In 261 ED patients over age 65 receiving first generation antihistamines, 15% had an adverse reaction. Most common was delirium and urinary retention. Age over 85, previous cognitive impairment and multiple doses increased the risk of adverse reaction. Along with previous literature, this should discourage use of first generation antihistamines in older ED patients.
References
Killen, E., Cusumano, M., Zhang, Z., Newman, R., Voigtmann, J., Sanford, A. M, & Bitter, C. C. (2025). First-Generation Antihistamine Use in Geriatric Emergency Department Patients: Retrospective Review. Western Journal of Emergency Medicine: Integrating Emergency Care with Population Health, 27(1). http://dx.doi.org/10.5811/westjem.47491 Retrieved from https://escholarship.org/uc/item/7230n5z1
