Trends in Pediatric Diphenhydramine Cases Reported to US Poison Centers (2014–2023)

BACKGROUND AND OBJECTIVE Recent toxicosurveillance trends indicate an increase in intentional pediatric diphenhydramine ingestions, raising concerns about accessibility, toxicity, social media influence, and the need for appropriate harm reduction. This study analyzes US national poison center data on intentional diphenhydramine ingestions to assess trends, clinical severity, and outcomes over the past decade. METHODS A retrospective review of the National Poison Data System (NPDS) identified intentional single-substance diphenhydramine ingestions in patients aged 19 years or younger from January 1, 2014, to December 31, 2023. Demographics, clinical severity, and outcomes were analyzed. To evaluate the pandemic’s impact on diphenhydramine-related call frequency, an interrupted time series analysis was performed. RESULTS Over the 10-year period, 45 085 pediatric diphenhydramine ingestions were reported to the NPDS, representing an 87.2% increase from 3183 cases in 2014 to 5960 cases in 2023. Ingestions were more common among females and adolescents, with suicidal intent as the leading cause, more than doubling from 2248 to 4688 cases. Cardiovascular and neurologic symptoms were most frequent. Most cases (90%) required treatment at a health care facility, with 20% admitted to a critical care unit. Post-pandemic onset monthly diphenhydramine-related calls increased significantly after April 2020, driven largely by a rise in ingestions associated with suicidal intent. CONCLUSION Intentional pediatric diphenhydramine ingestions reported to US poison centers increased significantly over the study period, particularly among adolescents engaging in self-harm. These findings highlight the continued need for targeted harm-reduction strategies and enhanced regulatory measures to mitigate the growing toxicity burden.