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Chlorambucil (Leukeran)

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This page tells you about the chemotherapy drug chlorambucil and its possible side effects. You can use the links below to go straight to sections about


What chlorambucil is

Chlorambucil is pronounced clor-am-byoo-sill. It is used mainly to treat chronic lymphocytic leukaemia (CLL), low grade non Hodgkin lymphoma and Hodgkin lymphoma. Its brand name is Leukeran. 


How chlorambucil works

Chlorambucil belongs to a group of drugs called alkylating agents. It works by sticking to one of the cancer cell's DNA strands. DNA is the genetic code that is in the heart of all animal and plant cells. It controls everything the cell does. The cell cannot then divide into 2 new cells.


How you have chlorambucil

Chlorambucil is a tablet. You should swallow the tablets whole with plenty of water. Take them half an hour to an hour before food. Keep them in the fridge but away from food. Also keep them away from children. Return any unused tablets to your pharmacy.

It is very important that you take tablets according to the instructions your doctor or pharmacist gives you. For example, whether you have a full or empty stomach can affect how much of a drug gets into your bloodstream. You should take the right dose, not more or less. And never stop taking a cancer drug without talking to your specialist first.

You usually have chemotherapy as a course of several cycles of treatment. The treatment plan for chlorambucil depends on which cancer you have. Chlorambucil is sometimes given in combination with other chemotherapy drugs as well as in combination with steroids. We have detailed information about how chemotherapy is planned.

The side effects associated with chlorambucil are listed below. You can use the links (underlined) to find out more about each side effect. Where there is no link please see our cancer drugs side effects section or use the search box at the top of the page.


Common side effects

More than 10 in every 100 people have one or more of the side effects listed below.

  • An 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, a sore throat, pain passing urine, or you may feel cold and shivery. If you have a severe infection this can be life threatening. Contact your treatment centre straight away if you have any of these effects or if your temperature goes above 38°C. You will have regular blood tests to check your blood cell levels
  • 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)
  • Tiredness and weakness (fatigue) during and after treatment – most people find their energy levels are back to normal within 6 months to a year
  • Women may stop having periods (amenorrhoea) but this may only be temporary
  • 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 may be able to store sperm before starting treatment

Occasional side effects

Between 1 and 10 in every 100 people have one or more of these effects.

  • Feeling or being sick – this is usually mild, but if you feel sick let your doctor or nurse know as they can give you tablets to prevent this
  • Loss of appetite
  • Weight loss
  • Skin rashes on your face, scalp and bodytell your doctor or nurse straight away if you develop a rash. You may have to stop treatment until it gets better
  • Diarrhoea – you should drink plenty of fluids. If diarrhoea becomes severe or continues you could become dehydrated, so let your doctor or nurse know
  • Mouth ulcers

There is a small risk that you may get a second cancer some years after chlorambucil treatment. This occurs in 1 to 10% of people treated.


Rare side effects

Fewer than 1 in 100 people have these effects.

  • Inflammation of the lungs – tell your doctor or nurse if you notice any difficulty breathing
  • Fits (seizures) – these are more likely in children or in people who have had a lot of chlorambucil treatment

Important points to remember

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

Coping with side effects

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

Other medicines

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

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 a few months afterwards. Talk to your doctor or nurse about effective contraception before starting treatment.


Do not breastfeed during this treatment because the drug may come through in the breast milk.


Immunisations and chemotherapy

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, yellow fever and Zostavax (shingles vaccine).

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 safe to have the flu vaccine.

It is safe for you to be in contact with other people who've had live vaccines as injections. There can be problems with vaccines you take by mouth (oral vaccines), but not many people in the UK have these now. So there is usually no problem in being with any baby or child who has recently had any vaccination in the UK. You might need to make sure that you aren't in contact with anyone who has had oral polio, cholera or typhoid vaccination recently, particularly if you live abroad.


Related information


More information about chlorambucil

This page does not list all the very rare side effects of this treatment that are very unlikely to affect you. For further information look at the Electronic Medicines Compendium website at

If you have a side effect not mentioned here that you think may be due to this treatment you can report it to the Medicines Health and Regulatory Authority (MHRA) at

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Updated: 25 July 2014