Abstracts

Rationale: Previously we had shown that retrospective review of initial usage of Levetiracetam (LEV) for seizures after FDA approval in outpatient setting had shown high efficacy and tolerability (O'Donovan, 2005). We sought to determine if; a)this benefit was sustained over time, and b)identify if seizure freedom with monotherapy or adjunctive therapy would occur after failure to respond to previous medications. Methods: Retrospective review of chart notes of 307 patients with epilepsy treated with LEV at referral center. Seizure type, seizure freedom rate using monotherapy and adjunctive therapy, retention rate as well as side effects were analyzed. Results: 91% of patients had partial epilepsy. Median dose in this group was 2000mgs and average duration of treatment was 48 months. 132 patients (43%) became seizure free on LEV in the overall group, including 36% of refractory patients (more than 2 AEDs) and 54% of those with no prior AEDs. The number of prior AEDs in the patients(n) who became seizure free on LEV in the refractory group were, 2 AEDs (n=31), 3 AEDs (n=11), 4 AEDs (n=11), and 5 AEDs (n=9). The number of patients who became seizure free (n) in refractory group when converted to LEV monotherapy was; 2 AEDs (n=9), 3 AEDs (n=4), 4 AEDs (n=3) and 5 AEDs (n=1). The percentage of patients achieving seizure freedom on other AEDs after LEV failure was only 5%(8/175). Psychological problems were present at baseline in 120 of 307 patients. 47 of 307 patients experienced side effects leading to discontinuation. 27 of 307 patients had psychiatric type side effects of which the most common was anger, hostility and irritability but depression was only seen in four patients. Conclusions: Levetiracetam (LEV) in the refractory group showed higher seizure freedom rates compared to prior reports. Seizure freedom was also seen with conversion to LEV monotherapy in the refractory groups even after several years of polypharmacy with up to 5 AED's. Given the high incidence of pre-existing psychiatric co-morbidities in this patient population, there is a relatively low incidence of psychological side effects seen with LEV.