A Retrospective Study of the Etiologies and Outcomes of Patients Admitted to a University Hospital with Presumed Acetaminophen Toxicity

Abstract

We evaluated the characteristics and outcomes of patients admitted with presumed acetaminophen (APAP) toxicity in a large university hospital over a 3-year period. There were 128 adults (mean age, 36 + 12.5 y) and 51 pediatric patients (mean age, 14.3 + 4 y). Seventy-eight (60.9%) adult patients presented with intentional toxic ingestion, 47 (36.7%) unintentional toxic ingestion, and seven (5.5%) cases in whom the intent of APAP ingestion was unknown. Conversely, 42 (82.4%) of the pediatric cases were intentional ingestion (P= 0.01 vs adults). Patients admitted with unintentional toxic ingestion had a greater degree of hepatic impairment; although, significant differences in serum chemistries were not seen in the pediatric patients. However, in the adult group, those with unintentional toxic ingestion had significantly greater peak serum concentrations of aspartame aminotransferase (AST), alanine aminotransferase (ALT), bilirubin, and prothrombin time (PT). There were 56 cases of unintentional toxic ingestion (47 adult, 9 pediatric). Acetaminophen was used for the treatment of pain in 37 adults (78.7%) and four children (44.4%); headache was the most frequent cause of pain (10 [27%] adult and three [75%] pediatric patients). Use of other potentially hepatotoxic medications was noted in 23 adult patients (62.2%), with hydrocodone/APAP (Vicodin) being used most frequently (51.4%). There were 31 patients who experienced fulminant hepatic failure. Eighteen (32%) patients developed fulminant hepatic failure following unintentional toxic APAP ingestion compared to 10 (8.3%) patients who had intentional toxic ingestion (P< 0.001) (see Table 4). Fulminant hepatic failure occurred most frequently in adults (26 patients, 93%) and in females (71%). The ubiquity of over-the-counter APAP and the ever increasing use of APAP prescription products have increased the risk in a population largely unaware of the potential toxicity. Health care providers need to document all medications that patients are ingesting and provide education to those who are at risk of APAP toxicity.