Contraceptive–Antiseizure Drug Interactions Common Among Medicaid Patients With Epilepsy

Nearly a third of Medicaid beneficiaries with epilepsy of childbearing potential who were prescribed hormonal contraception susceptible to hepatic enzyme induction also had at least 14 days of overlap with an enzyme-inducing antiseizure medication (ASM), according to a retrospective cohort study in Neurology.

The authors noted that people with epilepsy of childbearing potential need access to highly effective contraception, but many ASMs can reduce the effectiveness of some hormonal methods by inducing hepatic enzymes. Using Medicaid claims data for female beneficiaries from 2016 to 2021, they identified overlap periods of at least 14 days between enzyme-inducing ASMs and susceptible contraceptives based on prescription fill dates and contraceptive procedure dates.

The cohort included 110,976 people with epilepsy of childbearing potential (median age, 24 years; 54.8% White non-Hispanic). Of these, 21,923 were prescribed a susceptible contraceptive method from 2018 to 2021, and 7,154 (32.6%) had at least 1 overlap period of 14 days or longer. Median overlap in that group was 218 days (interquartile range, 74-511).

Any overlap was associated with intellectual disability (adjusted odds ratio [aOR], 2.33; 95% CI, 2.19-2.48), drug-resistant epilepsy (aOR, 1.73; 95% CI, 1.62-1.84), and age older than 35 years vs 19 to 34 years (aOR, 1.45; 95% CI, 1.32-1.59). The same 3 characteristics were also associated with longer periods of overlap.

The authors concluded that ASM drug interactions that reduce contraceptive effectiveness are common among people with epilepsy of childbearing potential prescribed susceptible hormonal contraception. They noted that the data set lacked information on adherence, counseling, pregnancy intentions, sexual orientation and activity, and barrier method use.

Source: Harrison E, Kirkpatrick L, Dutton C, et al. Contraceptive and enzyme-inducing antiseizure medication coprescription among US Medicaid beneficiaries with epilepsy. Neurology. 2026;107(9):e218679. doi:10.1212/WNL.0000000000218679