Irinotecan (Intravenous)

Irinotecan is prescribed by doctors for the treatment of small cell lung cancer as well as lung cancer in combination with other drugs and chemotherapy treatments.


Many cancer treatment drugs were developed to target specific types of cancer cells and Irinotecan is no different. This medication was developed as an antineoplastic enzyme inhibition treatment for colorectal cancer cells but has also been found to be effective on other cancer types. To discover why this medication has been recognized as effective in other cancer types, it is important to understand how it works.

Irinotecan interferes with the cellular structure in an enzyme found in the body called topoisomerase I. This enzyme regulates the way DNA is structured in the human body, directly affecting the way the cellular replication behaves and regulating the structure to be sound and effective. When this enzyme works properly, DNA cells are able to replicate themselves, recombine with other cells to create healthy growth and repair cellular structures throughout the body. When the topoisomerase I cells don't regulate DNA processes correctly, the damage they cause is often cancerous in nature.

Irinotecan enters the picture and bonds to the enzyme topoisomerase I and prevents the abnormal function that causes damage to the DNA processes. As a result, the structures that Irinotecan bonds with that have been previously damaged cannot replicate themselves and cause more cancer throughout the body. These damaged cells eventually die off.

While research and study were performed on colorectal cancer patients, Irinotecan has also been found to be effective in several other cancer treatments, typically in combination with other drugs and chemotherapy treatments. These other cancers include ovarian cancer, pancreatic cancer, cervical cancer and small cell lung cancer among others.

Irinotecan is an injected medication that is typically given in a cancer treatment center or hospital as part of a regimen of care that is designed to manage and treat the condition. The 20 milligram per milliliter injection is given through an intravenous line over a 90-minute period of time, typically once per week. Patients typically receive another medication during a week they are not being treated with Irinotecan and returned to this medication the following week. If there are severe ill health effects experienced by the patient during their treatment with Irinotecan, the schedule may be altered.

Colorectal cancer treatment with Irinotecan can also involve another drug known as 5-Fluorouracil/folinic acid and Bevacizumab. If the cancer is concentrated in the large intestine, Irinotecan may be combined with a medication called Cetuximab. All patients should follow their doctor's advice with regard to taking care of themselves with special diets to prevent diarrhea symptoms as well as any drug interactivity that can occur with combination therapy treatment.

Conditions Treated

  • Metastatic colorectal carcinoma
  • Metastatic colorectal carcinoma, recurrent
  • Cancer of the ovary
  • Ewing's com/health/coma/">sarcoma
  • Metastatic pancreatic adenocarcinoma, refractory
  • Malignant neoplasm of stomach
  • Rhabdomyosarcomas
  • Malignant neoplasm of pancreas
  • Esophageal cancers
  • IV-B cervical cancer, recurrent
  • Lung cancer small cell lung cancer
  • Lung cancer non-small cell cancer
  • Glioblastomas

Type Of Medication

  • Cytostatic

Side Effects

Patients who are being treated with Irinotecan have reported the following adverse health effects that have required medical treatment. If you should have the same symptoms, let your cancer care team know right away:

