Neonatal Antiepileptic Medication Treatment Patterns: A Decade of Change

Antiseizure medication at discharge in infants with hypoxic-ischaemic encephalopathy: an observational study

OBJECTIVES

To assess variability in continuation of antiseizure medication (ASM) at discharge and to evaluate if continuation of ASM at discharge is associated with death or disability among infants with hypoxic-ischaemic encephalopathy (HIE) and seizures.

DESIGN

Retrospective study of infants enrolled in three National Institute of Child Health and Human Development Neonatal Research Network Trials of therapeutic hypothermia.

SETTING

22 US centres.

PATIENTS

Infants with HIE who survived to discharge and had clinical or electrographic seizures treated with ASM.

EXPOSURES

ASM continued or discontinued at discharge.

OUTCOMES

Death or moderate-to-severe disability at 18-22 months, using trial definitions. Multivariable logistic regression evaluated the association between continuation of ASM at discharge and the primary outcome, adjusting for severity of HIE, hypothermia trial treatment arm, use of electroencephalogram, discharge on gavage feeds, Apgar Score at 5 min, birth year and centre.

RESULTS

Of 302 infants included, 61% were continued on ASMs at discharge (range 13%-100% among 22 centres). Electroencephalogram use occurred in 92% of the cohort. Infants with severe HIE comprised 24% and 22% of those discharged with and without ASM, respectively. The risk of death or moderate-to-severe disability was greater for infants continued on ASM at discharge, compared with those infants discharged without ASM (44% vs 28%, adjusted OR 2.14; 95% CI 1.13 to 4.05).

CONCLUSIONS

In infants with HIE and seizures, continuation of ASM at discharge varies substantially among centres and may be associated with a higher risk of death or disability at 18-22 months of age.

Association between anti-seizure medication and outcomes in infants

OBJECTIVE

To compare treatment failure between: (1) infants treated with phenobarbital versus levetiracetam for first-line treatment and (2) infants treated with phenytoin versus levetiracetam for second-line treatment following phenobarbital.

STUDY DESIGN

This retrospective cohort study included infants with seizures receiving phenobarbital or levetiracetam as the initial anti-seizure medication. Treatment failure was defined as the need for additional anti-seizure medication within 24-72 h and compared using mixed-effect logistic regression after adjustment for confounding factors, including center.

RESULTS

In this cohort of 6842 infants, the incidence of treatment failure was 31% vs. 38% in infants receiving first-line phenobarbital versus levetiracetam (adjusted OR: 0.70; 95% CI 0.58-0.84). There was no significant difference in second-line treatment failure (adjusted OR: 1.31; 95% CI 0.92-1.86).

CONCLUSIONS

First-line treatment of neonatal seizures with phenobarbital is associated with a lower rate of treatment failure than levetiracetam. There was no significant difference in second-line treatment failure.

Levetiracetam as the first-line treatment for neonatal seizures: a systematic review and meta-analysis

AIM

To assess the effectiveness and safety of levetiracetam when used as first-line treatment of neonatal seizures.

METHOD

Four electronic databases, Medline, Embase, Web of Science, and ClinicalTrials.gov were systematically searched from inception until 20th November 2020. Randomized controlled trials (RCTs) and observational studies that included neonates born preterm and term were eligible for inclusion. The primary outcome measure was levetiracetam effectiveness, defined as seizure cessation within 24 hours of starting treatment. Secondary outcomes included short-term adverse events, mortality before discharge, and long-term neurodevelopmental outcomes.

RESULTS

Fourteen studies assessing 1188 neonates were included: four RCTs, three observational trials with phenobarbital as the control arm, and seven observational studies of levetiracetam with no control arm. Pooled efficacy of levetiracetam from observational studies was 45% (95% confidence interval [CI] 34-57%) (GRADE - very low). Meta-analysis of RCTs evaluating levetiracetam versus phenobarbital showed that both were equally effective (risk ratio [95% CI] 0.6 [0.30-1.20]) (GRADE - very low). Levetiracetam resulted in a lower risk of short-term adverse events compared to phenobarbital (risk ratio [95% CI] 0.24 [0.06-0.92]) (GRADE - moderate).

INTERPRETATION

Very low certainty of evidence suggests levetiracetam might not be more effective than phenobarbital. Moderate certainty of evidence indicates levetiracetam is associated with a lower risk of adverse events. Future trials on neonatal antiseizure medication therapy should include continuous electroencephalogram (EEG) monitoring as standard of care and enrol a homogenous population with similar seizure aetiology. What this paper adds Levetiracetam is effective in 45% of neonatal seizures. Levetiracetam might not be more effective than phenobarbital. Levetiracetam is likely to be safer than phenobarbital. Evidence available is limited and of very low certainty.

