Treosulfan is a type of chemotherapy. You might have it as a treatment before a stem cell or bone marrow transplant

How does treosulfan work?

Treosulfan is an alkylating agent. It works by sticking to one of the cancer cell's DNA strands. Then the cell can't divide into 2 new cells. 

How do you have treosulfan?

You have treosulfan as a drip into your bloodstream (intravenously).

You might have treatment through a long plastic tube that goes into a large vein in your chest. The tube stays in place throughout the course of treatment. This can be a:

  • central line
  • PICC line
  • portacath

If you don't have a central line

You might have treatment through a thin short tube (a cannula) that goes into a vein in your arm each time you have treatment.

How often do you have treosulfan?

How often you have treosulfan depends on your individual situation. The following is an example.

If you’re having an allogenic stem cell transplant Open a glossary item you might have it once a day for 3 days. You have this as a drip over 2 hours each day. You have treosulfan on days 2, 3 and 4 before you have your stem cells Open a glossary item returned.


You have blood tests before and during your treatment. They check your levels of blood cells and other substances in the blood. They also check how well your liver and kidneys are working.

What are the side effects of treosulfan?

Side effects can vary from person to person. They also depend on what other treatments you're having. 

When to contact your team

Your doctor, nurse or pharmacist will go through the possible side effects. They will monitor you during treatment and check how you are at your appointments. Contact your advice line as soon as possible if:

  • you have severe side effects 

  • your side effects aren’t getting any better

  • your side effects are getting worse

Early treatment can help manage side effects better. 

Contact your advice line immediately if you have signs of infection, including a temperature above 37.5C or below 36C.

We haven't listed all the side effects here. Remember it is very unlikely that you will have all of these side effects. But you might have some of them at the same time.

Common side effects

These side effects happen in more than 10 in 100 people (more than 10%). You might have one or more of them. They include:

Increased risk of infection

Increased risk of getting an infection is due to a drop in white blood cells. Symptoms include a change in temperature, aching muscles, headaches, feeling cold and shivery and generally unwell. You might have other symptoms depending on where the infection is.

Infections can sometimes be life threatening. You should contact your advice line urgently if you think you have an infection. 


You might be breathless and look pale due to a drop in red blood cells. This is called anaemia.

Bruising and bleeding

This is due to a drop in the number of platelets in your blood. These blood cells help the blood to clot when we cut ourselves. You may have nosebleeds or bleeding gums after brushing your teeth. Or you may have lots of tiny red spots or bruises on your arms or legs (known as petechiae).

Tiredness (fatigue)

Tiredness and weakness (fatigue) can happen during and after treatment. Doing gentle exercises each day can keep your energy up. Don't push yourself, rest when you start to feel tired and ask others for help.

Feeling or being sick

Feeling or being sick is usually well controlled with anti sickness medicines. It might help to avoid fatty or fried foods, eat small meals and snacks and take regular sips of water. Relaxation techniques might also help.

It is important to take anti sickness medicines as prescribed even if you don’t feel sick. It is easier to prevent sickness rather than treat it once it has started.


Contact your advice line if you have diarrhoea. For example, 2 or more extra loose bowel movements than usual each day. If you have a stoma, you might have more output than normal. Your doctor may give you anti diarrhoea medicine to take home with you after treatment.

Try to eat small meals and snacks regularly. It’s best to try to have a healthy balanced diet if you can. You don’t necessarily need to stop eating foods that contain fibre. But if your diet is normally very high in fibre, it might help to cut back on high fibre foods such as beans, nuts, seeds, dried fruit, bran and raw vegetables. 

Drink plenty to try and replace the fluid lost. Aim for 8 to 10 glasses per day.

Tummy (abdominal) pain or swelling

Pain or rarely swelling of the abdomen. Tell your healthcare team if you have this. They can check the cause and give you medicine to help.

Sore mouth and ulcers

Mouth sores and ulcers can be painful. Rarely you might also get a dry mouth or your mouth might bleed.

Keep your mouth and teeth clean; drink plenty of fluids; avoid acidic foods such as oranges, lemons and grapefruits; chew gum to keep the mouth moist and tell your doctor or nurse if you have ulcers.

Liver changes

You might have liver changes that are usually mild and unlikely to cause symptoms. They usually go back to normal when treatment finishes. You have regular blood tests to check for any changes in the way your liver is working.

Rarely the small blood vessels which lead to the liver and that are inside get blocked. This can lead to yellowing of the whites of the eyes and skin, liver tenderness and enlargement, sudden weight gain or a build up of fluid in the tummy (abdomen).

Hair loss or thinning

You may have some hair loss or hair thinning. This can be upsetting. Your hair might grow back once treatment has finished.

