Poison center exposures due to therapeutic misuse of nonprescription acetaminophen-containing combination products in the United States 2007-2016

Background: Overdoses due to therapeutic misuse result when the maximum dose of a drug is exceeded while using it for its intended purpose, due to either intentionally exceeding the label dose, misunderstanding the label or use of more than one product with the same ingredient. Nonprescription acetaminophen-containing combination products have been hypothesized to be a risk for therapeutic misuse. This study assessed the contribution of nonprescription acetaminophen-containing products to Poison Center exposures and the time trend in these exposures since public attention was brought to their potential risks. Methods: The National Poison Data System (NPDS) was used to identify exposures involving acetaminophen-containing products in individuals 12 years or older for the period 2007-2016. Exposures due to therapeutic misuse of nonprescription acetaminophen-containing combination products were identified and demographic and clinical features of these exposures tabulated. Product sale and US population data were used to normalize the exposures. Results: Therapeutic misuse exposures involving nonprescription acetaminophen-containing combination products decreased from 8753 in 2007 to 6278 in 2016. The majority of exposures occurred in individuals 12-29 years of age. The rate of therapeutic misuse exposures was highest in the 12-19 years of age cohort with an estimated 638 exposures per million population per 10 years. More than one acetaminophen-containing product was involved in 24.8% of exposures. Individuals were hospitalized in 5.4% of exposures and 51 deaths occurred in the 10-year observation period in reported exposures. Conclusions: NPDS exposures due to therapeutic misuse of nonprescription acetaminophen-containing combination products are infrequent and the number of exposures decreased from 2007 to 2016. Nonetheless, these exposures impact poison centers, healthcare facilities and patients. Additional initiatives to educate consumers on the safe use of these products and innovative labeling efforts to prevent concurrent use of multiple acetaminophen-containing products should be continued and are encouraged.