Therapeutic Drug Monitoring of Levetiracetam in Different Trimesters of Pregnant Women with Epilepsy in a Tertiary Care Center: A Prospective Study

Abstract

Background: Levetiracetam is the most commonly used antiepileptic drug in pregnant women due to its low teratogenic risk profile, favorable pharmacokinetic characteristics, and safety profile. Serum levels of levetiracetam vary in epilepsy during pregnancy. Therefore, the aim of the study was to evaluate the serum levels of levetiracetam during different trimesters of pregnancy by using therapeutic drug monitoring (TDM). Materials and Methods: This was a single-center, prospective study. Pregnant women with epilepsy on levetiracetam were enrolled after getting written informed consent from them. Serum trough levels of levetiracetam were estimated at all trimesters by high-performance liquid chromatography (HPLC). Results: The study included 16 participants with mean ± standard deviation (SD) age of 27.75 ± 4 years. There were nine (56.2%) participants with generalized seizure disorder and seven (43.8%) participants of focal seizure disorder. Among 16 patients, 10 (62.5%) participants were on levetiracetam alone and six (37.5%) participants were on levetiracetam combined with other antiepileptic drugs. In a total of 48 trough samples, 45 sample concentrations were below the therapeutic range of 12–46 mg/l and three sample concentrations were within the therapeutic range. There was a statistically significant difference in the concentration–dose ratio (CDR) of levetiracetam between the third and first trimesters (P-value 0.018). Conclusion: There was a statistically significant difference in serum levetiracetam concentration between the third and first trimesters. A well-conducted, intensive pharmacokinetic sampling study in PWWE with a control group is needed in future to evaluate the whole pharmacokinetic profile of levetiracetam and to correlate the clinical outcome.