  • Stools are bloody or black and tar-like
  • Urine with signs of blood
  • Anxious demeanor
  • Blurry vision or changes
  • Skin color changes
  • Uncomfortable, painful chest feeling
  • Heavy, tight feeling in chest
  • Chills
  • Stools that are the color of clay
  • Feet or hands are cold
  • Confused demeanor
  • Pupils appear constricted
  • Hoarse voice
  • Coughing
  • Urine is dark in color
  • Diarrhea, sometimes with sweating or cramps in stomach
  • Dizzy, fainting spells
  • Irregular heart rhythm, slow or fast
  • Elevated body temperature
  • Bloated, full stomach or pressure
  • Headache
  • Increase in saliva, drooling
  • Increase in tears, eyes watering
  • Itchy skin
  • Lightheaded, dizzy when rising
  • Little to no appetite
  • Low pulse rate or blood pressure
  • Pain in side or lower back
  • Vomiting
  • Nausea
  • Numb, tingling arms, legs or face
  • Pain in calves, legs, groin or chest
  • Pain in arms, shoulders, neck or jaw
  • Urination is difficult or painful
  • Skin is pale
  • Tiny red dots on skin
  • Swollen, red legs
  • Nasal congestion, running or sneezing
  • Sudden, severe headache
  • Difficulty breathing
  • Rash on skin
  • Breathing at a slow rate
  • Speech is slurred
  • Throat soreness
  • Pain in stomach
  • Heart stops
  • Severe, sudden weak leg, arm or one entire side of body
  • Clumsy, uncoordinated demeanor
  • Sweating
  • Swollen stomach or abdominal area
  • Losing sight temporarily
  • Swollen, painful foot, leg or arm
  • Difficulty walking or speaking
  • White, ulcerated sore spots on mouth or lips
  • Passing out
  • Halitosis
  • Bruising or bleeding for no reason
  • Fatigue
  • Muscle weakness
  • Vomiting with signs of blood
  • Flushed, warm body
  • Yellow skin or eyes
  • Gums that bleed
  • Blood when coughing
  • Urination amount or frequency decreases
  • Swallowing difficulty
  • Mouth dryness
  • Menstrual flow or vaginal bleeding increases
  • Thirsty
  • Paralyzed in areas of the body
  • Cuts that do not stop bleeding or heal
  • Wheezing
  • Skin is wrinkled
  • Panting or rapid breathing
  • Hives on skin
  • Elevated blood pressure
  • Swollen, puffy eyes, lips, tongue or face
  • Gaining weight rapidly
  • Tender, painful abdomen or stomach
  • Agitated mood
  • Full, bloated stomach
  • Needles and pins, itchy, burning, numb, tingling sensations
  • Comatose
  • Constipated
  • Depressed mood
  • Indigestion, heartburn, acid reflux
  • Hostile, irritable demeanor
  • Lethargic, stupefied
  • Twitching or cramping in muscles
  • Pain in muscles
  • Abdominal or stomach pain that goes from side to back
  • Uncomfortable, painful jaw, arms, neck or back
  • Bleeding from the rectal area
  • Cramps or burning abdomen or stomach
  • Nausea that is severe or prolonged
  • Swollen ankles, lower legs, hands, fingers or face
  • Chest constriction or tightness
  • Unexplained fatigue or weakness
  • Vomiting of coffee-like material

Other adverse health effects that you may experience do not require medical attention unless they become prolonged or severe. Communicate to your cancer care team if you are experiencing these symptoms, however, in case they can be alleviated or shortened in any way:

  • Sour, acid stomach feeling
  • Excess gas or bloating
  • Palms or soles of feet are peeling, red or blistered and swollen
  • Lips are cracked
  • Vertigo or sensation of movement or spinning
  • Painful, tingling or numb palms or soles
  • Pain in upper right stomach or abdominal area
  • Feeling drowsy or sleepy
  • Insomnia
  • Uncomfortable, upset, painful stomach
  • Difficulty sleeping or staying asleep
  • Losing weight
  • Chronic hiccups

Still, other health conditions may occur in some patients, so it is best to report and changes to your mood, demeanor or health to your team of cancer specialists in case of any danger to your overall health.


Irinotecan dosage will be determined by your health care provider during your cancer treatment. This medication is an injected type of medication that is administered through an intravenous method. Irinotecan may be given by itself to treat certain cancers as part of a weekly regimen in which 125 milligrams is multiplied by the square meters of body surface area of the patient. This amount is infused over a 90-minute period on days 1, 8, 15 and 22. There will be a 14-day break and then this dosage will be repeated.

Alternatively, Irinotecan as a monotherapy treatment can be injected in an amount that is equal to the square meters of the body surface of the patient multiplied by 350 milligrams, given over thirty to ninety minute periods once in a three-week timeframe before dosing again.

Irinotecan is often used in combination with other drug therapies and, if so, can be given in 180 milligram doses multiplied by the patient's square meter calculation of body surface area in an infusion that lasts thirty to ninety minutes on days 1, 15 and 29 of treatment which is followed by the other drug in the combination. The whole cycle is repeated after 43 days.

