Abstracts

RATIONALE: A primary goal during pregnancy in women with epilepsy (WWE) is optimal seizure control. However, plasma levels of antiepileptic drugs (AED) decline during pregnancy and precipitous drops may provoke seizures. Free levels often fall less than total levels, but they still decline. The AAN QSS Practice Parameter on management issues for WWE recommends monitoring free AED levels at the beginning of each trimester and in the last month of pregnancy for the stable patient, with additional levels for seizure occurrence, side effects, and noncompliance. However, some individual authors still recommend monthly monitoring of AED levels for all patients. METHODS: Nine consecutive pregnant women in the Emory Epilepsy Clinic were asked to obtain monthly total and free AED levels. Six of these patients were compliant with medication regimens and blood draws and did not have significant emesis. Additional levels were obtained when clinically indicated. All seizures and AED dosage adjustments were recorded. The percent declines in AED levels were calculated between each blood draw. Free AED levels were preferentially used for comparison when available. Decreases of ?20% were considered significant. RESULTS: AED dosages were increased in all 6 patients during pregnancy. Three WWE had no significant decreases in AED levels. All 3 were on CBZ. Patient A (PHT) had 4 significant declines out of her 9 AED level comparisons, Patient B (VPA) 4/8, and Patient C (CBZ) 3/4. Patient A had seizures only with AED level declines, Patient B had seizures both with and without declines, and Patient C had no seizures. The AED level declines occurred in all 3 trimesters for all 3 drugs. CONCLUSIONS: Three of 6 WWE experienced significant declines in AED levels from just one month to the next despite stable or increasing AED dosages. No particular pattern was present for AED type or for which trimester the declines occurred in. AED level declines tended to provoke seizures in at least one patient. Given the substantial individual variability in AED level declines during pregnancy and the goal of seizure control, monthly free AED level monitoring during pregnancy may be warranted for all WWE.