Hydroxycarbamide (Hydrea®, hydroxyurea)

Hydroxycarbamide (Hydrea®, hydroxyurea) is a chemotherapy drug used to treat chronic myeloiod leukaemia (CML) and cervical cancer. It may also be used to treat other cancers.

It is best to read this information with our general information about chemotherapy and the type of cancer you have.

Hydroxycarbamide is usually given as capsules. You usually have it as an outpatient. Your cancer doctor or nurse will tell you how often you will have it.

Like all chemotherapy drugs, hydroxycarbamide can cause side effects. Some of the side effects can be serious, so it is important to read the detailed information below.

Your healthcare team can give you advice on how to manage any side effects. Tell your doctor or nurse straight away if you:

  • have a temperature
  • feel unwell
  • have severe side effects, including any we do not mention here.

Rarely, side effects may be life-threatening. Your cancer doctor or nurse can explain the risk of these side effects to you.

If you need medical attention for any reason other than cancer, always tell the healthcare staff that you are having this treatment.

What is hydroxycarbamide?

Hydroxycarbamide (Hydrea®) is a chemotherapy drug used to treat chronic myeloid leukaemia (CML) and some other types of cancer, 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 given

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 all right 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.

Going home

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.


About side effects

We explain the most common side effects of this treatment here. We also include some less common side effects.

You may get some of the side effects we mention, but you are unlikely to get all of them. If you are also having treatment with other cancer drugs, you may have some side effects that we haven’t listed here. Always tell your doctor, nurse or pharmacist about any side effects you have.

Your doctor can give you drugs to help control some side effects. It is important to take them exactly as your nurse or pharmacist explains. This means they will be more likely to work for you. Your nurse will give you advice about managing your side effects. After your treatment is over, most side effects start to improve.

Serious and life-threatening side effects

Some cancer treatments can cause severe side effects. Rarely, these may be life-threatening. Your cancer doctor or nurse can explain the risk of these side effects to you.

Contact the hospital

Your nurse will give you telephone numbers for the hospital. If you feel unwell or need advice, you can call them at any time of the day or night. Save these numbers in your phone or keep them somewhere safe.

More information

We cannot list every side effect for this treatment. There are some rare side effects that are not listed. You can visit the electronic Medicines Compendium (eMC) for more detailed information.


Possible side effects of hydroxycarbamide

Risk of infection

This treatment can reduce the number of white blood cells in your blood. These cells fight infection. If the number of white blood cells is low, you are more likely to get an infection. A low white blood cell count is called neutropenia.

If you have an infection, it is important to treat it as soon as possible. Contact the hospital straight away on the 24-hour contact number you have if:

  • your temperature goes over 37.5°C (99.5F)
  • you suddenly feel unwell, even with a normal temperature
  • you have symptoms of an infection.

Symptoms of an infection include:

  • feeling shivery
  • a sore throat
  • a cough
  • diarrhoea
  • needing to pass urine often.

It is important to follow any specific advice your cancer treatment team gives you.

The number of white blood cells will usually return to normal before your next treatment. You will have a blood test before having more chemotherapy. If your white blood cell count is low, your doctor may delay your treatment for a short time.

Bruising and bleeding

Chemotherapy can reduce the number of platelets in your blood. Platelets are cells that help the blood to clot. Tell your doctor or nurse if you have any bruising or bleeding that you can’t explain. This includes:

  • nosebleeds
  • bleeding gums
  • tiny red or purple spots on the skin that may look like a rash.

Some people may need a drip to give them extra platelets. This is called a platelet transfusion.

Anaemia (low number of red blood cells)

Chemotherapy 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. This is called a blood transfusion.

Feeling sick

You may feel sick in the first few days after chemotherapy. Your doctor will give you anti-sickness drugs to help prevent or control sickness. Take the drugs exactly as your nurse or pharmacist tells you. It is easier to prevent sickness than to treat it after it has started.

If you feel sick, take small sips of fluids and eat small amounts often. If you continue to feel sick, or if you vomit more than once in 24 hours, contact the hospital as soon as possible. They will give you advice and may change the anti-sickness drug to one that works better for you.

Loss of appetite

This treatment can affect your appetite. Do not worry if you don’t eat much for a day or two. But if your appetite does not come back after a few days, tell your nurse or dietitian. They will give you advice. They may give you food or drink supplements.

Diarrhoea

If you have diarrhoea, contact the hospital for advice. Try to drink at least two litres (three and a half pints) of fluids every day. It can help to avoid alcohol, caffeine, milk products, high-fat foods and high-fibre foods.

