Hydroxycarbamide, also known as hydroxyurea, is a chemotherapy drug usually given to treat chronic myeloid leukaemia(CML), cervical cancer and some pre-cancerous conditions.
What hydroxycarbamide looks like
Back to top
Hydroxycarbamide is available as 500mg pink and green capsules, as well as 500mg white capsules.
Your doctor will tell you how many capsules to take and when to take them. You'll need to make sure you are taking the right dose.
You should swallow the capsules whole with plenty of water. If you have trouble swallowing them, 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 you finish the whole drink.The glass and spoon should be washed and kept separate from your other crockery and cooking utensils.
Chemotherapy is usually given as a course of several sessions (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 you are being treated for. Your nurse or doctor will discuss your treatment plan with you.
Before you begin your treatment your doctor will arrange for you to have blood tests. You will usually be given anti-sickness drugs before and/or during your treatment.
Each person’s reaction to chemotherapy is different. Some people have very few side effects while others may experience more. The side effects described here won't affect everyone who has hydroxycarbamide and may be different if you are having more than one type of chemotherapy drug.
We have outlined the most common side effects but haven't included those that are rare and unlikely to affect you. If you notice any effects that aren't listed here, discuss them with your doctor, chemotherapy nurse or pharmacist.
Risk of infection
Hydroxycarbamide can reduce the number of white blood cells, which help fight infection. White blood cells are produced by the bone marrow. If the number of your white blood cells is low you'll be more prone to infections. A low white blood cell count is called neutropenia.
Neutropenia begins seven days after treatment, and your resistance to infection is usually at its lowest 10–14 days after chemotherapy. The number of your white blood cells will then increase steadily and usually return to normal before your next cycle of chemotherapy is due.
Contact your doctor or the hospital straight away if:
your temperature goes above 38ºC (100.4ºF)
you suddenly feel unwell even with a normal temperature.
You'll have a blood test before having more chemotherapy to check the number of white blood cells. Occasionally, your treatment may need to be delayed if the number of your blood cells (blood count) is still low.
Bruising and bleeding
Hydroxycarbamide can reduce the production of platelets, which help the blood to clot. Tell your doctor if you have any unexplained bruising or bleeding, such as nosebleeds, bleeding gums, blood spots or rashes on the skin. You may need to have a platelet transfusion if your platelet count is low.
Hydroxycarbamide can reduce the number of red blood cells, which carry oxygen around the body. A low red blood cell count is called anaemia. This may make you feel tired and breathless. Tell your doctor or nurse if you have these symptoms. You may need to have a blood transfusion if the number of red blood cells becomes too low.
Raised levels of uric acid in the blood
This is more likely to happen when you first start taking hydroxycarbamide. Too much uric acid can affect the kidneys and result in a condition called gout, which causes inflammation of the joints. To prevent these effects, you may be given a drug called allopurinol (Zyloric®), and you may be asked to drink plenty of fluids. While you're having hydroxycarbamide your uric acid levels will be checked regularly with blood tests.
Less common side effects
Back to top
Feeling sick (nausea) or being sick (vomiting)
Your doctor can prescribe very effective anti-sickness (anti-emetic) drugs to prevent or greatly reduce nausea and vomiting. If the sickness isn't controlled, or if it continues, tell your doctor they 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.
Your mouth may become sore or dry, 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 this happening. Some people may find sucking on ice soothing. Tell your nurse or doctor if you have any of these problems, as they can prescribe mouthwashes and medicine to prevent or clear mouth infections.
You may notice that food tastes different. Normal taste usually comes back after treatment finishes. A dietitian or specialist nurse at your hospital can give you advice about ways of coping with this side effect.
Feeling tired is a common side effect of chemotherapy, especially towards the end of treatment and for some weeks after it’s over. It’s important to try to pace yourself and get as much rest as you need. Try to balance this with some gentle exercise, such as short walks, which will help. If tiredness is making you feel sleepy, don’t operate or drive machinery.
