Hydroxycarbamide (Hydrea)

Hydroxycarbamide is a chemotherapy treatment. It is also known as Hydrea. It was once also called Hydroxyurea.  

It is a treatment for a number of different cancer types. 

You pronounce hydroxycarbamide as hi-drox-ee-car-bo-mide.

How does hydroxycarbamide work?

Hydroxycarbamide is one of a group of chemotherapy drugs known as anti metabolites. These drugs stop cells making and repairing DNA . Cancer cells need to make and repair DNA in order to grow and multiply.

How do you have hydroxycarbamide?

You have hydroxycarbamide as tablets or capsules. 

You should take the right dose, not more or less.

Talk to your healthcare team before you stop taking a cancer drug, or if you have missed a dose.

How often do you have hydroxycarbamide?

How often you have hydroxycarbamide depends on your cancer type.

You might have hydroxycarbamide as cycles of treatment. This means that you have the drug and then a rest to allow your body to recover.

Or you might have hydroxycarbamide as continuous treatment.

You can have hydroxycarbamide in combination with radiotherapy. When this happens, you usually start taking hydroxycarbamide 7 days before the radiotherapy treatment.

Your doctor can tell you more about how often you will have your treatment.

Tests

You have blood tests before and during your treatment. They check your levels of blood cells and other substances in the blood. They also check how well your liver and kidneys are working.

What are the side effects of hydroxycarbamide?

Side effects can vary from person to person. They also depend on what other treatments you're having. 

When to contact your team

Your doctor, nurse or pharmacist will go through the possible side effects. They will monitor you during treatment and check how you are at your appointments. Contact your advice line as soon as possible if:

• you have severe side effects 

• your side effects aren’t getting any better

• your side effects are getting worse

Early treatment can help manage side effects better. 

We haven't listed all the side effects here. Talk to your healthcare team if you have any new symptoms that you think might be a side effect of your treatment.

Remember it is very unlikely that you will have all of these side effects. But you might have some of them at the same time.

Common side effects

These side effects happen in more than 10 in 100 people (more than 10%). You might have one or more of them. They include:

Risk of bruising and bleeding

This is due to a drop in the number of platelets in your blood. These blood cells help the blood to clot when we cut ourselves. You may have nosebleeds or bleeding gums after brushing your teeth. Or you may have lots of tiny red spots or bruises on your arms or legs (known as petechiae).

Risk of infection

Increased risk of getting an infection is due to a drop in white blood cells. Symptoms include a change in temperature, aching muscles, headaches, feeling cold and shivery and generally unwell. You might have other symptoms depending on where the infection is.

Infections can sometimes be life threatening. You should contact your advice line urgently if you think you have an infection. 

Breathless and looking pale

You might be breathless and look pale due to a drop in red blood cells. This is called anaemia.

Loss of appetite

You might lose your appetite for various reasons while having cancer treatment. Sickness, taste changes or tiredness can put you off food and drinks.

Inflammation of the lining of the gut and bowel

This can cause bleeding from your back passage when pooing and blood in your poo. It can also be very painful. Contact your advice line or tell your doctor or nurse if you have any of these symptoms.

Tummy (abdominal) discomfort or pain

Tell your treatment team if you have this. They can check the cause and give you medicine to help. 

Hair loss

You could lose all your hair. This includes your eyelashes, eyebrows, underarms, legs and sometimes pubic hair. Your hair will usually grow back once treatment has finished but it is likely to be softer. It may grow back a different colour or be curlier than before. 

Skin and nail changes

Skin and nail problems include a skin rash, dry skin, itching and darker skin. Your nails may also become brittle, dry, change colour or develop ridges. This usually goes back to normal when you finish treatment.

Sore weak muscles 

Your muscles might feel sore, weak and tired especially when climbing stairs, walking or getting out of a chair. 

Problems passing urine

You might find it painful and difficult to pass urine. Contact your advice line or tell your doctor or nurse if this happens.

An increased level of certain substances in the blood

You might have an increased level of creatinine, urea and uric acid in the blood. You have regular blood tests to check these. 

High temperature

Tell your healthcare team straightaway if you get a high temperature. Ask them if you can take paracetamol to help lower your temperature.

Chills

You might feel cold for no apparent reason. Chills can also happen when you have a high temperature

Having no energy or strength

This is usually mild. You can do things to help yourself, including some gentle exercise. It’s important not to push yourself too hard and eat a well balanced diet.

Talk to your doctor or nurse if this effect is stopping you from doing your usual daily activities.

Feeling or being sick 

Feeling or being sick is usually well controlled with anti sickness medicines. It might help to avoid fatty or fried foods, eat small meals and snacks and take regular sips of water. Relaxation techniques might also help.

It is important to take anti sickness medicines as prescribed even if you don’t feel sick. It is easier to prevent sickness rather than treat it once it has started.

Diarrhoea or constipation

Tell your healthcare team if you have diarrhoea or constipation. They can give you medicine to help. 

