, felbamate, phenobarbital, and topiramate. Besides, they also inhibit sodium currents. Zonisamide, apparently sharing this common mechanism, also reduces the concentration of free radicals. Novel antiepileptic drugs are better tolerated by epileptic patients and practically are devoid of important pharmacokinetic drug interactions.

This paper summarizes current views on clinical manifestation, pathogenesis, prognosis and management of antiepileptic drug (AED)-induced adverse skin reactions. Cochrane Central Register of Controlled Trials, MEDLINE (PubMed) and ISI Web of Knowledge were searched. The recent classification, among drug-induced skin injuries, points to Stevens-Johnson syndrome/toxic epidermal necrolysis (SJS/TEN), acute generalized exanthematous pustulosis and hypersensitivity syndrome (HSS), which may be also recognized as a drug reaction with eosinophilia and systemic symptoms (DRESS) or drug-induced hypersensitivity syndrome (DIHS). The use of aromatic AEDs, e.g. phenytoin, carbamazepine, oxcarbazepine, phenobarbital, primidone, zonisamide, and lamotrigine is more frequently associated with cutaneous eruption and other signs or symptoms of drug hypersensitivity. There is a high degree of cross-reactivity (40-80%) in patients with hypersensitivity or allergic reactions to AEDs. Pharmacogenetic variations in drug biotransformation may also play a role in inducing these undesired effects. It is suggested that avoidance of specific AEDs in populations at special risk, cautious dose titration and careful monitoring of clinical response and, if applicable, laboratory parameters can minimize the serious consequences of idiosyncratic reactions.

Depression episodes in epilepsy is the most common commorbidity, affecting between 11% and 62% of patients with epilepsy. Although researchers have documented a strong association between epilepsy and psychiatric comorbidities, the nature of this relationship is poorly understood. The manifestation of depression in epilepsy is a complex issue having many interacting neurobiological and psychosocial determinants, including clinical features of epilepsy (seizure frequency, type, foci, or lateralization of foci) and neurochemical or iatrogenic mechanisms. Other risk factors are a family history of psychiatric illness, particularly depression, a lack of control over the seizures and iatrogenic causes (pharmacologic and surgical). In addition, treatment with antiepileptic drugs (AEDs) as well as social coping and adaptation skills have also been recognised as risk factors of depression associated with epilepsy. Epilepsy may foster the development of depression through being exposed to chronic stress. The uncertainty and unpredictability of seizures may instigate sadness, loneliness, despair, low self-esteem, and self-reproach in patients with epilepsy and lead to social isolation, stigmatization, or disability. Often, depression is viewed as a reaction to epilepsy's stigma and the associated poor quality of life. Moreover, patients with epilepsy display a 4-5 higher rate of depression and suicide compared with healthy population.

Apart from enzyme inducers, valproate (an even enzyme inhibitor) may also negatively affect BMD. However, the untoward effects of AEDs may depend upon their doses and duration of treatment. Although the problem of supplementation of vitamin D and calcium in epileptic patients on AEDs is controversial, there are recommendations to do so.