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 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.

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

Your nurse will give you irinotecan first as a drip (infusion) over about 2 hours. They usually run this through a pump, which gives the drug over a fixed time. After this, you will usually have folinic acid. But some people are given folinic acid at the same time as irinotecan. If you are given folinic acid separately, you will usually have it as a drip over about 2 hours. 

5FU is given after folinic acid. Your nurse will give some 5FU as an injection into your line. The rest will be given to you through a small portable pump. This may take between 20 and 46 hours. You will be able to go home once the pump is connected to your line and has been started. You can carry the pump on a belt or in a holder.

You may go back to the hospital to have the pump disconnected. 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 will complete 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. They may give you a copy of a treatment plan to take home with you.

About side effects

We explain the most common side effects of this treatment here. We also include some less common side effects. You may get some of the side effects we mention, but you are unlikely to get all of them.

You may also have some side effects that we have not listed here. Always tell your doctor, nurse or pharmacist about any side effects you have.

Your doctor can give you drugs to help control some side effects. It is important to take them exactly as your nurse or pharmacist explains. This means they will be more likely to work for you. Your nurse will give you advice about managing your side effects. After your treatment is over, most side effects start to improve.

Serious and life-threatening side effects

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

If you have low levels of an enzyme called DPD (DPD deficiency), you may have a higher risk of severe or life-threatening side effects.

Contact the hospital

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

More information

We cannot list every side effect for this treatment. There are some rare side effects that are not listed. You can visit the electronic Medicines Compendium (eMC) to download a Patient Information Leaflet (PIL) for these drugs. The leaflet lists all known side effects.

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
  • 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, it can be treated quickly.

Sometimes a reaction happens a few hours after treatment. If you develop any signs or feel unwell after you get home, contact the hospital straight away.

Irinotecan reaction (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. Contact your doctor or nurse if you have any of these symptoms. If this happens do not drive or operate machinery. 

Acute cholinergic syndrome can usually be prevented or controlled by a drug called atropine. If it is needed, your nurse gives you atropine as an injection under the skin (subcutaneously). 

Common side effects

Risk of infection

This treatment can reduce the number of white blood cells in your blood. These cells fight infection. If the number of white blood cells is low, you are more likely to get an infection. A low white blood cell count is sometimes 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. Contact the hospital straight away on the 24-hour contact number you have been given if:

  • your temperature goes over 37.5°C (99.5°F)
  • you suddenly feel unwell, even with a normal temperature
  • you have symptoms of an infection
  • your temperature goes below 36°C (96.8°F).

Symptoms of an infection include:

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

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

The number of white blood cells 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 or purple spots on the skin that may look like a rash.

Tell your doctor if you have any unexplained bruising or bleeding. 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 have symptoms such as:

  • pale skin
  • lack of energy
  • feeling breathless
  • feeling dizzy and light-headed.

Tell your doctor or nurse if you have these symptoms.

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 usual for you, or having watery or loose stools. If you have a stoma, it will be more active than usual.

Your hospital team may give you anti-diarrhoea drugs to take at home.

If you have diarrhoea or a mild increase in stoma activity:

  • follow any advice from your cancer team about taking anti-diarrhoea drugs
  • drink at least 2 litres (3½ pints) of fluids each day
  • avoid alcohol, caffeine, milk products, high-fat foods and high-fibre foods.

Contact the hospital straight away if:

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

You may need to go to hospital to have fluids through a drip.

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 for advice. Your doctor can give you drugs called laxatives to help.

Feeling sick

Your doctor will give you anti-sickness drugs to help prevent or control sickness during your treatment. Take the drugs exactly as your nurse or pharmacist tells you. It is easier to prevent sickness than to treat it after it has started.

If you feel sick, take small sips of fluids often and eat small amounts regularly. It is important to drink enough fluids. If you continue to feel sick, or are sick (vomit) more than once in 24 hours, contact the hospital as soon as possible. They will give you advice. Your doctor or nurse may change the anti-sickness drug to one that works better for you.

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 interrupted 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 has finished. Try to pace yourself and plan your day so you have time to rest. Gentle exercise, like short walks, can give you more energy.

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.

Your nurse can talk to you about ways to cope with [hair loss]. There are ways to cover up hair loss if you want to. Your scalp may be sensitive. It is important to cover your head to protect your skin when you are out in the sun.

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

Sore and red palms of hands and soles of feet

This is called palmar-plantar or hand-foot syndrome. It usually gets better when treatment ends. Your doctor or nurse can give you advice and prescribe creams to improve any symptoms you may have. It can help to:

  • keep your hands and feet cool
  • use moisturiser regularly
  • avoid tight-fitting socks, shoes and gloves.

Changes in the way the liver works

This treatment may affect how your liver works. This is usually mild and goes back to normal after treatment. You will have blood tests to check how well your liver is working.

