Abstracts

Rationale: Levetiracetam (LEV) is an FDA approved anti-epileptic drug (AED) for adjunctive therapy in partial and generalized seizures. It is not known whether LEV can be used safely in human pregnancy, it currently categorized as a class C medication during pregnancy by the FDA. International pregnancy registries and smaller case report series have reported the use of LEV monotherapy in pregnancy with initial favorable outcomes. AED serum level monitoring has been reported critical during pregnancy due to alterations in the metabolic state of the expectant mother. We propose to study the changes of LEV serum levels during pregnancy.Methods: This is a retrospective chart review of pregnant epilepsy patients referred to the Comprehensive Epilepsy Clinic at an academic medical center. Inclusion criteria were: 1) a diagnosis of epilepsy, 2)monotherapy with LEV initiated prior to or during pregnancy, 3)serum LEV levels obtained in the first, second, and third trimester of pregnancy. Patients were excluded due to: 1)history of non-compliance with AED therapy and 2)diagnosis of non-epileptic events. Results: A total of 11/16 patients met inclusion criteria. Patients were excluded due to lack of compliance with LEV serum level monitoring. An attempt to record levels at 4 week intervals was undertaken. LEV serum levels were averaged in the 1st, 2nd, and 3rd trimester with normal serum LEV levels reported as 10-65 µg/mL. Change in LEV serum levels were measured as percentage decrease of the average LEV levels between 1st and 2nd trimester and percentage decrease in average LEV serum levels between 2nd and 3rd trimester of pregnancy. These values were averaged as 36% and 28% decrease respectively. The average LEV dose was 2250 mg, 2700mg, and 3100mg in the in the 1st, 2nd, and third trimester respectively.Conclusions: LEV therapy has been shown in large case report series and clinical trials to be effective as monotherapy treatment for partial and generalized seizures. Safety of LEV use pregnancy has not been established, although its use has been reported in international pregnancy registries. Decline in serum AED levels may be attributed to multifactorial physiological changes in metabolism during pregnancy. Decline in serum AED levels during pregnancy may increase the risk of breakthrough seizures during pregnancy. Seizures during pregnancy may have negative fetal and maternal outcome. Our study demonstrates that monitoring of serum LEV levels is critical during pregnancy as serum levels were shown to significantly decline from the first, second, and third trimesters of pregnancy.