Treosulfan is a chemotherapy drug that is given as a treatment for some types of cancer. It is most commonly used to treat ovarian cancer. This information describes treosulfan, how it is given and some of its possible side effects. It should ideally be read with our general information about chemotherapy and about your type of cancer.

If you have any further questions you can ask your doctor or nurse at the hospital where you are having your treatment, or speak to one of our cancer support service nurses.

Treosulfan is available as white capsules of 250mg.

It is also available as a colourless fluid for injection, after being dissolved from powder.

Treosulfan may be given:

• As capsules (orally). The capsules should be swallowed whole with plenty of water.
• As a drip (infusion) through a fine tube (cannula) inserted into the vein. It may also be given through a central line, which is inserted under the skin into a vein near the collarbone, or into a PICC line, which is inserted into a vein in the crook of the arm.
• By injection into a vein (intravenously) through a cannula.
• By injection into the abdominal cavity (intraperitoneally).

Chemotherapy is usually given as a course of several sessions (or cycles) of treatment over a few months. The length of your treatment and the number of cycles you have will depend on the type of cancer for which you are being treated. Your nurse or doctor will discuss your treatment plan with you.

Each person’s reaction to chemotherapy is different. Some people have very few side effects, while others may experience more. The side effects described in this information will not affect everyone who is given treosulfan, and may be different if you are having more than one chemotherapy drug.

We have outlined the most common side effects as well as rarer ones, so that you can be aware of them if they occur. However, we have not included those that are very rare and therefore extremely unlikely to affect you. If you notice any effects which you think may be due to the drug, but which are not listed in this information, please discuss them with your doctor or chemotherapy nurse.

Lowered resistance to infection Treosulfan can reduce the production of white blood cells by the bone marrow, making you more prone to infection. This effect can begin seven days after treatment has been given, and your resistance to infection usually reaches its lowest point 10–14 days after chemotherapy. Your blood cells will then increase steadily and will usually have returned to normal levels before your next cycle of chemotherapy is due.

Contact your doctor or the hospital straightaway if:

• your temperature goes above 38ºC (100.5ºF)
• you suddenly feel unwell (even with a normal temperature).

You will have a blood test before having more chemotherapy to make sure that your cells have recovered. Occasionally it may be necessary to delay your treatment if the number of blood cells (the blood count) is still low.

Bruising or bleeding Treosulfan can reduce the production of platelets (which help the blood to clot). Let your doctor know if you have any unexplained bruising or bleeding, such as nosebleeds, blood spots or rashes on the skin, or bleeding gums.

Anaemia (low number of red blood cells) While having treatment with treosulfan you may become anaemic. This may make you feel tired and breathless. Let your doctor or nurse know if these symptoms are a problem.

Skin changes Treosulfan can cause a rash, which may be itchy. Your doctor can prescribe medicine to help with this. Your skin may darken due to excess production of pigment. This usually returns to normal a few months after the treatment has finished.

Tiredness and feeling weak You may feel very tired. It is important to allow yourself plenty of time to rest.

Feeling sick (nausea) and being sick (vomiting) If you do feel sick it may begin soon after the treatment is given and can last for about a day. Your doctor can prescribe very effective anti-sickness (anti-emetic) drugs to prevent or greatly reduce, nausea and vomiting. If the sickness is not controlled or continues tell your doctor, who can prescribe other anti-sickness drugs that may be more effective. Some anti-sickness drugs can cause constipation. Let your doctor or nurse know if this is a problem.

Hair loss It is very unusual for your hair to fall out. Some people notice that their hair becomes a little thinner, but not usually enough to be noticeable to other people.

Irritation of the bladder It is important to drink plenty of fluids for up to 24 hours after your chemotherapy to help prevent any irritation.

Leakage into the tissue If treosulfan leaks into the tissue around the vein it can damage the tissue in that area. If you notice any stinging or burning around the vein while the drug is being given, or any leakage of fluid from the cannula site, it is very important that you tell the doctor or nurse immediately.

If the area around the injection site becomes red or swollen at any time you should either tell the doctor or nurse on the ward, or if you are at home, ring the clinic or ward and ask to speak to the doctor or nurse.

Risk of blood clots Cancer can increase your risk of developing a blood clot (thrombosis), and having chemotherapy may increase this risk further. A blood clot may cause symptoms such as pain, redness and swelling in a leg, or breathlessness and chest pain. Blood clots can be very serious so it is important to tell your doctor straightaway if you have any of these symptoms. However, most clots can usually be successfully treated with drugs to thin the blood. Your doctor or nurse can give you more information.

Other medicines Some other medicines can be harmful to take when you are having chemotherapy. Let your doctor know about any medications you are taking, including non-prescribed drugs such as complementary therapies and herbal drugs.

Fertility Your ability to become pregnant or father a child may be affected by taking this drug. It is important to discuss fertility with your doctor before starting treatment.

Contraception It is not advisable to become pregnant or father a child while taking treosulfan, as the developing foetus may be harmed. It is important to use effective contraception while taking this drug, and for at least a few months afterwards. Again, discuss this with your doctor.

• Store the capsules in the original packaging, at room temperature and away from direct sunlight.
• It is important to take your capsules at the right times. You must take them as directed by your doctor.
• Keep the capsules in a safe place where children cannot reach them, as treosulfan could harm them.
• If your doctor decides to stop the treatment, return any remaining capsules to the pharmacist. Do not flush them down the toilet or throw them away.
• If you are sick just after taking the capsule let your doctor know, as you may need to take another one. Do not take another capsule without first informing your doctor.
• If you forget to take a capsule do not take a double dose. Let your doctor know and keep to your regular dose schedule.

This section is based on our Treosulfan factsheet which has been compiled using information from a number of reliable sources, including:

• Martindale: The Complete Drug Reference (35th edition). Eds. Sweetman et al. Pharmaceutical Press, 2007.
• British National Formulary (54th edition). British Medical Association and Royal Pharmaceutical Society of Great Britain, September 2007.
• The Medicines.org.uk website – www.medicines.org.uk (November 2007).
• The Chemotherapy Source Book (3rd edition). Ed. Perry. Lippincott Williams and Wilkins, 2001.

For further references, please see general bibliography.