Changes in Seizure Frequency and Antiepileptic Therapy during Pregnancy

Abstract

To the Editor: Pennell et al. (Dec. 2020 issue)¹ report that the frequency of seizures during pregnancy in women with epilepsy was similar to the seizure frequency in a comparator group of nonpregnant women with epilepsy. These results have not been observed in previous studies, but I would like to highlight some issues related to the article. Alterations during pregnancy in the pharmacokinetics of antiepileptic drugs (such as an increased volume of distribution, changes in the free [unbound] fraction of drugs, increased hepatic metabolism, and increased clearance)² and pharmacogenomic differences affect the disposition of these drugs during pregnancy. The investigators . . .