Hydroxycarbamide (Hydrea ®, hydroxyurea)
Hydroxycarbamide is a chemotherapy drug used to treat chronic myeloid leukaemia (CML) and other cancers, such as cervical cancer.
This information is best read together with our general information about chemotherapy and the type of cancer you have.
How hydroxycarbamide is givenBack to top
You usually have hydroxycarbamide as an outpatient. During treatment, you usually see a cancer doctor, a chemotherapy nurse or a specialist nurse. This is who we mean when we mention doctor or nurse in this information.
Before or on the day of treatment, a nurse or person trained to take blood (phlebotomist) will take a blood sample from you. This is to check that it is okay for you to have chemotherapy.
You will also see a doctor or nurse before you have chemotherapy. They will ask you about how you have been. If your blood results are alright on the day of treatment, the pharmacist will prepare your chemotherapy. Your nurse will tell you when your treatment is likely to be ready.
Taking your chemotherapy capsules
Hydroxycarbamide comes as capsules. Your nurse or pharmacist gives them to you to take at home. Always take them exactly as explained. This is important to make sure they work as well as possible for you.
You swallow the capsules whole with plenty of water. If you have trouble swallowing them, you can empty the capsules (without touching the contents) and dissolve them in a glass of water. Stir the mixture with a spoon until it has completely dissolved. Drink it straight away and always make sure you finish the whole drink. Wash the glass and spoon and don’t let other people use them.
If you are sick just after taking the capsules, contact the hospital. You may need to take another dose. If you forget to take your hydroxycarbamide, do not take a double dose. Keep to your regular schedule and let your doctor or nurse know.
Here are some other things to remember about your capsules:
- Keep them in the original package at room temperature away from heat and direct sunlight.
- Keep them safe and out of the reach of children.
- Return any remaining capsules to the pharmacist if your treatment is stopped.
Your course of hydroxycarbamide
The length of your treatment, and how often you get it, will depend on the type of cancer you are being treated for. Your nurse or doctor will talk to you about your treatment plan. If you have CML (chronic myeloid leukaemia), you might take hydroxycarbamide every day.
Before you go home, the nurse or pharmacist will give you anti-sickness (anti-emetic) drugs to take. Take all your tablets exactly as they have been explained to you.
Possible side effects of hydroxycarbamideBack to top
We explain the most common side effects of hydroxycarbamide here. But we don’t include all the rare ones that are unlikely to affect you.
You may get some of the side effects we mention but you are very unlikely to get all of them. If you are having other chemotherapy drugs as well, you may have some side effects that we don’t list here. Always tell your doctor or nurse about the side effects you have.
Your doctor can prescribe drugs to help control some side effects. It is very important to take them exactly as your nurse or pharmacist has explained. This means they will be more likely to work better for you. Your nurse will give you advice about managing your side effects. After your treatment is over, the side effects will start to improve.
Serious and life-threatening side effects
Sometimes cancer drugs can result in very severe reactions, which rarely may be life-threatening. Your cancer doctor and nurse can explain the risk of these side effects to you.
Contact the hospital
Your nurse will give you telephone numbers for the hospital. You can call them if you feel unwell or need advice any time of day or night. Save these numbers in your phone or keep them somewhere safe.
More information about this drug
We’re not able to list every side effect for this treatment here, particularly the rarer ones. For more detailed information you can visit the electronic Medicines Compendium (eMC).
Common side effects of hydroxycarbamideBack to top
Risk of infection
Chemotherapy can reduce the number of white blood cells in your blood. This will make you more likely to get an infection. When the number of white blood cells is low, it’s called neutropenia.
Contact the hospital straight away on the contact number you’ve been given if:
- your temperature goes over 37.5°C (99.5°F) or over 38°C (100.4°F), depending on the advice given by your chemotherapy team
- you suddenly feel unwell, even with a normal temperature
- you have symptoms of an infection – this can include feeling shaky, a sore throat, a cough, diarrhoea or needing to pass urine a lot.
The number of white blood cells usually increases steadily and returns to normal before your next treatment. You will have a blood test before having more chemotherapy. If your white blood cells are still low, your doctor may delay your treatment for a short time.
