Abstracts

Rationale: Over the past two decades, there has been an increase in the number of FDA-approved antiepileptic drugs (AEDs). Over the same period, there has been increasing knowledge about the potential teratogenic effects of AEDs, particularly valproic acid. Few studies have examined how increased AED options, data about teratogenicity and other factors might affect AED choice in women with epilepsy of childbearing age. Methods: As part of an ongoing retrospective longitudinal observation study examining AED choice, response and tolerability, we identified all AEDs that were newly started, either as monotherapy or in a polytherapy regimen, each year from January 1, 2000 to December 31, 2011 at Columbia Comprehensive Epilepsy Center. Using descriptive statistics, we compared the frequency of specific AEDs by year, stratifying by gender, age group (12-45 years and > 45 years) and epilepsy type (localization-related epilepsy, primary generalized epilepsy and symptomatic generalized epilepsy). Results: 7729 new antiepileptic drugs were started in 2692 patients (1217 males; median age 38 years (SD 17.0 years); median duration of epilepsy 12 years (SD 15.2 years)). The most commonly prescribed AEDs were lamotrigine and levetiracetam, accounting for 26.0% (range 18.5-33.3% per year) and 18.3% (range 14.6-23.6% per year) of all new prescriptions throughout the study period. In both men and women ages 12-45 years, there was a decline in the use of valproic acid in the first half of the study period, with a nadir in 2005-2006, and then a gradual increase in the use of valproic acid starting in 2007, persisting until the end of the study period. After 2006, there was a greater use of valproic acid in men aged 12-45 years than in women in the same age group, particularly in patients with primary generalized epilepsy, and this increase coincided with a decrease in the use of lamotrigine and levetiracetam. In patients starting new AEDs in a polytherapy regimen, and those with localization-related epilepsy, there was a steady decrease in the use of lamotrigine and levetiracetam over the study period, and an increase in the use of other (mainly second and third-generation) AEDs over the study period, with no differences based on age or gender. Conclusions: Based on the practice pattern at one tertiary care epilepsy center, the choice of valproic acid, particularly for the treatment of primary generalized epilepsy declined from 2000-2006, but then gradually increased from 2007 onward, particularly among men. We propose that this change could have been at least partially motivated by the publication of the SANAD study (Lancet 2007;369:1016-26) which provided evidence supporting the use of valproic acid as a "therapy of choice" for the treatment of primary generalized epilepsy. Valproic acid was used more commonly among men than women, likely resulting from concerns about teratogenicity in women of childbearing age.