Examination of the prescription of antiepileptic drugs to prenatal and postpartum women in Japan from a health administrative database.

PURPOSE

To evaluate the prevalence and patterns of prescriptions of antiepileptic drugs (AEDs) to prenatal and postpartum women in Japan using a large administrative database.

METHODS

The dates of pregnancy onset and delivery were estimated using published algorithms and infant birth months. The prevalence of prescribed AEDs, the maximum dose of some AEDs, and the frequency of potential combination therapy with AEDs were evaluated for the 180 days before pregnancy onset, during pregnancy, and at 180-day postpartum.

RESULTS

In total, 33 941 pregnant women were eligible for analysis. At least one AED was prescribed to 225 women (66 per 10 000 deliveries) between 180 days before pregnancy and 180-day postpartum and for 135 women (40 per 10 000 deliveries) during pregnancy. The prevalence of AED prescription declined during the first and second trimesters and increased in the third trimester and postpartum. Valproate was the most frequently prescribed drug, followed by clonazepam, lamotrigine, and carbamazepine. Nine (18.4%) of the 49 women with at least one prescription record of valproate in the first trimester were prescribed more than 600 mg/day of valproate. Concerning potential combination therapy, 40 (12 per 10 000 deliveries) concurrently received two or more AEDs between 180 days before pregnancy and 180-day postpartum, respectively, 31 (9 per 10 000 deliveries) women received these drugs during pregnancy.

CONCLUSIONS

Various AEDs were prescribed to pregnant Japanese women. Women of reproductive age should select the appropriate AED before becoming pregnant, depending on the risk benefit profile.