Irinotecan is a type of chemotherapy. It is also known by its brand name Campto.
It is a treatment for cancer that started in the bowel (bowel cancer). This includes the colon and back passage (rectum).
How irinotecan works
Irinotecan works by blocking an enzyme, called topoisomerase I. All cells need this enzyme to divide and grow. Irinotecan blocks this enzyme so the cancer cells can't divide.
How you have it
You have irinotecan as a drip into your bloodstream (intravenously). Each treatment takes between 30 and 90 minutes.
Into your bloodstream
You have the treatment through a drip into your arm or hand. A nurse puts a small tube (a cannula) into one of your veins and connects the drip to it.
You might need a central line. This is a long plastic tube that gives the drugs into a large vein, either in your chest or through a vein in your arm. It stays in while you’re having treatment, which may be for a few months.
When you have irinotecan
You usually have irinotecan every 2 to 3 weeks. You might have it on its own, or in combination with other cancer drugs such as:
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.
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.
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:
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.
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.
Loose or watery poo (diarrhoea)
You might have diarrhoea if you've had 4 or more loose watery poos (stools) in 24 hours.
Some people develop a set of side effects (syndrome) called cholinergic syndrome. As well as diarrhoea, you might have:
- increased sweating and chills
- increased saliva production
- eye problems such as watery eyes and changes to your eyesight
- stuffy nose
- tummy (abdominal) cramps
Your treatment team will give you instructions if diarrhoea starts more than 24 hours after your treatment. This includes taking anti diarrhoea medicines and drinking plenty of fluids. Ask them about soothing creams to apply around your back passage (anus). The skin in that area can get very sore and even break if you have severe diarrhoea.
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.
Feeling or being sick can be severe for some people, even if you take anti sickness medicines. Contact your treatment team straight away if you have this.
Tummy (abdominal) pain
Tell your treatment team if you have this. They can check the cause and give you medicine to help.
You could lose all your hair. This includes your eyelashes, eyebrows, underarm, leg and sometimes pubic hair. Your hair will usually grow back once treatment has finished but it is likely to be softer. It may grow back a different colour or be curlier than before.
Mouth sores and ulcers
Mouth sores and ulcers can be painful. It helps to keep your mouth and teeth clean, drink plenty of fluids, avoid acidic foods such as oranges, lemons and grapefruits, and chew gum to keep the mouth moist. Tell your doctor or nurse if you have ulcers.
High temperature (fever)
If you get a high temperature, let your health care team know straight away. Ask them if you can take paracetamol to help lower your temperature.
You might feel very tired and as though you lack energy.
Various things can help you to reduce tiredness and cope with it, for example exercise. Some research has shown that taking gentle exercise can give you more energy. It is important to balance exercise with resting.
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:
- liver changes that are usually mild and unlikely to cause symptoms. You have regular blood tests during treatment to check for this
- a drop in the level of platelets in your blood which can cause bruising and bleeding
Coping with side effects
We have more information about side effects and tips on how to cope with them.
What else do I need to know?
Other medicines, foods and drinks
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.
Loss of fertility
It is not known whether this treatment affects fertility 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
It is unknown whether treatment may or may not harm a baby developing in the womb. It is important not to become pregnant or father a child while you are having treatment. Let your team know straight away if you or your partner falls pregnant while having treatment.
Talk to your doctor or nurse about effective contraception you can use during treatment. Ask how long you should use it before starting treatment and after treatment has finished.
It is not known whether this drug comes through into the breast milk. Doctors usually advise that you don’t breastfeed during this treatment.
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 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
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 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 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.
This page is due for review. We will update this as soon as possible.