Cytarabine is a chemotherapy drug that is given as a treatment for some types of cancer. It is sometimes called Ara C. Cytarabine is most commonly used to treat acute myeloid leukaemia. This information describes cytarabine, how it is given and some of its possible side effects. It should ideally be read with our general information about chemotherapy and about acute myeloid leukaemia, which give more information and advice.

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.

Cytarabine is a colourless fluid.

Cytarabine may be given:

• as an injection into the vein (intravenously) through a fine tube inserted into the vein (cannula); 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 your arm
• by a drip (infusion) through the cannula or line. The infusion takes between ten minutes and two hours, depending on the dose
• by injection into the fluid around the spinal cord through a lumbar puncture (intrathecally). Only certain specially-trained staff are able to give cytarabine in this way, and it must be given in a special area, so it may be given in a different hospital and by different staff from the rest of your chemotherapy
• as an injection just under the skin (subcutaneous injection).

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 cytarabine, 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 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 do 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 Cytarabine 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 Cytarabine 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 cytarabine 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 after the treatment is given and last for several 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.

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

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.

Raised levels of uric acid in the blood You may be given a drug called allopurinol to stop this happening. It may also help to drink plenty of fluids. While you are taking cytarabine your uric acid levels may be checked by blood tests.

Gritty eyes due to inflammation of the lining of the eyelids (conjunctiva) If this happens, tell your doctor, as steroid eye drops can be prescribed. Some people may be given steroid eye drops to help prevent this side effect from occurring. It is important to follow the instructions that you are given.

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 to reduce the risk of this happening. Tell your doctor if you do have any of these problems, as they can prescribe special mouthwashes and medicine 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.

Hair loss This is rare, but your hair may thin, or occasionally fall out completely. If this happens it usually begins about 3–4 weeks after starting treatment, although it may occur earlier. Hair loss is temporary, and your hair will regrow once the treatment ends.

Your liver may be temporarily affected Cytarabine may cause changes in the way that your liver works, though 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.

Lack of energy (lethargy), sleepiness, confusion and loss of balance This is very rare and only happens with high dose treatment. If you notice any of these effects it is important to tell your doctor.

Changes to the lungs Cytarabine may cause some changes to lung tissue. Tell your doctor if you notice any cough or breathlessness.

Soreness and redness of the palms of the hands and soles of the feet (Sometimes known as palmar plantar or hand and foot syndrome) This is temporary and will improve when the treatment is finished.

Skin changes Cytarabine can cause a rash, which may be itchy. Your doctor can prescribe medicine to help with this.

A flu-like effect This can occur after the drug is given, and may last for a few days. You may have headaches, aching joints or muscles, a temperature, lethargy (a feeling of having no energy) and chills. If this does happen, it is important that you drink plenty of fluids and get plenty of rest.

Effect on the nervous system At very high doses, cytarabine can cause some damage to the nerves inside and outside the brain. This may cause a variety of symptoms, including fits (seizures) and mood changes.

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.

Pain at the injection site While cytarabine is being given, it can cause pain at the place where the injection is given, or along the vein. If you feel pain tell the doctor or nurse. They can slow the drip down to reduce the feeling.

When cytarabine is given by lumbar puncture (intrathecally) the side effects may be different from those mentioned in this information. Your doctor or nurse will be able to discuss this with you.

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 cytarabine, 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.

This section is based on our Cytarabine 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.