Skip to main content

Irinotecan Side Effects

Medically reviewed by Last updated on Nov 23, 2023.

Applies to irinotecan: intravenous solution.


Intravenous route (Solution)

Early and late forms of diarrhea can occur. Early diarrhea may be accompanied by cholinergic symptoms which may be prevented or ameliorated by atropine; late diarrhea can be life threatening and should be treated promptly with loperamide. Monitor patients with diarrhea and give fluid and electrolytes as needed. Institute antibiotic therapy if patients develop ileus, fever, or severe neutropenia. Interrupt irinotecan and reduce subsequent doses if severe diarrhea occurs. Severe myelosuppression may occur.

Serious side effects of Irinotecan

Along with its needed effects, irinotecan may cause some unwanted effects. Although not all of these side effects may occur, if they do occur they may need medical attention.

Check with your doctor or nurse immediately if any of the following side effects occur while taking irinotecan:

More common

Less common


Incidence not known

Other side effects of Irinotecan

Some side effects of irinotecan may occur that usually do not need medical attention. These side effects may go away during treatment as your body adjusts to the medicine. Also, your health care professional may be able to tell you about ways to prevent or reduce some of these side effects.

Check with your health care professional if any of the following side effects continue or are bothersome or if you have any questions about them:

More common

Incidence not known

For Healthcare Professionals

Applies to irinotecan: intravenous solution.


Very common (10% or more): Late diarrhea (23%), nausea (16%), dehydration (15%), abdominal pain (15%), Grade 3 diarrhea (15%), constipation, flatulence, stomatitis, dyspepsia, mucositis

Common (1% to 10%): Grade 4 diarrhea, early diarrhea, anorexia, constipation, abdominal enlargement

Uncommon (0.1% to 1%): Intestinal obstruction, ileus, megacolon, GI hemorrhage

Rare (less than 0.1%): Colitis, ischemic colitis, ulcerative colitis, pancreatitis[Ref]


Very common (10% or more): Neutropenia (54%) [Grade 3 neutropenia (30%), Grade 4 neutropenia (24%)], leucopenia (38%)

Common (1% to 10%): Anemia, neutropenic fever, thrombocytopenia, neutropenic infection, thrombophlebitis

Uncommon (0.1% to 1%): Biliary sepsis[Ref]


Very common (10% or more): Decreased appetite (49%), weight loss (20%), hypokalemia, hypomagnesemia, dehydration

Common (1% to 10%): Hypoglycemia, hyponatremia, hypophosphatemia, dehydration[Ref]


Very common (10% or more): Alopecia (22%), sweating, rash[Ref]


Very common (10% or more): Dyspnea, cough, rhinitis

Common (1% to 10%): Pneumonia, pulmonary embolism[Ref]

Nervous system

Very common (10% or more): Dizziness (23%), headache (17%)

Common (1% to 10%): Cholinergic syndrome, dysgeusia[Ref]


Common (1% to 10%): Hypotension, myocardial infarction

Uncommon (0.1% to 1%): Vasodilation

Postmarketing reports: Myocardial ischemic events[Ref]


Common (1% to 10%): Hypoalbuminemia, increased bilirubin, increased alanine aminotransferase, increased aspartate aminotransferase, increased international

Frequency not reported: Hepatic steatosis, steatohepatitis[Ref]


Very common (10% or more): Asthenia (20%), chills, edema

Common (1% to 10%): Pain, fever[Ref]


Uncommon (0.1% to 1%): Mild allergic reactions

Rare (less than 0.1%): Severe anaphylaxis[Ref]


Uncommon (0.1% to 1%): Renal insufficiency[Ref]


Very common (10% or more): Back pain (15%)[Ref]


Very common (10% or more): Bacterial, fungal. and viral infections[Ref]


Common (1% to 10%): Infusion related reaction[Ref]


Common (1% to 10%): Confusion[Ref]


1. (2019) "Product Information. Irinotecan Hydrochloride (irinotecan)." Areva Pharmaceuticals

Further information

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

Some side effects may not be reported. You may report them to the FDA.