perampanel and Epilepsy--Temporal-Lobe

The alpha-amino-3-hydroxy-5-methyl-4-isoxazole propionic acid (AMPA) receptors are the major mediators of glutamate-mediated excitatory neurotransmission, and are critical for synchronization and spread of epileptic activity. Areas covered: AMPA receptor antagonists have been also developed as antiepileptic drugs and perampanel (PER) is the first highly selective, non-competitive AMPA-type glutamate receptor antagonist that is available on the market. It is approved as adjunctive therapy for the treatment of partial-onset seizures with or without secondary generalization, and for primary generalized tonic-clonic seizures in idiopathic generalized epilepsy, in patients aged ≥ 12 years. This article reviews the role of AMPA receptors in the neuronal hyperexcitability underlying epilepsy, the mechanism of action and clinical experience on the anti-seizure activity of PER. Moreover, the rationale for targeting AMPA receptor in specific epileptic disorders, including brain tumor-related epilepsy, mesial temporal lobe epilepsy with/without hippocampal sclerosis, and status epilepticus is evaluated. Finally, the pharmacological rationale for the development of AMPA receptor antagonists in other neurological disorders beyond epilepsy is considered. Expert opinion: Further research aimed at better understanding the pharmacology and blocking mechanism of PER and other AMPA receptor antagonists will drive future development of therapeutic agents that target epilepsy and other neurological diseases.

Topics: Anticonvulsants; Brain Neoplasms; Epilepsy; Epilepsy, Generalized; Epilepsy, Temporal Lobe; Humans; Nitriles; Pyridones; Receptors, AMPA; Status Epilepticus

Mesial temporal lobe epilepsy associated with hippocampal sclerosis (MTLE-HS) is a syndrome that is often refractory to drug treatment. The effects on specific syndromes are not currently available from the pre-marketing clinical development of new AEDs; this does not allow the prediction of whether new drugs will be more effective in the treatment of some patients.. We have reviewed all the existing literature relevant to the understanding of a potential effectiveness in MTLE-HS patients for the latest AEDs, namely brivaracetam, eslicarbazepine, lacosamide, perampanel and retigabine also including the most relevant clinical data and a brief description of their pharmacological profile. Records were identified using predefined search criteria using electronic databases (e.g., PubMed, Cochrane Library Database of Systematic Reviews). Primary peer-reviewed articles published up to the 15 June 2015 were included.. All the drugs considered have the potential to be effective in the treatment of MTLE-HS; in fact, they possess proven efficacy in animal models; currently considered valuable tools for predicting drug efficacy in TLE. Furthermore, for some of these (e.g., lacosamide and eslicarbazepine) data are already available from post-marketing studies while brivaracetam acting on SV2A like levetiracetam might have the same potential effectiveness with the possibility to be more efficacious considering its ability to inhibit voltage gated sodium channels; finally, perampanel and retigabine are very effective drugs in animal models of TLE.

Topics: Acetamides; Anticonvulsants; Carbamates; Clinical Trials as Topic; Dibenzazepines; Epilepsy, Temporal Lobe; Hippocampus; Humans; Lacosamide; Levetiracetam; Nitriles; Phenylenediamines; Piracetam; Pyridones; Sclerosis; Syndrome

Temporal lobe epilepsy (TLE) has a low antiepileptic drug (AED) treatment response rate, and about 70% of patients eventually progress to refractory epilepsy. Perampanel (PER) is a noncompetitive α-amino-3-hydroxy-5-methyl-4-isoxazole propionic acid (AMPA) receptor antagonist, which is used clinically for the treatment of partially refractory epilepsy, but its mechanism of action is not completely clear. In this study, kainic acid (KA) was successfully used to induce TLE in 3-week-old C57BL/6 immature mice, and the effects of PER on the cognitive behavior of the epileptic mice were characterized using the Morris water maze paradigm. To determine the mechanism underlying the therapeutic effects of PER, the morphological evolution of the hippocampus and the expression of AP-1 and GluR1 were systematically evaluated. Compared to control TLE mice, escape latency was reduced and the number of target platform crossings was increased in the Morris water maze by treatment with PER. The therapeutic effects of PER were mediated mainly via inhibition of the expression of AP-1 and GluR1, as the TLE mice showed significantly improved learning and memory and decreased seizure frequency after treatment with PER.

