Hydroxycarbamide, also known as hydroxyurea, is a chemotherapy drug that is given as a treatment for some types of cancer. It is used to treat chronic myeloid leukaemia, cancer of the cervix and some pre-cancerous conditions. This information describes hydroxycarbamide, how it is given and some of its possible side effects. It should ideally be read with our 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.

Hydroxycarbamide is available as 500mg pink/green capsules.

Your doctor will tell you how many capsules to take and when to take them. You need to make sure that you are taking the right dose.

The capsules should be swallowed whole with plenty of water. If you have trouble swallowing capsules, you can empty the contents of the capsules into a glass of water and drink it straight away. You should avoid touching the contents of the capsules and make sure that you finish the whole drink.

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 hydroxycarbamide, 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 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 Hydroxycarbamide can reduce the production of white blood cells by the bone marrow, making you more prone to infection. 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 Hydroxycarbamide 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 hydroxycarbamide you may become anaemic. This may make you feel tired and breathless. Let your doctor or nurse know if these effects are a problem.

Raised levels of uric acid in the blood This is more likely to happen when you first start taking hydroxycarbamide. 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 hydroxycarbamide your uric acid levels will be checked regularly by blood tests.

Feeling sick (nausea) and being sick (vomiting) If you do feel sick this may begin soon after the treatment is given. This is very unusual, but if it occurs 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.

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 nurse or doctor if you 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 usually come back after the treatment finishes.

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

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

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

Skin changes Hydroxycarbamide can cause a rash, which may be itchy. Your doctor can prescribe medicine to help with this. You may also develop leg sores (or ulcers). Let your doctor know if you develop a leg ulcer, as your treatment may need to be adjusted. Areas of skin which have previously been treated with radiotherapy may become red and sore. Let your doctor know if this happens. Your face may also redden.

A high temperature and chills may occur from soon after the drug is given, but they do not usually last long. Your doctor may prescribe medicines to reduce this side effect.

Hydroxycarbamide may be prescribed for conditions other than cancer. The drug dosage may 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. 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 hydroxycarbamide, 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.

• Store the capsules in their original packaging, in a cool dry place.
• 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 hydroxycarbamide 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 capsules let your doctor know, as you may need to take another dose. Do not take another capsule without first telling your doctor.
• If you forget to take a capsule do not take a double dose. Tell your doctor and keep to your regular dose schedule.

This section is based on our Hydroxycarbamide 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.