Perampanel in the management of partial-onset seizures: a review of safety, efficacy, and patient acceptability

The AMPAR antagonist perampanel protects the neurovascular unit against traumatic injury via regulating Sirt3

Introduction

Perampanel is a highly selective and noncompetitive α‐amino‐3 ‐hydroxy‐5‐methyl‐4‐isoxazole propionate receptor (AMPAR) antagonist, which has been used as an orally administered antiepileptic drug in more than 55 countries. Recently, perampanel was shown to exert neuroprotective effects in hemorrhagic and ischemic stroke models via regulating blood–brain barrier (BBB) function.

Aim

Here, the protective effects of perampanel were investigated in an in vitro neurovascular unit (NVU) system established using a triple cell co‐culture model (neurons, astrocytes, and brain microvascular endothelial cells) and in an in vivo traumatic brain injury (TBI) model.

Results

Neurons in the NVU system exhibit a more mature morphological phenotype compared with neurons cultured alone, and the co‐culture system mimicked an impermeable barrier in vitro. Perampanel protects the NVU system against traumatic and excitotoxic injury, as evidenced by reduced lactate dehydrogenase (LDH) release and apoptotic rate. Treatment with perampanel attenuated lipid peroxidation and expression of inflammatory cytokines. In addition, perampanel increased Sirt3 protein expression, enhanced the activities of mitochondrial enzyme IDH2 and SOD2, and preserved BBB function in vitro. Knockdown of Sirt3 using specific siRNA (Si‐Sirt3) partially reserved the effects of perampanel on neuronal injury and BBB function. Treatment with perampanel in vivo attenuated brain edema, preserved neurological function, inhibited apoptosis and microglia activation after TBI. Furthermore, perampanel increased the expression of Sirt3 and preserved BBB function after TBI. The effect of perampanel on BBB function and brain edema was abolished by knockdown of Sirt3 in vivo.

Conclusion

Our results indicate that the noncompetitive AMPAR antagonist perampanel protects the NVU system and reduces brain damage after TBI via activating the Sirt3 cascades.

The impact of perampanel treatment on quality of life and psychiatric symptoms in patients with drug-resistant focal epilepsy: An observational study in Italy

An observational, prospective study has been conducted to evaluate the effects of adjunctive treatment with perampanel (PER) on psychological functioning and quality of life (QoL) in patients with drug-resistant focal epilepsy. Fifty-six adult patients treated with PER in addition to antiepileptic drugs (AEDs) were recruited in 2 Italian Epilepsy Centers. Irritability in Adult Patients with Epilepsy (I-EPI), Quality of Life in Epilepsy (QOLIE-31), Beck Depression Inventory II (BDI-II), and State-Trait Anxiety Inventory Y-1 and Y-2 (STAI) questionnaires were administered at baseline and 3 and 6 months after the treatment onset. Adverse events (AEs) were collected during the observational 6 months period. Retention rate of treatment with PER was 82.1% at 3 months and 64.3% at 6 months. Thirteen patients reported a significant seizure frequency reduction, and one seizure freedom case was observed after 4 months of PER treatment. Perampanel was stopped because of inefficacy or paradoxical effects in 28.6% of cases and because of AEs in 7.1%. The peak dose was not associated with discontinuation probability. Irritability, QoL, depression, trait, and state anxiety did not change significantly during the PER therapy. A tendency of association between higher level of irritability at baseline and PER discontinuation was found. The results of this observational study have shown that the addition of PER to AEDs may improve seizure control, does not increase levels of irritability, depression, and anxiety, and does not reduce patients' QoL. This study also confirms the importance of a comprehensive clinical assessment, including psychiatric symptoms evaluation before offering a new treatment, to improve therapy compliance.

Pharmacokinetic and pharmacodynamic considerations for the clinical efficacy of perampanel in focal onset seizures

INTRODUCTION

Medical therapy is the mainstay of management of epilepsy. Despite the increasing number of available antiepileptic drugs (AEDs), approximately one-third of epileptic patients do not have adequate control of seizures. There is still a need for the development of new AEDs with enhanced effectiveness and tolerability. Areas covered: The present manuscript is based on an Internet and PubMed search (January 2005 to August 2018). It is focused on pharmacokinetic and clinical data of perampanel (PER) for the treatment of epilepsy. Expert opinion: PER has a novel mechanism of action, which opens up new options for a rational combination therapy. Phase III trials have demonstrated the efficacy and safety of PER as adjunctive therapy for the treatment of partial-onset seizures (POS) and primary generalized tonic-clonic seizures in patients aged ≥12 years. PER is also approved by FDA as monotherapy for the treatment of POS. A clinical trial is ongoing to verify the efficacy and safety of PER monotherapy in untreated patients with POS. In the future, head-to-head comparisons are needed to determine the exact position of PER relative to other AEDs. Moreover, further studies are needed to evaluate the efficacy and safety of PER in patients aged <12 years.

