What is Irinotecan with fluorouracil (5FU) and folinic acid?

Irinotecan with fluorouracil (5FU) and folinic acid is used to treat bowel cancer. It is sometimes used to treat other cancer types. 

It is sometimes called FOLFIRI or IrMdG. We use the name FOLFIRI in this information.

FOLFIRI is named after the initials of the drugs used in the treatment. The drugs are:

Fluorouracil is often called 5FU, which is the name we use in this information.

You might hear folinic acid being called calcium folinate or leucovorin. Folinic acid is not a chemotherapy drug. It is often given alongside 5FU because it has been shown to make it work better.

It is best to read this information with our general information about chemotherapy and the type of cancer you have.

Your doctor will talk to you about this treatment and its possible side effects before you agree (consent) to have treatment.

More information about this treatment

This information is correct at time of publishing. But sometimes the types of cancer this treatment is used for, or treatment side effects, may change between revision dates.

You can talk to your cancer team if you want more detailed information about this treatment. Or visit the electronic Medicines Compendium (eMC) website, which has patient information leaflets (PIL) for individual drugs.

DPD testing before treatment

Before starting this treatment, you should have a blood test. This test checks for gene changes that affect how your body produces DPD. DPD is an enzyme that helps the body break down 5FU. 

If you have low DPD levels or no DPD (DPD deficiency), you have more risk of serious or life-threatening side effects from 5FU. To reduce your risk, your doctor may give you:

  • a lower dose of 5FU to start with
  • a different type of chemotherapy.

Having low DPD levels does not usually cause any symptoms. Without a test, you will not know whether your DPD levels are low. Testing finds most people who are affected, but not all. Your doctor, nurse or pharmacist can give you more information about your risk of DPD deficiency, before you start treatment.

How FOLFIRI is given

You will be given FOLFIRI in a chemotherapy day unit or during a short stay in hospital. A chemotherapy nurse will give it to you.

During treatment you usually see a cancer doctor, a chemotherapy nurse or a specialist nurse, and a specialist pharmacist. This is who we mean when we mention doctor, nurse or pharmacist in this information.

Before or on the day of treatment, a nurse or person trained to take blood (phlebotomist) will take a blood sample from you. This is to check that your blood cells are at a safe level to have chemotherapy.

You will see a doctor or nurse before you have chemotherapy. They will talk to you about your blood results and ask you how you have been feeling. If your blood results are okay, the pharmacist will prepare your chemotherapy. Your nurse will tell you when your treatment is likely to be ready.

Your nurse usually gives you anti-sickness (anti-emetic) drugs before the chemotherapy. The chemotherapy drugs can be given through:

  • a cannula – a short, thin tube the nurse puts into a vein in your arm or hand
  • a central lines – a fine tube that goes under the skin of your chest and into a vein close by
  • a PICC line – a fine tube that is put into a vein in your arm and goes up into a vein in your chest
  • an implantable port (portacath) – a disc that is put under the skin on your chest or arm and goes into a vein in your chest.

First, your nurse will give you irinotecan as a drip (infusion). They usually run this through a pump, which gives the drug over a fixed time. This takes between 30 minutes and 90 minutes. 

After this, you will usually have folinic acid. Some people are given folinic acid at the same time as irinotecan. Your nurse will tell you how long this will take. 

After the folinic acid, you are given 5FU in 2 ways. Your nurse will give some 5FU as an injection into your line. The rest will be given to you continuously through a small portable pump over 46 hours. Once the pump is connected to your line and has been started, you can go home. You can carry the pump on a belt or in a holder.

When it is time to have the pump disconnected, you may go back to hospital. Sometimes a district nurse will do this for you at home. Your chemotherapy nurse will explain how to look after the pump. They can also tell you what to do if there is a problem.

If you have a cannula, you will need to stay in hospital to have the 5FU.

When the 5FU infusion is finished, you will have a rest period with no chemotherapy. This completes 1 cycle of treatment. Each cycle takes 14 days.

Your course of chemotherapy

You usually have a course of several cycles of treatment over a few months. Your nurse or doctor will talk to you about how the treatment will be given. 

About side effects

We explain the most common side effects of this treatment here. We also include some that are less common.

