Hydroxycarbamide is also known as Hydrea®. It is used to treat chronic myeloid leukaemia (CML), myeloproliferative disorders, and other cancers, such as cervical cancer.

What is hydroxycarbamide (Hydrea®)?

Hydroxycarbamide is used to treat blood cancers such as chronic myeloid leukaemia (CML) and the following myeloproliferative disorders:

It may sometimes be used to treat other cancers, such as  cervical cancer.

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

Your doctor will talk to you about this treatment and its possible side effects before you agree (consent) to have treatment.

How hydroxycarbamide is given

During treatment, you usually see a cancer doctor, a chemotherapy nurse or a specialist nurse, and a specialist pharmacist. This is who we mean when we mention doctor, nurse, or pharmacist in this information.

While you are having this treatment, you will have regular blood tests. These are done to check that your blood cells are at a safe level for you to have chemotherapy.

You will see a doctor or nurse before and during chemotherapy. They will ask you how you have been feeling. If your blood results are okay, the pharmacist will prepare your chemotherapy.

Your course of chemotherapy

Hydroxycarbamide comes in capsules, so you can take it at home.

How often you take the capsules, and how long you take them for, will depend on the type of cancer you have. If you have a blood cancer, you might take hydroxycarbamide capsules every day. Your nurse or doctor will discuss your treatment plan with you. They may give you a copy of the treatment plan to take home with you.

The nurse or pharmacist will give you the capsules to take home. Always take them exactly as explained. This is important to make sure they work as well as possible for you.

Your nurse or pharmacist may also give you anti-sickness drugs and other medicines to take home. Take all your capsules and tablets exactly as the nurse or pharmacist explains to you.

Taking hydroxycarbamide capsules

Take the capsules at the same time every day. Tell your doctor, nurse or pharmacist if you have difficulties swallowing the capsules. They can give you advice.

If you forget to take the capsules, you should take the missed dose as soon as possible within the same day. If a full day has gone by, tell your doctor or nurse. Do not take a double dose unless your doctor tells you to.

Other things to remember about your capsules:

  • Wash your hands after taking them.
  • Other people should avoid direct contact with your chemotherapy drugs.
  • Keep them in the original package at room temperature, away from heat and direct sunlight.
  • Keep them safe and out of sight and reach of children.
  • If you are sick just after taking the capsules, contact the hospital. Do not take another dose.
  • If your treatment is stopped, return any unused capsules to the pharmacist.

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 have not 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.

Common side effects

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 (99.5°F)
  • 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 treatment. If your white blood cell count is low, your doctor may delay your treatment for a short time.

Bruising and bleeding

This treatment 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 that you cannot 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)

This treatment 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 during this treatment. 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 straight away. 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 do not 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

This treatment may cause diarrhoea. Diarrhoea means passing more stools (poo) than is usual for you, or having watery or loose stools. If you have a stoma, it will be more active than usual.

If you have diarrhoea:

  • try to drink at least 2 litres (3½ pints) of fluids each day
  • avoid alcohol, caffeine, milk products, high-fat foods and high-fibre foods
  • contact the hospital for advice.

Constipation

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

  • Drink at least 2 litres (3½ 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.

Tummy pain

This treatment can cause tummy pain and indigestion. It can also cause inflammation of the pancreas, but this is rare. Tell your nurse or doctor if you have pain in your tummy (abdomen).

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

This treatment 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 also darken. It will return to its normal colour after you finish treatment. If you have had radiotherapy, either recently or in the past, the area that was treated may become red or sore.

Taking hydroxycarbamide for a long time can increase your risk of developing skin cancer. It is important to protect your skin by:

  • avoiding being out in the sun 
  • using sunscreen
  • wearing protective clothing and a hat.

Your doctor or nurse can give you more advice. They can also tell you about skin changes to look out for.

Always tell your doctor or nurse about any changes to the skin. 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.

Leg ulcers

If you take hydroxycarbamide for a long time, you may get ulcers on your legs and feet. Tell your doctor if you notice a break in the skin of your leg or foot. Your treatment may need to be adjusted. Leg and foot ulcers usually get better after treatment finishes.

Nail changes

Your nails may grow more slowly or break more easily. You may notice white lines across your nails, or other changes to their shape or colour. Once the treatment has ended, any changes usually take a few months to grow out.

There are things you can do to look after your nails:

  • Keep your nails and hands moisturised.
  • Wear gloves to protect your nails when you are doing things in the house or garden.
  • Do not use false nails during this treatment. It is fine to wear nail varnish.
  • 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. 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 the liver and kidneys work

Hydroxycarbamide can affect how your liver and kidneys work. This is usually mild and goes back to normal after treatment.

You will have blood tests before, during, and after chemotherapy to check how well your kidneys and liver are working.

Problems passing urine (peeing)

Hydroxycarbamide may cause problems with passing urine. Tell your doctor or nurse straight away if you have pain or difficulty peeing.

Raised levels of uric acid (tumour lysis syndrome)

This treatment may cause the cancer 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 to 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 allopurinol (Zyloric®) tablets to help prevent this. Drinking at least 2 litres (3½ pints) of fluid a day will also help. You will have regular blood tests to check the uric acid levels.

Less common side effects

Effects on the nervous system

Hydroxycarbamide can affect the nervous system. You may feel:

  • drowsy
  • confused
  • dizzy
  • unsteady.

Very rarely, hydroxycarbamide can cause seizures (fits).

Tell your doctor or nurse straight away if you notice any of these symptoms. It is important not to drive or operate machinery if you have these symptoms.

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, hydroxycarbamide can cause an allergic reaction. Signs of a reaction can include:

  • a rash
  • feeling itchy
  • wheezing
  • 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 straight away, or go to the nearest accident and emergency (A&E) 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.

It is important to tell your doctor straight away if you feel unwell or have any severe side effects, even if they are not mentioned here.

Other information

Other conditions

You may have hydroxycarbamide to treat conditions other than cancer. The dose is usually much lower than when it is used to treat cancer. This means you may not have the side effects we mention.

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 how this treatment works or be harmful when you are having it. Always tell your cancer doctor about any drugs you are taking or planning to take, such as:

  • medicines you have been prescribed
  • medicines you buy in a shop or chemist
  • vitamins, herbal drugs and complementary therapies.

Tell other doctors, pharmacists or dentists who prescribe or give you medicines that you are having this cancer treatment.

You can visit the electronic Medicines Compendium (eMC) for more detailed information about your treatment.

Problems with lactose

These tablets contain a type of sugar called lactose. If you have been told by a doctor that you cannot digest lactose (lactose intolerant) or other sugars, talk to your doctor before taking this drug.

Vaccinations

Your doctor or nurse may talk to you about vaccinations. These help reduce your risk of getting infections.

Doctors usually recommend that you have a flu jab, which is an inactivated vaccination. People with weak immune systems can have this type of vaccination.

If your immune system is weak, you need to avoid live vaccinations such as shingles. Your cancer doctor or GP can tell you more about live vaccinations.

Fertility

Some cancer drugs can affect whether you can get pregnant or make someone pregnant. 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 become pregnant or father a child while having this treatment. The drugs may harm a developing baby. It is important to use effective contraception during, and for a few months after, treatment. You can talk to your doctor or nurse about this.

Sex

If you have sex during this course of 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

This treatment can sometimes stop the ovaries working. You may not get a period every month and they may stop. For some women, this is temporary and the ovaries start working again. For some women, this is permanent and they start menopause early.

Breastfeeding

Women are advised not to breastfeed while having this treatment. 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.

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