Abstracts

Rationale: Clobazam is a benzodiazepine with a marginally different chemical structure from other commonly used benzodiazepines, and exhibits fewer sedative properties due to its partial agonism to the GABA-A receptors. Clobazam was approved in the United States in 2011 for the treatment of seizures associated with Lennox-Gastaut Syndrome (LGS). Prior to its introduction in the US, Clobazam had been used in other countries for the treatment of various seizure types and epilepsy syndrome since the 1970s. In the US, off-label use of Clobazam for the treatment of various seizure types is common. The purpose of this study is to compare the effectiveness of Clobazam among different epilepsy syndromes.


Methods: We retrospectively reviewed the charts of all patients treated with Clobazam at a single center. Demographic data, epilepsy syndrome, comorbidities, and seizure types were collected. Response to the addition of clobazam was classified either as Poor Outcome (persistence of frequent seizures) or Good Outcome (seizure freedom or occurrence of rare breakthrough seizures).


Results: A total of 98 charts were identified (61 F). Of those, 63 had focal epilepsy (FE), 26 had symptomatic generalized epilepsy (SGE), and 8 had primary generalized epilepsy (PGE). Seizure types varied by epilepsy syndrome. The most common comorbidity was Autism Spectrum Disorder (ASD) which was present in 16 patients, of which, 11 had focal epilepsy. Cerebral Palsy (CP) was present in 13 patients, of which, 9 patients had symptomatic generalized epilepsy.



Effectiveness of Clobazam was determined based on seizure frequency reported in the last visit during which the patient was still taking Clobazam. We divided patients into three categories, Seizure Fee, Rare Seizures, and Frequent Seizures, then combined the Seizure Free and Rare Seizures categories under a single category called Good Outcome and compared it to patients with frequent seizures, or Poor Outcome.



FE: Of 63 patients, 27 (43%) were seizure free, and 15 (24%) had rare seizures, with total Good Outcome 42 (67%). SGE: Of 26 patients, 7 (27%) were seizure free, and 7 (27%) had rare seizures, with total Good Outcome 14 (54%). PGE: Of 8 patients, 3 (38%) were seizure free and none had rare seizures, with total Good Outcome 3 (38%). No statistical significance (P >0.05) was found among all three groups.



Patients with ASD fared the same as non-ASD patients (56% vs 58% Good Outcome).Patients with CP fared better than non-CP patients (69% vs 57% Good Outcome), but this was not statistically significant.


Conclusions: In this study, we found that the effectiveness of Clobazam as measured by the rate of improved seizure control was not statistically different among patients with focal epilepsy compared to patients with LGS or other types of generalized epilepsy. Although Clobazam is only indicated for patients with seizures associated with LGS, it should be considered as a reasonable option, especially for refractory seizures, in patients with different epilepsy syndromes.


Funding: None