Cross-allergic reactions between etoposide and penicillin in autologous bone marrow transplant patient

Etoposide is a chemotherapeutic agent that belongs to the podophyllotoxin drug class. Etoposide is used in treating many types of cancers including blood cancers. However, hypersensitivity reactions to etoposide and other chemotherapeutic agents are common. A 29-year-old female was admitted to the bone marrow transplant center for autologous hematopoietic stem cell transplantation. She was previously diagnosed with Hodgkin's lymphoma. The Lomustine, Etoposide, Cytarabine and Melphalan, (LEAM) protocol has been prescribed as a conditioning regimen before stem cell transplantation for this patient. On the 4th day of LEAM protocol, after the last day of the etoposide dose, the patient develops a severe allergic reaction to etoposide. After investigation, we found that the patient was allergic to penicillin which also appeared when the patient takes piperacillin + tazobactam. The possibility of cross-allergic reactions between etoposide and penicillin is unknown. The cross-allergic reactions between etoposide and penicillin are not reported in previous studies.