Anastrozole-induced liver injury after a prolonged latency: a very rare complication of a commonly prescribed medication

Anastrozole is an aromatase inhibitor that has been used more frequently over the last decade especially for oestrogen receptor-positive breast cancer. It has a relatively safe side effect profile. However, occasionally it has been associated with serious adverse events. Here, we present the case of a 58-year-old woman who presented with significantly elevated liver enzymes 4 years after starting anastrozole. She was not taking any other medications and an extensive workup did not reveal any other cause for her liver injury. The patient's liver enzymes normalised after discounting the anastrozole. She scored 4 on the updated Roussel Uclaf Causality Assessment Method grading system which was possible for drug-induced liver injury. A review of the literature revealed six prior cases of anastrozole-related liver injury. Anastrozole should be considered as a possible culprit in patients who develop an unexplained acute liver injury.