Another choice is a six-week cycle, in which 125 milligrams per square meters of body surface area is injected on the first, 8th, 15th and 22nd days over a 90-minute time period. This treatment is followed by the other drugs in the therapy for treatment over the entire six-week period.


If you have had past experience with sensitivities to any other medications including Irinotecan, it is best that you inform your physician prior to receiving this treatment. Also include any hypersensitivity to foods, animals, perfumes, dyes or preservatives when communicating with your cancer treatment specialist.

With regard to the use of Irinotecan on the pediatric population, it has not been proven that Irinotecan is effective in treatment with this age group nor has its use been proven safe.

The geriatric population, on the other hand, can expect the same risks and effectiveness from Irinotecan treatment but it is cautioned that their dosage may need to be adjusted due to age-related sensitivity to the medication. This age group may experience a higher rate of severe diarrhea as the result of being treated with this drug.

Women who are pregnant should be treated with Irinotecan unless it cannot be avoided, as this medication has been proven to cause harmful side effects to the development of the fetus. If you become pregnant during your cancer treatment therapy with Irinotecan, alert your physician immediately.

Breastfeeding women should not continue to do so if they are being treated with Irinotecan. Discuss breastfeeding with your team of cancer care specialists before taking this medication.

Irinotecan is often combined with other drug therapies in order to form a more comprehensive, effective attack on cancer and symptoms. There are, however, certain inoculations and medications that should be avoided during your treatment with Irinotecan. If you are taking the following medications or scheduled for inoculations listed here, let your physician know:

  • Itraconzole
  • Atazanavir
  • Ketoconazole
  • Mumps live vaccination
  • Measles live vaccination
  • Rotavirus live vaccination
  • Varicella live vaccination
  • Rubella live vaccination

The following medications, while not recommended, may be necessary for you to take in combination with Irinotecan. You should, however, notify your physician that you are taking them, as they could alter the effectiveness or increase the risk of adverse health effects:

  • Adenovirus vaccination
  • Boceprevir
  • Bacillus of Calmette and Guerin vaccination
  • Cholera vaccination
  • Carbamazepine
  • Cobicistat
  • Clarithromycin
  • Fosphenytoin
  • Conivaptan
  • Indinavir
  • Idelalisib
  • Lopinavir
  • Influenza Virus live vaccination
  • Nelfinavir
  • Nefazodone
  • Poliovirus live vaccination
  • Phenytoin
  • Rifabutin
  • Posaconazole
  • Rifapentine
  • Rifampin
  • Saquinavir
  • Ritonavir
  • St John's Wort
  • Smallpox vaccination
  • Telithromycin
  • Telaprevir
  • Typhoid vaccination
  • Tipranavir
  • com/health/yellow-fever/">Yellow Fever vaccination
  • Voriconazole

Finally, with regard to the following medication, you can expect an increased instance of certain adverse health effects if you are in treatment with Irinotecan and taking this medication as well, so let your doctor know if you are currently on:

  • Citalopram

Avoid the use of tobacco products and drinking anything containing grapefruit juice while you are being treated with Irinotecan, as these substances do not combine well with the drug. Check with your doctor on any special diets you should be observing and any foods to avoid altogether. You will also need to talk with your doctor if you are a regular consumer of alcoholic beverages, as this could alter your cancer treatment medication as well.

For your own health and safety, it is best to communicate all medications you are currently taking including those found without a prescription. Be sure to include any vitamins or herbal supplements that you regularly take as well as any holistic treatments you participate in.

The following conditions may also subject you to certain risks if they are combined with Irinotecan treatment, including worsening of the condition themselves. Let your doctor know if you suffer from:

  • Diabetes
  • Bleeding problems
  • Fructose intolerance
  • High blood sugar
  • Disease of the kidneys
  • Disease of the liver
  • Disease of the lungs
  • Severe diarrhea
  • Bone marrow cancer or disease
  • Blockage of the bowels or intestines
  • Gilbert's syndrome
  • Low white blood cell count
  • Enzyme issues including low UGT1A1

Your body may be less able to fight off infections and viruses while you are in treatment with Irinotecan. For this reason, it is best to avoid people who have flu, cold or another sickness if possible while you are in cancer therapy. Also, avoid those persons who have had live vaccinations of any kind for your own safety.


