Busulfan is an antineoplastic from the alkylating agent drug class. Although, its structure is not an analog of the nitrogen mustard drug. This drug is indicated as a combination with cyclophosphamide for a regimen prior to allogeneic hematopoietic progenitor cell transplantation for chronic myelogenous leukemia. Busulfan can also be used as a component of a pretransplant conditioning agent before bone marrow transplantation for acute myeloid leukemia and nonmalignant disease. This drug is cell cycle-nonspecific and works by three different mechanisms. Those all lead to the disruption of the DNA and the apoptosis of the cell. Busulfan contains two labile methanesulfonate groups. After the hydrolyzation of the molecule, the methanesulfonate groups are released and carbonium ions are produced. These carbonium ions alkylate DNA, mostly the guanine bases. This leads to the inhibition of DNA replication and RNA transcription. Specifically, busulfan creates intrastrand crosslinks between guanine and adenine bases. Those damages cannot be repaired by the cellular machinery. This drug is administered as an intravenous injection or as an oral tablet.

Busulfan Pathway References