General Information

Mesnex (mesna) is a cytoprotective agent indicated as a prophylactic agent in reducing the incidence of ifosfamide-induced hemorrhagic cystitis.

Mesnex may be given on a fractionated dosing schedule of three bolus intravenous injections or a single bolus injection followed by two oral administrations of Mesnex tablets. The dosing schedule should be repeated on each day that ifosfamide is administered. When the dosage of ifosfamide is adjusted, the ratio of Mesnex to ifosfamide should be maintained. See drug label for dosing schedule.

Mechanism of Action

Mesnex (mesna) was developed as a prophylactic agent to reduce the risk of hemorrhagic cystitis induced by Ifex (ifosfamide). Mesna is rapidly oxidized to its major metabolite, mesna disulfide, which then remains in the intravascular compartment and is rapidly eliminated by the kidneys. In the kidney, mesna disulfide is reduced to mesna, which reacts with the urotoxic ifosfamide metabolites, resulting in their detoxification. 

Side Effects

Adverse effects associated with the use of Mesnex may include (but are not limited to) the following:

• Nausea
• Vomiting
• Fatigue
• Constipation
• Leukopenia
• Anemia
• Asthenia

Clinical Trial Results

Approval of Mesnex Tablets is supported by two clinical studies with over 100 cancer subjects receiving Ifex. Trials compared three intravenous doses of Mesnex to an initial intravenous dose followed by two oral doses for the prevention of hemorrhagic cystitis induced by treatment with Ifex. Both dosing regimens successfully reduced incidences of grade three or four hematuria, the primary efficacy endpoint.