Treatment Patterns of Antiseizure Medication for Poststroke Prophylaxis Among Older Adults

BACKGROUND: Antiseizure medications are commonly prescribed for poststroke seizures, yet long-term use lacks clear clinical guidance. We examined medication treatment patterns among older adults who initiated levetiracetam, the most frequently prescribed antiseizure medication, within 30 days after an acute ischemic stroke discharge. METHODS: We analyzed a national 20% random sample of US Medicare beneficiaries aged ≥65 years, who were hospitalized for a first acute ischemic stroke between 2009 and 2021 and initiated levetiracetam within 30 days of discharge. To analyze time-varying Levetiracetam treatment patterns over the first year after initiation, we calculated an adjusted proportion of days covered that accounts for prescription overlap, hospitalization, and non-persistence. Adherence to levetiracetam treatment strategy was defined as having a proportion of days covered ≥80%. A latent-class mixed model on proportion of days covered trajectories was applied to identify and characterize different treatment patterns, adjusting for clinical factors. RESULTS: In our sample of 1697 levetiracetam initiators, the mean age was 77.5 years, and 58% were women. The latent-class mixed model on proportion of days covered trajectories identified 3 distinct levetiracetam treatment patterns: (1) 907 patients (53%) were nonadherent to treatment after 2 months, (2) 99 patients (6%) were nonadherent to treatment after 10 months, and (3) 691 patients (41%) remained consistently adherent to treatment for at least 1 year. White patients and women were more likely to be adherent to the levetiracetam treatment strategy. CONCLUSIONS: Approximately 41% of older adults remained consistently adherent to the levetiracetam treatment strategy within a year after outpatient initiation, with race and sex significantly associated with adherence-to-treatment probabilities.