Truncal Ataxia and Prolonged Coma in an Exploratory Pediatric Perampanel Ingestion

Abstract

Introduction Several overdoses of the antiepileptic drug perampanel have been reported in adults, but very few have been reported in children. We report the case of an observed exploratory ingestion of perampanel in a 2-year-old child that resulted in ataxia and prolonged coma. Case Report A previously healthy 2-year-old female patient presented to the emergency department (ED) 30 minutes after the witnessed ingestion of 30 mg of perampanel (2 mg/kg). Within minutes of ingestion, she displayed ataxia and inability to walk. Upon ED presentation, she had normal vital signs but was minimally responsive with physical stimulation. Naloxone was given without response. She was intubated because of profound central nervous system depression and transferred to a pediatric tertiary care facility. She remained intubated with no pharmacological sedation. Physical exam showed a horizontal nystagmus. Detailed neurologic examination of ataxia and coordination was not possible, and she did not demonstrate hyperreflexia, clonus, or rigidity. Her mental status gradually improved, and she was extubated approximately 72 hours after exposure. After extubation, the patient still exhibited truncal ataxia and did not return to baseline until 96 hours post ingestion. Serum drawn approximately 16 hours after exposure showed 870 ng/mL perampanel (ref < 20 ng/mL). She remained hemodynamically stable throughout her hospital course, despite protracted depressed mental status. Discussion Given the severity of our patient's presentation, pediatric patients showing symptoms of perampanel overdose should be triaged to the ED for evaluation in anticipation of a prolonged clinical course with decreased consciousness and hypoventilation.

Effectiveness and tolerability of adjunctive perampanel in pediatric patients (aged 4–12 years) with refractory epilepsy: An observational study

“…[24][25][26] Although there was no considerable difference in terms of pharmacology, pediatric patients did differ from adult patients in some aspects, particularly with respect to drug sensitivity and toxicity. [16,27,28] Second, several studies have normalized dosage increases every 1 to 3 weeks under the guidance of a target dose (12 mg/day), [27,29] and some patients had dose adjustments only after 4 to 8 weeks. [2] Nevertheless, perampanel was up-titrated on a more frequent schedule for patients who had inadequately controlled seizures than the prespecified schedule (every 1-2 weeks).…”

“…[ 13 , 14 ] Currently, most studies on pediatric patients have focused on patients who were >12 years of age. However, dose-related toxicity has been reported in patients aged ≤2 years who received perampanel [ 15 , 16 ] ; hence, it is important to assess the safety and tolerability of treatment protocols in younger pediatric patients with epilepsy. This study reported the effectiveness and tolerability of perampanel in pediatric patients ≤12 years of age with refractory epilepsy.…”