Safety evaluation of perampanel as monotherapy or first adjunctive therapy in patients with epilepsy

Switching from zonisamide to perampanel improved the frequency of seizures caused by hyperthermia in Dravet syndrome: a case report

BACKGROUND

Dravet syndrome is a severe epilepsy disorder characterized by drug-resistant seizures and cognitive dysfunction, often caused by SCN1A gene mutations. It leads to neurodevelopmental delays and motor, behavioral, and cognitive impairments, with a high mortality rate. Treatment options include sodium valproate, clobazam, and newer agents such as cannabidiol and fenfluramine. Zonisamide, which is used in some cases, can cause hyperthermia and oligohydrosis. Herein, we present a case of a patient with Dravet syndrome whose seizures were controlled by treating infections and switching from zonisamide to perampanel.

CASE PRESENTATION

A 24-year-old Japanese man with Dravet syndrome presented to our department with aspiration pneumonia. The patient had been treated with valproate, sodium bromide, and zonisamide for a long time. His seizures were triggered by hyperthermia. The patient was experiencing a sustained pattern of hyperthermia caused by infection, zonisamide, and persistent convulsions, which caused a vicious cycle of further seizures. In this case, the control of infection and switching from zonisamide to perampanel improved seizure frequency.

CONCLUSION

Dravet syndrome usually begins with generalized clonic seizures in its infancy because of fever and progresses to various seizure types, often triggered by fever or seizure-induced heat due to mutations in the SCN1A gene that increases neuronal excitability. Seizures usually diminish with age, but the heat sensitivity remains. In this case, seizures were increased by repeated infections, and hyperthermia was induced by zonisamide, resulting in status epilepticus. Perampanel, an aminomethylphosphonic acid receptor antagonist, decreased seizures but caused psychiatric symptoms. It was effective in suppressing seizures of Dravet syndrome in this patient.

Perampanel's forgiveness factor in a variable medication adherence paradigm in a rat model of chronic epilepsy

BACKGROUND

Poor medication adherence contributes to increased morbidity and mortality in patients with epilepsy and may be under-addressed in clinical practice. Ethical concerns make it impossible to study the impact of medication nonadherence in clinical trials, but our previous work emphasizes the importance of using preclinical approaches to address these questions. With over 30 clinically available antiseizure medicines (ASM's), it remains an important question to understand the relationship between poor adherence and seizure incidence across mechanistically distinct ASM's, including the broad-spectrum ASM, perampanel (PER).

METHODS

We formulated PER into chow pellets to deliver to rats in a 100% fully adherent or 50% variable nonadherent paradigm via our novel automated medication-in-food delivery system. Chronic oral dosing was initiated in male rats with chronic epilepsy while monitoring 24/7 for videoEEG evidence of seizures during a 4-week placebo baseline and 4-week treatment phase. PER concentrations were monitored in plasma at 1-week intervals and correlated with degree of seizure control. The relationship between missed doses and extended patterns of nonadherence were correlated with breakthrough seizures.

RESULTS

Fully adherent rats demonstrated a median reduction in seizure frequency of 50%, whereas nonadherent rats had a median increase of 54%. Plasma concentrations of PER were stable over the 4-week treatment period in both fully adherent and nonadherent groups, with levels being twice as high in fully adherent animals. There was no correlation between a single missed dose or series of missed doses and the incidence of breakthrough seizures. However, those animals in the nonadherent group that received PER for every meal during a 24-h period had a reduced likelihood of seizure incidence.

CONCLUSIONS

If our preclinical data is supported in the clinic, PER's favorable pharmacokinetic profile in humans, combined with a lowered risk of breakthrough seizures suggests that it may provide a certain forgiveness factor if a dose is missed within a 24-h window.

Mining and analysis of adverse drug reactions associated with perampanel based on FAERS database

INTRODUCTION

Perampanel (PER) is a non-competitive AMPA glutamate receptor antagonist used as an anti-seizure medication. Large post-marketing databases are still lacking for safety analysis of the new generation of anti-seizure medications. Based on the FDA's adverse event reporting system (FAERS) database, this study aimed to investigate, assess, and offer evidence for the safety of PER to support clinical decision-making.

METHODS

Perampanel-related adverse reaction signals were mined using the reporting odds ratio (ROR), medicines and healthcare products regulatory agency (MHRA), and Bayesian confidence propagation neural network (BCPNN). The rate and occurrence of reported adverse responses were examined.

RESULTS

With the three methodologies used in combination, 83 signals mostly related to psychosis and different nervous system disorders were detected. Among them, suicide behavior, respiratory depression, hepatotoxicity, cognitive impairment, and other possible novel signals warranted consideration. Further examination of the age and gender differences in the detected signals revealed that elderly patients should be closely monitored for any change in consciousness and the occurrence of movement disorders; male patients should be observed for negative mental reactions like a personal attack and homicidal ideation; and female patients should be watched for the occurrence of negative reactions in memory, weight, vision, liver function, and other specific areas.

CONCLUSIONS

This study found that PER had the risk of causing suicide behavior, respiratory depression, hepatotoxicity, and cognitive impairment among other adverse effects. When used clinically, PER should be closely monitored for the occurrence of adverse effects on mental health and behavior. However, these results should be interpreted with caution.