Irinotecan

Irinotecan is a type of chemotherapy. You pronounce irinotecan as i-rin-o-te-can. It is also known by its brand name Campto. 

It is a treatment for:

• bowel cancer
• Ewing sarcoma – a type of soft tissue sarcoma
• rhabdomyosarcomas – a type of soft tissue sarcoma
• ovarian cancer 
• some gastrointestinal cancers such as stomach cancer and cancer of the food pipe (oesophageal cancer)  

How does irinotecan work?

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 do you have irinotecan?

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

How often do 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:

• fluorouracil (5FU)
• cetuximab

Tests

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 irinotecan?

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. 

We haven't listed all the side effects here. Talk to your healthcare team if you have any new symptoms that you think might be a side effect of your treatment.

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.

Side effects during or soon after having irinotecan

You might have acute cholinergic syndrome. The symptoms include diarrhoea, sweating, abdominal pain, watery eyes and increased production of spit (saliva). This can happen while having irinotecan or within 24 hours after.

You might have a drug called atropine before your irinotecan to help stop this.

These side effects generally go away very soon.

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, cough, headaches, feeling cold and shivery, pain or burning feeling when weeing, or generally feeling 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. 

Breathlessness 

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 while having cancer treatment. Sickness, taste changes or tiredness can put you off food and drinks.

Diarrhoea 

Diarrhoea means having loose, watery poo. This can happen during your treatment, or at any time between treatments.

Your healthcare team might give you medicines to take home. They will explain how and when to use them.

Acute cholinergic syndrome

Irinotecan can cause some people to develop a set of side effects during or within the first 24 hours after having the drug. These side effects include diarrhoea which may be severe. Other symptoms are - sweating, stomach cramps, increased production of saliva, and watery eyes. You may have an injection of atropine before the irinotecan to reduce these side effects.

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.

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. 

Hair loss

You could lose all your hair. This includes your eyelashes, eyebrows, underarms, legs 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 and avoid acidic foods such as lemons. Chewing gum can help to keep your mouth moist. Tell your doctor or nurse if you have ulcers.

High temperature (fever)

Tell your healthcare team straightaway if you get a high temperature. Ask them if you can take paracetamol to help lower your temperature.

Lack of energy and strength

This is usually mild. You can do things to help yourself, including some gentle exercise. It’s important not to push yourself too hard and eat a well balanced diet.

Talk to your doctor or nurse if this effect is stopping you from doing your usual daily activities.

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:

• constipation

• 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 you need to know?

Other medicines, foods and drinks

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 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 get someone pregnant while you are having treatment. Let your team know straight away if you or your partner become 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.

Breastfeeding

Don’t breastfeed during this treatment because the drug may come through into your breast milk.

Treatment for 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.

Immunisations

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 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.