Mesna
Mesna is a drug given with some types of chemotherapy to protect the bladder from irritation.
Why mesna is given
The chemotherapy drugs ifosfamide and cyclophosphamide can irritate the lining of the bladder. This can cause bleeding from the bladder, which may lead to blood in your urine (pee). This is called haematuria. Mesna helps to protect your bladder and 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 a high dose. This means they will not need mesna. Your doctor, nurse or pharmacist can tell you if you are having a high dose of cyclophosphamide.
While you are having mesna, your urine 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:
- Drink plenty of water – at least 2 litres (3½ pints) daily. Your nurse can tell you how much you should drink.
- Empty your bladder often during the treatment.
More information about this treatment
This information is correct at time of publishing. But sometimes the types of cancer this treatment is used for, or treatment side effects, may change between revision dates.
You can talk to your cancer team if you want more detailed information about this treatment. Or visit the electronic Medicines Compendium (eMC) website, which has patient information leaflets (PIL) for individual drugs.
How mesna is given
Mesna can be given in the following ways:
- As a drip (infusion) – you have this into a vein at the same time as your chemotherapy.
- As a liquid that you drink – this is added to a flavoured soft drink, such as orange juice or cola. Your doctor, nurse or pharmacist can explain more about having mesna as a drink.
- As a tablet – it is important to take mesna tablets exactly as your doctor, nurse or pharmacist explains.
During your course of treatment, you will meet with someone from your cancer team, such as a:
- cancer doctor
- chemotherapy nurse or specialist nurse
- specialist pharmacist.
This is who we mean when we mention doctor, nurse or pharmacist in this information.
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 doctor, nurse or pharmacist will give you 24-hour contact numbers for the hospital. If you feel unwell or need advice, you can call 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 serious side effects. Sometimes, these may be life-threatening. Your doctor, nurse or pharmacist can explain the risk of these side effects to you.
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, some people have an allergic reaction while having this treatment. Allergic reactions are most common with the first few doses, but can happen at any time during treatment. A reaction is usually mild.
Signs of a reaction include:
- feeling hot or flushed
- shivering
- itching
- a skin rash
- feeling dizzy or sick
- a headache
- feeling breathless or wheezy
- swelling of your face or mouth
- pain in your back, tummy or chest.
Your nurse will check you for signs of a reaction during your treatment. If you feel unwell or have any of these signs, tell them straight away. If you do have a reaction, they can treat it quickly.
Sometimes a reaction happens a few hours after treatment. If you develop any of these signs or feel unwell after you get home, contact the hospital straight away on the 24-hour number.
Pain or irritation to the vein
If you have mesna as a drip (infusion), it can cause a reaction at the place where it is given or further along the vein. Symptoms of a reaction include:
- pain
- a rash
- red or darker skin
- swelling
- itchy skin where the drip is given.
If you have these symptoms, tell your nurse straight away. They can check the site.
Possible side effects
Feeling sick
You may feel sick while having this treatment. But your doctor, nurse or pharmacist may prescribe you anti-sickness drugs to help prevent or control sickness. Take the drugs exactly as they tell you to. If you feel sick, take small sips of fluid often and eat small amounts regularly. It is important to drink enough fluids.
If you continue to feel sick, or if you are sick (vomit) 1 to 2 times in 24 hours, contact the hospital on the 24-hour number as soon as possible.
If you are sick immediately after taking mesna tablets, contact the hospital for advice. It is important you do not miss a dose of mesna .
Headaches
This treatment may cause headaches. If you have headaches, tell your doctor, nurse or pharmacist. They can give you advice about painkillers that may help. Tell them if the headache does not get better, or gets worse.
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 normal for you, or having watery or loose stools. You may also have stomach cramps. If you have a stoma, it may be more active than usual.
If you are passing loose stools 3 or more times a day and this is not normal for you, contact the hospital as soon as possible on the 24-hour number. Follow the advice they give you about:
- taking anti-diarrhoea medicines
- drinking enough fluids to keep you hydrated and to replace lost salts and minerals
- any changes to your diet that might help.
They might also ask you for a specimen of your stool to check for infection.
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 ends. Try to pace yourself and plan your day so you have time to rest. Gentle exercise, like short walks, can help you feel less tired.
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, nurse or pharmacist. They can give you painkillers and advice. They can also tell you if any of the painkillers you usually take are suitable.
Tell them if the pain does not get better. Having warm baths and resting regularly 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 and nightmares. It may also make it hard for you to concentrate. If you have any of these side effects, tell your doctor, nurse or pharmacist. 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:
- medicines you have been prescribed
- medicines you buy in a shop, pharmacy or online
- vitamins or supplements
- herbal drugs and complementary or homeopathic therapies
- recreational drugs – for example, cannabis.
Medical and dental treatment
If you need medical treatment for any reason other than cancer, always tell the healthcare professional that you are having cancer treatment. Give them the contact details for your cancer doctor or cancer team so they can ask for advice.
If you have appointments with a dentist, always tell them you are having cancer treatment. Talk to your cancer team before you have any dental 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
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References
Visit the electronic Medicines Compendium (eMC) to download a Patient Information Leaflet (PIL) for more detailed information. The leaflet lists all known side effects.
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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.
The language we use
We want everyone affected by cancer to feel our information is written for them.
We want our information to be as clear as possible. To do this, we try to:
- use plain English
- explain medical words
- use short sentences
- use illustrations to explain text
- structure the information clearly
- make sure important points are clear.
We use gender-inclusive language and talk to our readers as ‘you’ so that everyone feels included. Where clinically necessary we use the terms ‘men’ and ‘women’ or ‘male’ and ‘female’. For example, we do so when talking about parts of the body or mentioning statistics or research about who is affected.
You can read more about how we produce our information here.
Date reviewed
This content is currently being reviewed. New information will be coming soon.

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