Drug Liver Injury Induced by Olmesartan Mediated by Autoimmune-Like Mechanism: A Case Report

Autoimmune hepatitis (AIH) was the first liver disease for which an effective therapeutic intervention was carried out, using prednisolone; its usefulness was demonstrated in several clinical trials. Nevertheless, AIH still remains a difficult diagnosis in some cases, because it is necessary to dismiss other possible diagnoses, and perhaps due to it being a heterogeneous disease. The relationship between drug-induced liver injury (DILI) and AIH is complex and not fully understood. There are three possible scenarios: (1) DILI with a strong immunoallergic component mimicking AIH; (2) AIH mimicking a DILI due to drug exposure and (3) AIH triggered by exposure to an offending drug (drug-induced AIH). Drug-induced AIH is well described and documented for some drugs such as nitrofurantoin and minocycline. Histologically distinguishing DILI from AIH remains a challenge. We present an interesting case report which met serologic criteria and histological confirmation to establish AIH, but discontinuation of a suspected drug resolved hypertransaminasaemia. LEARNING POINTS: Idiosyncratic drug-induced liver injury is one of the most challenging liver disorders. Diagnosis of drug-induced liver injury is a complex question; this can evolve to severe hepatotoxicity if it is not diagnosed promptly. Usually, olmesartan and similar anti-hypertensive drugs are not considered drugs with the potential to cause liver damage.