How does this medication work? What will it do for me?

Mesna is used to protect the bladder against some of the harmful effects of certain cancer medications known as oxazaphosphorines (e.g., cyclophosphamide, ifosfamide). After injection, mesna stays in the blood and is quickly moved to the kidney. Once in the kidney, it attaches to the byproducts of cancer medications that can cause harm to the bladder, making them harmless.

Your doctor may have suggested this medication for conditions other than those listed in these drug information articles. As well, some forms of this medication may not be used for all of the conditions discussed here. If you have not discussed this with your doctor or are not sure why you are being given this medication, speak to your doctor. Do not stop taking this medication without consulting your doctor.

What form(s) does this medication come in?

Each mL of Mesna for Injection contains 100 mg mesna. Nonmedicinal ingredients: benzyl alcohol, edetate disodium, water for injection, and sodium hydroxide for pH adjustment.

How should I use this medication?

Mesna is injected into a vein through a specially prepared site on your skin. The recommended dose is usually 20% of the dose of cyclophosphamide. The injection is given at the time of a cyclophosphamide dose injection, then 4 and 8 hours later.

In the case of ifosfamide, the recommended dose is 10 mg to 12 mg per kilogram of body weight at the time of the ifosfamide dose, and 4 and 8 hours later.

This medication may also be given by mouth under certain circumstances. When this is the case, the dose may be higher than those suggested here.

Mesna may also be given to people being prepared for bone marrow transplantations. Under these circumstances, the doses may be given around the clock for a brief period of time.

Many things can affect the dose and schedule of medication that a person needs, such as body size, other medical conditions, and other medications. Your doctor may choose a different dose or schedule than the ones listed here. Mesna is always given under the direct supervision of your doctor.

Do not dispose of medications in wastewater (e.g. down the sink or in the toilet) or in household garbage. Ask your pharmacist how to dispose of medications that are no longer needed or have expired.

Who should NOT take this medication?

Mesna should not be used by anyone who is allergic to mesna or to any of the ingredients of the medication.

What side effects are possible with this medication?

Many medications can cause side effects. A side effect is an unwanted response to a medication when it is taken in normal doses. Side effects can be mild or severe, temporary or permanent. The side effects listed below are not experienced by everyone who takes this medication. If you are concerned about side effects, discuss the risks and benefits of this medication with your doctor.

The following side effects have been reported by at least 1% of people taking this medication. Many of these side effects can be managed, and some may go away on their own over time.

Contact your doctor if you experience these side effects and they are severe or bothersome. Your pharmacist may be able to advise you on managing side effects.

  • abdominal pain
  • diarrhea
  • dizziness or lightheadedness
  • headache
  • nausea or vomiting
  • skin rash, itching

Although most of these side effects listed below don't happen very often, they could lead to serious problems if you do not check with your doctor or seek medical attention.

Check with your doctor as soon as possible if any of the following side effects occur:

  • fast heart rate
  • signs of a serious allergic reaction (i.e., abdominal cramps, difficulty breathing, nausea and vomiting, or swelling of the face and throat)

Some people may experience side effects other than those listed. Check with your doctor if you notice any symptom that worries you while you are taking this medication.

Are there any other precautions or warnings for this medication?

Before you begin using a medication, be sure to inform your doctor of any medical conditions or allergies you may have, any medications you are taking, whether you are pregnant or breast-feeding, and any other significant facts about your health. These factors may affect how you should use this medication.

HEALTH CANADA ADVISORY

September 6, 2011

Health Canada has issued new restrictions concerning the use of Uromitexan® (mesna). To read the full Health Canada Advisory, visit Health Canada's web site at www.hc-sc.gc.ca.

Tests for ketones in urine: Mesna may cause tests for ketones in the urine to be falsely positive.

Pregnancy: This medication should not be used during pregnancy unless the benefits outweigh the risks. If you become pregnant while taking this medication, contact your doctor immediately. Because the use of oxazaphosphorines is not recommended during pregnancy, this should eliminate the need for mesna.

Breast-feeding: It is not known if mesna passes into breast milk. It has not been shown to cause problems in breast-fed babies. Women should weigh potential benefits against risks before breast-feeding while using this medication.

What other drugs could interact with this medication?

Tell your doctor or prescriber about all prescription, over-the-counter (non-prescription), and herbal medications that you are taking. Also tell them about any supplements you take. Since caffeine, alcohol, the nicotine from cigarettes, or street drugs can affect the action of many medications, you should let your prescriber know if you use them. Depending on your specific circumstances, your doctor may want you to:

  • stop taking one of the medications,
  • change one of the medications to another,
  • change how you are taking one or both of the medications, or
  • leave everything as is.

An interaction between two medications does not always mean that you must stop taking one of them. In many cases, interactions are intended or are managed by close monitoring. Speak to your doctor about how any drug interactions are being managed or should be managed.