Carmustine (BCNU)

Carmustine is a type of chemotherapy drug. It is also known as BCNU.

It is a treatment for brain tumours, non-Hodgkin's lymphoma and Hodgkin's lymphoma. 

For adults with a type of brain tumour called glioma doctors might use a form of carmustine called Gliadel wafers. This is a wafer that contains carmustine and is put in during surgery to remove the brain tumour.

You pronounce carmustine as car-mus-teen.

How does carmustine work?

Carmustine is a type of chemotherapy drug called an alkylating agent. 

These drugs work by interfering with the DNA in cancer cells. The cells can’t divide into 2 new cells so the cancer can’t grow.

How do you have carmustine?

You have carmustine as a drip into your bloodstream (intravenously). 

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
  • portacath

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. You have a new cannula each time you have treatment.

How often do you have carmustine?

You usually have carmustine as a drip into your bloodstream over 1 or 2 hours. 

When and for how long you have carmustine will depend on your cancer type. Your healthcare team can give you more details about your treatment plan.


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 carmustine?

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. 

Contact your advice line immediately if you have signs of infection, including a temperature above 37.5C or below 36C.

We haven't listed all the side effects here. 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:

Increased risk of getting an 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. 

Bruising, bleeding gums and nosebleeds

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).

Lung problems

You might develop a cough or breathing problems. This could be due to infection, such as pneumonia, inflammation of the lungs (pneumonitis) or scarring of the lungs (interstitial fibrosis). 

Let your healthcare team know straight away if you suddenly become breathless or develop a cough.

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.


Let your healthcare team know if you have headaches. They can give you painkillers to help.


This drug might make you feel dizzy. You might also feel dizzy when standing or moving around. Or it might feel like the world is spinning.

Don’t drive or operate machinery if you have this.

Changes in speech, balance and coordination

You might find it difficult to speak because your speech might become slurred. You might feel unbalanced and the way you walk might be affected. You might find that you struggle to do tasks that need a lot of control such as writing or eating.

Let your healthcare team know if you notice any of changes. 

Eye problems

Carmustine can cause eye problems such as redness in the eyes, blurred vision, or you might have small bleeds in the eye.

Tell your healthcare team if you have eye problems. They can prescribe eye drops to soothe them. 

Low blood pressure

Low blood pressure can make you feel light headed, dizzy, sick, confused, weak and tired.

This mostly happens when you have high amount (dose) of carmustine. You’ll have your blood pressure checked regularly while having this treatment.

Let your healthcare team know if have any of these symptoms.

Inflammation of the vein

The vein into which the drip is going might become inflamed, red and sore.

Let your nurse know straight away if this happens. 

Skin changes

You might notice skin changes, such as dryness, itching and rashes similar to acne on your face, neck and trunk. If carmustine comes into contact with your skin it can also cause darkening to that area of skin.

Tell your healthcare team if you have any rashes, itching or darkening of an area of skin

If your skin gets dry or itchy, using unperfumed moisturising cream may help. Check with your doctor, nurse or pharmacist before using any creams or lotions.

Tiredness and weakness (fatigue)

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.

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:

  • a second cancer such as acute leukaemia
  • swelling in the brain causing symptoms such as memory loss, seizures (fits), drowsiness, personality changes and confusion. This usually happens with high dose carmustine and can be life threatening
  • loss of appetite
  • diarrhoea
  • constipation
  • hair loss
  • reddening (flushing) of the skin
  • sore mouth
  • breathlessness and looking pale due to a decrease in the red blood cells (anaemia)
  • liver changes that are picked up on blood tests. This usually happens with high dose carmustine

Rare side effects

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

  • kidney damage - you have regular blood tests to check for this
  • growth of breast tissue in men
  • blood clots (DVT) that can be life threatening; signs are pain, redness and swelling where the clot is. Feeling breathless can be a sign of a blood clot in the lung. Contact your health advice line or doctor straight away if you have any of these symptoms
  • liver condition called veno occlusive disease (VOD) – symptoms include jaundice, ascites, swelling of your liver, arms, legs and tummy

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

It is not known whether this treatment affects fertility Open a glossary item in people. Talk to your doctor before starting treatment if you think you may want to have a baby in the future.

Contraception and pregnancy

This drug may harm a baby developing in the womb. It is important not to become pregnant or get someone pregnant while you are having treatment with this drug and for at least 6 months 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.


It is not known whether this drug comes through into the breast milk. Doctors usually advise that you don’t breastfeed during this treatment.

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.


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 Open a glossary item 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.

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