You may get some of the side effects we mention, but you are unlikely to get all of them. And you may have some side effects, including rarer ones, that we have not listed here. 

Always tell your doctor, nurse or pharmacist about any side effects you have. They can give you: 

  • drugs to help control some side effects
  • advice about managing side effects. 

It is important to take any drugs exactly as explained. This means they will be more likely to work for you. 

Serious and life-threatening side effects

Some cancer treatments can cause serious side effects. Sometimes, these may be life-threatening. Your doctor, nurse or pharmacist can explain the risk of these side effects to you.

If your body does not produce enough of an enzyme called DPD, you may have a higher risk of severe or life-threatening side effects.

Contact the hospital

Your doctor, nurse or pharmacist will give you 24-hour contact numbers for the hospital. If you feel unwell or need advice, you can call at any time of the day or night. Save these numbers in your phone or keep them somewhere safe.

Side effects while treatment is being given

Some people may have side effects while they are being given the chemotherapy or shortly after they have it:

Allergic reaction

Some people have an allergic reaction while having this treatment. Signs of a reaction can include: 

  • feeling hot or flushed 
  • shivering
  • itching
  • a skin rash
  • feeling dizzy or sick
  • a headache
  • feeling breathless or wheezy
  • swelling of your face or mouth
  • pain in your back, tummy or chest. 

Your nurse will check you for signs of a reaction during your treatment. If you feel unwell or have any of these signs, tell them straight away. If you do have a reaction, they can treat it quickly. 

Sometimes a reaction happens a few hours after treatment. If you develop any of these signs or feel unwell after you get home, contact the hospital straight away on the 24-hour number.

Acute cholinergic syndrome

Some people may have side effects within 24 hours of having irinotecan. These include:

  • diarrhoea
  • tummy cramps
  • sweating more than usual
  • producing a lot of saliva
  • dizziness
  • problems with vision

This is called acute cholinergic syndrome. It can usually be prevented or controlled by a drug called atropine. Your nurse gives you atropine as an injection under the skin (subcutaneously). If you have any of these symptoms, contact your doctor or nurse.

Common side effects

Risk of infection

This treatment can reduce the number of white blood cells in your blood. These cells fight infection. If your white blood cell count is low, you may be more likely to get an infection. A low white blood cell count is called neutropenia.

An infection can be very serious when the number of white blood cells is low. It is important to get any infection treated as soon as possible. If you have any of the following symptoms, contact the hospital straight away on the 24-hour number:

  • a temperature above 37.5°C  
  • a temperature below 36°C 
  • you feel unwell, even with a normal temperature
  • you have symptoms of an infection.

Symptoms of an infection include:

  • feeling shivery and shaking
  • a sore throat
  • a cough 
  • breathlessness
  • diarrhoea
  • needing to pass urine (pee) often, or discomfort when you pass urine.

It is important to follow any specific advice your cancer treatment team gives you.

Your white blood cell count will usually return to normal before your next treatment. You will have a blood test before having more treatment. If your white blood cell count is low, your doctor may delay your treatment for a short time, until your cell count increases.

Bruising and bleeding

This treatment can reduce the number of platelets in your blood. Platelets are cells that help the blood to clot.

If the number of platelets is low, you may bruise or bleed easily. You may have:

  • nosebleeds
  • bleeding gums
  • heavy periods
  • blood in your urine (pee) or stools (poo)
  • tiny red, brown or purple spots that may look like a rash – these spots can be harder to see if you have black or brown skin. 

If you have any unexplained bruising or bleeding, contact the hospital straight away on the 24-hour number. You may need a drip to give you extra platelets. This is called a platelet transfusion.

Anaemia (low number of red blood cells)

This treatment can reduce the number of red blood cells in your blood. Red blood cells carry oxygen around the body. If the number of red blood cells is low, this is called anaemia. You may feel:

  • very low in energy
  • breathless 
  • dizzy and light-headed. 

If you have these symptoms, contact the hospital straight away on the 24-hour number. You may need treatment for anaemia. If you are very anaemic, you may need a drip to give you extra red blood cells. This is called a blood transfusion.

Diarrhoea

This treatment may cause severe diarrhoea. Diarrhoea means passing more stools (poo) than is normal for you, or having watery or loose stools. If you have a stoma, it will be more active than usual. 

