Excretion of sodium 2-mercaptoethanesulphonate (MESNA) in the urine of volunteers after oral dosing.

Sodium 2-mercaptoethanesulphonate (MESNA) is a uroprotective agent generally given i.v. to prevent haemorrhagic cystitis during oxazaphosphorine cancer chemotherapy. Oral administration of the drug is described since this might be an important route during long-term oxazaphosphorine treatment. MESNA is absorbed from the GI tract and excreted in the urine (about 41.5% of the dose), peak excretion being 2-3 hr after administration. A proportion of the excreted dose is as free thiols (about 24.2%) and the remainder is as disulphides. MESNA is shown to enhance excretion of cysteine in urine.