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

This treatment may make your eyes feel sore, red and itchy (conjunctivitis). Your doctor can prescribe eye drops to help treat this. Your pharmacist will tell you how to use your eye drops. It is important to follow their advice.

It may also 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. Do not worry if you do not eat much for a day or two. But if your appetite does not come back after a few days, tell your nurse or dietitian. They will give you advice. They may give you food or drink supplements.

Changes to your taste

You may get a bitter or metal taste in your mouth. Sucking sugar-free sweets may help with this. Some foods may taste different or have no taste. Try different foods to find out what tastes best to you. Taste changes usually get better after treatment finishes. Your nurse can give you more advice.

Less common side effects of FOLFIRI

Changes in the way the heart works

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

It is still possible for the heart to be affected even if these test results are normal. Very rarely, this can cause heart failure or a heart attack. The risk of this happening is very low (less than 1 in 100 or 1%). But it is important that you know about it.

Call your doctor straight away on the 24-hour number the hospital has given you if you have any of these symptoms at any time during treatment:

  • pain or tightness in your chest
  • breathlessness
  • changes to your heartbeat.

If you cannot get through to your doctor, call the NHS urgent advice number which is 111.

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. Sometimes nails can become loose or fall out. When treatment finishes, any changes usually disappear as the nails grow out.

There are things you can do to look after your nails:

  • Moisturise your nails and cuticles regularly.
  • Keep your nails clipped short.
  • Wear gloves to protect your nails when you are doing things in the house or garden.
  • Keep your hands and nails clean to help avoid infection, but avoid bathing in very hot water.
  • Do not use false nails, gels or other acrylics during this treatment, as they may increase the risk of infection.
  • It is fine to wear nail varnish, but try to use a water-based polish. Avoid using harsh chemicals, such as acetone, when taking off the polish.
  • If your toenails are affected, wear well-fitted shoes to cushion them.

Tell your doctor or nurse if you notice changes to your nails. They can give you advice or arrange for you to see a podiatrist for foot care advice if needed.

Difficulty breathing

5FU can cause a sudden tightness in your chest, making it difficult to breath. This can happen if the muscles in your airway contract for a short time (spasm). This can also cause a cough or wheeze. Contact your doctor straight away 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.

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. Symptoms of a blood clot include:

  • throbbing pain, redness or swelling in a leg or arm
  • suddenly feeling breathless or coughing
  • sharp chest pain, which may be worse when you cough or take a deep breath.

If you have any of these symptoms, contact the hospital straight away on the 24-hour contact number you have been given. If you cannot get through to your doctor, call the NHS urgent advice number on 111.

A blood clot is serious, but it can be treated with drugs that thin the blood (anticoagulants). Your doctor or nurse can give you more information.

You can help reduce the risk of developing a blood clot by:
  • staying active during treatment
  • drinking plenty of fluids, especially water.

You may be given anticoagulants to help prevent a clot.

Other medicines

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

  • medicines you have been prescribed
  • medicines you buy in a shop or chemist
  • vitamins, herbal drugs and complementary therapies.

Tell other doctors, pharmacists or dentists who prescribe or give you medicines that you are having this cancer treatment.

You can visit the electronic Medicines Compendium (eMC) for more detailed information about your treatment.

Vaccinations

Vaccinations can reduce your risk of getting certain infections. Your doctor or nurse may talk to you about having vaccinations.

Doctors usually recommend that people with cancer have a flu vaccination and a coronavirus vaccination. These are both inactivated vaccinations that can help reduce the risk of infection. People with weak immune systems can have these, as they are not live vaccinations.

If your immune system is weak, you need to avoid live vaccinations. This is because they can make you unwell. Live vaccines, such as shingles, contain a very weak version of the illness they are vaccinating you against. Your cancer doctor or GP can tell you more about live and inactivated vaccinations.

Sex

If you have sex in the first few days after chemotherapy, you need to use a condom. This is to protect your partner in case there is any chemotherapy in semen or vaginal fluids.

Contraception

Your doctor will advise you not to get pregnant or make someone pregnant while having this treatment. The drugs may harm a developing baby. It is important to use contraception during your treatment and for a while after treatment finishes. Your doctor, nurse or pharmacist can tell you more about this.

Fertility

Some cancer drugs can affect whether you can get pregnant or make someone pregnant

If you are a woman, your periods may become irregular or stop. This may be temporary, but for some women it is permanent. Your menopause may start sooner than it would have done.

There may be ways to preserve fertility for men and women. If you are worried about fertility, it is important to talk with your doctor before you start treatment.

Breastfeeding

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

Your doctor or nurse can give you more information.

Medical and dental treatment

If you need medical treatment for any reason other than cancer, always tell the doctors and nurses you are having cancer treatment. Give them the contact details for your cancer doctor so they can ask for advice.

If you think you need dental treatment, talk to your cancer doctor or nurse. Always tell your dentist you are having cancer treatment.