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Generic name: irinotecan [ EYE-ri-noe-TEE-kan ]
Brand name: Camptosar
Dosage form: intravenous solution (20 mg/mL)
Drug class: Miscellaneous antineoplastics

Medically reviewed by on Apr 13, 2021. Written by Cerner Multum.

What is irinotecan?

Irinotecan is used to treat cancers of the colon and rectum. It is usually given with other cancer medicines.

Irinotecan may also be used for purposes not listed in this medication guide.


Irinotecan can cause severe diarrhea, which can be life-threatening. Call your doctor whenever you have diarrhea during your treatment with irinotecan.

Before taking this medicine

You should not use irinotecan if you are allergic to it.

Tell your doctor if you have ever had:

  • liver or kidney disease;

  • lung disease;

  • an intestinal disorder or obstruction;

  • Gilbert's syndrome;

  • fructose intolerance (irinotecan contains sorbitol);

  • radiation treatment to your abdomen or pelvic area; or

  • if you take a diuretic or "water pill."

Irinotecan can harm an unborn baby if the mother or the father is using irinotecan.

  • If you are a woman, you may need to have a negative pregnancy test. Use effective birth control to prevent pregnancy while you are using this medicine and for at least 6 months after your last dose.

  • If you are a man, use effective birth control if your sex partner is able to get pregnant. Keep using birth control for at least 3 months after your last dose.

  • Tell your doctor right away if a pregnancy occurs while either the mother or the father is using irinotecan.

Pregnancy may be less likely to occur while the mother or the father is using this medicine. Both men and women should still use birth control to prevent pregnancy because the medicine can harm an unborn baby.

Do not breastfeed while using this medicine, and for at least 7 days after your last dose.

How is irinotecan given?

Your doctor may recommend a DNA test before your first dose. Some people are genetically more likely to have certain side effects from irinotecan.

Irinotecan is given as an infusion into a vein. A healthcare provider will give you this injection.

This medicine must be given slowly, and the infusion can take up to 90 minutes to complete.

Tell your caregivers if you feel any burning, pain, or swelling around the IV needle.

If any of this medicine gets on your skin, wash right away with soap and water.

Irinotecan can cause severe diarrhea, which can be life-threatening if it leads to dehydration.

Your doctor may recommend keeping anti-diarrhea medicine on hand at all times (such as loperamide or Imodium). Take this medicine at the first sign of loose or frequent bowel movements. Do not take loperamide for longer than 2 full days without your doctor's advice.

Call your doctor whenever you have diarrhea during your treatment with irinotecan.

You may need frequent medical tests to be sure this medicine is not causing harmful effects. Your cancer treatments may be delayed based on the results.

What happens if I miss a dose?

Call your doctor for instructions if you miss an appointment for your irinotecan injection.

What happens if I overdose?

Seek emergency medical attention or call the Poison Help line at 1-800-222-1222.

What should I avoid while using irinotecan?

Avoid using a laxative or stool softener.

Avoid being near people who are sick or have infections. Tell your doctor at once if you develop signs of infection.

Avoid driving or hazardous activity until you know how irinotecan will affect you. Your reactions could be impaired.

Irinotecan side effects

Get emergency medical help if you have signs of an allergic reaction: hives; difficult breathing; swelling of your face, lips, tongue, or throat.

Irinotecan may cause serious side effects. Call your doctor at once if you have:

  • severe or ongoing vomiting or diarrhea;

  • black or bloody stools;

  • nausea or vomiting that keeps you from drinking enough fluids;

  • sores or white patches in or around your mouth;

  • new or worsening cough or shortness of breath;

  • dehydration symptoms--feeling very thirsty or hot, being unable to urinate, heavy sweating, or hot and dry skin;

  • low blood cell counts--fever, tiredness, skin sores, easy bruising, unusual bleeding, pale skin, cold hands and feet, feeling light-headed; or

  • symptoms of sepsis--confusion, fever or chills, severe drowsiness, fast heartbeats, rapid breathing, feeling very ill.

Severe diarrhea may be more likely in older adults.

Common side effects of irinotecan may include:

This is not a complete list of side effects and others may occur. Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088.

Irinotecan dosing information

Usual Adult Dose for Colorectal Cancer:

125 mg/m2 IV over 90 minutes on Days 1, 8,15, and 22 with LV 20 mg/m2 IV bolus on Days 1, 8, 15, and 22 followed by 5-FU 500 mg/m2 IV bolus on Days 1, 8, 15, and 22 every 6 weeks

180 mg/m2 IV over 90 minutes on Days 1, 15, and 29 with LV 200 mg/m2 IV over 2 hours on Days 1, 2, 15, 16, 29, and 30 followed by 5-FU 400 mg/m2 IV bolus on Days 1, 2, 15, 16, 29, and 30 and 5-FU 600 mg/m2 IV over 22 hours on Days 1, 2, 15, 16, 29, 30 (NOTE: 5-FU IV follows 5-FU bolus)

125 mg/m2 IV over 90 minutes on Days 1, 8, 15, and 22 then 2-week rest

350 mg/m2 IV over 90 minutes on Day 1 every 3 weeks

-It is recommended that patients receive premedication with antiemetics (e.g., 10 mg dexamethasone given in conjunction with another antiemetic agent, such as a 5-HT 3 blocker [e.g., ondansetron or granisetron]).
-Antiemetic agents should be given at least 30 minutes before this drug.
-Physicians should consider providing patients with an antiemetic regimen (e.g., prochlorperazine) for subsequent use as needed.
-A similar antiemetic regimen should be used with combination therapy.
-Prophylactic or therapeutic administration of atropine should be considered in patients experiencing cholinergic symptoms.

-First-line therapy in combination with 5-fluorouracil (5-fu) and leucovorin (LV) for patients with metastatic carcinoma of the colon or rectum
-Patients with metastatic carcinoma of the colon or rectum whose disease has recurred or progressed following initial fluorouracil-based therapy

What other drugs will affect irinotecan?

Sometimes it is not safe to use certain medications at the same time. Some drugs can affect your blood levels of other drugs you take, which may increase side effects or make the medications less effective.

Many drugs can affect irinotecan. This includes prescription and over-the-counter medicines, vitamins, and herbal products. Not all possible interactions are listed here. Tell your doctor about all your current medicines and any medicine you start or stop using.

Further information

Remember, keep this and all other medicines out of the reach of children, never share your medicines with others, and use this medication only for the indication prescribed.

Always consult your healthcare provider to ensure the information displayed on this page applies to your personal circumstances.