Abstracts

Rationale: Women with epilepsy (WWE) and their neonates benefit from planned pregnancies, yet 50% of their pregnancies are unplanned, similar to the general population. Effective contraception allows for medication optimization to reduce fetal risk as well as to establish folic acid supplementation but can be challenging for WWE. Oral contraceptives are widely used, but complex drug interactions limit their efficacy and safety for WWE. We sought to characterize the safety, acceptability and pharmacokinetic impact of the hormonal, levonorgestrel intrauterine system (LNG IUS) in WWE. Methods: We recruited 20 women with well-controlled epilepsy and a stable antiepileptic drug (AED) regimen who initiated the LNG IUS for contraception. Participants recorded seizures and menstrual bleeding in daily diaries for one month before IUS insertion and for six months thereafter. We measured serum trough levels of AEDs and LNG (radio-immuno assay) on the day of IUS insertion and three weeks, three months and six months thereafter. We administered an acceptability questionnaire at three and six months. Results: Participants' average age was 28 years and 60% were nulligravid. Participants reported a history of generalized tonic-clonic (55%), complex-partial (40%) and simple-partial (35%) seizures. Fourteen were treated with one AED, six received polytherapy. Lamotrigine was the most common drug used in monotherapy (seven) as well as part of a polytherapy regimen (five). Other AEDs used in monotherapy included levetiracetam (four), oxcarbazepine (two), and carbamazepine (one). All participants continued LNG IUS use at six months. At three months, 50% of participants were very satisfied with the IUS overall and by six months 65% were very satisfied. None reported the IUS worsened her seizure control. We successfully obtained LNG (n=80) and AED (n=26) trough levels for all participants at all visits for a total of 104 AED levels. Samples were at drawn at consistent intervals from the last AED dose. We are currently analyzing seizure and drug interaction data. Conclusions: Data from this this pilot study support recommending the LNG IUS as a first line contraceptive method for WWE. Both WWE and their neonates benefit greatly from avoiding unplanned pregnancy. Investigator initiated study supported by funds from Bayer