Literature Review

Trial finds three drugs equally effective for established status epilepticus


 

FROM NEJM

Among children and adults with benzodiazepine-refractory status epilepticus, fosphenytoin, valproate, and levetiracetam each stop seizures by 60 minutes in approximately half of patients, according to a study published Nov. 27 in the New England Journal of Medicine. The effectiveness and safety of the intravenous medications do not differ significantly, the researchers wrote.

“Having three equally effective second-line intravenous medications means that the clinician may choose a drug that takes into account individual situations,” wrote Phil E.M. Smith, MD, in an accompanying editorial (doi: 10.1056/NEJMe1913775). Clinicians may consider “factors such as the presumed underlying cause of status epilepticus; coexisting conditions, including allergy, liver and renal disease, hypotension, propensity to cardiac arrhythmia, and alcohol and drug dependence; the currently prescribed antiepileptic treatment; the cost of the medication; and governmental agency drug approval,” said Dr. Smith, who is affiliated with University Hospital of Wales in Cardiff.

A gap in guidance

Evidence supports benzodiazepines as the initial treatment for status epilepticus, but these drugs do not work in up to a third of patients, said first study author Jaideep Kapur, MBBS, PhD, and colleagues. “Clinical guidelines emphasize the need for rapid control of benzodiazepine-refractory status epilepticus but do not provide guidance regarding the choice of medication on the basis of either efficacy or safety,” they wrote. Dr. Kapur is a professor of neurology and the director of UVA Brain Institute at University of Virginia in Charlottesville.

Levetiracetam, fosphenytoin, and valproate are the three most commonly used medications for benzodiazepine-refractory status epilepticus. The Food and Drug Administration has labeled fosphenytoin for this indication in adults, and none of the drugs is approved for children. To determine the superiority or inferiority of these medications, the researchers conducted the Established Status Epilepticus Treatment Trial (ESETT). The blinded, comparative-effectiveness trial enrolled 384 patients at 57 hospital EDs in the United States. Patients were aged 2 years or older, had received a generally accepted cumulative dose of benzodiazepines for generalized convulsive seizures lasting more than 5 minutes and continued to have persistent or recurrent convulsions between 5-30 minutes after the last dose of benzodiazepine.

Patients randomly received one of the three trial drugs, which “were identical in appearance, formulation, packaging, and administration,” the authors said. The primary outcome was absence of clinically apparent seizures and improving responsiveness at 60 minutes after the start of the infusion without administration of additional anticonvulsant medication. ED physicians determined the presence of seizure and improvement in responsiveness.

Trial was stopped for futility

The trial included 400 enrollments of 384 unique patients during 2015-2017. Sixteen patients were enrolled twice, and their second enrollments were not included in the intention-to-treat analysis. A planned interim analysis after 400 enrollments to assess the likelihood of success or futility found that the trial had met the futility criterion. “There was a 1% chance of showing a most effective or least effective treatment if the trial were to continue to the maximum sample size” of 795 patients, Dr. Kapur and coauthors wrote. The researchers continued enrollment in a pediatric subcohort for a planned subgroup analysis by age.

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