Your doctor, nurse or pharmacist may give you anti-diarrhoea drugs to take at home. 

If you have diarrhoea or a mild increase in stoma activity, follow their advice about: 

  • taking anti-diarrhoea drugs 
  • how much and what type of fluids to drink 
  • any changes to your diet that might help. 

Contact the hospital straight away on the 24-hour number if:

  • you have diarrhoea at night 
  • you have uncomfortable stomach cramps
  • you have diarrhoea 4 or more times in a day 
  • you have a moderate increase in stoma activity 
  • the anti-diarrhoea drugs do not work within 24 hours.

You may need to give a stool sample, or go to hospital to have fluids through a drip or antibiotics.

Constipation

This treatment can cause constipation. Constipation means that you are not able to pass stools (poo) as often as you normally do. It can become difficult or painful. Here are some tips that may help:

  • Drink at least 2 litres (3½ pints) of fluids each day.
  • Eat high-fibre foods, such as fruit, vegetables and wholemeal bread.
  • Do regular gentle exercise, like going for short walks.

If you have constipation, contact the hospital on the 24-hour number for advice. They can give you drugs called laxatives to help. 

If you have not been able to pass stools for over 2 days and are being sick, contact the 24-hour number straight away. 

Feeling sick

Your doctor, nurse or pharmacist will prescribe anti-sickness drugs to help prevent or control sickness. Take the drugs exactly as they tell you to, even if you do not feel sick. It is easier to prevent sickness than to treat it after it has started.

If you feel sick, take small sips of fluid often and eat small amounts regularly. It is important to drink enough fluids. If you continue to feel sick, or if you are sick (vomit) 1 to 2 times in 24 hours, contact the hospital on the 24-hour number as soon as possible. They will give you advice. They may change your anti-sickness treatment. Let them know if you still feel sick.

Sore mouth and throat

You may get a sore mouth and throat. You may also get mouth ulcers. This can make you more likely to get a mouth or throat infection. Use a soft toothbrush to clean your teeth or dentures in the morning, at night and after meals.

If your mouth or throat is sore:

  • tell your nurse or doctor – they can give you a mouthwash or medicines to help
  • try to drink plenty of fluids
  • avoid alcohol, tobacco and foods that irritate your mouth and throat.

Your treatment may need to be stopped for a while until you recover.

If you are having continuous treatment through a pump it is important to contact the hospital without delay if your mouth becomes sore.

Feeling tired

Feeling tired is a common side effect of this treatment. It is often worse towards the end of treatment and for some weeks after it ends. Try to pace yourself and plan your day so you have time to rest. Gentle exercise, like short walks, can help you feel less tired. 

If you feel sleepy, do not drive or use machinery.

Hair loss

Your hair will get thinner. Or you may lose all the hair from your head. You may also lose your eyelashes and eyebrows, as well as other body hair. Hair loss usually starts after your first or second treatment.

If you want to cover up hair loss, there are different ways you can do this. Your nurse will give you information about coping with hair loss

Remember to protect your skin from the sun. Use suncream with a sun protection factor (SPF) of at least 30 on your scalp. Or cover up with a hat or scarf.

Hair loss is almost always temporary. Your hair will usually grow back after treatment ends.

Hand-foot (palmar-plantar) syndrome

This treatment can affect the palms of your hands and the soles of your feet. This is called palmar-plantar or hand-foot syndrome. 

If you have white skin these areas may become red. If you have black or brown skin, these areas might get darker. 

The skin on the palms of your hands and the soles of your feet may:

  • be sore
  • be painful, tingle, or swell
  • peel, crack or blister. 

If you have any of these symptoms, contact the hospital straight away on the 24-hour number. They can give you advice. This is especially important if you have any broken skin or if walking is difficult. They can prescribe creams and painkillers to help.

You can care for your hands and feet by: 

  • keeping your hands and feet cool by washing in cool water
  • gently moisturising your hands and feet regularly
  • wearing gloves to protect your hands and nails when working in the house or garden
  • wearing loose cotton socks and avoiding tight-fitting shoes and gloves.

Effects on the liver

FOLFIRI can affect how your liver works. You will have regular blood tests to check this. Any changes are usually mild, and go back to normal after treatment.

