Cyclophosphamide is a chemotherapy drug that is given as a treatment for many types of cancer. It is most commonly used to treat lymphomas; cancers of the ovary, breast and bladder; and chronic lymphocytic leukaemia. This information describes cyclophosphamide, 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.

Cyclophosphamide is a colourless fluid after being dissolved from powder. It is also available as pink or white tablets of 50mg.

Cyclophosphamide is given:

• as an injection into the vein (intravenously) through a fine tube (cannula) inserted into the vein. It may 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 drip (intravenous infusion) through a cannula or line
• as tablets, which should be swallowed whole.

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 cyclophosphamide, and may be different if you are having more than one chemotherapy drug.

We have outlined the most common side effects and some of the less common ones, so 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 Cyclophosphamide 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 course 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 Cyclophosphamide 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 cyclophosphamide you may become anaemic. This may make you feel tired and breathless. Let your doctor or nurse know if you develop these symptoms.

Feeling sick (nausea) and being sick (vomiting) If you do feel sick this may begin 2–3 hours after the treatment is given and last for up to 24 hours. 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; they can prescribe other anti-sickness drugs which may be more effective. Some anti-sickness drugs can cause constipation. Let your doctor or nurse know if this is a problem.

Loss of appetite A dietitian or specialist nurse at your hospital can give advice and tips on boosting appetite, coping with eating difficulties and maintaining weight.

Irritation of the bladder lining It is important to drink plenty of fluids (2–3 litres a day) to help prevent any irritation. If you notice any blood in your urine, tell your doctor. With high-dose cyclophosphamide, fluids are given into the vein, along with a drug called mesna (Uromitexan®), which can help to prevent bladder irritation.

Hair loss You may lose your hair completely or it may just thin. This usually starts 2–4 weeks after the first dose of cyclophosphamide, although it may occur earlier. You may also have thinning and loss of eyelashes, eyebrows and other body hair. Hair loss is temporary and all your hair will start to regrow within a few weeks of the end of treatment. To help reduce hair loss, scalp cooling may be suitable for some people.

Your liver may be temporarily affected Cyclophosphamide may cause changes in the way that your liver works, but your liver will return to normal when the treatment is finished. This is very unlikely to cause you any harm, but your doctor will monitor this carefully. Samples of your blood will be taken from time to time to check your liver is working properly.

Sore mouth and ulcers Your mouth may become sore or you may notice small ulcers during this treatment. Drinking plenty of fluids, and cleaning your teeth regularly and gently with a soft toothbrush, can help reduce the risk of these effects. If you do have them, tell your nurse or doctor, who can give you special mouthwashes and medicines to prevent or clear any mouth infection.

Taste changes You may notice that your food tastes different. Normal taste will come back after the treatment finishes.

Diarrhoea This can usually be easily controlled with medicine, but tell your doctor if it is severe or persistent. It is important to drink plenty of fluids if you have diarrhoea.

Changes in nails Your nails may become darker, or ridged. These changes grow out over a few months once the treatment has finished.

Skin changes Your skin may darken, due to excess production of pigment, but this is rare.

Changes to the lungs Cyclophosphamide may cause some changes to lung tissue. Tell your doctor if you smoke and if you notice any coughing or breathlessness.

Second cancer With long-term use of this drug there is a very small risk of developing a second cancer after many years. Your doctor or nurses can discuss this risk with you further.

Changes in the way your heart works This is very rare with standard doses, but may occasionally occur with high-dose treatment. The muscle of the heart may be affected, usually temporarily. Tests to see how well your heart is working may be carried out before the drug is given, and occasionally before each treatment.

Some people have hot flushes, dizziness, a strange taste and a feeling of having a blocked nose when the drug is being given. If you have any of these symptoms ask the doctor or nurse to slow down the drip to reduce the feeling.

Cyclophosphamide may be prescribed for conditions other than cancer. The drug dosage will then be much lower and therefore these side effects will probably not occur.

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 medicines can be harmful to take when you are having chemotherapy. Tell your doctor 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 cyclophosphamide, as the developing foetus may be harmed. It is necessary to use effective contraception while taking this drug, and for at least a few months afterwards. Again, discuss this with your doctor.

• It is important to take your tablets at the right times. You must take them as directed by your doctor.
• Keep the tablets in the original packaging and store them in the fridge.
• Keep the tablets in a safe place where children cannot reach them, as cyclophosphamide could harm them.
• If your doctor decides to stop the treatment, return any remaining tablets to the pharmacist. Do not flush them down the toilet or throw them away.
• If you are sick just after taking the tablet tell your doctor as you may need to take another dose. Don't take another tablet without first telling your doctor.
• If you forget to take a tablet do not take a double dose. Let your doctor know and keep to your regular dose schedule.

This section is based on our Cyclophosphamide 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.