ABBREVIATIONS

4βOHC: 4β-hydroxycholesterol; AUC: area under the curve; CBZ: Carbamazepine; CLCr: creatinine clearance; Cmax: maximum plasma concentration; CYP: cytochrome P; EIAED: enzyme-inducing antiepileptic drug; EMA: European Medicines Agency; FDA: Food and Drug Administration; GI: gastrointestinal; OXC: oxcarbazepine; PER: perampanel; PGTC: primary generalized tonic-clonic; PHT: phenytoin; POS: partial-onset seizures; QD: once-daily; TEAE: treatment-emergent adverse event; Tmax: median time to reach peak concentration; UGT: uridine diphosphoglucose-glucuronosyltransferase; VPA: valproic acid.

[Perampanel as a therapy option in patients with epilepsy]

BACKGROUND

This article describes a monocentric retrospective analysis of clinical experience with the latest antiepileptic drug perampanel with non-competitive modulation of postsynaptic AMPA receptors.

MATERIAL AND METHODS

Evaluation of electronic medical charts of patients newly treated with perampanel between 2012 and 2014 at the epilepsy center of the University Hospital Freiburg regarding effectiveness and tolerability.

RESULTS

A total of 85 patients (45 male, mean age 37.4 years, range 14-80 years) with therapy resistance to an average of 6 antiepileptic medications were newly treated with add-on perampanel. Of the patients 35 % experienced a relevant reduction in seizures. The most commonly reported side effects were tiredness (32.5 %), dizziness (24.5 %) and irritability (10.5 %). The dosages resulting in a significant reduction in seizures which varied between patients from 4 to 12 mg/day. Even multidrug-resistant patients who had not benefited from vagus nerve and deep brain stimulation, profited from add-on treatment with perampanel.

CONCLUSION

In this cohort, even epilepsy patients who did not respond to multiple previous antiepileptic treatment profited from add-on therapy with the new mode of action of perampanel.

New antiepileptic drugs: focus on ezogabine, clobazam, and perampanel

Ezogabine, clobazam, and perampanel are among the newest antiseizure drugs approved by the Food and Drug Administration between 2011 and 2012. Ezogabine and perampanel are approved for adjunctive treatment of partial epilepsy. Perampanel is also approved for adjunctive treatment of primary generalized tonic–clonic seizures. Ezogabine and perampanel have novel mechanisms of action. Ezogabine binds to voltage-gated potassium channels and increases the M-current thereby causing membrane hyperpolarization. Perampanel is a selective, non-competitive 2-amino-3-(3-hydroxy-5-methyl-isoxazol-4-yl)propanoic acid receptor antagonist, which reduces neuronal excitation. Clobazam has been used worldwide since the 1970s and is approved for adjunctive treatment of seizures associated with Lennox-Gastaut syndrome. Clobazam is the only 1,5-benzodiazepine currently in clinical use, which is less sedating than the commonly used 1,4-benzodiazepines. Phase III multicenter, randomized, double-blind, placebo-controlled trials demonstrated efficacy and good tolerability of these 3 new antiepileptic drugs. These drugs represent a welcome addition to the armamentarium of practitioners, but it remains to be seen how they will affect the landscape of pharmacoresistant epilepsy.

Cutaneous Adverse Effects of Neurologic Medications

Life-threatening and benign drug reactions occur frequently in the skin, affecting 8 % of the general population and 2-3 % of all hospitalized patients, emphasizing the need for physicians to effectively recognize and manage patients with drug-induced eruptions. Neurologic medications represent a vast array of drug classes with cutaneous side effects. Approximately 7 % of the United States (US) adult population is affected by adult-onset neurological disorders, reflecting a large number of patients on neurologic drug therapies. This review elucidates the cutaneous reactions associated with medications approved by the US Food and Drug Administration (FDA) to treat the following neurologic pathologies: Alzheimer disease, amyotrophic lateral sclerosis, epilepsy, Huntington disease, migraine, multiple sclerosis, Parkinson disease, and pseudobulbar affect. A search of the literature was performed using the specific FDA-approved drug or drug classes in combination with the terms 'dermatologic,' 'cutaneous,' 'skin,' or 'rash.' Both PubMed and the Cochrane Database of Systematic Reviews were utilized, with side effects ranging from those cited in randomized controlled trials to case reports. It behooves neurologists, dermatologists, and primary care physicians to be aware of the recorded cutaneous adverse reactions and their severity for proper management and potential need to withdraw the offending medication.