OBJECTIVES

Six individual case reports of enoxaparin induced liver injury were published which indicated enoxaparin as a suspected drug that resulted in hepatotoxicity. However, there is no formal pharmacovigilance or epidemiological study which further investigated the association between enoxaparin and liver injury. This study, quantified the association (signal) between enoxaparin and liver injury using data from the US Food and Drug administration adverse event reporting system (FAERS).

METHODS

A data of 15 drugs and adverse drug event was collected from RED BOOK for the year 1993 to 2017 in US. Proportional reporting ratio (PRR) and reporting odds ratio (ROR), Information component (IC) and empirical Bayes geometric mean (EBGM) were applied to measure the association between these drugs and the adverse event, hepatotoxicity.

RESULTS

Of the 3,900 co-matching reports between the 15 drugs and hepatotoxicity, enoxaparin was co-matched 850 times. It was the second highest among all anticoagulant drugs in the study following rivaroxaban (1143 times). Enoxaparin had a PRR (95% CI): 2.35 (1.80,3.07); ROR (95% CI): 2.41 (2.23,2.61); IC (95% CI) 1.04 (0.93,1.12) and EBGM (95% CI) 2.06 (1.84,2.23). PRR of at least 2 is defined as signal and a positive IC represents a signal indicating an association between the drug and adverse drug reaction. Moreover, rivaroxaban had a PRR of 0.45 (95% CI: 0.36,0.57), ROR (95%CI) 0.45 (0.42,0.48); IC of -0.70 (-0.80, -0.63) and EBGM of 0.61; (0.56,0.66). The measure of association showed enoxaparin has a higher signal for drug induced liver injury and was statistically significant. On the other hand, there was no evidence for a signal between rivaroxaban and liver injury despite it had the highest drug-adverse event reports.

CONCLUSIONS

Enoxaparin had a strong association (signal) with liver injury. However, a signal is not a causal association between a drug and adverse event. Therefore, a formal epidemiological study is warranted.