[Drug-induced liver injury (DILI)]

We present a case of recurrent international normalised ratio (INR) derailment during treatment with phenprocoumon for sinus vein thrombosis. During the course of the illness, the patient developed signs of bleeding, such as epistaxis, gross haematuria and vaginal bleeding, as well as elevated liver enzyme levels. This ultimately led to hospitalisation, where a diagnosis of acute hepatitis associated with drug-induced liver injury (DILI) was made. Following the discontinuation of phenprocoumon and a switch to apixaban for anticoagulation therapy, as well as repeated administration of vitamin K, the patient's condition stabilised. The laboratory findings, liver biopsy and clinical course are most consistent with toxic hepatitis caused by phenprocoumon.