Risk Factors for Acetaminophen-induced Liver Injury: A Single-center Study from Japan.

PURPOSE: Acetaminophen has been increasingly used for the treatment of cancer-related pain in Japan since the revision of the package insert on January 21, 2011. However, high-dose acetaminophen may cause liver injury. The objectives of this study were to investigate the prevalence of liver injury in patients receiving acetaminophen and to identify the risk factors.

METHODS

The subjects were patients who were treated with acetaminophen ≥1500 mg/d for ≥4 weeks at Ehime University Hospital between April 2011 and December 2014. Drug-induced liver injury was evaluated by alanine aminotransferase and alkaline phosphatase levels, Naranjo score, and Child-Pugh classification.

FINDINGS: A total of 287 of 562 patients were treated for 4 weeks with acetaminophen ≥1500 mg/d. Twenty of 102 patients analyzed had drug-induced liver injury. Multivariate analysis was performed with variables from the results of univariate analysis (sex, age ≥70 years, abnormal alanine aminotransferase and alkaline phosphatase levels, and serious liver disease), and age ≥70 years and serious liver disease were significant risk factors.

IMPLICATIONS: The findings from the present observational, single-center study suggest that serious liver disease before administration is an independent risk factor for acetaminophen-induced liver injury.