Hydroxycarbamide can cause diarrhoea. This can usually be easily controlled with medicine, but tell your doctor if it is severe or continues. It's important to drink plenty of fluids if you have diarrhoea.
It's very unusual to lose your hair during treatment. Some people notice that their hair becomes a little thinner but not usually enough to be noticeable to other people.
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 that have previously been treated with radiotherapy may become red and sore. Let your doctor know if this happens. Rarely, your skin may darken. If it does, it usually returns to normal a few months after the treatment has finished.
Fever and chills
These may occur from the time your treatment is given, but they don’t usually last long. Your doctor may prescribe medicines to reduce these effects.
It’s important to let your doctor know straight away if you feel unwell or have any severe side effects, even if they’re not mentioned above.
Back to top
Conditions other than cancer
Hydroxycarbamide may be prescribed for conditions other than cancer. The drug dosage will be much lower and so the side effects mentioned in this fact sheet will probably not occur. You should discuss the treatment and any possible side effects with your relevant specialist.
Risk of developing a blood clot
Cancer can increase the risk of developing a blood clot (thrombosis), and 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’s important to tell your doctor straight away if you notice any of these symptoms. Most clots can be treated with drugs that thin the blood. The doctor or nurse can give you more information.
Some medicines, including those you can buy in a shop or chemist, can be harmful to take when you are having chemotherapy. Tell your doctor about any medicines you are taking, including over-the-counter drugs, complementary therapies and herbal drugs.
Your ability to become pregnant or father a child may be affected by having this treatment. It's important to discuss fertility with your doctor before starting treatment.
It's not advisable to become pregnant or father a child while having hydroxycarbamide, as it may harm the developing baby. It’s important to use effective contraception while having this drug and for at least a few months afterwards. You can discuss this with your doctor.
It’s not known whether chemotherapy drugs can be present in semen or vaginal fluids. To protect your partner, it’s safest to either avoid sex or use a barrier form of contraception for about 48 hours after chemotherapy.
There's a potential risk that chemotherapy drugs may be present in breast milk. Women are advised not to breastfeed during chemotherapy and for a few months afterwards.
If you’re admitted to hospital for a reason not related to the cancer, it’s important to tell the doctors and nurses looking after you that you're having chemotherapy treatment. You should tell them the name of your cancer specialist so that they can ask for advice.
It’s a good idea to know who you should contact if you have any problems or troublesome side effects when you’re at home. Your chemotherapy nurse or doctor will give you details of who to contact for advice. This should include ‘out-of hours’ contact details if you need to call someone at evenings, overnight or at the weekend.
Things to remember about hydroxycarbamide
Back to top
It’s important to take your capsules at the right times as directed by your doctor.
Always tell any doctors treating you for non-cancerous conditions that you're taking a course of chemotherapy capsules that should not be stopped or restarted without advice from your cancer specialist.
Keep the capsules in their original packaging, and store them at room temperature away from heat and direct sunlight.
Keep the capsules in a safe place and out of the reach of children.
If your doctor decides to stop the treatment, return any remaining capsules to the pharmacist. Don't flush them down the toilet or throw them away.
If you're sick just after taking the capsules tell your doctor as you may need to take another dose. Don't take another capsule without telling your doctor first.
If you forget to take a capsule, don't take a double dose. Let your doctor know and keep to your regular dose schedule.
This section is based on our hydroxycarbamide fact sheet, which has been compiled using information from a number of reliable sources, including:
Sweetman, et al. Martindale: The Complete Drug Reference. 37th edition. 2011. Pharmaceutical Press.
British National Formulary. 62nd edition. 2011. British Medical Association and Royal Pharmaceutical Society of Great Britain.
electronic Medicines Compendium. (accessed October 2011).
Perry MC. The Chemotherapy Source Book. 4th edition. 2007. Lippincott Williams and Wilkins.