Changes in Serum Valproate and Levetiracetam Levels Related to Sex Steroids in Adolescent Girls

Abstract

Abstract Background The goal of this study was to explore the changes in serum antiepileptic drug levels and their relation with sex steroid levels during the menstrual cycles of adolescent girls. In addition, valproate and levetiracetam were compared in terms of their effects on body mass index, ovulation, and sex steroid levels. Methods Adolescent girls using valproate (n = 16) and levetiracetam (n = 9) were included in the study. Serum antiepileptic drug, progesterone, and estradiol levels were analyzed in two periods, when the levels of sex hormones might be the highest (midluteal phase) and the lowest (early follicular phase). Results Serum antiepileptic drug levels were not significantly different between the two periods in both antiepileptic drug groups. Serum antiepileptic drug levels during menstruation increased in 69.2% of the valproate group, whereas they decreased in 88.9% of the levetiracetam group ( P = 0.011). A positive correlation between serum valproate and progesterone levels ( r = 0.767, P = 0.001) and between levetiracetam and estradiol levels ( r = 0.259, P > 0.05) was present in the menstrual phase. Body mass index, body mass index percentile, z score, and ovulation rates were not different between the two groups. Conclusions This study indicates a strong correlation between valproate and progesterone levels in the early follicular phase of the menstrual cycle. The findings of this study also suggest that valproate and levetiracetam have different relationships with sex steroid levels, during menstrual cycle. Especially in catamenial seizures, taking this interaction into account may be beneficial.