FOLFIRI Patient Information
This page gives general information about this cancer treatment.
You Will Learn:
- who to contact for help
- what the treatment is
- how it is given
- what to expect while on treatment

This information was created by Ontario Health (Cancer Care Ontario) together with patients and their caregivers who, like you, have gone through cancer treatment. It is meant to help support you through your cancer treatment and answer some of your questions.
This information does not replace the advice of your healthcare team. Always talk to your healthcare team about your treatment.
What Is This Treatment?
FOLFIRI is the code name of your colorectal cancer treatment regimen.
A regimen is a combination of medications to treat cancer.
This regimen name is made up of one or more letters from the names of the 3 medications in your treatment.
Here are the names of the medications in this regimen:
FOL = FOLinic acid (also called leucovorin)
F = Fluorouracil (also called 5-FU)
IRI = IRInotecan
Treatment is divided into cycles. Each cycle is 2 weeks long. Your healthcare team will tell you how many cycles you need.
Here is a picture of the schedule for FOLFIRI treatment:
During each 2-week cycle, you will have FOLFIRI treatment on day 1 at the hospital. Your nurse will also start an infusion (IV) of fluorouracil that will continue at home for a total of 46 hours. See below for more information.
Each cycle looks like this:
Day 1 Treatment Day: Go to the hospital for FOLFIRI treatment. Fluorouracil infusion will continue for 46 hours |
2 Fluorouracil infusion continues at home |
3 Fluorouracil infusion continues at home. A nurse will disconnect it |
4 No FOLFIRI Treatment |
5 No FOLFIRI Treatment |
6 No FOLFIRI Treatment |
7 No FOLFIRI Treatment |
8 No FOLFIRI Treatment |
9 No FOLFIRI Treatment |
10 No FOLFIRI Treatment |
11 No FOLFIRI Treatment |
12 No FOLFIRI Treatment |
13 No FOLFIRI Treatment |
14 No FOLFIRI Treatment |
Remember to:
- Tell your healthcare team about all of the other medications you are taking.
- Keep taking other medications that have been prescribed for you, unless you have been told not to by your healthcare team.
How Is This Treatment Given?
The medications in your treatment are given through an IV (injected into a vein) at the hospital on day 1 of your treatment. You will also be given a device to take home that will continue to give you fluorouracil at home. The device looks like a bottle. It slowly gives you fluorouracil over 46 hours.
Your healthcare team may suggest that you get a PICC line or a Port-a-Cath.
- These are special IVs used to give medicines and fluids into larger veins.
- A PICC or Port-a-Cath can be safer for some medications that can cause reactions when given through an IV in your hand.
- If you have a PICC or Port-a-Cath you do not need an IV (needle) put into your arm every time you come for treatment.

You will have a blood test before each treatment cycle to make sure it is safe for you to get treatment.
What Other Medications Are Given With This Treatment?
To prevent nausea and vomiting
You will be given medications to help prevent nausea (feeling like throwing up) and vomiting (throwing up) before they start.
- These are called anti-nausea medications and include medications such as ondansetron (Zofran®), granisetron (Kytril®), dexamethasone or others.
To treat diarrhea
The irinotecan in your treatment regimen can cause diarrhea. Diarrhea is when you have loose bowel movements (watery poo) or you need to have bowel movements (go poo) more often than usual. Diarrhea may start a few days after your treatment.
You will be given a medication called loperamide (Imodium®) to help treat your diarrhea. Take this medication only if you need it.
Keep your loperamide with you all the time. When diarrhea starts, take the loperamide right away.
If you start to have diarrhea:
- Take 2 tablets (4mg) of loperamide right away.
- Take 1 tablet (2mg) every 2 hours after that.
- During the night you may take 2 tablets (4mg) every 4 hours.
- Keep taking loperamide until you have no diarrhea for 12 hours.
DO This While on Treatment

- DO tell your healthcare team about any other medical conditions that you have such as heart, liver, lung or kidney problems, diabetes or any allergies.
- DO check with your healthcare team before getting any vaccinations, surgery, dental work or other medical procedures.
- DO protect your skin from the sun. Wear a long-sleeved shirt, long pants and a hat. Apply sunscreen with UVA and UVB protection and an SPF of at least 30. Your skin may be more sensitive to the sun and you could develop a bad sunburn or rash more easily.
- DO talk to your healthcare team about your risk of getting other cancers and heart problems with this treatment.
- DO consider asking someone to drive you to and from the hospital on your treatment days. You may feel drowsy or dizzy after your treatment.
DO NOT Do This While on Treatment

- DO NOT take any other medications, such as vitamins, over-the-counter (non-prescription) drugs, or natural health products without checking with your healthcare team.
- DO NOT start any complementary or alternative therapies, such as acupuncture or homeopathic medications, without checking with your healthcare team.
- DO NOT eat or drink grapefruit, starfruit, Seville oranges or their juices (or products that contain these) while on this treatment. They may increase side effects.
- DO NOT smoke or drink alcohol while on treatment without talking to your healthcare team first. Smoking and drinking can make side effects worse and make your treatment not work as well.
Will This Treatment Interact with Other Medications or Natural Health Products?
Yes, the medications in this regimen can interact with other medications, vitamins, foods and natural health products. Interactions can make the treatment not work as well or cause severe side effects.
Tell your healthcare team about all of your:
- prescription and over-the-counter (non-prescription) medications
- natural health products such as vitamins, herbal teas, homeopathic medicines and other supplements
Check with your healthcare team before starting or stopping any of them.
If you are taking seizure medications (such as phenytoin), your healthcare team will monitor your blood levels closely and may change your dose.

