Detective Work in Drug-Induced Liver Injury: Sometimes It Is All About Interviewing the Right Witness

Diagnosing drug-induced liver injury (DILI) relies primarily on history taking. We report 4 cases in which DILI was missed or the drug was misidentified when physicians relied solely on patient history. We reviewed 27 cases referred with possible DILI from August 1, 2009, to February 1, 2010. Four patients seemed to be reliable historians, but their cases were greatly clarified by a call to their pharmacist. One subject, who forgot a new medication, underwent an unfruitful evaluation including surgery. Another patient had acetaminophen toxicity that was missed because she grossly underreported her pain medication use. The third and fourth patients forgot taking amoxicillin/clavulanate, so other agents mistakenly were implicated. Roussel Uclaf Causality Assessment Method scores were 8 (probable) or 9 (highly probable) for all 4 cases. Without pharmacy input, DILI was missed in 2 cases and the wrong agent was implicated twice. Reviewing pharmacy records can be crucial for patients and DILI research. We recommend calling the pharmacist directly for increased liver enzyme levels of unclear source or suspected DILI regardless of patient history.