Antiseizure medication selection and retention for adult-onset focal epilepsy in a Swedish health service region: a population-based cohort study.

Levetiracetam and lamotrigine were the dominating first ASMs for adult-onset focal epilepsy in our region, indicating good awareness of problems with enzyme induction or teratogenicity of older drugs. The most striking finding is the high retention rates, perhaps reflecting a shift towards an older epilepsy population, higher tolerability of newer ASMs, or suboptimal follow-up. The finding that treatment retention differed among patients receiving levetiracetam and lamotrigine aligns with the recent SANAD II results. It suggests lamotrigine may be underutilized in our region and that education efforts are needed to ensure it is considered the first choice more often.