Tamoxifen-induced hepatotoxicity caused by drug interaction with direct-acting antiviral agents for hepatitis C.

A 68-year-old man develops acute hepatocellular injury during treatment with direct-acting antiviral agents (DAA) for hepatitis C. Medical history reveals the intake of tamoxifen as adjuvant treatment for breast cancer, currently in remission. After stopping tamoxifen, despite the continuation of the anti-HCV agents, a complete resolution of liver injury occurs. This interesting case illustrates tamoxifen hepatotoxicity induced by CYP3A4 interaction with direct anti-HCV agents. It stresses the importance of checking for interactions before starting treatment for hepatitis C.