Constipation

This treatment can cause constipation. Here are some tips that may help:

  • Drink at least two litres (three and a half pints) of fluids each day.
  • Eat high-fibre foods, such as fruit, vegetables and wholemeal bread.
  • Do regular gentle exercise, like going for short walks.

If you have constipation, contact the hospital for advice. Your doctor can give you drugs called laxatives to help.

Sore mouth

You may get a sore mouth or mouth ulcers. This can make you more likely to get a mouth infection. Use a soft toothbrush to clean your teeth or dentures in the morning, at night and after meals.

If your mouth is sore:

  • tell your nurse or doctor – they can give you a mouthwash or medicines to help
  • try to drink plenty of fluids
  • avoid alcohol, tobacco, and foods that irritate your mouth.

Feeling tired

Feeling tired is a common side effect. It is often worse towards the end of treatment and for some weeks after it has finished. Try to pace yourself and plan your day so you have time to rest. Gentle exercise, like short walks, can give you more energy. If you feel sleepy, do not drive or operate machinery.

Hair loss

Your hair may get thinner but you are unlikely to lose all the hair from your head. Hair loss usually starts after your first or second treatment. It is almost always temporary and your hair will usually grow back after treatment ends. Your nurse can talk to you about ways to cope with hair loss.

Skin changes

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.

Nail changes

Chemotherapy may make your nails grow more slowly or become brittle or flaky. You may notice white lines appearing across them, or changes in the shape or colour of your nails. This should go back to normal after chemotherapy.

Protect your nails and hands by keeping them well moisturised. Wear gloves to protect them when doing things in the house or garden etc. It’s fine to wear nail varnish but don’t use false nails during chemotherapy. If your toenails are affected wear well fitted shoes to cushion them.

Numb or tingling hands or feet (peripheral neuropathy)

This treatment affects the nerves, which can cause numb, tingling or painful hands or feet. You may 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 or delay treatment for a short time. The symptoms usually improve slowly after treatment finishes, but for some people they may never go away. Talk to your doctor if you are worried about this.

Headaches

This treatment may cause headaches. If this happens, tell your doctor or nurse. They can give you painkillers.

Changes in the way your liver or kidneys work

This treatment can affect how your kidneys and liver work. This is usually mild and goes back to normal after treatment. You will have blood tests to check how well your kidneys and liver are working.

Raised levels of uric acid in the blood

This treatment may cause the cancer/leukaemia cells to break down quickly. This releases uric acid (a waste product) into the blood. The kidneys usually get rid of uric acid but may not be able cope with large amounts. 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 of fluid a day will also help. You will have regular blood tests to check the uric acid levels.


Less common side effects of hydroxycarbamide

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

This treatment can cause changes to the lungs. Tell your doctor if you develop: 

  • a cough
  • wheezing
  • a fever (high temperature)
  • breathlessness.

You should also tell them if any existing breathing problems get worse. You may have tests to check your lungs.

Allergic reaction

Rarely, this treatment can cause an allergic reaction. Signs of a reaction can include

  • a rash
  • feeling itchy
  • wheeziness
  • shortness 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.

Second cancer

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.


Other information about hydroxycarbamide

Other conditions

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.

Leg ulcers

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 and some cancer treatments can increase the risk of a blood clot. Symptoms of a blood clot include:

  • pain, redness or swelling in a leg or arm
  • breathlessness
  • chest pain. 

If you have any of these symptoms, contact a doctor straight away. 

A blood clot is serious, but can be treated with drugs that thin the blood. Your doctor or nurse can give you more information.

Other medicines

Some medicines can affect chemotherapy or be harmful when you are having it. This includes medicines you can buy in a shop or chemist. Tell your cancer doctor about any drugs you are taking, including vitamins, herbal drugs and complementary therapies.

Fertility

Some cancer drugs can affect whether you can get pregnant or father a child. If you are worried about this, it is important to talk with your doctor before you start treatment.

Contraception

Your doctor will advise you not to get pregnant or father a child while having this treatment. The drugs may harm the developing baby. It is important to use effective contraception during your treatment.

Sex

If you have sex in the first few days after chemotherapy, you need to use a condom. This is to protect your partner in case there is any chemotherapy in semen or vaginal fluids.

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.

Breastfeeding

Women are advised not to breastfeed while having this treatment and for some time afterwards. This is because the drugs could be passed to the baby through breast milk.

Medical and dental treatment

If you need medical treatment for any reason other than cancer, always tell the doctors and nurses that you are having cancer treatment. Give them the contact details for your cancer doctor so they can ask for advice.

If you think you need dental treatment, talk to your cancer doctor or nurse. Always tell your dentist you are having cancer treatment.