Hepatotoxicity Secondary to Ribociclib and Echinacea

The consumption of medicinal herbs has increased in recent years. There is little evidence with regards to their real benefits and a small number of scientific papers about adverse effects. A case of a 55-year-old woman is presented, with recent diagnosis of luminal A de novo metastatic breast cancer. She starts first-line treatment with Ribociclib in combination with letrozole. After 2 months, a partial response is achieved. However, the patient presents grade 4 hepatotoxicity. She had started to take Echinacea two months ago. Other causes of liver failure are ruled out. Both Echinacea and Ribociclib present hepatic metabolism through cytochrome p450, which means that there could be a potential interaction between them. This is the first reported case of a potential interaction between Ribociclib and Echinaea. We highly recommend avoiding the concomitant use of both medications.