Skin changes

Chemotherapy may affect your skin. Your doctor or nurse can tell you what to expect. If your skin feels dry, try using an unperfumed moisturising cream every day.

During treatment and for several months afterwards, you will be more sensitive to the sun. Your skin may burn more easily than usual. You can still go out in the sun, but:

  • use a sun cream with a sun protection factor (SPF) of at least 30
  • cover up with clothing
  • wear a hat.

Your skin may darken. It usually returns to its normal colour after you finish treatment. If you have had radiotherapy (either recently or in the past), the area that was treated may become red or sore.

Always tell your doctor or nurse about any skin changes. They can give you advice. They may give you creams or medicines to help. Any changes to your skin are usually temporary. They usually improve when treatment finishes.

Eye problems

Your eyes may become watery and feel sore. Your doctor can give you eye drops to help with this. If your eyes get red and inflamed (conjunctivitis), tell your doctor as you may need treatment.

This treatment may make your eyes more sensitive to light and cause blurry vision. If you have pain or notice any change in your vision, always tell your doctor or nurse.

Loss of appetite

This treatment can affect your appetite. Don’t worry if you do not eat much for 1 or 2 days. But if your appetite does not come back after a few days, or if you are losing weight, tell your doctor, nurse or pharmacist. They can give you advice. They may give you food or drink supplements. Or they may suggest changes to your diet or eating habits to help.

Changes to your taste

Some foods may taste different or have no taste. Try different foods to find out what tastes best to you. You may also get a bitter or metallic taste in your mouth. Your doctor, nurse or pharmacist can give you advice. It might help to try:

  • sucking sugar-free sour or boiled sweets
  • eating cold foods
  • eating sharp-tasting fresh fruit.

Taste changes usually get better after treatment ends. We have more information about coping with changes to taste.

Less common side effects

Effects on the heart

5FU can affect how the heart works. You may have tests to check how well your heart is working. These may be done before, during and after treatment. 

You may develop heart problems even if these test results are normal. Very rarely, 5FU causes heart failure or a heart attack. The risk of this happening is very low. It happens to less than 1 in 100 (1%) of people who have 5FU. But it is important that you know about it. 

Contact the hospital straight away on the 24-hour number if you have any of these symptoms during or after treatment:

  • breathlessness
  • dizziness
  • changes to your heartbeat
  • swollen feet and ankles.

Always call 999 if you have:

  • chest pain, pressure, heaviness, tightness or squeezing across the chest
  • difficulty breathing.

Nail changes

This treatment can affect your nails. They may grow more slowly or break more easily. You might notice ridges or white or dark lines across your nails. These changes usually disappear as the nails grow out after treatment. Sometimes nails can become loose or fall out.

If the skin around your nails becomes sore and swollen, contact the hospital straight away on the 24-hour number. These might be signs of an infection.

Tips to look after your nails:

  • Keep your nails clipped short and clean. 
  • Avoid using very hot water when washing your hands or bathing.
  • Moisturise your nails and cuticles regularly.
  • Avoid false nails, gels or other acrylics during treatment – it is okay to use water-based nail polish. 
  • Wear gloves to protect your nails when working in the house or garden.
  • If your toenails are affected, wear well-fitting shoes, or shoes with open toes to cushion them.

Tell your doctor or nurse about any changes to your nails. They can give you advice or arrange for you to see a podiatrist. They are a foot care specialist.

Difficulty breathing

5FU can cause sudden tightness (spasm) in the muscles in your chest for a short time. Contact the hospital straight away on the 24-hour number if you have any of these symptoms during treatment:

  • breathlessness
  • a cough that does not go away
  • wheezing.

Always call 999 if you have difficulty breathing.

Effects on the nervous system

5FU can affect the nervous system. This is rare. Contact the hospital straight away if you develop any of the following:

  • confusion
  • mood changes (such as feeling excitable or agitated)
  • drowsiness
  • difficulty with speech, balance, movement or coordination.

Your doctor or nurse will assess you. They will give you treatment if needed.

Tumour lysis syndrome (TLS)

Some people are at risk of developing a condition called tumour lysis syndrome (TLS) during this treatment. When treatment makes large numbers of cancer cells die and break down quickly, they release lots of waste products into the blood. This can affect how well the kidneys work. It may also cause problems with the heart rhythm.