Expect to keep a regular schedule of treatment and follow-up examinations that include blood samples or urine samples while you are on a treatment regimen that includes Irinotecan. During these visits, you will be regularly examined for any adverse health effects that you are experiencing as the result of this drug.

If you are pregnant, be certain to communicate this to your physician prior to receiving treatment with Irinotecan, as it is known to cause harmful effects on fetal development. If you think you've become pregnant during your cancer treatment cycle, let your doctor know right away.

Anaphylaxis, a life-threatening hypersensitivity to Irinotecan, can be caused by treatment with this drug.

Report symptoms such as skin rashes or itching, hives, chills, hoarse voice, difficulty breathing, fever, difficulty swallowing or swollen areas on your face, mouth or hands after you have received your Irinotecan injection as these could be signs of anaphylaxis.

During your cancer treatment therapy and for a certain period of time after your treatment is finished, you will be unable to have immunizations of any kind without checking with your doctor first. Having a vaccine that contains a live strain of any disease could give you the actual disease it was supposed to prevent you from as your immunity will be lowered at this time. It is also best to avoid people who have had live vaccinations during and after your cancer treatment therapy to keep yourself safe. If you cannot avoid these persons, be sure to wear a protective mask that covers the mouth and nose.

Irinotecan has been known to cause severe, prolonged diarrhea symptoms in patients who are in treatment. This condition can cause other health complications and should be treated to avoid these. The following recommendations should be followed with regard to severe diarrhea:

  • Alert your cancer treatment team right away if your severe diarrhea started during your injection or within 24 hours of your injection.
  • Communicate any symptoms such as sweating and cramps or pains in your stomach or abdomen that also occurred with the diarrhea symptoms.
  • If it has been more than 24 hours after your Irinotecan injection that you have had the onset of diarrhea, it is okay to take an over the counter remedy known as Imodium A-D. Keep this medication on hand before your treatment so that it is available to you should you need it.
  • The Imodium A-D should be taken as directed by your physician, which will typically be a 4-milligram amount, which is equal to 2 tablets or capsules or 4 teaspoons of oral solution on to be taken every two hours. A dose of 4 milligrams can be taken every four hours during the nighttime if desired.
  • Continue your dosage of Imodium until you have been symptom-free for 12 hours.
  • Follow your doctor's instructions on the dosage and notify them if you do not experience relief after taking the Imodium as directed for 24 hours.
  • You may become dehydrated if your severe diarrhea is not treated and controlled, leading to serious health complications. It is important to stay hydrated when you are experiencing severe diarrhea by drinking more clear liquids than normal. Caffeine-free beverages including teas, broths and sodas are permissible as is water. Your doctor may indicate a sports drink that contains potassium and sodium that will also benefit you during this time. Follow what your physician recommends exactly.
  • Avoid beverages that contain caffeine as well as those that contain alcohol as they can increase the rate at which your body loses fluid, a dangerous combination when you are already experiencing severe diarrhea. Also avoid foods that are spicy or high in fat and fried, raw fruits and vegetables and fiber-rich foods such as bran, as they can exacerbate the problem of diarrhea.
  • Be alert for the signs of dehydration, which include being dizzy or lightheaded, having a dry mouth, a decrease in urination production or frequency, passing out, raging thirstiness and skin wrinkles. Get in touch with your doctor right away if you have any of these symptoms.

Your white blood cell count will be lowered on a temporary basis when you are in cancer treatment with Irinotecan. This condition will increase your chances of contracting an infection during this time. Additionally, the number of platelets in your blood will be lowered as well, making it difficult for your blood to clot properly. The following precautions should be taken if your cancer care team has informed you, through blood testing, that your white blood cell and platelet counts are low:

  • Avoid people who have infections, colds or viruses. If you think you're coming down with something and have chills, elevated body temperature, coughing, a hoarse voice or pain in your side or lower back accompanied by difficulty urinating, get in touch with your doctor immediately.
  • Report any strange bruising or bleeding as well as symptoms such as blood in your urine or stools, stools that look like tar or tiny red dots on your skin.
  • Use caution when brushing your teeth or flossing your teeth or using a toothpick, as these activities can cause excessive bleeding if done aggressively. Your dentist may be able to suggest ways to gently practice oral hygiene during your cancer treatment.
  • Avoid touching your nose or eyes unless you've just washed your hands.
  • Take care when shaving or clipping nails.
  • Avoid rough sports or other injury-prone activities.

