Authors :
Presenting Author: Lilach Goldstein, MD – Tel Aviv Medical Center
Noam Fallik, MD – Tel Aviv Sourasky Medical Center; Ilia Trakhtenbroit, MD – Barzilay, University Medical Center; Firas Fahoum, MD – Tel Aviv Sourasky Medical Center
Rationale:
Levetiracetam (LEV) is an anti-seizure medication indicated for the treatment of focal and generalized seizures and is mainly excreted by the kidneys. Due to its low teratogenic risk, LEV is frequently used in pregnant women. Physiological changes during different stages of gestation may affect the pharmacokinetic characteristics of LEV.
The goal of our study is to characterize the alterations in LEV clearance during pregnancy and the post-partum period, in order to better plan LEV dosing paradigm in pregnant women
Methods:
This retrospective observational study included a cohort of women that were followed at the epilepsy in pregnancy clinic at Tel Aviv Sourasky Medical Center (TASMC) between the years 2020 to 2022. The target LEV blood concentration was determined for every patient on an Individual basis and an empiric post-partum taper was used to reduce the likelihood of maternal toxicity. Trough LEV blood levels were measured before conception, every one to two months during pregnancy, and in the 12 weeks post-partum period. All measurements were done in a single lab at TASMC. Week of gestation and LEV dosage at the time of level measurement were documented. Office visits during pregnancy occurred every one to two months with review of medication diaries, blood sampling, and seizure frequency. Total LEV concentration/dose were calculated based on LEV levels and dosage as an estimation of LEV clearance.
Results:
A total of 266 samples were collected from 39 pregnant patients. We observed a decrease in LEV concentration/dose as the pregnancy progressed, followed by an abrupt post-partum increase in LEV concentration/dose. LEV dose was gradually increased by 61% on average during pregnancy compared to pre-conception dosage. The mean serum levels (ug/ml) decreased from 19.1 before pregnancy to 12.1, 13.5, and 16.6 at first, second, and third trimester respectively. In the post-partum period, there was an increase in average LEV level to 25.9 as the average dosage was decreased by 24%.
Conclusions:
LEV serum level monitoring is essential for women with epilepsy upon planning pregnancy and during pregnancy. Our data contributes to a rational treatment plan and dosing paradigm for LEV use during pregnancy and the post-partum period.
Funding: None