Talk to your healthcare team BEFORE taking or using these:
- Anti-inflammatory medications such as ibuprofen (Advil® or Motrin®), naproxen (Aleve®) or Aspirin®
- Over-the-counter products such as dimenhydrinate (Gravol®)
- Natural health products such as St. John’s Wort
- Supplements such as vitamin C
- Alcoholic drinks
- Tobacco
- All other drugs, such as marijuana (medical or recreational)
What Should I Do If I Feel Unwell, Have Pain, a Headache or a Fever?
- Always check your temperature to see if you have a fever before taking any medications for fever or pain (such as acetaminophen (Tylenol) or ibuprofen (Advil)).
- Fever can be a sign of infection that may need treatment right away.
- If you take these medications before you check for fever, they may lower your temperature and you may not know you have an infection.
How to check for fever
Keep a digital (electronic) thermometer at home and take your temperature if you feel hot or unwell (for example, chills, headache, mild pain).
- You have a fever if your temperature taken in your mouth (oral temperature) is:
- 38.3°C (100.9°F) or higher at any time
OR
- 38.0°C (100.4°F) or higher for at least 1 hour.
If you do have a fever
- Try to contact your healthcare team. If you are not able to talk to them for advice, you MUST get emergency medical help right away.
- Download theFever pamphlet for more information.
If you do not have a fever but have mild symptoms such as headache or mild pain:
Ask your healthcare team about the right medication for you. Acetaminophen (Tylenol®) is a safe choice for most people.