Serious lung problems have been reported by some patients who are being treated with Irinotecan, so report any shortness of breath or difficulty breathing, elevated body temperature or wheezing and coughing after your treatment.

You may experience blood clots after you have been treated with Irinotecan, so be on the lookout for sudden, severe headaches, difficulty breathing, vision problems or difficulty speaking or walking that may occur after your treatment and get in touch with your physician right away.

Some patients become dizzy or sleepy with slower reaction times and alertness than normal. Before you operate tools or machinery or drive a motor vehicle, be aware of how your alertness has been affected by your Irinotecan treatment.

Avoid the use of Ketoconazole, also known as Nizoral and any supplements containing St. John's wort while you are in treatment with Irinotecan. Discontinue your use of St. John's wort at least two weeks before you are to begin your treatment cycle and avoid Ketoconazole for at least one week prior to your treatment to be safe. Let your doctor know you have been taking these two drugs for your own safety.

Avoid taking other medications unless your doctor has specifically reviewed and approved their use. This includes any non-prescription and vitamin therapies as well as holistic and herbal treatments.


Irinotecan is stored by your cancer care specialist team in refrigerated conditions, carefully monitored for the expiration date and disposed of safely when expired. Irinotecan is kept in its original packaging to protect it from being exposed to too much light. After the concentrated amount of Irinotecan is diluted, it should be refrigerated and used within 24 hours.


Irinotecan is part of a cancer treatment therapy prescribed for patients who suffer from colorectal cancers. It has also been proven effective in other types of cancer including ovarian cancer, cancer of the esophagus, small cell lung cancer, pancreatic cancer, cervical cancer and certain stomach cancers. It can be given as a monotherapeutic drug or in combination with other treatments. The treatment period can be three-week rotations or six-week cycles, depending on the patient's health, type of cancer and other treatments that are to be used in combination.

Irinotecan directly affects the DNA structure of the cancer cells, causing the abnormal cells to die because they cannot replicate and repair themselves. Irinotecan inhibits the repair and replication of cancer cells and was developed with colorectal cancer treatment in mind.

In doing its work, Irinotecan can also have an effect on other healthy processes of the body and cause unwanted health symptoms. Patients should report any onset of severe diarrhea that occurs within 24 hours as this symptom requires immediate medical care. Patients should also be aware of the possibility of lung symptoms as well as hypersensitivity to the drug itself and report these conditions right away.

Diarrhea that occurs longer than 24 hours after the first treatment of Irinotecan can be treated with an over-the-counter medication known as the brand Imodium A-D. The dosage, however, should be different for cancer patients, who will be advised by their cancer treatment specialist to keep a supply of this medication on hand as well as given instructions on how to treat themselves should they have these symptoms.

It is advised that patients avoid being vaccinated for any diseases during their treatment and that they avoid others that have been vaccinated as well. This is due to a lowered white blood cell count that comes with being treated by Irinotecan. It is also advised that patients avoid being exposed to any illnesses or viruses during their treatment and that they report any cold or flu-like symptoms immediately.

A lowered count of the platelets in the blood is also a side effect of being treated with Irinotecan, so patients should avoid rough sports and other activities during their treatment. They should also take care when shaving, brushing their teeth, flossing or trimming nails, as they could inadvertently cause excessive bleeding.

Patients are advised to maintain good health and follow the diet they are prescribed by their physician during their cancer treatment. Avoid alcoholic beverages, tobacco products and foods and beverages that contain high fiber and grapefruit juice during this time. Keep all appointments for continuing treatment and follow-up health checks.

Last Reviewed:
March 26, 2018
Last Updated:
April 16, 2018