Background: Convulsive status epilepticus is the most common neurological emergency in children. Its management is important to avoid or minimise neurological morbidity and death. The current first-choice second-line drug is phenytoin (Epanutin, Pfizer Inc., New York, NY, USA), for which there is no robust scientific evidence.
Objective: To determine whether phenytoin or levetiracetam (Keppra, UCB Pharma, Brussels, Belgium) is the more clinically effective intravenous second-line treatment of paediatric convulsive status epilepticus and to help better inform its management.
Design: A multicentre parallel-group randomised open-label superiority trial with a nested mixed-method study to assess recruitment and research without prior consent.
Setting: Participants were recruited from 30 paediatric emergency departments in the UK.
Participants: Participants aged 6 months to 17 years 11 months, who were presenting with convulsive status epilepticus and were failing to respond to first-line treatment.
Interventions: Intravenous levetiracetam (40 mg/kg) or intravenous phenytoin (20 mg/kg).
Main outcome measures: Primary outcome - time from randomisation to cessation of all visible signs of convulsive status epilepticus. Secondary outcomes - further anticonvulsants to manage the convulsive status epilepticus after the initial agent, the need for rapid sequence induction owing to ongoing convulsive status epilepticus, admission to critical care and serious adverse reactions.
Results: Between 17 July 2015 and 7 April 2018, 286 participants were randomised, treated and consented. A total of 152 participants were allocated to receive levetiracetam and 134 participants to receive phenytoin. Convulsive status epilepticus was terminated in 106 (70%) participants who were allocated to levetiracetam and 86 (64%) participants who were allocated to phenytoin. Median time from randomisation to convulsive status epilepticus cessation was 35 (interquartile range 20-not assessable) minutes in the levetiracetam group and 45 (interquartile range 24-not assessable) minutes in the phenytoin group (hazard ratio 1.20, 95% confidence interval 0.91 to 1.60; p = 0.2). Results were robust to prespecified sensitivity analyses, including time from treatment commencement to convulsive status epilepticus termination and competing risks. One phenytoin-treated participant experienced serious adverse reactions.
Limitations: First, this was an open-label trial. A blinded design was considered too complex, in part because of the markedly different infusion rates of the two drugs. Second, there was subjectivity in the assessment of 'cessation of all signs of continuous, rhythmic clonic activity' as the primary outcome, rather than fixed time points to assess convulsive status epilepticus termination. However, site training included simulated demonstration of seizure cessation. Third, the time point of randomisation resulted in convulsive status epilepticus termination prior to administration of trial treatment in some cases. This affected both treatment arms equally and had been prespecified at the design stage. Last, safety measures were a secondary outcome, but the trial was not powered to demonstrate difference in serious adverse reactions between treatment groups.
Conclusions: Levetiracetam was not statistically superior to phenytoin in convulsive status epilepticus termination rate, time taken to terminate convulsive status epilepticus or frequency of serious adverse reactions. The results suggest that it may be an alternative to phenytoin in the second-line management of paediatric convulsive status epilepticus. Simple trial design, bespoke site training and effective leadership were found to facilitate practitioner commitment to the trial and its success. We provide a framework to optimise recruitment discussions in paediatric emergency medicine trials.
Future work: Future work should include a meta-analysis of published studies and the possible sequential use of levetiracetam and phenytoin or sodium valproate in the second-line treatment of paediatric convulsive status epilepticus.
Trial registration: Current Controlled Trials ISRCTN22567894 and European Clinical Trials Database EudraCT number 2014-002188-13.
Funding: This project was funded by the National Institute for Health Research (NIHR) Health Technology Assessment programme and will be published in full in Health Technology Assessment; Vol. 24, No. 58. See the NIHR Journals Library website for further project information.
Keywords: CONVULSIVE; EPILEPSY; LEVETIRACETAM; PAEDIATRIC; PHENYTOIN; RANDOMISED; SEIZURE; STATUS EPILEPTICUS; TRIA.
Most epileptic tonic–clonic seizures, also called convulsions, last for < 4 minutes and stop spontaneously. A convulsion that lasts for > 5 minutes is called convulsive status epilepticus. This may cause neurological abnormalities or, rarely, death. There is good scientific evidence for the best first-line medicine, called a benzodiazepine, to stop convulsive status epilepticus. When a benzodiazepine has not stopped status, a second-line medicine is given. The usual second-line medicine, which has been used for > 50 years, is phenytoin (Epanutin, Pfizer Inc., New York, NY, USA). However, it stops status in only half of children. It must be given slowly because it can cause unpleasant and potentially serious side effects. A new medicine called levetiracetam (Keppra, UCB Pharma, Brussels, Belgium) may be more effective. It seems to have less serious side effects than phenytoin. However, there is no good scientific evidence as to whether phenytoin or levetiracetam is better. A randomised controlled trial is the best scientific way to decide which of these two medicines is better. The Emergency treatment with Levetiracetam or Phenytoin in Status Epilepticus in children (EcLiPSE) trial was a randomised controlled trial that compared levetiracetam with phenytoin. A total of 152 children were randomised to receive levetiracetam and a total of 134 children were randomised to receive phenytoin. Research without prior consent was shown to be acceptable to parents, doctors and nurses. Parents’ consent to use their child’s data and continue in the trial was provided after the emergency situation was resolved. Convulsive status epilepticus stopped in 70.4% of the levetiracetam-treated children and in 64% of the phenytoin-treated children. The median time to status stopping was 35 minutes in the levetiracetam-treated children and 45 minutes in the phenytoin-treated children. Only one participant on phenytoin (vs. none on levetiracetam) experienced serious side effects that were thought to be caused by their treatment. None of the results showed any statistically significant or meaningful difference between levetiracetam and phenytoin. However, the results suggest that levetiracetam might be an alternative choice to phenytoin.