Bruising and bleeding
Hydroxycarbamide can reduce the number of platelets in your blood. Platelets are cells that help the blood to clot. Tell your doctor if you have any bruising or bleeding you can’t explain. This includes nosebleeds, bleeding gums, blood spots or rashes on the skin. Some people may need a drip to give them extra platelets.
Anaemia (low number of red blood cells)
Hydroxycarbamide can reduce the number of red blood cells in your blood. These cells carry oxygen around the body. If the number of red blood cells is low, you may be tired and breathless. Tell your doctor or nurse if you feel like this. If you are very anaemic, you may need a drip to give you extra red blood cells (blood transfusion).
Your doctor will prescribe anti-sickness (anti-emetic) drugs to help prevent or control sickness. Take the drugs exactly as your nurse or pharmacist explains to you. It’s easier to prevent sickness than to treat it after it has started.
If you still feel sick or are vomiting, contact the hospital as soon as possible. They can give you advice and change the anti-sickness drug to one that works better for you.
Loss of appetite
You may lose your appetite during your treatment. Try to eat small meals regularly. Don’t worry if you don’t eat much for a day or two. If your appetite doesn’t improve after a few days, let your nurse or dietitian know. They can give you advice on getting more calories and protein in your diet. They may give you food supplements or meal replacement drinks to try. Your doctor can prescribe some of these and you can buy them from chemists.
Your doctor can prescribe drugs to control diarrhoea. Let them know if it is severe or if it doesn’t get better. Make sure you drink at least two litres (three and a half pints) of fluids every day if you have diarrhoea.
Tummy pain and constipation
Hydroxycarbamide may make you constipated and cause tummy pain. Drinking at least two litres (three and a half pints) of fluids every day will help. Try to eat more foods that contain fibre (such as fruit, vegetables and wholemeal bread) and do some regular gentle exercise.
Your mouth may become sore and you may get ulcers. This can make you more likely to get an infection in your mouth. Gently clean your teeth and/or dentures morning and night and after meals. Use a soft-bristled or children’s toothbrush. Your nurse might ask you to rinse your mouth regularly or use mouthwashes. It’s important to follow any advice you are given and to drink plenty of fluids.
Tell your nurse or doctor if you have any problems with your mouth. They can prescribe medicines to prevent or treat mouth infections and reduce any soreness.
Feeling very tired is a common side effect. It’s often worse towards the end of treatment and for some weeks after it’s finished. Try to pace yourself and get as much rest as you need. It helps to balance this with some gentle exercise, such as short walks. If you feel sleepy, don’t drive or operate machinery.
Your hair may thin, but you’re unlikely to lose all the hair from your head. Hair thinning usually starts after your first or second cycle of chemotherapy. It is almost always temporary and your hair will grow back after chemotherapy ends. Your nurse can give you advice about coping with hair loss.
Chemotherapy may affect your skin. Your doctor or nurse can tell you what to expect. If your skin feels dry, try using an unperfumed moisturising cream every day. Your skin may darken. It will return to its normal colour after you finish treatment. If you’ve had radiotherapy, either recently or in the past, the area that was treated may become red or sore.
Always tell your doctor or nurse about any skin changes. They can give you advice and may prescribe creams or medicines to help. Any changes to your skin are usually temporary and improve when treatment finishes.
Your nails may become brittle and break easily. They may get darker or discoloured. These changes grow out after treatment finishes. Wear gloves when washing dishes or using detergents to help protect your nails during treatment.
Numb or tingling hands or feet
These symptoms are caused by the effect of hydroxycarbamide on nerves. It’s called peripheral neuropathy. You may also find it hard to fasten buttons or do other fiddly tasks.
Tell your doctor if you have these symptoms. They sometimes need to lower the dose of the drug. The symptoms usually improve slowly after treatment finishes, but in some people they may never go away. Talk to your doctor if you are worried about this.
This treatment may cause headaches. If this happens, let your doctor or nurse know. They can give you painkillers.
