Among 766,930 patient encounters, 127 unique patients met inclusion criteria with 72 (56.7%) cases adjudicated as probable DILI and 55 (43.3%) as non-DILI. In the probable DILI group, the most frequent suspect drug classes were: antimicrobials (41.9%), herbal and dietary supplements (9.5%), and antineoplastics (8.1%). Twenty-three of the 72 DILI patients (31.9%) had a history of drug allergy before the DILI episode compared to 16 (29.1%) of the 55 non-DILI cases (
p = 0.89). However, none of the allergy drugs and suspect DILI drugs were the same although many were in the same drug class. DILI patients with a prior drug allergy were more likely to be female (73.9% vs. 44.9%,
p = 0.04) and have lower serum bilirubin (4.0 vs. 7.8,
p = 0.08) and INR (1.1 vs. 1.6,
p = 0.043) levels at presentation. The likelihood of death or liver transplantation among probable DILI cases with prior drug allergy was lower than those without prior drug allergy (0% vs. 8.2%,
p = 0.35). The suspect drug was subsequently documented in the “
Drug Allergy” section of the EMR in only 23 (31.9%) of the 72 probable DILI patients, and these patients were more likely to present with a rash (7% vs. 2%,
p = 0.006) and higher serum bilirubin levels (10.5 vs. 4.7,
p = 0.008) compared to those in whom the suspect drug was not listed as “drug allergy.”