Abstracts

Rationale: Lacosamide (LCM) is a newly approved antiepileptic medication (AED) with a novel anticonvulsant activity. The efficacy of LCM was reported in patients with partial epilepsy in pivotal trials, and the safety of intravenous LCM infusion (200-800 mg/day) over 10, 15 or 30 minutes was demonstrated in an open-label study. Its availability in intravenous solution, favorable pharmacokinetics, tolerability and lack of respiratory suppression make LCM as an attractive choice to treat patients in acute/critical settings. However, experiences of using LCM in these critical settings are quite limited. We reviewed the effectiveness of intravenous LCM in the treatment of status epilepticus (SE). Methods: We retrospectively reviewed our inpatient hospital record to identify patients who had received intravenous LCM for status epilepticus between August 2009 and April 2010 at the Barrow Neurological Institute after obtaining IRB approval. Relevant clinical data including age, etiology of status epilepticus, AEDs administered prior to LCM and disposition were collected, in addition to EEG interpretations. Only the patients who had a diagnosis of SE by EEG criteria prior to receiving LCM were included in the study. All patients had continuous and /or routine EEGs prior to receiving intravenous LCM and during the first day after the first dose of LCM. Those patients who had been taking LCM prior to the diagnosis of SE were excluded from the study. Results: We identified a total of 19 patients (12 males) who had received intravenous LCM for the treatment of refractory SE during this study period. Median age was 58 (ranged from 3 to 77) and only one patient was less than 18 years of age. Etiology of status epilepticus included vascular, neoplastic, infectious and anoxic causes. Prior to receiving LCM, patients were most frequently treated with lorazepam, fosphenytoin, and levetiracetam, followed by valproate, phenobarbital, carbamazepine, midazolam, diazepam, and propofol. The initial dose of LCM ranged from 50mg to 400mg followed by maintenance doses ranging from 100mg to 400mg per day. The pretreatment EEGs showed unilateral or bilateral periodic discharges in 7 patients, continuous or rhythmic epileptiform discharges in 10 patients, and burst-suppression patterns in 2 patients. 16 of the 19 patients (84.2%) had improvement in their EEG during the first day after receiving LCM, although12 of the 19 patients (63%) had recurrence of seizures during the hospitalization. Conclusions: Our retrospective study suggests that intravenous LCM was effective in treating refractory SE. Coupled with its favorable pharmacokinetic profile and tolerability, LCM may be an useful alternative in the treatment of refractory SE. Further prospective study is needed to establish the definite efficacy of LCM in treating SE as well as its loading dose and infusion rate.