Surveillance of First-Generation H1-Antihistamine Use for Older Patients with Dementia in Japan: A Retrospective Cohort Study

Abstract

Background. This study aimed to investigate the rate of first-generation H1-antihistamines use for older adults with dementia in Japan. Methods. The study design was retrospective cohort using claims data between fiscal years 2010 and 2013. Subjects were 75 years or older, diagnosed with dementia, and given H1-antihistamines orally during the study period after being diagnosed with dementia. We investigated the cumulative number of oral H1-antihistamines administered and the relationship between first-generation H1-antihistamine use and each explanatory variable using crude and adjusted odds ratio. Results. The cumulative total for use of first-generation H1-antihistamine for older adults with dementia accounted for 32.1% of all antihistamine medication. The majority of first-generation H1-antihistamine prescriptions were indicated for cold treatment. Those with upper respiratory infection or asthma had a significantly positive relationship with first-generation H1-antihistamine use. Conclusion. The study showed that first-generation H1-antihistamine drugs were highly prescribed in older adults with dementia in Japan.