Busulfan (Myleran, Busilvex)

• What busulfan is
• Common side effects
• Occasional side effects
• Rare side effects
• Important points to remember
• Immunisations and chemotherapy

Busulfan is a chemotherapy drug most often given as low dose treatment for a long time to treat chronic myeloid leukaemia. Or you may have it in higher doses before a bone marrow or stem cell transplant for other types of cancer and leukaemia. Busulfan tablets are called Myleran and the injections are called Busulfix. Busulfan is an alkylating agent, which works by sticking to one of the cancer cell's DNA strands. The cell cannot then divide into 2 new cells.

Busulfan comes in 2mg white tablets, 25mg capsules and as a clear liquid given by injection into a vein.

Chemotherapy is usually given as a course of several cycles of treatment. The treatment plan for busulfan depends on which cancer you are being treated for. There is detailed information about the way chemotherapy treatment is planned in our planning chemotherapy section.

We've listed the side effects associated with busulfan below. You can click on the links to find out more about each side effect. Where there is no link please see our chemotherapy side effects section, or use the search box at the top of the page.

With this drug, many people have a temporary drop in the number of blood cells made by the bone marrow, leading to the following side effects

• Increased risk of getting an infection from a drop in white blood cells - it is harder to fight infections and you can become very ill. You may have headaches, aching muscles, a cough, sore throat, pain passing urine or feel cold and shivery. 
• Tiredness and breathlessness due to a drop in red blood cells (anaemia) - you may need a blood transfusion
• Bruising more easily due to a drop in platelets - you may have nosebleeds, bleeding gums after brushing your teeth, or lots of tiny red spots or bruises on your arms or legs (known as petechia).

These effects on your bone marrow can begin about 7 days after each treatment and usually go back to normal after about 21 to 28 days. Some of these side effects can be life threatening, particularly infections.  You should contact your doctor if you have any of these side effects.  Your doctor will check your blood counts regularly to see how well your bone marrow is working

Other common side effects include

• Fatigue (tiredness) - during and after treatment – most people find their energy levels are back to normal within 6 months to a year
• Feeling or being sick is rare with low dose treatment, but common with higher doses (especially before a bone marrow or stem cell transplant) - taking busulfan tablets on an empty stomach may help
• Loss of appetite is rare with low dose treatment, but common with higher doses
• Busulfan may have a harmful effect on a developing baby - it is not advisable to get pregnant or father a child while taking this drug, so talk about contraception with your doctor before having treatment if there is any chance that you or your partner could become pregnant
• Loss of fertility may happen with this drug - you may not be able to get pregnant or father a child after treatment so it is important to talk to your doctor about your fertility before starting treatment
• Women may stop having periods (amenorrhoea) - this may only be temporary

Some people have the following side effects

• Hair loss is rare with low doses, but can happen with high dose treatment
• Sore mouth is rare with low dose treatment, but can be severe with high doses - do tell your doctor as you can take painkillers and use mouthwashes to help
• Skin changes you may get an itchy rash or your skin may darken in places, particularly your hands and nail beds
• Diarrhoea is rare with low doses, but can happen with high dose treatment.  drink plenty of fluid and tell your doctor if diarrhoea becomes severe, or continues for more than 3 days

 

A few people may have the following side effects

• Lung problems - you may have a cough or wheezing, which can happen straight away or up to 10 years after your treatment
• Fits (seizures) with high dose treatment - your doctor will give you tablets to prevent this
• Busulfan can affect your liver - you will have blood tests to check for this
• Difficulty sleeping, dizziness or depression can happen with high dose treatment - tell your doctor about this
• There is a small risk of developing another cancer in the future after treatment with busulphan
• Soreness, tenderness and swelling of the breasts
• There is a small risk of developing cataracts of the eye, causing blurred or cloudy vision

The side effects above may be mild or more severe. A side effect may get better or worse through your course of treatment, or more side effects may develop as the course goes on. This depends on

• How many times you've had the drug before
• Your general health
• The amount of the drug you have (the dose)
• Other drugs you are having

Some side effects are inconvenient or upsetting but not damaging to your health.

Some side effects are serious medical conditions and need treating. Where we have urged you to contact your doctor, this is because

• Your side effect may need treating
• Your drug dose may need reducing to try to prevent the side effect

Tell your doctor about any other medicines you are taking, including vitamins, herbal supplements and other over the counter remedies - some drugs can react together.

Talk to your doctor, pharmacist or nurse about all your side effects so that they can help you manage them. Your chemotherapy nurse, clinic or ward nurse will have given you a contact number. You can ring if you have any questions or problems. They can give you advice or reassure you. If in doubt, call.

You should not have immunisations with live vaccines while you are having chemotherapy or for at least 6 months afterwards. In the UK, these include rubella, mumps, measles (usually given together as MMR), BCG and yellow fever. You can have other vaccines, but they may not give you as much protection as usual until your immune system has fully recovered from your chemotherapy.

It is perfectly safe for you to be in contact with other people who've had live vaccines as injections. There can be problems with oral vaccines, but no one in the UK is given an oral vaccine now. So there is no problem in being with any baby or child who has recently had any vaccination in the UK. If you live abroad, you might need to make sure that you aren't in contact with anyone who has had oral polio or oral typhoid vaccination recently.