mesna

Mesna, or sodium 2-mercaptoethane sulfonate, is a chemoprotective agent used to prevent hemorrhagic cystitis caused by the alkylating chemotherapy drugs cyclophosphamide and ifosfamide. It is available in intravenous and oral formulations and is marketed under brand names such as Mesnex and Uromitexan.

Mesna works by providing a sulfhydryl group that binds to the urotoxic metabolite acrolein, forming non-toxic adducts in the urine and thereby protecting the bladder mucosa.

Dosing is regimen-specific, but commonly mesna is given as three doses around the chemotherapy: one before infusion and then at 4 and 8 hours after. The dose is typically about 20% of the cytotoxic agent dose, with adjustments for high-dose regimens. In some protocols, oral mesna is substituted or used to supplement the IV regimen.

In addition to preventing hemorrhagic cystitis, mesna may be used with high-dose cyclophosphamide in stem cell transplantation protocols. It does not prevent other chemotherapy toxicities.

Common side effects include nausea, vomiting, headache, flushing, and fever. Rare allergic reactions and anaphylactoid responses have been reported. Mesna is generally well tolerated, but contraindications include hypersensitivity to mesna or sulfhydryl compounds. Caution is advised in patients with severe renal impairment because mesna and its metabolites are renally cleared.