Coenzyme M

A metabolite called acrolein is produced when ifosfamide and cyclophosphamide are metabolized. This metabolite concentrates in the bladder and causes cell death via upregulation of reactive oxygen species (ROS), and activates inducible nitric oxide synthase (iNOS) which leads to production of nitric oxide (NO). Both ROS and NO produce products which are detrimental to lipids, proteins and DNA strands. Furthermore, ROS stimulate gene expression of pro-inflammatory cytokines such as TNF-α AND IL-1β. Acrolein may also lead to ulceration of the bladder urothelium. Mesna protects against cyclophosphamide and ifosfamide induced hemorrhagic cystitis by binding to their toxic metabolites. Mesna is metabolized to dimesna and excreted by the kidneys. Glutathione dihydrogenase acts on the reabsorbed portion and produces free sulfhydryl groups. These free sulfhydryl groups bind acrolein in the bladder, allowing effective excretion and prevention of toxic effects. In addition, Mesna binds to and detoxifies a urotoxic ifosfamide metabolite called 4-hydroxy-ifosfamide.