Limited Knowledge of Acetaminophen in Patients with Liver Disease.

Unintentional acetaminophen overdose remains the leading cause of acute liver failure in the United States. Patients with underlying liver disease are at higher risk of poor outcomes from acetaminophen overdose. Limited knowledge of acetaminophen may be a preventable contributor to elevated rates of overdose and thus acute liver failure. The purpose of this study is to assess knowledge of acetaminophen dosing and presence of acetaminophen in common combination products in patients with liver disease. We performed a cross-sectional study of patients with liver disease at the Pfleger Liver Institute at the University of California, Los Angeles between June 2015 and August 2016. Patients completed a demographic questionnaire and an acetaminophen knowledge survey. Additional information was obtained from the medical record. Of 401 patients with liver disease, 30 (15.7%) were able to correctly identify that people without liver disease can safely take up to 4 g/day of acetaminophen. The majority of patients (79.9%-86.8%) did not know that Norco® (hydrocone/acetaminophen), Vicodin® (hydrocone/acetaminophen) and Percocet® (oxycodone/acetaminophen) contained acetaminophen. Only 45.3% of the patients knew that Tylenol® #3 contained acetaminophen. We conclude that patients with liver disease have critically low levels of knowledge of acetaminophen, putting them at risk both of acetaminophen overdose, as well as undermedication, and inadequate management of chronic pain. We recommend an increase in education efforts regarding acetaminophen dosage and its safety in the setting of liver disease. Increasing education for those at risk of low acetaminophen knowledge is essential to minimizing acetaminophen overdose rates and optimizing pain management.