Irinotecan (Campto)

Irinotecan (Campto) is a chemotherapy drug used to treat bowel cancer. It works by blocking an enzyme, called topoisomerase I. The cell needs this enzyme to divide and grow into 2 new cells. If this enzyme is blocked by irinotecan, then the cell's DNA gets tangled up and the cell can't divide. DNA is the genetic code that is in the heart of all animal and plant cells. It controls everything the cell does.

You have irinotecan (Campto) by injection into your bloodstream (intravenously). You can have it through a thin, short tube (a cannula) put into a vein in your arm each time you have treatment. Or you may have it through a central line, a portacath or a PICC line. These are long, plastic tubes that give the drugs directly into a large vein in your chest. You have the tube put in just before your course of treatment starts and it stays in place as long as you need it.

You usually have chemotherapy as a course of several cycles of treatment. The treatment plan for irinotecan depends on your type of bowel cancer and whether it has spread. You may have irinotecan along with other chemotherapy drugs. You can find out about how doctors plan chemotherapy in the chemotherapy section.

We've listed the side effects associated with irinotecan below. You can use the links to find out more about each side effect. If there is no link, go to the cancer drug side effects section or use the 'search' box at the top of the page.

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

• Increased sweating
• Increased saliva production
• Watery eyes
• Abdominal cramps
• Diarrhoea can occasionally become severe –  it can happen on the day you are having treatment but may also happen a day or so after treatment. You will have an anti diarrhoea medicine to take at home for 48 hours after your chemotherapy to try to control it. It is important that you take this medicine exactly as it has been prescribed for you. Make sure you follow any special advice you have been given about how to cope with diarrhoea. Contact your specialist if in doubt.

If you get any of the above effects while having treatment, let your chemotherapy nurse know as they can give atropine to reduce these effects.

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

• 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 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).

Some of these side effects can be life threatening, particularly infections. You should contact your doctor or specialist nurse if you have any of them. Your doctor will check your blood counts regularly to see how well your bone marrow is working.

Other common side effects include

• Tiredness (fatigue) during and after treatment – most people find their energy levels are back to normal from 6 months to a year after treatment finishes
• Feeling or being sick
• Loss of appetite – this is usually mild, lasting for a day or so
• Hair loss or hair thinning – a cold cap may help to stop you losing your hair, but they are not recommended for all types of cancer so you need to talk to your doctor about it

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

• Mouth sores and ulcers
• Muscle cramps
• Liver changes that are very mild and unlikely to cause symptoms – these will almost certainly go back to normal when treatment finishes, but you will have regular blood tests to check how well your liver is working
• Skin rashes, which may be itchy
• Loss of fertility could be a problem with this drug so talk to your doctor about your fertility before starting treatment if having a baby is important to you
• Women may stop having periods (amenorrhoea), but this may only be temporary
• Dizziness – do not drive or operate machinery if you have this
• Temporary eyesight changes

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

Talk to your doctor, pharmacist or nurse about all your side effects so that 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.

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

• St John’s Wort (a herbal supplement)
• Some antibiotics
• Some anti epileptic drugs
• Some blood thinning drugs
• Some HIV drugs
• Drugs that lower the immune function

Irinotecan may have a harmful effect on a developing baby so you should not become pregnant or father a child whilst taking this drug. Talk to your doctor or nurse about contraception before beginning treatment if there is any possibility that you or your partner could become pregnant. Women need to continue with reliable contraception for a month after treatment ends and men need to continue for 3 months. 

Breastfeeding is not advisable during this treatment because the drug may come through in the breast milk.

You should not have immunisations with live vaccines while you are having this treatment or for at least 6 months afterwards. In the UK, live vaccines 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.

It is 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 not many people in the UK have oral vaccines 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.

This information 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 www.medicines.org.uk.

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 www.mhra.gov.uk.