<i>Notes from the Field: </i>Antihistamine Positivity and Involvement in Drug Overdose Deaths — 44 Jurisdictions, United States, 2019–2020
Amanda T. Dinwiddie, Lauren J. Tanz, Jessica Bitting
Abstract
Antihistamines are frequently used to treat allergy symptoms (1). Misuse of antihistamines has been documented primarily in adolescents and young adults (2); however, antihistamine involvement in overdose deaths has not been widely studied. Among the various antihistamine subtypes, the first-generation H1 subtype can cause anticholinergic effects, including strong sedation (3) that might be exacerbated when co-used with other sedative drugs (e.g., opioids).* Diphenhydramine, a common over-the-counter first-generation H1 antihistamine, has been combined with opioids as an adulterant in illicit drug supply (4) and can be used to reduce opioid-related side effects (e.g., itchy skin because of histamine release from opioid use).