Occasional side effects

These side effects happen in between 1 and 10 out of every 100 people (between 1 and 10%). You might have one or more of them. They include:

  • an allergic reaction that can cause a rash, shortness of breath, redness or swelling of the face and dizziness - some allergic reactions can be life-threatening, alert your nurse or doctor if notice any of these symptoms
  • lung problems which can cause difficulty in breathing and a cough. Rarely it can happen due to inflammation of the lung or a build up of fluid around the lung
  • loss of appetite
  • difficulty sleeping (insomnia)
  • headaches
  • dizziness – do not drive or use machinery if you are dizzy
  • changes to heart rhythm – you might have regular heart trace tests (ECG) to check for this
  • high blood pressure and looking flushed
  • indigestion
  • constipation
  • difficulty swallowing
  • redness, soreness or peeling on palms or soles of feet (palmar plantar syndrome)
  • pain in different parts of the body such as back pain or pain in muscles, joints or bones. Rarely you might also have pain in your food pipe
  • kidney problems, such as blood in the urine – you might have blood and urine tests to check for this
  • fluid build up in different parts of the body such as hands and legs
  • your blood tests might show you have inflammation in the body
  • inflammation and irritation to the lining of the stomach (gastritis)– you might have symptoms such as bloating or feeling full after eating, feeling or being sick, indigestion, and stomach pain
  • skin problems such as small raised bumps which may be red or purple. Your skin might be itchy. Rarely you might a rash which develops suddenly, the bumps may be filled with pus or have a crust that develops over them
  • high temperature and chills
  • weight changes

Rare side effects

These side effects happen in fewer than 1 in 100 people (less than 1%). You might have one or more of them. They include:

  • high blood sugar levels (hyperglycaemia) – you will have regular blood tests to check for this
  • feeling confused
  • numbness or tingling in your fingers or toes
  • hiccups
  • chest pain
  • low blood pressure making you feel lightheaded or dizzy
  • inflammation of the throat and voice box, you might also have pain in your voice box
  • sweating more than usual

Other side effects

There isn't enough information to work out how often this side effect might happen. But treosulfan can cause a second cancer to develop some years after treatment.

Coping with side effects

We have more information about side effects and tips on how to cope with them.

What else do I need to know?

Other medicines, foods and drink

Cancer drugs can interact with some other medicines and herbal products. Tell your doctor or pharmacist about any medicines you are taking. This includes vitamins, herbal supplements and over the counter remedies.

Pregnancy and contraception

This treatment may harm a baby developing in the womb. It is important not to become pregnant or get someone pregnant while you're having treatment and for at least 6 months afterwards.

Talk to your doctor or nurse about effective contraception before starting treatment. Let them know straight away if you or your partner become pregnant while having treatment. 

Loss of fertility

You may not be able to become pregnant or get someone pregnant after treatment with this drug. Talk to your doctor before starting treatment if you think you may want to have a baby in the future.

Men might be able to store sperm before starting treatment. And women might be able to store eggs or ovarian tissue. But these services are not available in every hospital, so you would need to ask your doctor about this.    


It is not known whether this drug comes through into the breast milk. Doctors usually advise that you don’t breastfeed during this treatment.

Treatment for other conditions

If you are having tests or treatment for anything else, always mention your cancer treatment. For example, if you are visiting your dentist.


Don’t have immunisations with live vaccines while you’re having treatment and for up to 12 months afterwards. The length of time depends on the treatment you are having. Ask your doctor or pharmacist how long you should avoid live vaccinations.

In the UK, live vaccines include rubella, mumps, measles, BCG, yellow fever and one of the shingles vaccines called Zostavax.

You can have:

  • other vaccines, but they might not give you as much protection as usual
  • the flu vaccine (as an injection)
  • the coronavirus (COVID-19) vaccine - talk to your doctor or pharmacist about the best time to have it in relation to your cancer treatment

Members of your household who are aged 5 years or over are also able to have the COVID-19 vaccine. This is to help lower your risk of getting COVID-19 while having cancer treatment and until your immune system Open a glossary item recovers from treatment.

Contact with others who have had immunisations - You can be in contact with other people who have had live vaccines as injections. Avoid close contact with people who have recently had live vaccines taken by mouth (oral vaccines) such as the oral typhoid vaccine. Sometimes people who have had the live shingles vaccine can get a shingles type rash. If this happens they should keep the area covered.

If your immune system is severely weakened, you should avoid contact with children who have had the flu vaccine as a nasal spray as this is a live vaccine. This is for 2 weeks following their vaccination.

Babies have the live rotavirus vaccine. The virus is in the baby’s poo for about 2 weeks and could make you ill if your immunity is low. Get someone else to change their nappies during this time if you can. If this isn't possible, wash your hands well after changing their nappy.

More information about this treatment

For further information about this treatment and possible side effects go to the electronic Medicines Compendium (eMC) website. You can find the patient information leaflet on this website.

You can report any side effect you have to the Medicines Health and Regulatory Authority (MHRA) as part of their Yellow Card Scheme.

  • Electronic Medicines Compendium 
    Accessed August 2021

  • Immunisation against infectious disease: Chapter 6: General contraindications to vaccination
    Public Health England
    First published: March 2013 and regularly updated on the Gov.UK website

  • COVID-19 - SARS-CoV-2: The Greenbook, Chapter 14a
    Public Health England
    First published: 27 November 2020 and regularly updated on the GOV.UK website

  • Clinician Frequently Asked Questions (FAQs) and guidance on COVID-19 vaccine for patients receiving Systemic Anti-Cancer Therapy (updated December 2021)
    UK Chemotherapy Board
    Accessed January 2022

Last reviewed: 
04 May 2022
Next review due: 
04 May 2025

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