Safety of Early Discontinuation of Antiseizure Medication After Acute Symptomatic Neonatal Seizures

Question

Is discontinuation of antiseizure medication (ASM) after resolution of acute symptomatic neonatal seizures and prior to discharge from the hospital associated with functional neurodevelopment or epilepsy at 24 months?

Findings

In this comparative effectiveness study of 303 children with neonatal seizures from 9 centers, 64% had ASM maintained at hospital discharge. No difference was found between ASM maintenance and discontinuation groups in functional neurodevelopment or epilepsy; 13% of children developed epilepsy, including more than one-third with infantile spasms.

Meaning

These results support discontinuing ASMs for most neonates with acute symptomatic seizures prior to discharge from the hospital, an approach that may represent an evidence-based change in practice for many clinicians.

Importance

Antiseizure medication (ASM) treatment duration for acute symptomatic neonatal seizures is variable. A randomized clinical trial of phenobarbital compared with placebo after resolution of acute symptomatic seizures closed early owing to low enrollment.

Objective

To assess whether ASM discontinuation after resolution of acute symptomatic neonatal seizures and before hospital discharge is associated with functional neurodevelopment or risk of epilepsy at age 24 months.

Design, Setting, and Participants

This comparative effectiveness study included 303 neonates with acute symptomatic seizures (282 with follow-up data and 270 with the primary outcome measure) from 9 US Neonatal Seizure Registry centers, born from July 2015 to March 2018. The centers all had level IV neonatal intensive care units and comprehensive pediatric epilepsy programs. Data were analyzed from June 2020 to February 2021.

Exposures

The primary exposure was duration of ASM treatment dichotomized as ASM discontinued vs ASM maintained at the time of discharge from the neonatal seizure admission. To enhance causal association, each outcome risk was adjusted for propensity to receive ASM at discharge. Propensity for ASM maintenance was defined by a logistic regression model including seizure cause, gestational age, therapeutic hypothermia, worst electroencephalogram background, days of electroencephalogram seizures, and discharge examination (all P ≤ .10 in a joint model except cause, which was included for face validity).

Main Outcomes and Measures

Functional neurodevelopment was assessed by the Warner Initial Developmental Evaluation of Adaptive and Functional Skills (WIDEA-FS) at 24 months powered for propensity-adjusted noninferiority of early ASM discontinuation. Postneonatal epilepsy, a prespecified secondary outcome, was defined per International League Against Epilepsy criteria, determined by parent interview, and corroborated by medical records.

Results

Most neonates (194 of 303 [64%]) had ASM maintained at the time of hospital discharge. Among 270 children evaluated at 24 months (mean [SD], 23.8 [0.7] months; 147 [54%] were male), the WIDEA-FS score was similar for the infants whose ASMs were discontinued (101 of 270 [37%]) compared with the infants with ASMs maintained (169 of 270 [63%]) at discharge (median score, 165 [interquartile range, 150-175] vs 161 [interquartile range, 129-174]; P = .09). The propensity-adjusted average difference was 4 points (90% CI, −3 to 11 points), which met the a priori noninferiority limit of −12 points. The epilepsy risk was similar (11% vs 14%; P = .49), with a propensity-adjusted odds ratio of 1.5 (95% CI, 0.7-3.4; P = .32).

Conclusions and Relevance

In this comparative effectiveness study, no difference was found in functional neurodevelopment or epilepsy at age 24 months among children whose ASM was discontinued vs maintained at hospital discharge after resolution of acute symptomatic neonatal seizures. These results support discontinuation of ASM prior to hospital discharge for most infants with acute symptomatic neonatal seizures.

Novel Therapeutics for Neonatal Seizures

Neonatal seizures are a common neurologic emergency for which therapies have not significantly changed in decades. Improvements in diagnosis and pathophysiologic understanding of the distinct features of acute symptomatic seizures and neonatal-onset epilepsies present exceptional opportunities for development of precision therapies with potential to improve outcomes. Herein, we discuss the pathophysiology of neonatal seizures and review the evidence for currently available treatment. We present emerging therapies in clinical and preclinical development for the treatment of acute symptomatic neonatal seizures. Lastly, we discuss the role of precision therapies for genetic neonatal-onset epilepsies and address barriers and goals for developing new therapies for clinical care.