Abstracts

Rationale: Refractory status epilepticus (RSE) is one of the most challenging medical conditions encountered by neurologists. It is defined as status epilepticus (SE) that does not resolve following treatment with a first-line agent (typically a benzodiazepine) or a second-line antiepileptic drug (AED). It accounts for 30-40% of all cases of SE and is associated with poor outcome in up to 75% of cases. Such outcomes suggest the need for alternative therapies for patients who fail first, second, and third line therapies, or in whom seizures return when such therapies are weaned.One of the newer AEDs approved for the treatment of epileptic seizures is clobazam (trade name Onfi). Unfortunately, there is currently limited information regarding the safety and effectiveness of clobazam for the treatment of SE in humans. Therefore, we performed a historical cohort study to evaluate our experience with this newer AED in the treatment of SE. Methods: The electronic medical records of all adult patients seen at the University of Cincinnati Medical Center between 10/27/2012 and 8/3/2015 were queried for diagnoses consistent with SE. Only those patients who were administered at least one dose of clobazam were subsequently analyzed. Information was abstracted from their medical records to determine the potential efficacy of clobazam at treating SE and outcomes following treatment. Results: Seventeen patients (11 men, 6 women) were identified. The mean age at SE presentation was 43.0+/-15.4 years (range 24-83). The majority (14/17, 82.4%) had a prior history of epilepsy prior to presentation in SE. Only 6/17 (35.3%) had a diagnosis of Lennox-Gastaut syndrome. Etiologies for SE included underlying seizure disorder (n=5, 29.4%), infection lowering the seizure threshold (4, 23.5%), AED weaning (2, 11.8%), AED noncompliance (1, 5.9%), neoplasm (1, 5.9%), and unknown (4, 23.5%). The majority of SE cases (n=14, 82.4%) were convulsive at presentation; only 3 (17.6%) were nonconvulsive. The mean duration of SE prior to clobazam initiation was 3.2+/-2.8 days (range 1-9). The mean maximum dosage utilized was 23.8+/-15.4 mg/day (range 5-45 mg/day). Following clobazam initiation, SE ultimately terminated in all patients (mean 2.5+/-2.9 days following first dose, range 1-13). Two patients required no further AED changes prior to SE termination after the initiation of clobazam. The mean hospital stay was 13.5+/-12.8 days (range 2-46). One patient died prior to discharge but after resolution of SE. Upon discharge, a good outcome (modified Rankin scale 0-2) was recorded in 5 patients (29.4%). Conclusions: Clobazam may be useful in the treatment algorithm for RSE. Clobazam’s long half-life (67.5 hours for clobazam’s active metabolite N-desmethylclobazam) makes it potentially ideal for the longer term treatment of patients in SE, alleviating the need for repeated boluses (as is required for benzodiazepines with shorter distribution half-lives). Further studies are warranted to explore the safety and effectiveness of this newer AED in the treatment of SE. Funding: No funding was received for this abstract.