Sore mouth 

Mouth sores and ulcers can be painful. It helps to keep your mouth and teeth clean, drink plenty of fluids and avoid acidic foods such as lemons. Chewing gum can help to keep your mouth moist. Tell your doctor or nurse if you have ulcers.

Indigestion

You might have heartburn, which is a burning sensation in the lower chest. The backflow of food and stomach acid from the stomach into the food pipe (oesophagus) causes heartburn.

Your doctor or nurse can prescribe medicine to help.

Inflammation of the pancreas

This drug can cause inflammation of the pancreas (pancreatitis). Tell your doctor straight away if you have sudden and severe pain in your tummy (abdomen).

Occasional side effects

These side effects happen in between 1 and 10 out of every 100 people (between 1 and 10%). You might have one or more of them. They include:

• skin cancer - cover up or use sunblock when you go out in the sun. Check your skin regularly, and tell your doctor if you notice any changes to your skin.
• feeling disorientated and having hallucinations
• fits (convulsions), dizziness, headaches and feeling drowsy
• damage to the nerves in your hands and feet causing pain, tingling or numbness
• changes to your lungs included fluid on the lung and inflammation causing shortness of breath
• changes or damage to your liver, including hepatitis

Rare side effects

This side effects happens in fewer than 1 in 100 people (fewer than 1%). You might have one or more of them. They include:

• loss of blood supply to parts of the body (gangrene)
• changes to the levels of chemicals in your blood due to the breakdown of tumour cells (tumour lysis syndrome) – you have regular blood tests to check for this

Other side effects

There isn't enough information to work out how often this side effect might happen. People who take hydroxycarbamide as a long term treatment can develop a second cancer (leukaemia). If this is a concern for you, talk to your doctor.

Coping with side effects

We have more information about side effects and tips on how to cope with them.

What else do you need to know?

Other medicines, food and drink

Cancer drugs can interact with medicines, herbal products, and some food and drinks. We are unable to list all the possible interactions that may happen. An example is grapefruit or grapefruit juice which can increase the side effects of certain drugs.

Tell your healthcare team about any medicines you are taking. This includes vitamins, herbal supplements and over the counter remedies. Also let them know about any other medical conditions or allergies you may have.

Loss of fertility

You may not be able to become pregnant or get someone pregnant after treatment with this drug. Talk to your doctor before starting treatment if you think you may want to have a baby in the future.

Hydroxycarbamide can affect the production of sperm. Men might be able to store sperm before starting treatment. 

Contraception and pregnancy

This treatment may harm a baby developing in the womb. It is important not to become pregnant or father a child while you are having treatment.

Women must not become pregnant for at least 6 months after the end of treatment. Men should not father a child for at least a year after treatment. 

Talk to your doctor or nurse about effective contraception before starting treatment. Let them know straight away if you or your partner falls pregnant while having treatment.

Breastfeeding

Don’t breastfeed during this treatment because the drug may come through into your breast milk.

Do not handle the tablets or capsules if you are breastfeeding. 

Treatment for other conditions

If you are having tests or treatment for anything else, always mention your cancer treatment. For example, if you are visiting your dentist.

Immunisation

Don’t have immunisations with live vaccines while you’re having treatment and for up to 12 months afterwards. The length of time depends on the treatment you are having. Ask your doctor or pharmacist how long you should avoid live vaccinations.

In the UK, live vaccines include rubella, mumps, measles, BCG, yellow fever and one of the shingles vaccines called Zostavax.

You can have:

• other vaccines, but they might not give you as much protection as usual
• the flu vaccine (as an injection)
• the coronavirus (COVID-19) vaccine - talk to your doctor or pharmacist about the best time to have it in relation to your cancer treatment

Members of your household who are aged 5 years or over are also able to have the COVID-19 vaccine. This is to help lower your risk of getting COVID-19 while having cancer treatment and until your immune system recovers from treatment.

Contact with others who have had immunisations - You can be in contact with other people who have had live vaccines as injections. Avoid close contact with people who have recently had live vaccines taken by mouth (oral vaccines) such as the oral typhoid vaccine. Sometimes people who have had the live shingles vaccine can get a shingles type rash. If this happens they should keep the area covered.

If your immune system is severely weakened, you should avoid contact with children who have had the flu vaccine as a nasal spray as this is a live vaccine. This is for 2 weeks following their vaccination.

Babies have the live rotavirus vaccine. The virus is in the baby’s poo for about 2 weeks and could make you ill if your immunity is low. Get someone else to change their nappies during this time if you can. If this isn't possible, wash your hands well after changing their nappy.

More information about this treatment

For further information about this treatment and possible side effects go to the electronic Medicines Compendium (eMC) website. You can find the patient information leaflet on this website.

You can report any side effect you have to the Medicines Health and Regulatory Authority (MHRA) as part of their Yellow Card Scheme.