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Find out what treosulfan is, how you have it and other important information.

What is it

Treosulfan is a chemotherapy drug used to treat ovarian cancer. It can also be used to treat other types of cancer when other treatments are no longer working. 

You can have treosulfan alone or in combination with other cancer drugs. 

How it works

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 you have it

Treosulfan comes as 250mg strength capsules that you swallow or as a clear liquid given into your bloodstream. Rarely, you may also have it as an injection into the tummy (abdominal cavity).

Taking your tablets or capsules

You must take tablets and capsules according to the instructions your doctor or pharmacist gives you.

Whether you have a full or empty stomach can affect how much of a drug gets into your bloodstream.

You should take the right dose, not more or less.

Never stop taking a cancer drug without talking to your specialist first.

Drugs into your bloodstream

You have the treatment through a drip into your arm. A nurse puts a small tube (a cannula) into one of your veins and connects the drip to it.

You might need a central line. This is a long plastic tube that gives the drugs into a large vein, either in your chest or through a vein in your arm. It stays in while you’re having treatment, which may be for a few months.

Injection into the tummy

You may have treosulfan as an injection straight into the tummy (abdomen). This is called intraperitoneal injection. 

This is usually only as part of research trials. This method might cause less side effects than taking treosulfan capsules or having it into a vein. 

When you have it

You usually have treosulfan as a course of several cycles of treatment. Your treatment plan depends on which type of cancer you have and how you have treosulfan. 

Treosulfan capsules

You may have the capsules in 1 of the following ways: 

  • 4 times a day for 4 weeks, followed by 4 weeks with no treatment
  • 4 times a day for 2 weeks, followed by 2 weeks with no treatment
  • 3 times a day for 1 week, followed by 3 weeks with no treatment

Your treatment is repeated as necessary and your doctor will adjust the dose if needed. 

Treosulfan into your bloodstream

You usually have it every 1 to 3 weeks. 

Tests during treatment

You have blood tests before starting treatment 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.

Side effects

Important information

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 might harm a baby developing in the womb. It is important not to become pregnant or father a child while you are having treatment and for a few months afterwards. Talk to your doctor or nurse about effective contraception before starting treatment.


Don’t breastfeed during this treatment because the drug may come through in your breast milk.


You may not be able to become pregnant or father a child 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 may be able to store sperm before starting treatment. Women may be able to store eggs or ovarian tissue but this is rare.

Treatment for other conditions

Always tell other doctors, nurses or dentists that you’re having this treatment if you need treatment for anything else, including teeth problems.


Don’t have immunisations with live vaccines while you’re having treatment and for at least 6 months afterwards.

In the UK, live vaccines include rubella, mumps, measles, BCG, yellow fever and Zostavax (shingles vaccine).

You can:

  • have other vaccines, but they might not give you as much protection as usual
  • have the flu vaccine
  • be in contact with other people who've had live vaccines as injections

Avoid contact with people who’ve had live vaccines taken by mouth (oral vaccines). This includes the rotavirus vaccine given to babies. The virus is in the baby’s urine for up to 2 weeks and can make you ill. So, you mustn't change their nappies for 2 weeks after their vaccination.

You also need to avoid anyone who has had oral polio or typhoid vaccination recently.

More information about this treatment

For further information about this treatment go to the electronic Medicines Compendium (eMC) website.

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

Information and help

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About Cancer generously supported by Dangoor Education since 2010.