Mes-D Injectable Solution (IV)

Indications

Mesna and its disulfide form (dimesna) are used to protect the bladder in people receiving the cancer medicines Ifosfamide or high-dose Cyclophosphamide. These medicines produce a breakdown product called acrolein that collects in the urine and can damage the bladder lining, causing bleeding (haemorrhagic cystitis). Mesna prevents this damage. It does not treat cancer itself.

How It Works

After it enters the blood, mesna is quickly changed into its disulfide form, which is inactive and does not interfere with the anticancer medicine. In the kidneys this disulfide is turned back into free mesna, which passes into the urine. There its sulfur (thiol) group binds to acrolein and other toxic breakdown products, making them harmless before they can injure the bladder.

Dosage and Administration

Mesna is given in hospital by a doctor or nurse, as an injection or infusion into a vein, and sometimes partly as tablets by mouth. The dose and timing are calculated by the specialist from the dose of Ifosfamide or Cyclophosphamide, and doses are usually given before, during and for several hours after the chemotherapy. Drinking plenty of fluids and passing urine often, as advised, also helps protect the bladder. If tablets are prescribed and you vomit within 2 hours of a dose, tell the care team.

Interactions

Mesna does not reduce the anticancer effect of Ifosfamide or Cyclophosphamide. It can cause a false-positive result for ketones in urine dipstick tests and may affect some other laboratory tests; tell the laboratory or doctor that you are receiving it.

Contraindications

Do not use if you are allergic to mesna or to other medicines containing a thiol (sulfur) group, or to any ingredient of the product.

Side Effects

Side effects are often hard to separate from those of the chemotherapy given with it. Possible effects include:

• Nausea, vomiting, diarrhoea and abdominal pain
• Headache, tiredness and dizziness
• Flushing, a bad taste in the mouth
• Rash, itching and pain at the injection site
• Low blood pressure or fast heartbeat (rare)

Tell the care team at once if you see blood in your urine, as bladder protection may not be complete. Get urgent medical help if you have signs of a serious allergic or skin reaction, such as swelling of the face or throat, difficulty breathing, widespread rash, blisters or peeling skin, or a high fever.

Pregnancy and Lactation

Mesna itself has not been shown to harm the unborn baby, but it is always used with chemotherapy that can. Pregnancy should be avoided during treatment, and breastfeeding must be stopped because of the chemotherapy. Follow the specialist's advice.

Precautions and Warnings

Urine is checked for blood during treatment. Mesna does not protect against other side effects of the chemotherapy, such as kidney or nerve damage. People with autoimmune conditions may be more likely to have allergic reactions. Some injection forms contain benzyl alcohol, which is not suitable for newborn babies.

Overdose

Large doses may cause nausea, vomiting, diarrhoea, abdominal pain and headache. Treatment is supportive and given by the hospital team.

Therapeutic Class

Detoxifying agent; uroprotective agent used with antineoplastic therapy.

Storage

Hospital medicine: store as directed on the pack, usually below 30°C and protected from light. Do not freeze. Keep tablets in a dry place, out of the reach of children.