List of products in the National Drug Code with proprietary name . This medication is used to reduce the risk of bleeding in the bladder (hemorrhagic cystitis), which is a very serious side effect of treatment with a cancer chemotherapy drug called ifosfamide. Mesna helps to protect the lining of the bladder against damage from ifosfamide. The body breaks down ifosfamide to form a product that can harm the bladder, and mesna works by making this product less harmful. However, mesna does not change ifosfamide's anti-cancer effects.