Why mesna is given

The chemotherapy drugs ifosfamide and cyclophosphamide can sometimes irritate the lining of the bladder. This can cause bleeding from the bladder and may show up as blood in your urine (pee). This is called haematuria. Mesna helps protect your bladder to prevent irritation and bleeding.

People being treated with ifosfamide will always have mesna. 

Cyclophosphamide only causes bleeding from the bladder when it is given in high doses. Most people who have treatment with cyclophosphamide do not have it as a high dose. They will not need mesna. Your doctor can tell you if you are having a high dose of cyclophosphamide. 

While you are having mesna, your urine (pee) is tested for signs of blood. If you have blood in your urine, you will be given extra mesna. 

Doing these things can help protect your bladder during treatment:

  • Drinking plenty of water – at least 2 litres (3½ pints) daily. Your nurse can tell you how much you should drink.
  • Emptying your bladder often during the treatment.

How mesna is given

Mesna can be given in the following ways:

  • As a drip (infusion) into a vein at the same time as your chemotherapy
  • As a liquid that you drink. The mesna liquid is added to a flavoured soft drink, such as orange juice or cola. Your doctor, nurse or pharmacist can explain more about this to you.
  • As a tablet. The tablets can be taken with food or on an empty stomach. If you are given tablets, it is important to take them as exactly as your nurse or pharmacist explains.

Your course of chemotherapy

You usually have a course of several cycles of treatment over a few months. Your doctor, nurse or pharmacist will discuss your treatment plan with you.

About side effects

We explain the most common side effects of this treatment here. We also include some less common side effects.

You may get some of the side effects we mention, but you are unlikely to get all of them. It is often difficult to know which side effects may be caused by mesna and which ones may be caused by the chemotherapy. Always tell your doctor or nurse about the side effects you have.

Your doctor can give you drugs to help control some side effects. It is important to take them exactly as your nurse or pharmacist explains. This means they will be more likely to work for you. Your nurse will give you advice about managing your side effects. After your treatment is over, most side effects start to improve.

Contact the hospital

Your nurse will give you telephone numbers for the hospital. If you feel unwell or need advice, you can call them at any time of the day or night. Save these numbers in your phone or keep them somewhere safe.

Serious and life-threatening side effects

Some cancer treatments can cause severe side effects. Rarely, these may be life-threatening. Your cancer doctor or nurse can explain the risk of these side effects to you.

More information

We cannot list every side effect for this treatment. There are some rare side effects that are not listed. You can visit the electronic Medicines Compendium (eMC) for more detailed information.

Side effects while treatment is being given

Some people may have side effects while they are being given the chemotherapy or shortly after they have it:

Allergic reactions

Rarely, mesna may cause an allergic reaction. Your nurse will check you for this. If you have a reaction, they will treat it quickly. Allergic reactions are most common with the first few doses. A reaction is usually mild. Rarely, it can be more severe.

Signs of an allergic reaction can include:

  • a skin rash
  • itching
  • feeling breathless
  • swelling of your face or mouth
  • pain in your back, tummy or chest.
  • flu-like symptoms such as a headache, feeling flushed, having a fever, chills or dizziness.

Tell your nurse straight away if you notice any of these symptoms. If you develop any of these symptoms or feel unwell when you are at home, contact the hospital straight away on the number you have been given. They can give you advice.

Possible side effects

Feeling or being sick

You may feel sick. Your doctor will give you anti-sickness drugs to help prevent or control sickness. Take the drugs exactly as your nurse or pharmacist tells you. It is easier to prevent sickness than to treat it after it has started.

If you are sick after taking mesna by mouth, contact the hospital for advice. It is important you do not miss a dose of mesna so that your bladder lining is protected.

Headaches

This treatment may cause headaches. If you have headaches, tell your doctor. They may give you painkillers to help.

Tummy pain

You may get pain or discomfort in your tummy (abdomen), feel bloated or have wind. Your doctor can give you drugs to help improve these symptoms. Tell them if the pain does not improve or if it gets worse.

Diarrhoea

This treatment may cause diarrhoea. Diarrhoea means passing more stools (poo) than is usual for you, or having watery or loose stools. If you have a stoma, it will be more active than usual.

If you have diarrhoea:

  • try to drink at least 2 litres (3½ pints) of fluids each day
  • avoid alcohol, caffeine, milk products, high-fat foods and high-fibre foods
  • contact the hospital for advice.

Feeling tired

Feeling tired is a common side effect of this treatment. It is often worse towards the end of treatment and for some weeks after it has finished. Try to pace yourself and plan your day so you have time to rest. Gentle exercise, like short walks, can give you more energy.

If you feel sleepy, do not drive or use machinery.

Muscle or joint pain

You may get pain in your muscles or joints for a few days after treatment. If this happens, tell your doctor so they can give you painkillers. Tell them if the pain does not get better. Having warm baths and taking regular rests may help.

Skin changes

This treatment may affect your skin. Your doctor or nurse can tell you what to expect. If your skin feels dry, try using an unperfumed moisturising cream every day. This treatment can cause a rash, which may be itchy.

Always tell your doctor or nurse about any skin changes. They can give you advice and may give you creams or medicines to help. Any changes to your skin are usually temporary and improve when treatment finishes.

Behaviour changes

Mesna can cause difficulty sleeping, nightmares and a low attention span. Tell your doctor or nurse if you have any of these side effects. They may make some changes to your treatment if the side effects become a problem.

Other information

Lactose

These tablets contain lactose. Tell your doctor if you have an allergy to lactose.

Other medicines

Some medicines can affect how this treatment works or be harmful while you are having it. Always tell your cancer doctor, nurse or pharmacist about any drugs you are taking or planning to take, such as: 

Medical and dental treatment

If you need medical treatment for any reason other than cancer, always tell the doctors and nurses you are having cancer treatment. Give them the contact details for your cancer doctor so they can ask for advice.

If you think you need dental treatment, talk to your cancer doctor or nurse. Always tell your dentist you are having cancer treatment.

Pregnancy and breastfeeding

Ask your doctor or pharmacist for advice before taking this medicine if you:

  • are pregnant
  • think you may be pregnant
  • are planning to have baby.

You are also advised not to breastfeed when taking this treatment. This is because the medicine may be passed to the baby through breast milk. 

About our information

  • Reviewers

    This information has been written, revised and edited by Macmillan Cancer Support’s Cancer Information Development team. It has been reviewed by expert health professionals and people living with cancer.

    Our cancer information has been awarded the PIF TICK. Created by the Patient Information Forum, this quality mark shows we meet PIF’s 10 criteria for trustworthy health information.

Date reviewed

Reviewed: 01 October 2022
|
Next review: 01 April 2025
Trusted Information Creator - Patient Information Forum
Trusted Information Creator - Patient Information Forum

Our cancer information meets the PIF TICK quality mark.

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