Mesna is used to prevent urothelial toxicity associated with oxazaphosphorine, ifosfamide or cyclophosphamide. It acts in the kidney; reacting with thiol groups of urotoxic metabolites (e.g. acrolein) of ifosfamide and cyclophosphamide. It is used as a mucolytic in the management of some respiratory tract conditions e.g. cystic fibrosis where other mucolytics have failed. It acts by reducing the viscosity of pulmonary secretions; the drug’s free sulfhydryl group is thought to reduce disulfide linkages of mucoproteins.