Mesna reacts with acrolein and other urotoxic metabolites of oxazaphosphorines (cyclophosphamide or ifosfamide) to form stable, non-urotoxic compounds. Mesna does not have any antitumour activity, nor does it appear to interfere with the antitumour activity of antineoplastic drugs. This medication is used to protect the bladder wall from the harmful effects of some cancer-fighting drugs.