Busulfan is a chemotherapy drug and is also known by its brand names Myleran or Busilvex. Busulfan tablets are called Myleran and the injections are called Busilvex.
You might have it as a treatment for:
- chronic myeloid leukaemia (CML)
- other types of cancer that need treatment with a stem cell or bone marrow transplant
- certain types of blood disorders called myelodysplastic syndromes (MDS)
How busulfan works
Busulfan is a type of chemotherapy drug called an alkylating agent. It works by sticking to one of the DNA strands of the cancer cell. The cell cannot then divide into 2 new cells.
How you have busulfan
You have busulfan as tablets or you might have it as a drip into your bloodstream (intravenously).
Taking your tablets
You should take the right dose, not more or less.
Talk to your specialist or advice line before you stop taking a cancer drug.
Into your bloodstream
You might have treatment through a long plastic tube that goes into a large vein in your chest. The tube stays in place throughout the course of treatment. This can be a:
- central line
- PICC line
If you don't have a central line
You might have treatment through a thin short tube (a cannula) that goes into a vein in your arm each time you have treatment.
When you have busulfan
You usually have busulfan as a course of several cycles of treatment.
For CML, you usually have busulfan at a low dose for as long as it is working. You have busulfan in higher doses if it is part of your preparation for a bone marrow or stem cell transplant.
For MDS, you might have busulfan for as long as it is working and your blood tests are OK. Or you might have it over 6 weeks for example. This depends on your type of MDS and your situation.
Your doctor or pharmacist will explain how often and when you have busulfan.
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.
We haven't listed all the side effects. It's very unlikely that you will have all of these side effects, but you might have some of them at the same time.
How often and how severe the side effects are can vary from person to person. They also depend on what other treatments you're having. For example, your side effects could be worse if you're also having other drugs or radiotherapy.
When to contact your team
Your doctor, nurse or pharmacist will go through the possible side effects. They will monitor you closely 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.
Common side effects
Each of these effects happens in more than 1 in 10 people (10%). You might have one or more of them. They include:
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.
You might be breathless and look pale due to a drop in red blood cells. This is called anaemia.
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).
Tiredness and weakness (fatigue) can happen during and after treatment - doing gentle exercises each day can keep your energy up. Don't push yourself, rest when you start to feel tired and ask others for help.
Feeling or being sick
Feeling or being sick is usually well controlled with anti sickness medicines. Avoiding fatty or fried foods, eating small meals and snacks, drinking plenty of water, and relaxation techniques can all 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 treating it once it has started.
Sickness is more common with higher doses of busulfan (especially before a bone marrow or stem cell transplant). It is rare with low dose busulfan.
Loss of appetite
You might lose your appetite for various reasons when you are having cancer treatment. Sickness, taste changes or tiredness can put you off food and drinks.
This is common with high dose busulfan. But rare with low dose treatment.
Mouth sores and ulcers
Mouth sores and ulcers can be painful. Keep your mouth and teeth clean; drink plenty of fluids; avoid acidic foods such as oranges, lemons and grapefruits; chew gum to keep the mouth moist and tell your doctor or nurse if you have ulcers.
Tummy (abdominal) pain
Tell your treatment team if you have this. They can check the cause and give you medicine to help.
Diarrhoea or constipation
Tell your doctor or nurse if you have diarrhoea or constipation. They can give you medicine to help.
Contact your doctor or pharmacist if you have indigestion or heartburn. They can prescribe medicines to help.
Yellowing of the skin and whites of the eyes
This is called jaundice. It is caused by high levels of bile pigments in the blood. Let your doctor or nurse know straight away if you have this.
Difficulty sleeping, dizziness and depression
Difficulty sleeping, dizziness and depression can happen with high dose busulfan. Talk to your doctor if you have any of these.
You could lose all your hair if you have this drug into your vein (intravenous). This is less likely to happen if you have the busulfan tablets. This includes your eyelashes, eyebrows, underarm, leg and sometimes pubic hair. Your hair will grow back once treatment has finished. But it is likely to be softer. And it may grow back a different colour or be curlier than before.
Occasional side effects
Each of these effects happens in more than 1 in 100 people (1%). You might have one or more of them. They include:
- cough or breathing problems due to infection such as pneumonia
- an increased the risk of developing a blood cancer such as acute leukaemia
- blood in the urine
Rare side effects
Each of these effects happens in fewer than 1 in 100 people (1%). You might have one or more of them. They include:
- clouding of the eyes (cataract)
- fits (seizures)
- skin changes such as dryness, itching, rashes and reddening
- high uric acid levels in your body due to the breakdown of tumour cells (tumour lysis syndrome) - you have regular blood tests to check for this and may take a tablet called allopurinol to treat this
Coping with side effects
We have more information about side effects and tips on how to cope with them.
Other medicines, foods and drink
Cancer drugs can interact with some other medicines and herbal products. Tell your doctor or pharmacist about any medicines you are taking. This includes vitamins, herbal supplements and over the counter remedies.
Pregnancy and contraception
This drug may harm a baby developing in the womb. It is important not to become pregnant or father a child while you are having treatment with this drug and for at least 6 months afterwards. Talk to your doctor or nurse about effective contraception before starting treatment.
Loss of fertility
You may not be able to become pregnant or father a child 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.
Men might be able to store sperm before starting treatment. And women might be able to store eggs or ovarian tissue. But these services are not available in every hospital, so you would need to ask your doctor about this.
Don’t breastfeed during this treatment because the drug may come through into your breast milk.
Treatment for other conditions
Always tell other doctors, nurses, pharmacists or dentists that you’re having this treatment if you need treatment for anything else, including teeth problems.
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 the shingles vaccine (Zostavax).
- have other vaccines, but they might not give you as much protection as usual
- have the flu vaccine (as an injection)
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.
If your immune system is severely weakened, you should avoid contact with children who have had the flu vaccine as a nasal spray. 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 go to the electronic Medicines Compendium (eMC) website.
You can report any side effect you have to the Medicines Health and Regulatory Authority (MHRA) as part of their Yellow Card Scheme.