Abstracts

Rationale: Levetiracetam is an antiepileptic drug with a distinct mechanism of action, shown in regulatory trials to be effective. However, controlled trials do not always predict how useful a drug will be in day to day clinical practice. Retention rates can provide a better indication of efficacy and tolerability in everyday use. The elderly have the highest incidence of seizures among all age groups and there are currently no published studies exploring the retention rate of levetiracetam in the elderly. Methods: This was a retrospective data analysis of subjects who were ≥50 years of age at the time of initiation of therapy with levetiracetam. All subjects seen over an eight-year period who met these criteria were included. The following data were collected: date of initiation of levetiracetam, date of discontinuation of levetiracetam if applicable, age at start of treatment with levetiracetam, gender, race, and number of concurrent AEDs. Additionally, it was documented whether or not patient ever achieved seizure freedom for at least three months while on levetiracetam. Results: Data were collected on 101 subjects who met the criteria for inclusion. The mean age at the time of initiation of levetiracetam was 58 years old (range 50-86). 45.5% of the subjects were male and 71.3% of the subjects were white. Out of the 101 subjects included in the study, 76 (75.2%) continued levetiracetam at the last follow up included for the period of observation. Seizure freedom was achieved in 70% of the patients that continued on levetiracetam for the period of observation. However, of those patients who had discontinued levetiracetam, only 32% had been seizure free. The average duration of levetiracetam therapy for those who continued levetiracetam was 3.8 years (SD 2.55). The average duration of levetiracetam therapy for those subjects who had discontinued levetiracetam at the last follow up was 1.55 years (SD 1.55). The average number of concomitant AEDs in the group that continued LEV was 2.29 (SD 0.83) whereas the number of concomitant AEDs in the group that discontinued LEV was 2.72 (SD 0.89). Kaplan-Meier curve demonstrates retention of 89%, 82%, 78%, 76%, 73%, 66%, and 61% at 1, 2, 3, 4, 5, 6, and >6 years, respectively. Conclusions: The retention rate of levetiracetam in elderly subjects appears to be favorable in a retrospective cohort of elderly subjects. There appears to be a greater chance of discontinuation of levetiracetam therapy if seizure freedom is not achieved. There do not appear to be strong differences in the discontinuation rate of levetiracetam on the basis of age, sex, or number of concomitant AEDs that are used. (Source of funding: UCB, Inc.)