TLS can be prevented. You will have regular blood tests to check for TLS. If you are at risk of TLS, you may have:

  • extra fluids through a drip
  • medicines such as rasburicase through a drip, or allopurinol as tablets.

Drinking at least 2 litres (3½ pints) of fluid a day will also help.

Other information

Driving and using machines

If you feel sick, have blurred vision or notice any effects on your nervous system, do not drive or use machines. Your doctor can tell you more about this.

Blood clot risk

Cancer and some cancer treatments can increase the risk of a blood clot. Contact the hospital straight away on the 24-hour number if you have any of these symptoms during or after treatment:

  • throbbing pain or swelling in a leg or arm
  • reddening of the skin in the area – if you have black or brown skin, this can be harder to notice, but the skin might become darker
  • suddenly feeling breathless or coughing.

Always call 999 if you have:

  • chest pain
  • difficulty breathing.

A blood clot is serious, but it can be treated with drugs called anticoagulants. These thin the blood. Your doctor, nurse or pharmacist can give you more information about preventing and treating blood clots.

Other medicines

Some medicines can affect how this treatment works or be harmful while you are having it. Always tell your cancer doctor, nurse or pharmacist about any drugs you are taking or planning to take, such as: 

Vaccinations

Doctors usually recommend that people with cancer have vaccinations for flu and for coronavirus (covid). These help reduce your risk of serious illness from these infections. Most people can have these vaccines, including people with weak immune systems. 

If your immune system is weak, you should not have live vaccinations. This is because they can make you unwell. Live vaccines, such as the yellow fever vaccine, contain a very weak version of the illness they will protect you against. It is important to ask your doctor, nurse or pharmacist for advice about having vaccinations. They can explain what vaccines are right for you and when it is best to have them.

Sex

It is possible that small amounts of chemotherapy may be passed on through vaginal fluids or semen. If you have sex in the first few days after treatment, your cancer team will usually advise using condoms or a dental dam to protect your partner.

Contraception

Your doctor, nurse or pharmacist will advise you not to get pregnant or make someone pregnant while having this treatment and for some time afterwards. The drugs may harm a developing baby. It is important to use contraception to prevent pregnancy. Follow their advice about:

  • what types of contraception to use 
  • how long after treatment you should continue to use contraception. 

Fertility

Some cancer drugs can affect whether you can get pregnant or make someone pregnant. If you are worried about this, it is important to talk with your doctor before you start treatment.

Changes to periods

If you have a period, these may become irregular or stop while you are having this treatment. This may be temporary, but it can sometimes be permanent. Your menopause may start sooner than it would have done. Your doctor or nurse can give you more information.

Breastfeeding

You are advised not to breastfeed while having this treatment, or for some time after treatment ends. This is because the drugs could be passed to the baby through breast milk. 

Your doctor, nurse or pharmacist can give you more information.

Medical and dental treatment

If you need medical treatment for any reason other than cancer, always tell the healthcare professional that you are having cancer treatment. Give them the contact details for your cancer doctor or cancer team so they can ask for advice.

If you have appointments with a dentist, always tell them you are having cancer treatment. Talk to your cancer team before you have any dental treatment.

About our information

  • Reviewers

    This information has been written, revised and edited by Macmillan Cancer Support’s Cancer Information Development team. It has been reviewed by expert health professionals and people living with cancer.

    Our cancer information has been awarded the PIF TICK. Created by the Patient Information Forum, this quality mark shows we meet PIF’s 10 criteria for trustworthy health information.

The language we use

We want everyone affected by cancer to feel our information is written for them.

We want our information to be as clear as possible. To do this, we try to:

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  • use illustrations to explain text
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We use gender-inclusive language and talk to our readers as ‘you’ so that everyone feels included. Where clinically necessary we use the terms ‘men’ and ‘women’ or ‘male’ and ‘female’. For example, we do so when talking about parts of the body or mentioning statistics or research about who is affected.

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Date reviewed

Reviewed: 01 April 2022
|
Next review: 01 October 2024
Trusted Information Creator - Patient Information Forum
Trusted Information Creator - Patient Information Forum

Our cancer information meets the PIF TICK quality mark.

This means it is easy to use, up-to-date and based on the latest evidence. Learn more about how we produce our information.