[Phenprocoumon-induced necrotizing hepatitis]

A 52-year-old female patient presented at our hospital with right upper abdominal pain and impaired general condition. During the previous 7 months, the patient had received anticoagulation treatment with phenprocoumon due to a prosthetic aortic valve replacement.

Serological tests for virologic, autoimmune or metabolic causes of hepatitis were negative. The histologic examination of liver biopsies showed necrotizing hepatocellular injury in zone 3 of the acinus without relevant fibrosis. Initially, a lymphocyte transformation test with phenprocoumon was negative. A second test after one week turned out to be positive. DIAGNOSIS AND CLINICAL COURSE: After withdrawal from phenprocoumon therapy and switching to anticoagulation with a low molecular weight heparin, liver tests gradually became normal. Aminotransferase levels rapidly increased when phenprocoumon treatment was resumed. Phenprocoumon-associated necrotizing hepatitis was diagnosed by clinical course, liver histology and the positive lymphocyte transformation test. After immunosuppressive treatment with prednisolone was started again, liver enzymes gradually normalized. Anticoagulation was further performed with low molecular weight heparin.

This case stresses the fact that an adequate and detailed history on concomitant medication is mandatory in patients who present with cryptic hepatitis. Though severe hepatic adverse effects of phenprocoumon are rare, physicians should consider coumarin derivatives as a potential source of hepatitis.