Association between repeated antibiotic prescribing and seizure- and other neuropsychiatric disorders-related hospitalization among people living with dementia: a population-based cohort study.

Antibiotic use is common among people living with dementia (major neurocognitive disorder) and is associated with seizures and other neuropsychiatric disorders. This population-based cohort study aims to understand the association of repeated antibiotic prescriptions with seizure-related, other neuropsychiatric disorders-related and all-cause hospitalization among people living with dementia, using electronic health records from the Hong Kong Clinical Data Analysis Reporting System. There were 79,367 patients with dementia who were aged 65 or older and had seizure-related high-risk antibiotic prescriptions from 2004 to 2019. There were 71,920 patients with dementia who had other neuropsychiatric disorders-related high-risk antibiotic prescriptions. The seizure-related, other neuropsychiatric disorders-related and all-cause hospitalization risks within 30 days after a high-risk antibiotic prescription in the three highest quartiles of antibiotic use in the past 6 months were compared to the lowest. The increased seizure risks associated with frequent high-risk antibiotic prescribing within 1-30 days are likely due to protopathic bias. In the sensitivity analyses, where the frequency of antibiotic exposure changed from 6 months to 1-year prior and the risks within 15-30 days were examined, no increase in seizure risks was observed. Frequent high-risk antibiotic prescribing did not incur a significantly higher risk of other neuropsychiatric disorders. A progressive increase in risks of all-cause hospitalization was observed with increased high-risk antibiotic prescribing. The findings suggest that clinicians should carefully balance the benefits of repeated antibiotic courses against potential risks when prescribing to people living with dementia.