Changes in the way the kidneys and liver work
Hydroxycarbamide can affect how your kidneys and liver work. This is usually mild and goes back to normal after treatment. You will have blood tests before chemotherapy to check how well your kidneys and liver are working.
Raised levels of uric acid in the blood
Hydroxycarbamide may cause the leukaemia or cancer cells to break down quickly. This releases uric acid (a waste product) into the blood. Too much uric acid can cause swelling and pain in the joints, which is called gout. Your doctor may give you tablets called allopurinol (Zyloric ®) to help prevent this. Drinking at least two litres (three and a half pints) of fluid a day will also help. You will have regular blood tests to check the uric acid levels.
Less common side effects of hydroxycarbamideBack to top
Effects on the nervous system
Hydroxycarbamide can affect the nervous system. You may feel drowsy, confused, dizzy or unsteady. Very rarely, hydroxycarbamide can cause seizures (fits).Tell your doctor or nurse straight away if you notice any of these symptoms. It’s important not to drive or operate machinery if you notice these effects.
Effects on the lungs
Hydroxycarbamide can cause changes to the lungs. Always tell your doctor if you develop wheezing, a cough, a fever or feel breathless. You should also let them know if any existing breathing problems get worse. If necessary, they can arrange for you to have tests to check your lungs.
Rarely, hydroxycarbamide can cause an allergic reaction. Signs of a reaction can include:
- a rash
- feeling itchy
- feeling short of breath
- swelling of your face or lips
- feeling unwell.
Tell your nurse straight away if you have any of these symptoms. If you develop any of these symptoms after you get home, contact the hospital on the numbers you’ve been given immediately, or go to the nearest accident and emergency department.
Rarely, hydroxycarbamide can increase the risk of developing a second cancer years later. But the benefits of treatment usually far outweigh this risk. Your doctor can talk to you about this.
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 here.
Other information about hydroxycarbamideBack to top
Hydroxycarbamide can be given to treat conditions other than cancer. The dose used will be much lower than with leukaemia or cancer, so the side effects mentioned in this fact sheet will probably not happen.
Let your doctor know if you have any ulcers or sores on your legs. Hydroxycarbamide can affect how well these heal. Your doctor may need to adjust your treatment.
Blood clot risk
Cancer increases the chance of a blood clot (thrombosis) and chemotherapy can add to this. A clot can cause symptoms such as pain, redness and swelling in a leg, breathlessness and chest pain. Contact your doctor straight away if you have any of these symptoms. A blood clot is serious but your doctor can treat it with drugs that thin the blood. Your doctor or nurse can give you more information.
Some medicines can interact with chemotherapy or be harmful when you are having chemotherapy. This includes medicines you can buy in a shop or chemist. Tell your doctor about any medicines you are taking, including over-the-counter drugs, complementary therapies and herbal drugs.
Hydroxycarbamide may affect your fertility (being able to get pregnant or father a child). If you are worried about this, you can talk to your doctor or nurse before treatment starts.
Your doctor will advise you not to become pregnant or to father a child during treatment. This is because the drugs may harm a developing baby. It’s important to use effective contraception during and for a few months after chemotherapy. You can talk to your doctor or nurse about this.
If you have sex while having chemotherapy, you need to use a condom. This is to protect your partner in case there is any chemotherapy in your semen or vaginal fluid.
Changes to your periods
Chemotherapy can sometimes stop the ovaries working. You may not get a period every month and they may eventually stop. In some women, this is temporary, but for others it is permanent and they start the menopause.
Women are advised not to breastfeed during treatment and for a few months after. This is in case there is chemotherapy in their breast milk.
Medical and dental treatment
If you need to go into hospital for any reason other than cancer, always tell the doctors and nurses that you are having chemotherapy. Explain you are taking chemotherapy tablets that no one should stop or restart without advice from your cancer doctor. Give them the contact details for your cancer doctor.
Talk to your cancer doctor or nurse if you think you need dental treatment. Always tell your dentist you are having chemotherapy.
This page has been compiled using information from a number of reliable sources, including the electronic Medicines Compendium (eMC; medicines.org.uk). If you’d like further information on the sources we use, please feel free to contact us.
This information was reviewed by a medical professional.
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