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Irinotecan 341 and 342

Irinotecan 341 and 342

This leaflet provides information about a chemotherapy treatment called irinotecan.  It will explain what this is and when and how it will be given.  It will also tell you about common side effects that you may experience.  Contact telephone numbers and details of how to obtain further information on this chemotherapy are given at the end of the leaflet. 

This leaflet should be read alongside the ‘General information for patients receiving chemotherapy leaflet.  If you haven’t received this leaflet then please ask your nurse for a copy.

What is irinotecan chemotherapy?

Irinotecan is a chemotherapy which is given as a drip 

Why am I having irinotecan chemotherapy?

Your doctor has prescribed this chemotherapy because it has been found to be effective in treating your type of cancer.

How often will I have my chemotherapy?

For this treatment to be most effective it will be given at specific time intervals.  These are known as cycles. You may have a cycle of irinotecan either every 2 weeks or every 3 weeks, usually for at least 12 weeks. Your doctor will discuss with you the exact number of cycles you will receive, and whether you are to have 2 weekly or 3 weekly treatment. 

How often will I see the specialist team?

You will see the specialist team before each cycle.  You will have regular blood tests and we will check how you are feeling and discuss any problems you may be having.  This is so we can check how the chemotherapy is affecting you.  If your blood results are satisfactory, your chemotherapy will be prescribed.

How will my irinotecan chemotherapy be given?

First we will give you anti sickness medicine.  Then we will give you an injection of a medicine called atropine.  The atropine is given to prevent some of the side effects which can occur.  This is explained in more detail later in this leaflet. 

The irinotecan is given through a drip connected to a small needle which is placed in your hand or arm.  Alternatively it may be suggested that a fine tube called a PICC line is inserted into one of the large veins in your upper arm.  This line can remain in place for the whole of your treatment.  Your doctor or nurse will explain this in more detail, and will give you a leaflet if needed.

How long will I be in the hospital?

Your chemotherapy appointment will usually be on a different day to your clinic appointment.  The chemotherapy treatment will take about an hour.  Please allow an extra 30 minutes for your first treatment.  If you are having scalp cooling, please allow approximately one and a half hours extra for your treatment.

If you live far away your chemotherapy may be arranged for the same day as your clinic appointment.  There is always a delay between seeing the doctor and being given your chemotherapy.  If your chemotherapy is on the same day as your clinic appointment you should expect to be in the hospital for between four and six hours. 

Can I bring relatives and friends with me? 

You are welcome to bring someone to stay with you during your treatment. Space is limited so there is not usually room for more than one person.  Treatment areas are not suitable for young children.

What are the possible side effects?

There are a number of possible side effects which can occur with this chemotherapy.  The doctor, nurses and pharmacists can give you advice or answer any questions you may have.

Hair loss

You may lose your hair with this chemotherapy.  This is temporary and your hair will grow back when you finish your chemotherapy.  We can arrange a wig if you would like one, please ask your nurse for more information.  

We have a leaflet on coping with hair loss.  Please ask your nurse if you would like a copy. A method known as ‘scalp cooling’ or ‘cold capping’ can sometimes be used to prevent hair loss.  


Nausea and vomiting are uncommon these days as we give you anti-sickness medicines which are usually extremely effective.  If you are sick more than once in 24 hours despite taking regular anti-sickness medicine contact Velindre Cancer Centre.  The telephone number is at the end of the leaflet.


You are at an increased risk of picking up infections because your white blood cells which help fight infections can be reduced by this treatment.  

If you develop an infection whilst your white blood cells are low, you are at risk of sepsis, this can be life threatening. 

Contact Velindre Cancer Centre immediately if you develop any signs of infection, for example flu like symptoms or a temperature above 37.5°centigrade or below 35.5°centigrade  The telephone number is at the end of the leaflet.


Diarrhoea is a recognised side effect of irinotecan.  This can either occur within 24 hours following treatment or from about five days after starting treatment.

Diarrhoea within 24 hours of irinotecan

Diarrhoea which occurs at the time of treatment or up to 24 hours after irinotecan can come with other symptoms.  For example sweating, stomach pains, watering eyes, blurred vision or dizziness.  The atropine injection we give you before your treatment usually stops these symptoms. 

We do not recommend that you take anti-diarrhoeal tablets with this type of diarrhoea.  If you develop diarrhoea or any of the symptoms described within the first 24 hours after treatment please contact Velindre Cancer Centre immediately for advice.  The telephone number is at the end of the leaflet.

Diarrhoea starting more than 24 hours after irinotecan

We will have given you medication to help stop diarrhoea. These are called loperamide.  You should take these as follows:

  • Take two loperamide tablets the first time you have the diarrhoea, then one tablet every 2 hours for at least 12 hours.  You must continue to take the loperamide tablets until you have gone 12 hours without diarrhoea.  However, do not take them for more than 48 hours.
  • If the diarrhoea lasts more than 24 hours you should take the antibiotic tablets you have been given.  These are called ciprofloxacin.  Take these as directed on the box.  You should also contact Velindre Cancer Centre immediately for advice.  The telephone number is on page 7.

It is important that you drink plenty of water and salty type liquids if you have diarrhoea.  These include soda water, carbonated water and soups.

Tiredness and fatigue

Chemotherapy can make you feel more tired than usual.  It is important to listen to your body and rest if you need to, but to carry out your normal activities if you feel able.  Some people find it beneficial to take gentle exercise as well as taking rest.

Sore mouth

Your mouth may become sore or you may notice small ulcers. Please follow the advice on caring for your mouth in the general chemotherapy leaflet.  Your doctor may prescribe mouthwashes or medication to prevent or clear any infection.

Blood clots

A diagnosis of cancer can increase your risk of developing a blood clot (thrombosis), and having cancer treatment may increase this risk further.  It is important to tell your doctor immediately if you have symptoms such as pain, redness and swelling in your leg, or breathlessness and chest pain.  

Blood clots can be very serious.  However, most clots can usually be successfully treated with drugs to thin the blood.  Your doctor or nurse can give you more information.

Other side effects

Women sometimes find that chemotherapy treatment affects their periods.  They could become heavier, lighter or even stop altogether.  

It is important you do not become pregnant or father a child whilst having chemotherapy treatment as chemotherapy could damage the unborn baby.  

Sometimes cancer drugs can have very serious side effects which rarely can be life threatening. It is important to inform Velindre cancer centre if you are concerned about any side-effects.

Manufacturer’s patient information leaflets

Velindre leaflets provide information about very common and commonly reported side-effects (we are unable to list all of the common side effects), for more information regarding these and the less common side-effects please refer to the manufacturers patient information leaflets, obtained from Velindre pharmacy and/or on the internet at Sometimes patients may find these leaflets difficult to read however. Please ask if you would like a copy from your doctor or from Velindre pharmacy

Contact telephone numbers

Velindre Cancer Centre 029 2061 5888

Ask for the treatment helpline if you are unwell at home and need immediate advice at any time of the day or night. For example you should phone if you:

  • Are sick more than once in 24 hours
  • Have a temperature of 37.5°C or above or below 35.5°centigrade
  • Have diarrhoea

Pharmacy department 029 2061 5888 ext 6223

Monday – Friday 9am – 5pm for queries about your medicines

Tenovus freephone 0808 808 1010

cancer helpline 


This leaflet was written by health professionals.  The information contained in this leaflet is evidence based. It has been approved by doctors, nurses and patients.  It is reviewed and updated every 2 years.