Topics: Animals; Behavior, Animal; Cognition; Disease Models, Animal; Epilepsy, Temporal Lobe; Female; Hippocampus; Kainic Acid; Male; Mice, Inbred C57BL; Morris Water Maze Test; Neurons; Nitriles; Pyridones; Receptors, AMPA; Transcription Factor AP-1

The temporal lobe plays a central role in the regulation of the "Central Autonomic Network" and cardiovascular functions. The blockade of glutamatergic pathways in the temporal lobe affects cardio-autonomic control. Perampanel (PER) is a non-competitive agonist of the AMPA receptor. This study evaluated PER effects on cardiac autonomic control in patients affected by drug-resistant TLE (DRTLE).. We enrolled 40 adults with DRTLE treated with PER as add-on therapy (PER group) and 32 DRTLE age, sex, and seizure-frequency matched controls treated with different additional anti-seizure medication (ASM) as add-on therapy (No-PER group). HRV analysis was performed on 5-minute EKG recording in resting state before and 6-months after the introduction of add-on ASM. Linear Mixed Models (LMM) were used to analyzed HRV variables according to time (baseline and 6-months follow-up) and groups.

Topics: Adult; Drug Resistant Epilepsy; Epilepsy, Temporal Lobe; Heart Rate; Humans; Nitriles; Pyridones; Seizures; Sudden Unexpected Death in Epilepsy; Temporal Lobe

To evaluate the efficacy of perampanel (PER) in patients with a diagnosis of mesial temporal lobe epilepsy (MTLE) taking PER as first add-on option due to inefficacy of first antiepileptic drug (AED), rather than late add-on choice.. Thirty-seven MTLE patients aged ≥ 12 years were recruited consecutively with a minimum duration of follow-up of 1 year and intermediate follow-up of 3 months. Patients were divided into two groups: 20/37 taking PER as first add-on due to inefficacy of first AED (first group) and 17/37 taking PER as late add-on due to inefficacy of ≥ 2 AEDs (second group). Efficacy, retention rate, and safety were evaluated.. At 3 months, the 70% of the first group had a reduction > 50% of seizure frequency, with six patients becoming also seizure free, while in the second group, only the 23.5% had a reduction > 50% of seizure frequency and none became seizure free (p = 0.005). Six patients of first group were also switched to a monotherapy of PER and five out of six remained seizure free at 12 months. At 1 year of follow-up, efficacy of PER was 70% for the first group, while only of 29.4% for the second group (p = 0.014). Retention rate of the first group at 3 months and 1 year was 85%, while for the second group was, respectively, 82.3% and 64.7%.. PER was significantly successful and tolerated in MTLE patients when used as first add-on option rather than as late add-on.

Topics: Aged; Anticonvulsants; Epilepsy, Temporal Lobe; Humans; Nitriles; Pyridones; Seizures; Treatment Outcome

Perampanel (PER) is a novel antiepileptic drug approved as an add-on therapy for focal onset seizures with or without generalization and primary generalized tonic-clonic seizures. Aim of this study was to evaluate PER efficacy and tolerability as add-on therapy in patients with drug-resistant focal onset seizures and especially temporal lobe epilepsy (TLE).. An observational, prospective, multicentre study on adult with drug-resistant focal epilepsy consecutively recruited from six Italian tertiary epilepsy centres. All patients received add-on PER according to indication and clinical judgement. Seizure frequency and adverse events (AEs) were recorded at 6 and 12 months after PER introduction.. Study sample comprised 246 patients, 77 of which with TLE. Seventy-five (35.9%) out of 209 and 66 (38.8%) out of 170 patients still taking PER resulted to be responders (i.e. ≥50% of seizure frequency or seizure free) after six and 12 months, respectively. In the TLE group, 39 (57.3%) out of 68 subjects on PER after 6 months and 32 (60.4%) out of 53 subjects taking PER after 12 months were responders. Overall reported incidence of AEs was 26.1%. In 28 cases (11.3%) AEs lead/contributed to PER discontinuation. The most frequently reported AE were dizziness (14/84) and somnolence (14/84). Regarding TLE patients, 25.9% of them experienced at least one AE and discontinuation for AEs occurred in eight (10.4%).. This study confirmed the good efficacy and safety of PER for drug-resistant focal epilepsy in real-life conditions and, above all, for the first time provide its effectiveness in patients with TLE.

Topics: Adult; Anticonvulsants; Drug Therapy, Combination; Epilepsy, Temporal Lobe; Humans; Italy; Nitriles; Pharmaceutical Preparations; Prospective Studies; Pyridones; Treatment Outcome

Mesial temporal lobe epilepsy (MTLE) is a common epilepsy syndrome often refractory to antiepileptic drug (AED) treatment. The purpose of this study was to evaluate the effectiveness and tolerability of perampanel (PER) as add-on treatment for patients of MTLE.We pooled retrospective data from adult patients with MTLE, from a tertiary center in Taiwan, who were prescribed PER between March 2016 and December 2016. The retention, responder, and seizure-free rate as well as the treatment emergent adverse events were assessed after 6 months of PER adjunctive treatment in this single-center postmarketing study.Review of medical records revealed that adequate data were available for 44 patients who were being administered PER (mean age: 42.0 ± 13.3 years, 24 females; baseline mean seizure frequency: 5.4 per 28 days). Twelve patients exhibited hippocampal sclerosis (HS). Open-label PER was added to ongoing medications. Twelve patients withdrew because of ineffectiveness (n = 6) or adverse effects (n = 6). The retention rate was 72.7% at 6 months. On final evaluation, with a mean PER dose of 5.7 mg/day for 6 months, a ≥50% reduction in seizure frequency was observed in 46.9% of the patients, and 5 patients became seizure-free. The effectiveness was similar for patients with or without HS. Twenty-three patients (52.3%) experienced adverse effects. The most common adverse effects were dizziness, ataxia, and irritability.Our results suggest that PER, at doses of 2 to 12 mg/day, reduces seizure frequency effectively with acceptable safety profiles for adults with MTLE.

