Mesna (Mesnex®)

Mesna is not a cancer treatment, but a medication, called a chemoprotectant, used to protect the bladder from a harmful side effect of certain chemotherapy medications (ifosfamide, cyclophosphamide) called hemorrhagic cystitis (bleeding in the bladder).

How to Take Mesna

Mesna is given by intravenous (IV, into a vein) infusion or by mouth, in a pill form. It can be given before, after, and/or at the same time as chemotherapy. The actual dose depends on your body size and the dose of chemotherapy you are receiving. You should contact your healthcare provider if you vomit (throw up) within two hours of taking oral mesna or if you miss a dose. You should drink 1-2 liters of fluid daily while receiving this medication.

If taking the oral form of mesna, it is important to make sure you are taking the correct amount of medication every time. Before every dose, check that what you are taking matches what you have been prescribed.

Intravenous (IV) mesna contains a small amount of alcohol, which may cause you to experience drowsiness, dizziness, lightheadedness, and blurred vision, which can impair your ability to drive.

If you are in the hospital, the nursing staff may use a test strip to check your urine periodically for microscopic blood (not visible to the eye) to be sure that cystitis is not developing. You should report any burning or urgency with urination to your care team. You should also let your provider know if you are taking any blood-thinning medications (coumadin, aspirin, Plavix), as these put you at a higher risk of bleeding. Drink plenty of non-alcoholic fluids while taking mesna.

Possible Side Effects of Mesna

Most side effects experienced while taking mesna are actually caused by the chemotherapy medication it is given with. These are some of the most common or important side effects related to mesna.

Nausea and/or Vomiting

Some patients reported a bad taste or nausea when taking mesna in a pill form. Talk to your doctor or nurse so they can prescribe medications to help you manage nausea and vomiting. In addition, dietary changes may help. Avoid things that may worsen the symptoms, such as heavy or greasy/fatty, spicy or acidic foods (lemons, tomatoes, oranges). Try antacids, (e.g. milk of magnesia, calcium tablets such as Tums), saltines, or ginger ale to lessen symptoms.

Important but Less Common Side Effects

• Allergic Reactions: Some patients may experience an allergic reaction to this medication. This can range from a mild reaction to anaphylaxis. Symptoms of a reaction include itching, flushing, burning, swelling of the face, or difficulty breathing. A serious skin reaction that starts as a rash and progresses to painful blisters, can happen in rare cases. Report any unusual symptoms to your healthcare provider.
• Stevens Johnson Syndrome: Stevens Johnson Syndrome is a rare, but serious, allergic reaction that affects the skin and mucous membranes. It typically starts as a rash or painful blisters and can progress to serious damage to the skin and in some cases, death. It is important that you report any rash to your oncology care team immediately.

Reproductive Concerns

Exposure of an unborn child to this medication could cause birth defects, so you should not become pregnant or father a child while on this medication. Effective birth control for women is necessary during treatment and for 6 months after the last dose. Effective birth control for men is necessary during treatment and for 3 months after the last dose. Even if your menstrual cycle stops or you believe you are not producing sperm, you could still be fertile and conceive. You should not breastfeed while taking this medication and for 1 week after the last dose.