How Will This Treatment Affect Sex, Pregnancy and Breast Feeding?
Talk to your healthcare team about:
- How this treatment may affect your sexual health.
- How this treatment may affect your ability to have a baby, if this applies to you.
This treatment may harm an unborn baby. Tell your healthcare team if you or your partner are pregnant, become pregnant during treatment, or are breastfeeding.
- If there is any chance of pregnancy happening, you and your partner together must use 2 effective forms of birth control at the same time until at least 6 months after your last treatment dose. Talk to your healthcare team about which birth control options are best for you.
- Do not breastfeed while on this treatment.
What Are the Side Effects of This Treatment?
The following table lists side effects that you may have when getting FOLFIRI treatment. The table is set up to list the most common side effects first and the least common last. It is unlikely that you will have all of the side effects listed and you may have some that are not listed.
Read over the side effect table so that you know what to look for and when to get help. Refer to this table if you experience any side effects while on FOLFIRI treatment.
It is common for people who are treated with FOLFIRI to have mild side effects only.
Side effect and what to do |
When to contact healthcare team |
---|---|
Low neutrophils (white blood cells) in the blood (neutropenia)(May be severe) When neutrophils are low, you are at risk of getting an infection more easily. It is important to watch for early signs of infection and tell your healthcare team about them right away. Download theNeutropenia (Low white blood cell count) pamphlet for more information. What to look for:
You have a fever if your temperature taken in your mouth (oral temperature) is:
OR
What to do:If your healthcare team has told you that you have low neutrophils:
If you have a fever: If you have a fever, try to contact your healthcare team. If you are unable to talk to the team for advice, you must get emergency medical help right away. |
If you have a fever, try to contact your healthcare team. If you are unable to talk to the team for advice, you MUST get emergency medical help right away. |
Low platelets in the blood(May be severe) When your platelets are low you are at risk for bleeding and bruising. Download theLow Platelet Count pamphlet for more information. What to look for:
What to do:If your healthcare team has told you that you have low platelets:
If you have signs of bleeding:
If you have bleeding that does not stop or is severe (very heavy), you must get emergency medical help right away. |
Talk to your healthcare team if you have any signs of bleeding. If you have bleeding that doesn’t stop or is severe (very heavy), you MUST get emergency medical help right away. |
Anemia (low red blood cells)(May be severe) What to look for:
What to do:If your healthcare team has told you that you have anemia (low red blood cells):
If it is very bad, your doctor may need to make changes to your treatment regimen. |
Talk to your healthcare team if it does not improve or if it is severe. |
Nausea and vomiting (Generally mild)What to look for:
What to do:To help prevent nausea:
If you have nausea or vomiting:
|
Talk to your healthcare team if nausea lasts more than 48 hours or vomiting lasts more than 24 hours or if it is severe. |
FatigueWhat to look for:
What to do:
Download theFatigue pamphlet for more information. |
Talk to your healthcare team if it does not improve or if it is severe. |
Hair thinning or lossWhat to look for:
What to do:
|
Talk to your healthcare team if this bothers you. |
Low appetite, weight changesWhat to look for:
What to do:
Download theLoss of Appetite pamphlet for more information. |
Talk to your healthcare team if it does not improve or if it is severe. |
Diarrhea and other early side effects of irinotecan that start during treatment or within 24 hoursWhat to look for:
|
Tell your healthcare team right away if you have any of these symptoms. |
Diarrhea that starts more than 24 hours after treatment.
What to do:If you have diarrhea:
Download theDiarrhea pamphlet for more information. |
Talk to your healthcare team if no improvement after 24 hours of taking diarrhea medication or if severe (more than 7 times in 1 day). |
Side effect and what to do |
When to contact healthcare team |
---|---|
Liver problemsYour healthcare team may check your liver function with a blood test. The liver changes do not usually cause any symptoms. What to look for:
What to do:If you have any symptoms of liver problems, get emergency medical help right away. |
Get emergency medical help right away. |
ConstipationWhat to look for:
What to do:To help prevent constipation:
To help treat constipation:
Download theConstipation pamphlet for more information. |
Talk to your healthcare team if it does not improve or if it is severe. |
Mouth soresWhat to look for:
What to do:To help prevent mouth sores:
If you have mouth sores:
Download theMouth Care pamphlet for more information. |
Talk to your healthcare team as soon as you notice mouth or lip sores or if it hurts to eat, drink or swallow. |
Eye problemsWhat to look for:
What to do:
|
Talk to your healthcare team as soon as possible. |
Side effect and what to do |
When to contact healthcare team |
---|---|
Cough and feeling short of breath(May be severe) What to look for:
What to do:
|
Talk to your healthcare team. If you are not able to talk to your healthcare team for advice, and you have a fever or severe symptoms, you MUST get emergency medical help right away. |
Rash; dry, itchy skinWhat to look for:
What to do:To prevent and treat dry skin:
Rash may be severe in some rare cases and cause your skin to blister or peel. If this happens, get emergency medical help right away. |
Talk to your healthcare team if it does not improve or if it is severe. |
Trouble sleepingYour medications may cause trouble sleeping. It may get better once your body gets used to the medication or when your treatment ends. What to look for:
What to do:Talk to your healthcare team if no improvement or if severe. |
Talk to your healthcare team if it does not improve or if it is severe. |
Headache; Mild joint, muscle pain or crampsWhat to look for:
What to do:
Download thePain pamphlet for more information. |
Talk to your healthcare team if it does not improve or if it is severe. |
Swelling inside your noseWhat to look for:
What to do:
|
Talk to your healthcare team if it does not improve or if it is severe. |
DizzinessWhat to look for:
What to do:
|
Talk to your healthcare team if it does not improve or if it is severe. |
Rash on your hands and feet (hand-foot syndrome)What to look for:
What to do:To help prevent hand-foot syndrome:
Download theHand-Foot Syndrome pamphlet for more information. |
Talk to your healthcare team if it does not improve or if it is severe. |
FlushingWhat to look for:
What to do:Talk to your healthcare team if no improvement or if severe. |
Talk to your healthcare team if it does not improve or if it is severe. |
Heartburn; upset stomach; bloatingWhat to look for:
What to do:
|
Talk to your healthcare team if it does not improve or if it is severe. |
Mild swellingWhat to look for:
What to do:To help prevent swelling:
If you have swelling:
|
Talk to your healthcare team if it does not improve or if it is severe. |
Other Rare but Serious Side Effects Are Possible with This Treatment.
If you have any of the following, talk to your cancer healthcare team or get emergency medical help right away:
- Severe belly pain
- Severe headache, passing out (fainting)
- Confusion, seizures
- Any changes in your vision (eye sight)
- Coughing up blood or trouble breathing
- Pain and swelling of a vein in your arm or leg
- Severe weakness, problems with your balance, or having falls
- Unusual muscle spasms, tremors, irregular or jerky movements
- Signs of allergic reaction: flushing, itchiness, rash, swollen lips, face or tongue, wheezing, chest and throat tightness
- Unusual weight gain
- Passing very little or no pee
- Red-brown coloured pee
For more information on how to manage your symptoms, ask your healthcare provider or go to Managing Symptoms, Side Effects & Well-Being.
The information set out in the medication information sheets, regimen information sheets, and symptom management information (for patients) contained in the Drug Formulary (the "Formulary") is intended to be used by health professionals and patients for informational purposes only. The information is not intended to cover all possible uses, directions, precautions, drug interactions or side effects of a certain drug, nor should it be used to indicate that use of a particular drug is safe, appropriate or effective for a given condition.
A patient should always consult a healthcare provider if he/she has any questions regarding the information set out in the Formulary. The information in the Formulary is not intended to act as or replace medical advice and should not be relied upon in any such regard. All uses of the Formulary are subject to clinical judgment and actual prescribing patterns may not follow the information provided in the Formulary.