FRIDAY, Oct. 9, 2026 (HealthDay News) -- For people with epilepsy of child-bearing potential (PWECP) prescribed hormone contraception susceptible to hepatic enzyme induction, drug interactions with antiseizure medications (ASMs) leading to reduced contraceptive effectiveness are common, according to a study published online Oct. 7 in Neurology.
Elizabeth Harrison, M.D., from the University of Virginia School of Medicine in Charlottesville, and colleagues examined the proportion of PWECP prescribed a susceptible hormonal contraceptive method who were concurrently prescribed an interacting ASM. A cohort of people with epilepsy on ASMs prescribed at least one susceptible hormonal contraceptive method was defined using Medicaid claims data from 2016 to 2021 for female beneficiaries.
The cohort included 110,976 PWECP, of whom 21,923 were prescribed a susceptible contraceptive method from 2018 to 2021. Overall, 32.6 percent of that group had at least a 14-day period of overlap with an enzyme-inducing ASM; for this group, there was a median of 218 days of overlap. Patient characteristics associated with any period of overlap and longer periods of overlap included intellectual disability (adjusted odds ratios, 2.33 and 2.27, respectively), drug-resistant epilepsy (adjusted odds ratios, 1.73 and 1.27, respectively), and age 35 years or older versus 19 to 34 years (adjusted odds ratios, 1.45 and 1.51, respectively).
"It is important for people with epilepsy to know that not all forms of contraception are affected by these medication interactions," study author Laura Kirkpatrick, M.D., from the University of Pittsburgh School of Medicine, said in a statement. "With informed counseling, people can choose a contraceptive method that aligns with their preferences and health needs. Our study did not look at pregnancy outcomes or determine whether participants experienced contraceptive failure, so more research is needed to better understand the real-world impact of these overlapping prescriptions."
Several authors disclosed ties to the biopharmaceutical and medical technology industries.
