What is busulfan?

Busulfan is used in high doses before a stem cell transplant to treat blood cancers. It is also used in low doses to treat other types of blood cancers, such as essential thrombocythaemia and polycythaemia vera. It is sometimes used to treat chronic myeloid leukaemia (CML).

It is best to read this information with our general information about chemotherapy and the type of blood cancer you have. We also have information about stem cell transplants.

How busulfan is given

During treatment you usually see a blood cancer doctor (haematologist), 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.

Busulfan can be given by drip into a vein (infusion) or as tablets.

If you are having high-dose busulfan you will have it as a drip during a stay in hospital.

If you are having low-dose busulfan, you have it as tablets to take at home. You see your doctor regularly during your treatment so they can monitor its effects.

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 your blood cells are at a safe level to have chemotherapy.

You will see a doctor or nurse before you have chemotherapy. They will ask you how you have been feeling. If your blood results are okay, the pharmacist will prepare your chemotherapy. Your nurse will tell you when your treatment is likely to be ready.

As an infusion

Your nurse usually gives you anti-sickness (anti-emetic) drugs before the chemotherapy. The chemotherapy drugs can be given through: 

  • a short thin tube the nurse puts into a vein in your arm or hand (cannula)
  • a fine tube that goes under the skin of your chest and into a vein close by (central line)
  • a fine tube that is put into a vein in your arm and goes up into a vein in your chest (PICC line).

Your nurse gives you busulfan as a drip into your cannula or line. It usually takes around 2 to 3 hours. 

Taking busulfan tablets 

The tablets must be swallowed whole with a glass of water. They should not be chewed, opened or crushed. Take them at the same time every day. 
If you forget to take the tablets, you should take the missed dose as soon as possible within the same day. If a full day has gone by, let your doctor or nurse know. Do not take a double dose unless your doctor tells you to.

Other things to remember about your tablets:

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

Your course of busulfan

High-dose busulfan is usually given for a few days as part of your conditioning treatment. This happens before a stem cell transplant.

If you are having low-dose busulfan, your doctor or nurse will explain how often you have it. 

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.

Side effects during treatment

Some people may have side effects while they are being given the chemotherapy or shortly after they have it:

Allergic reaction

Some people have an allergic reaction while having this treatment. Signs of a reaction can include:

  • feeling hot or flushed
  • a skin rash
  • itching
  • shivering
  • feeling dizzy
  • a headache
  • feeling breathless
  • swelling of your face or mouth
  • pain in your back, tummy or chest.

Your nurse will check you for signs of a reaction during your treatment. If you feel unwell or have any of these signs, tell them straight away. If you do have a reaction, it can be treated quickly.

Sometimes a reaction can happen a few hours after treatment. If you get any signs or feel unwell after you get home, contact the hospital straight away.

The drug leaks outside the vein

If the drug leaks outside the vein, it can damage the surrounding tissue. This is called extravasation. Extravasation is not common but if it happens it is important to treat it quickly. Tell your nurse straight away if you have any stinging, pain, redness or swelling around the vein.

If you get any of these symptoms after you get home, contact the doctor or nurse straight away on the contact telephone number they gave you.

Common side effects

The side effects will depend on the dose of busulfan. If you are having low-dose busulfan, the side effects are likely to be mild.

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 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.

Feeling sick

You may feel sick in the first few days of your treatment. The nurses will give you anti-sickness drugs regularly. If you still feel sick, tell your nurse or doctor. They can change the anti-sickness drug to one that works better for you.

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.

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. Busulfan can cause a rash, which may be itchy. Your skin may darken. It will return to its normal colour after you finish treatment. 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.

Hair loss

Hair loss is rare with low doses of busulfan. If you are having high-dose treatment with busulfan, all of the hair from your head will fall out. Your eyelashes, eyebrows and other body hair may also thin or fall out. It is almost always temporary and your hair will grow back after chemotherapy ends. It is important to cover your scalp when you are out in the sun until your hair grows back. Your nurse can give you advice about coping with hair loss.

Bladder irritation

Having high-dose busulfan treatment may irritate your bladder and cause discomfort when you pass urine. Drink plenty of fluids – at least 2 litres (3½ pints) during the 24 hours following chemotherapy. It is also important to empty your bladder regularly and to try to pass urine as soon as you feel the need to go.

You may be given fluids through a drip (infusion) to help prevent bladder irritation. Contact the hospital straight away on the number you have been given if you feel any discomfort or stinging when you pass urine. Or if you notice any blood in it.

Diarrhoea

If you have diarrhoea, tell your nurse. Try to drink at least 2 litres (3½ 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 2 litres (3½ pints) of fluids each day.
  • Eat high-fibre foods, such as fruit, vegetables and wholemeal bread unless there are any restrictions on what you eat.
  • 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.

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.

Changes in the way the kidneys and liver work

Busulfan can affect how your kidneys and liver work. This is usually mild and goes back to normal after treatment. You may be given medication to help protect your liver. You will have blood tests before chemotherapy to check how well your kidneys and liver are working.

Eye problems

This treatment may make your eyes dry. Your doctor can prescribe eye drops to help with this. Rarely, it may cause cataracts (clouding of the eye's lens) years later. Let your doctor know if you notice any changes in your vision.

Less common side effects

Effects on the nervous system

High doses of busulfan can may make it difficult to sleep. Or you may feel dizzy or anxious and less commonly it may make you feel confused. Tell your doctor or nurse straight away if you notice any of these symptoms.

Rarely, this treatment can cause seizures (fits). You will be prescribed drugs to prevent this. Your doctor will explain more about this.

Effects on the heart

Chemotherapy can affect the way the heart works. You may have tests to see how well your heart is working. These may be done before, during and sometimes after treatment. If the treatment is causing heart problems, your doctor can change the type of chemotherapy you are having.

Contact a doctor straight away if you:

  • have pain or tightness in your chest
  • feel breathless or dizzy
  • feel your heart is beating too fast or too slowly.

Other conditions can cause these symptoms, but it is important to get them checked by a doctor.

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.

Second cancer

Rarely, busulfan 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

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.

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.

Contraception

Your doctor will advise you not to get pregnant or make someone pregnant while having this treatment. The drugs may harm a developing baby. It is important to use contraception during your treatment and for a while after treatment finishes. Your doctor, nurse or pharmacist can tell you more about this.

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.

Fertility

Some cancer drugs can affect whether you can get pregnant or make someone pregnant.

If you are a woman, your periods may become irregular or stop. This may be temporary, but for some women it is permanent. Your menopause may start sooner than it would have done.

There may be ways to preserve fertility for men and women. If you are worried about fertility, it is important to talk with your doctor before you start 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.

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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