About Mesna Synthetic Thiol derivative, Antidote, Uroprotectant. Mechanism of Action of Mesna Mesna rapidly oxidized to major metabolite, mesna disulfide (dimesna). In the kidney dimesna reduced into free thiol compound. This compound reacts with the metabolites of oxazaphosphorins (cyclophosphamide or ifosfamide) to form stable nonurotoxic compounds. During this detoxification there is binding of mesna to the 4-hydroxy-ifosfamide forming a nonurotoxic 4-sulfoethylthioifosfamide.Mesna also bind to the double bonds of acrolein and to other urotoxic metabolites. Indications for Mesna 1. Hemarragic cystitis secondary to cyclophosphamide or ifosamide 2. Toxicity to the urinary passage caused by oxazaphosphorins such as ifosamide