Topics: Adult; Anticonvulsants; Drug Therapy, Combination; Epilepsy, Temporal Lobe; Female; Humans; Male; Middle Aged; Nitriles; Product Surveillance, Postmarketing; Pyridones; Retrospective Studies; Taiwan; Treatment Outcome

Anticonvulsive monotherapy fails to be effective in one third of patients with epilepsy resulting in the need for polytherapy regimens. However, with the still limited knowledge, drug choices for polytherapy remain empirical. Here we report experimental data from a chronic epilepsy model for the combination of perampanel and zonisamide, which can render guidance for clinical studies and individual drug choices.. The anticonvulsant effects of the combination of perampanel and zonisamide were evaluated in a rat amygdala kindling model. Furthermore, the potential for motor impairment was evaluated. The type of interaction was quantitatively assessed based on isobolographic analysis.. When administered alone, zonisamide dose-dependently increased the afterdischarge threshold in fully kindled rats. Moreover, data confirmed efficacy of perampanel to inhibit seizure initiation and progression with an impact on propagation of activity from the focus. Pronounced threshold increases were observed following administration of a constant zonisamide dosage combined with different doses of perampanel. Isobolographic analysis of drug responses, which is based on individual drug dose-effect data, revealed a synergistic interaction substantiating the high efficacy of the combination. Furthermore, rotarod data indicated that the combination has a favorable tolerability profile when zonisamide is coadministered with low doses of perampanel. Plasma concentration analysis argued against a pharmacokinetic interaction as a basis for the synergism.. The findings clearly indicate a pronounced synergistic anticonvulsant effect for the combination of the noncompetitive α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA) receptor antagonist perampanel with zonisamide, which modulates voltage-sensitive sodium channels and T-type calcium currents. Consequently, polytherapy using these two antiepileptic drugs might be efficacious for clinical management of partial-onset seizures. The findings indicate that the impact of dose ratios on tolerability needs be taken into account. With regard to conclusions about the extent of the synergism and its implications further antiepileptic drug combinations need to be evaluated allowing direct comparison.

Topics: Animals; Anticonvulsants; Disease Models, Animal; Dose-Response Relationship, Drug; Drug Synergism; Drug Therapy, Combination; Epilepsy, Temporal Lobe; Female; Isoxazoles; Kindling, Neurologic; Nitriles; Pyridones; Rats; Rats, Sprague-Dawley; Zonisamide

The AMPA receptor subtype of glutamate receptors, which mediates fast synaptic excitation, is of primary importance in initiating epileptiform discharges, so that AMPA receptor antagonists exert anti-seizure activity in diverse animal models of partial and generalized seizures. Recently, the first AMPA receptor antagonist, perampanel, was approved for use as adjunctive therapy for the treatment of resistant partial seizures in patients. Interestingly, the competitive AMPA receptor antagonist NBQX has recently been reported to prevent development of spontaneous recurrent seizures (SRS) in a neonatal seizure model in rats, indicating the AMPA antagonists may exert also antiepileptogenic effects. This prompted us to evaluate competitive (NBQX) and noncompetitive (perampanel) AMPA receptor antagonists in an adult mouse model of mesial temporal lobe epilepsy. In this model, SRS develop after status epilepticus (SE) induced by intrahippocampal injection of kainate. Focal electrographic seizures in this model are resistant to several major antiepileptic drugs. In line with previous studies, phenytoin was not capable of blocking such seizures in the present experiments, while they were markedly suppressed by NBQX and perampanel. However, perampanel was less tolerable than NBQX in epileptic mice, so that only NBQX was subsequently tested for antiepileptogenic potential. When mice were treated over three days after kainate-induced SE with NBQX (20 mg/kg t.i.d.), no effect on development or frequency of seizures was found in comparison to vehicle controls. These results suggest that AMPA receptor antagonists, while being effective in suppressing resistant focal seizures, are not exerting antiepileptogenic effects in an adult mouse model of partial epilepsy.

Topics: Animals; Anticonvulsants; Chronic Disease; Disease Models, Animal; Electroencephalography; Epilepsy, Temporal Lobe; Female; Hippocampus; Kainic Acid; Mice; Nitriles; Phenytoin; Pyridones; Quinoxalines; Receptors, AMPA; Seizures; Status Epilepticus